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Multiprocessing Services Reference

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Import Statement


Swift

import CoreServices

Objective-C

@import CoreServices;

Multiprocessing Services is an API that lets you create preemptive tasks in your application that can run on one or more microprocessors. Unlike the cooperative threads created by the Thread Manager, Multiprocessing Services automatically divides processor time among the available tasks, so that no particular task can monopolize the system. This document is relevant to you if you want to add multitasking capability to your Mac OS applications.

In OS X, Carbon supports Multiprocessing Services with the following restrictions:

  • Debugging functions are not implemented. Use the mach APIs provided by the system to implement debugging services.

  • Opaque notification IDs are local to your process; they are not globally addressable across processes.

  • Global memory allocation is not supported.

Functions

  • Indicates whether Multiprocessing Services is available for use.

    Declaration

    Objective-C

    Boolean _MPIsFullyInitialized ( void );

    Return Value

    If true, Multiprocessing Services is available for use; otherwise, false.

  • Obtains the next CPU ID in the list of physical processors of the specified memory coherence group.

    Declaration

    Objective-C

    OSStatus MPGetNextCpuID ( MPCoherenceID owningCoherenceID, MPCpuID *cpuID );

    Parameters

    owningCoherenceID

    The ID of the memory coherence group whose physical processor IDs you want to obtain. Pass kMPInvalidIDErr, as only one coherence group, internal RAM, is currently defined.

    cpuID

    On return, cpuID points to the ID of the next physical processor.

    Return Value

    A result code. See Multiprocessing Services Result Codes.

    Discussion

    By iterating on this function (after calling MPProcessors , for example), you can obtain the IDs of all the processors available on the host computer. Generally, you would only use this function in diagnostic programs.

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.4 and later.

    Deprecated in OS X v10.7.

  • MPProcessors MPProcessors (OS X v10.7)

    Returns the number of processors on the host computer.

    Declaration

    Objective-C

    ItemCount MPProcessors ( void );

    Return Value

    The number of physical processors on the host computer.

    Discussion

    See also the function MPProcessorsScheduled.

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

    Deprecated in OS X v10.7.

  • Returns the number of active processors available on the host computer.

    Declaration

    Objective-C

    ItemCount MPProcessorsScheduled ( void );

    Return Value

    The number of active processors available on the host computer.

    Discussion

    The number of active processors is defined as the number of processors scheduled to run tasks. This number varies while the system is running. Advanced power management facilities may stop or start scheduling processors in the system to control power consumption or to maintain a proper operating temperature.

    See also the function MPProcessors.

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

    Deprecated in OS X v10.7.

  • Creates a message queue.

    Declaration

    Objective-C

    OSStatus MPCreateQueue ( MPQueueID *queue );

    Parameters

    queue

    On return, the variable contains the ID of the newly created message queue.

    Return Value

    A result code. See Multiprocessing Services Result Codes. If a queue could not be created, MPCreateQueue returns kMPInsufficientResourcesErr.

    Discussion

    This call creates a message queue, which can be used to notify (that is, send) and wait for (that is, receive) messages consisting of three pointer-sized values in a preemptively safe manner.

    Message queues are created from dynamically allocated internal resources. Other tasks may be competing for these resources so it is possible this function may not be able to create a queue.

    See also the functions MPDeleteQueue and MPSetQueueReserve.

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

    Deprecated in OS X v10.7.

  • Deletes a message queue.

    Declaration

    Objective-C

    OSStatus MPDeleteQueue ( MPQueueID queue );

    Parameters

    queue

    The ID of the message queue you want to delete.

    Return Value

    A result code. See Multiprocessing Services Result Codes.

    Discussion

    After calling MPDeleteQueue, the specified queue ID becomes invalid, and all internal resources associated with the queue (including queued messages) are reclaimed. Any tasks waiting on the queue are unblocked and their respective MPWaitOnQueue calls will return with the result code kMPDeletedErr.

    Also see the function MPCreateQueue.

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

    Deprecated in OS X v10.7.

  • Sends a message to the specified message queue.

    Declaration

    Objective-C

    OSStatus MPNotifyQueue ( MPQueueID queue, void *param1, void *param2, void *param3 );

    Parameters

    queue

    The queue ID of the message queue you want to notify.

    param1

    The first pointer-sized value of the message to send.

    param2

    The second pointer-sized value of the message to send.

    param3

    The third pointer-sized value of the message to send.

    Return Value

    A result code. See Multiprocessing Services Result Codes.

    Discussion

    This function sends a message to the specified queue, which consist of the three parameters, param1, param2, and param3. The system does not interpret the three values which comprise the text of the message. If tasks are waiting on the specified queue, the first waiting task is unblocked and the task’s MPWaitOnQueue function completes.

    Depending on the queue mode, the system either allocates messages dynamically or assigns them to memory reserved for the queue. In either case, if no more memory is available for messages MPNotifyQueue returns kMPInsufficientResourcesErr.

    You can call this function from an interrupt handler if messages are reserved on the queue. For more information about queueing modes and reserving messages, see MPSetQueueReserve.

    Also see the function MPWaitOnQueue.

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

    Deprecated in OS X v10.7.

  • Reserves space for messages on a specified message queue.

    Declaration

    Objective-C

    OSStatus MPSetQueueReserve ( MPQueueID queue, ItemCount count );

    Parameters

    queue

    The ID of the queue whose messages you want to reserve.

    count

    The number of messages to reserve.

    Return Value

    A result code. See Multiprocessing Services Result Codes.

    Discussion

    MPNotifyQueue allocates spaces for messages dynamically; that is, memory to hold the message is allocated for the queue at the time of the call. In most cases this method is both speed and storage efficient. However, it is possible that, due to lack of memory resources, space for the message may not be available at the time of the call; in such cases, MPNotifyQueue will return kInsufficientResourcesErr.

    If you must have guaranteed message delivery, or if you need to call MPNotifyQueue from an interrupt handler, you should reserve space on the specified queue by calling MPSetQueueReserve. Because such allocated space is reserved for duration of the queue’s existence, you should avoid straining internal system resources by reserving messages only when absolutely necessary. Note that if you have reserved messages on a queue, additional space cannot be added dynamically if the number of messages exceeds the number reserved for that queue.

    The number of reserved messages is set to count, lowering or increasing the current number of reserved messages as required. If count is set to zero, no messages are reserved for the queue, and space for messages is allocated dynamically.

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

    Deprecated in OS X v10.7.

  • Obtains a message from a specified message queue.

    Declaration

    Objective-C

    OSStatus MPWaitOnQueue ( MPQueueID queue, void **param1, void **param2, void **param3, Duration timeout );

    Parameters

    queue

    The ID of the message queue from which to receive the notification.

    param1

    On return, the first pointer-sized value of the notification message. Pass NULL if you do not need this portion of the message.

    param2

    On return, the second pointer-sized value of the notification message. Pass NULL if you do not need this portion of the message.

    param3

    On return, the third pointer-sized value of the notification message. Pass NULL if you do not need this portion of the message.

    timeout

    The time to wait for a notification before timing out. See Timer Duration Constants for a list of constants you can use to specify the wait interval.

    Return Value

    A result code. See Multiprocessing Services Result Codes.

    Discussion

    This function receives a message from the specified message queue. If no messages are currently available, the timeout specifies how long the function should wait for one. Tasks waiting on the queue are handled in a first in, first out manner; that is, the first task to wait on the queue receives the message from the MPNotifyQueue call.

    After calling this function, when a message appears, it is removed from the queue and the three fields, param1, param2, and param3 are set to the values specified by the message text. Note these parameters are pointers to variables to be set with the message text.

    If you call this function from a cooperative task, you should specify only kDurationImmediate for the timeout length; other waits will cause the task to block.

    Also see the function MPNotifyQueue.

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

    Deprecated in OS X v10.7.

  • Creates a semaphore.

    Declaration

    Objective-C

    OSStatus MPCreateSemaphore ( MPSemaphoreCount maximumValue, MPSemaphoreCount initialValue, MPSemaphoreID *semaphore );

    Parameters

    maximumValue

    The maximum allowed value of the semaphore.

    initialValue

    The initial value of the semaphore.

    semaphore

    On return, semaphore contains the ID of the newly–created semaphore.

    Return Value

    A result code. See Multiprocessing Services Result Codes.

    Discussion

    If you want to create a binary semaphore, you can call the macro MPCreateBinarySemaphore (MPSemaphoreID *semaphore) instead, which simply calls MPCreateSemaphore with both maximumValue and initialValue set to 1.

    Also see the function MPDeleteSemaphore.

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

    Deprecated in OS X v10.7.

  • Removes a semaphore.

    Declaration

    Objective-C

    OSStatus MPDeleteSemaphore ( MPSemaphoreID semaphore );

    Parameters

    semaphore

    The ID of the semaphore you want to remove.

    Return Value

    A result code. See Multiprocessing Services Result Codes.

    Discussion

    Calling this function unblocks all tasks waiting on the semaphore and the tasks’ respective MPWaitOnSemaphore calls will return with the result code kMPDeletedErr.

    Also see the function MPCreateSemaphore.

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

    Deprecated in OS X v10.7.

  • Signals a semaphore.

    Declaration

    Objective-C

    OSStatus MPSignalSemaphore ( MPSemaphoreID semaphore );

    Parameters

    semaphore

    The ID of the semaphore you want to signal.

    Return Value

    A result code. See Multiprocessing Services Result Codes. If the value of the semaphore was already at the maximum, MPSignalSemaphore returns kInsufficientResourcesErr.

    Discussion

    If tasks are waiting on the semaphore, the oldest (first queued) task is unblocked so that the corresponding MPWaitOnSemaphore call for that task completes. Otherwise, if the value of the semaphore is not already equal to its maximum value, it is incremented by one.

    Note that you can call this function from an interrupt handler.

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

    Deprecated in OS X v10.7.

  • Waits on a semaphore

    Declaration

    Objective-C

    OSStatus MPWaitOnSemaphore ( MPSemaphoreID semaphore, Duration timeout );

    Parameters

    semaphore

    The ID of the semaphore you want to wait on.

    timeout

    The maximum time the function should wait before timing out. See Timer Duration Constants for a list of constants you can use to specify the wait interval.

    Return Value

    A result code. See Multiprocessing Services Result Codes.

    Discussion

    If the value of the semaphore is greater than zero, the value is decremented and the function returns with noErr. Otherwise, the task is blocked awaiting a signal until the specified timeout is exceeded.

    If you call this function from a cooperative task, you should specify only kDurationImmediate for the timeout length; other waits will cause the task to block.

    Also see the function MPSignalSemaphore.

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

    Deprecated in OS X v10.7.

  • MPCreateTask MPCreateTask (OS X v10.7)

    Creates a preemptive task.

    Declaration

    Objective-C

    OSStatus MPCreateTask ( TaskProc entryPoint, void *parameter, ByteCount stackSize, MPQueueID notifyQueue, void *terminationParameter1, void *terminationParameter2, MPTaskOptions options, MPTaskID *task );

    Parameters

    entryPoint

    A pointer to the task function. The task function should take a single pointer-sized parameter and return a value of type OSStatus.

    parameter

    The parameter to pass to the task function.

    stackSize

    The size of the stack assigned to the task. Note that you should be careful not to exceed the bounds of the stack, since stack overflows may not be detected. Specifying zero for the size will result in a default stack size of 4KB.

    Note that in OS X prior to version 10.1, this parameter is ignored, and all stacks have the default size of 512 KB. Versions 10.1 and later do not have this limitation.

    notifyQueue

    The ID of the message queue to which the system will send a message when the task terminates. You specify the first two values of the message in the parameters terminationParameter1 and terminationParameter2 respectively. The last message value contains the result code of the task function.

    terminationParameter1

    A pointer-sized value that is sent to the message queue specified by the parameter notifyQueue when the task terminates.

    terminationParameter2

    A pointer-sized value that is sent to the message queue specified by the parameter notifyQueue when the task terminates.

    options

    Optional attributes of the preemptive task. See Task Creation Options for a list of possible values.

    task

    On return, task points to the ID of the newly created task.

    Return Value

    A result code. See Multiprocessing Services Result Codes. If MPCreateTask could not create the task because some critical resource was not available, the function returns kMPInsufficientResourcesErr. Usually this is due to lack of memory to allocate the internal data structures associated with the task or the stack. The function also returns kMPInsufficientResourcesErr if any reserved option bits are set.

    Discussion

    Tasks are created in the unblocked state, ready for execution. A task can terminate in the following ways:

    • By returning from its entry point

    • By calling MPExit

    • When specified as the target of an MPTerminateTask call

    • If a hardware-detected exception or programming exception occurs and no exception handler is installed

    • If the application calls ExitToShell

    Task resources (its stack, active timers, internal structures related to the task, and so on) are reclaimed by the system when the task terminates. The task's address space is inherited from the process address space. All existing tasks are terminated when the owning process terminates.

    To set the relative processor weight to be assigned to a task, use the function MPSetTaskWeight.

    See also the function MPTerminateTask.

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

    Deprecated in OS X v10.7.

  • Obtains the task ID of the currently-executing preemptive task

    Declaration

    Objective-C

    MPTaskID MPCurrentTaskID ( void );

    Return Value

    The task ID of the current preemptive task. See the description of the MPTaskID data type.

    Discussion

    Returns the ID of the current preemptive task. If called from a cooperative task, this function returns an ID which is different than the ID of any preemptive task. Nonpreemptive processes may or may not have different task IDs for each application; future implementations of this API may behave differently in this regard.

    Note that you can call this function from an interrupt handler.

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

    Deprecated in OS X v10.7.

  • Sets the type of the task.

    Declaration

    Objective-C

    OSStatus MPSetTaskType ( MPTaskID task, OSType taskType );

    Return Value

    The noErr result code. See Multiprocessing Services Result Codes.

    Discussion

    This function does nothing and should not be used.

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.1 and later.

    Deprecated in OS X v10.8.

  • MPExit MPExit (OS X v10.7)

    Allows a task to terminate itself

    Declaration

    Objective-C

    void MPExit ( OSStatus status );

    Parameters

    status

    An application-defined value that indicates termination status. This value is sent to the termination message queue in place of the task’s result code.

    Discussion

    When called from within a preemptive task, the task terminates, and the value indicated by the parameter status is sent to the termination message queue you specified in MPCreateTask. Note that you cannot call MPExit from outside a preemptive task.

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

    Deprecated in OS X v10.7.

  • Obtains the next task ID in the list of available tasks.

    Declaration

    Objective-C

    OSStatus MPGetNextTaskID ( MPProcessID owningProcessID, MPTaskID *taskID );

    Parameters

    owningProcessID

    The ID of the process (typically the application) that owns the tasks. This ID is the same as the process ID handled by the Code Fragment Manager.

    taskID

    On return, taskID points to ID of the next task in the list of tasks.

    Return Value

    A result code. See Multiprocessing Services Result Codes.

    Discussion

    By iterating on this function, you can obtain the IDs of all the tasks in a given process. These tasks may be running, ready, or blocked. Generally you would only use this function in diagnostic programs.

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.4 and later.

    Deprecated in OS X v10.7.

  • Assigns a relative weight to a task, indicating how much processor time it should receive compared to other available tasks.

    Declaration

    Objective-C

    OSStatus MPSetTaskWeight ( MPTaskID task, MPTaskWeight weight );

    Parameters

    task

    The ID of the task to which you want to assign a weighting.

    weight

    The relative weight to assign. This value can range from 1 to 10,000, with the default value being 100.

    Return Value

    A result code. See Multiprocessing Services Result Codes.

    Discussion

    The approximate processor share is defined as:

    • weight of the task / total weight of available tasks

    For a set of ready tasks, the amount of CPU time dedicated to the tasks will be determined by the dynamically computed share. Note that the processor share devoted to tasks may deviate from the suggested weighting if critical tasks require attention. For example, a real-time task (such as a QuickTime movie) may require more than its relative weight of processor time, and the scheduler will adjust proportions accordingly.

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

    Deprecated in OS X v10.7.

  • Determines whether a task is preemptively scheduled.

    Declaration

    Objective-C

    Boolean MPTaskIsPreemptive ( MPTaskID taskID );

    Parameters

    taskID

    The task you want to check. Pass kMPNoID or kInvalidID if you want to specify the current task.

    Return Value

    If true, the task is preemptively scheduled. If false, the task is cooperatively scheduled.

    Discussion

    If you have code that may be called from either cooperative or preemptive tasks, that code can call MPTaskIsPreemptive if its actions should differ depending on its execution environment.

    Note that you can call this function from an interrupt handler.

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

    Deprecated in OS X v10.7.

  • Terminates an existing task.

    Declaration

    Objective-C

    OSStatus MPTerminateTask ( MPTaskID task, OSStatus terminationStatus );

    Parameters

    task

    The ID of the task you wish to terminate.

    terminationStatus

    A value of type OSStatus indicating termination status. This value is sent to the termination status message queue you specified in MPCreateTask in place of the task function’s result code.

    Return Value

    A result code. See Multiprocessing Services Result Codes. If the task to be terminated is already in the process of termination, MPTerminateTask returns kMPInsufficientResourcesErr. You do not need to take any additional action if this occurs.

    Discussion

    You should be very careful when calling MPTerminateTask. As defined, this call will asynchronously and abruptly terminate a task, potentially leaving whatever structures or resources it was operating upon in an indeterminate state. OS X exacerbates this problem, as MP tasks can use many more system services that are not expecting client threads to asynchronously terminate, and these services do not take the rather complicated steps necessary to protect against, or recover from, such a situation.

    However, there are situations in which calling MPTerminateTask is useful and relatively safe. One such situation is when your application or service is quitting and you know that the task you wish to terminate is waiting on an MP synchronization construct (queue, event, semaphore or critical region). While you could do this more cleanly by waking the task and causing it to exit on its own, doing so may not always be practical.

    For example, suppose you have several service tasks performing background processing for your application. These service tasks wait on a queue, onto which the application places requests for processing. When the task is done with a request, it notifies another queue, which the application polls. Since the main application task is placing items on the shared queue, and receiving notifications when the requests are done, it can track whether or not there are outstanding requests being processed. If all outstanding requests have, in fact, been processed, it is relatively safe to terminate a task (or all tasks) waiting on the request queue.

    You should not assume that the task has completed termination when this call returns; the proper way to synchronize with task termination is to wait on the termination queue (specified in MPCreateTask ) until a message appears. Because task termination is a multistage activity, it is possible for a preemptive task to attempt to terminate a task that is already undergoing termination. In such cases, MPTerminateTask returns kMPInsufficientResourcesErr.

    Note that Multiprocessing Services resources (event groups, queues, semaphores, and critical regions) owned by a preemptive task are not released when that task terminates. If a task has a critical region locked when it terminates, the critical region remains in the locked state. Multiprocessing Services resources no longer needed should be explicitly deleted by the task that handles the termination message. All Multiprocessing Services resources created by tasks are released when their owning process (that is, the host application) terminates.

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

    Deprecated in OS X v10.7.

  • MPYield MPYield (OS X v10.7)

    Allows a task to yield the processor to another task.

    Declaration

    Objective-C

    void MPYield ( void );

    Discussion

    This function indicates to the scheduler that another task can run. Other than possibly yielding the processor to another task or application, the call has no effect. Note that since tasks are preemptively scheduled, an implicit yield may occur at any point, whether or not this function is called.

    In most cases you should not need to call this function. The most common use of MPYield is to release the processor when a task is in a loop in which further progress is dependent on other tasks, and the task cannot be blocked by waiting on a Multiprocessing Services resource. You should avoid such busy waiting whenever possible.

    Note that you can call this function from an interrupt handler.

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

    Deprecated in OS X v10.7.

  • Creates a critical region object.

    Declaration

    Objective-C

    OSStatus MPCreateCriticalRegion ( MPCriticalRegionID *criticalRegion );

    Parameters

    criticalRegion

    On return, the criticalRegion contains the ID of the newly created critical region object.

    Return Value

    A result code. See Multiprocessing Services Result Codes.

    Discussion

    Also see the function MPDeleteCriticalRegion.

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

    Deprecated in OS X v10.7.

  • Removes the specified critical region object.

    Declaration

    Objective-C

    OSStatus MPDeleteCriticalRegion ( MPCriticalRegionID criticalRegion );

    Parameters

    criticalRegion

    The critical region object you want to remove.

    Return Value

    A result code. See Multiprocessing Services Result Codes.

    Discussion

    Calling this function unblocks all tasks waiting to enter the critical region and their respective MPEnterCriticalRegion calls will return with the result code kMPDeletedErr.

    Also see the function MPCreateCriticalRegion.

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

    Deprecated in OS X v10.7.

  • Attempts to enter a critical region.

    Declaration

    Objective-C

    OSStatus MPEnterCriticalRegion ( MPCriticalRegionID criticalRegion, Duration timeout );

    Parameters

    criticalRegion

    The ID of the critical region you want to enter.

    timeout

    The maximum time to wait for entry before timing out. See Timer Duration Constants for a list of constants you can use to specify the wait interval.

    Return Value

    A result code. See Multiprocessing Services Result Codes.

    Discussion

    If another task currently occupies the critical region, the current task is blocked until the critical region is released or until the designated timeout expires. Otherwise the task enters the critical region and MPEnterCriticalRegion increments the region’s use count.

    Once a task enters a critical region it can make further calls to MPEnterCriticalRegion without blocking (its use count increments for each call). However, each call to MPEnterCriticalRegion must be balanced by a call to MPExitCriticalRegion ; otherwise the region is not released for use by other tasks.

    Note that you can enter a critical region from a cooperative task. Each cooperative task is treated as unique and different from any preemptive task. If you call this function from a cooperative task, you should specify only kDurationImmediate for the timeout length; other waits will cause the task to block.

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

    Deprecated in OS X v10.7.

  • Exits a critical region.

    Declaration

    Objective-C

    OSStatus MPExitCriticalRegion ( MPCriticalRegionID criticalRegion );

    Parameters

    criticalRegion

    The ID of the critical region you want to exit.

    Return Value

    A result code. See Multiprocessing Services Result Codes. If the task does not own the critical region specified by criticalRegion, MPExitCriticalRegion returns kMPInsufficientResourcesErr.

    Discussion

    This function decrements the use count of the critical region object. When the use count reaches zero, ownership of the critical region object is released (which allows another task to use the critical region).

    Also see the function MPEnterCriticalRegion.

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

    Deprecated in OS X v10.7.

  • Creates an event group.

    Declaration

    Objective-C

    OSStatus MPCreateEvent ( MPEventID *event );

    Parameters

    event

    On return, event contains the ID of the newly created event group.

    Return Value

    A result code. See Multiprocessing Services Result Codes.

    Discussion

    Event groups are created from dynamically allocated internal resources. Other tasks may be competing for these resources so it is possible that this function will not be able to create an event group.

    Also see the function MPDeleteEvent.

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

    Deprecated in OS X v10.7.

  • Removes an event group.

    Declaration

    Objective-C

    OSStatus MPDeleteEvent ( MPEventID event );

    Parameters

    event

    The ID of the event group you want to remove.

    Return Value

    A result code. See Multiprocessing Services Result Codes.

    Discussion

    After deletion, the event ID becomes invalid, and all internal resources associated with the event group are reclaimed. Calling this function unblocks all tasks waiting on the event group and their respective MPWaitForEvent calls will return with the result code kMPDeletedErr.

    Also see the function MPCreateEvent.

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

    Deprecated in OS X v10.7.

  • MPSetEvent MPSetEvent (OS X v10.7)

    Merges event flags into a specified event group.

    Declaration

    Objective-C

    OSStatus MPSetEvent ( MPEventID event, MPEventFlags flags );

    Parameters

    event

    The ID of the event group you want to set.

    flags

    The flags you want to merge into the event group.

    Return Value

    A result code. See Multiprocessing Services Result Codes.

    Discussion

    The flags are logically ORed with the current flags in the event group. This procedure is an atomic operation to ensure that multiple updates do not get lost. If tasks are waiting on this event group, the first waiting task is unblocked.

    Note that you can call this function from an interrupt handler.

    Also see the function MPWaitForEvent.

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

    Deprecated in OS X v10.7.

  • Retrieves event flags from a specified event group.

    Declaration

    Objective-C

    OSStatus MPWaitForEvent ( MPEventID event, MPEventFlags *flags, Duration timeout );

    Parameters

    event

    The event group whose flags you want to retrieve.

    flags

    On return, flags contains the flags of the specified event group. Pass NULL if you do not need any flag information.

    timeout

    The maximum time to wait for events before timing out. See Timer Duration Constants for a list of constants you can use to specify the wait interval.

    Return Value

    A result code. See Multiprocessing Services Result Codes.

    Discussion

    This function obtains event flags from the specified event group. The timeout specifies how long to wait for events if none are present when the call is made. If any flags are set when this function is called, all the flags in the event group are moved to the flag field and the event group is cleared. This obtaining and clearing action is an atomic operation to ensure that no updates are lost. If multiple tasks are waiting on an event group, only one can obtain any particular set of flags.

    If you call this function from a cooperative task, you should specify only kDurationImmediate for the timeout length; other waits will cause the task to block.

    Also see the function MPSetEvent.

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

    Deprecated in OS X v10.7.

  • Signals a kernel notification.

    Declaration

    Objective-C

    OSStatus MPCauseNotification ( MPNotificationID notificationID );

    Parameters

    notificationID

    The ID of the kernel notification you want to signal.

    Return Value

    A result code. See Multiprocessing Services Result Codes.

    Discussion

    You call this function to signal a kernel notification much as you would signal any simple notification (for example, MPNotifyQueue ).

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

    Deprecated in OS X v10.7.

  • Creates a kernel notification

    Declaration

    Objective-C

    OSStatus MPCreateNotification ( MPNotificationID *notificationID );

    Parameters

    notificationID

    On return, notificationID points to the newly created kernel notification.

    Return Value

    A result code. See Multiprocessing Services Result Codes.

    Discussion

    After creating the kernel notification object, you can add simple notifications by calling the function MPModifyNotification.

    Also see the function MPDeleteNotification.

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

    Deprecated in OS X v10.7.

  • Removes a kernel notification.

    Declaration

    Objective-C

    OSStatus MPDeleteNotification ( MPNotificationID notificationID );

    Parameters

    notificationID

    The ID of the notification you want to remove.

    Return Value

    A result code. See Multiprocessing Services Result Codes.

    Discussion

    Also see the function MPCreateNotification.

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

    Deprecated in OS X v10.7.

  • Adds a simple notification to a kernel notification.

    Declaration

    Objective-C

    OSStatus MPModifyNotification ( MPNotificationID notificationID, MPOpaqueID anID, void *notifyParam1, void *notifyParam2, void *notifyParam3 );

    Parameters

    notificationID

    The ID of the kernel notification you want to add to..

    anID

    The ID of the simple notification (semaphore, message group, or event group) you want to add to the kernel notification.

    notifyParam1

    If anID specifies an event group, this parameter should contain the flags to set in the event group when MPCauseNotification is called. If anID specifies a message queue, this parameter should contain the first pointer-sized value of the message to be sent to the message queue when MPCauseNotification is called.

    notifyParam2

    If anID specifies a message queue, this parameter should contain the second pointer-sized value of the message to be sent to the message queue when MPCauseNotification is called. Pass NULL if you don’t need this parameter.

    notifyParam3

    If anID specifies a message queue, this parameter should contain the third pointer-sized value of the message sent to the message queue when MPCauseNotification is called. Pass NULL if you don’t need this parameter.

    Return Value

    A result code. See Multiprocessing Services Result Codes.

    Discussion

    You specify the parameters for the simple notifications just as if you were calling the MPSetTimerNotify function.

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

    Deprecated in OS X v10.7.

  • Declaration

    Objective-C

    OSStatus MPModifyNotificationParameters ( MPNotificationID notificationID, MPOpaqueIDClass kind, void *notifyParam1, void *notifyParam2, void *notifyParam3 );

    Return Value

    A result code. See Multiprocessing Services Result Codes.

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.1 and later.

    Deprecated in OS X v10.7.

  • Returns an index number to access per-task storage.

    Declaration

    Objective-C

    OSStatus MPAllocateTaskStorageIndex ( TaskStorageIndex *taskIndex );

    Parameters

    index

    On return, index contains an index number you can use to store task data.

    Return Value

    A result code. See Multiprocessing Services Result Codes.

    Discussion

    A call to the function MPAllocateTaskStorageIndex returns an index number that is common across all tasks in the current process. You can use this index number in calls to MPSetTaskStorageValue and MPGetTaskStorageValue to set a different value for each task using the same index.

    You can think of the task storage area as a two dimensional array cross-referenced by the task storage index number and the task ID. Note that since the amount of per-task storage is determined when the task is created, the number of possible index values associated with a task is limited.

    Also see the function MPDeallocateTaskStorageIndex.

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

    Deprecated in OS X v10.7.

  • Frees an index number used to access per-task storage

    Declaration

    Objective-C

    OSStatus MPDeallocateTaskStorageIndex ( TaskStorageIndex taskIndex );

    Parameters

    index

    The index number you want to deallocate.

    Return Value

    A result code. See Multiprocessing Services Result Codes.

    Discussion

    Also see the function MPAllocateTaskStorageIndex.

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

    Deprecated in OS X v10.7.

  • Gets the storage value stored at a specified index number.

    Declaration

    Objective-C

    TaskStorageValue MPGetTaskStorageValue ( TaskStorageIndex taskIndex );

    Parameters

    index

    The index number of the storage value you want to obtain.

    Return Value

    The value stored at the specified index number. See the description of the TaskStorageValue data type.

    Discussion

    Calling this function from within a task effectively reads a value in a two-dimensional array cross-referenced by task storage index value and the task ID.

    Note that since this function does not return any status information, it may not be immediately obvious whether the returned storage value is valid.

    Also see the function MPSetTaskStorageValue.

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

    Deprecated in OS X v10.7.

  • Sets the storage value for a given index number.

    Declaration

    Objective-C

    OSStatus MPSetTaskStorageValue ( TaskStorageIndex taskIndex, TaskStorageValue value );

    Parameters

    index

    The index number whose storage value you want to set.

    value

    The value you want to set.

    Return Value

    A result code. See Multiprocessing Services Result Codes.

    Discussion

    Typically you use MPSetTaskStorageValue to store pointers to task-specific structures or data.

    Calling this function from within a task effectively assigns a value in a two-dimensional array cross-referenced by task storage index value and the task ID.

    Also see the function MPGetTaskStorageValue.

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

    Deprecated in OS X v10.7.

  • MPAllocate MPAllocate (OS X v10.7)

    Allocates a nonrelocatable memory block.

    Deprecation Statement

    Use MPAllocateAligned instead.

    Declaration

    Objective-C

    LogicalAddress MPAllocate ( ByteCount size );

    Parameters

    size

    The size, in bytes, of the memory block to allocate.

    Return Value

    A pointer to the allocated memory. If the function cannot allocate the requested memory or the requested alignment, the returned address is NULL.

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

    Deprecated in OS X v10.7.

  • Allocates a nonrelocatable memory block.

    Declaration

    Objective-C

    LogicalAddress MPAllocateAligned ( ByteCount size, UInt8 alignment, OptionBits options );

    Parameters

    size

    The size, in bytes, of the memory block to allocate.

    alignment

    The desired alignment of the allocated memory block. See Memory Allocation Alignment Constants for a list of possible values to pass. Note that there will be a minimum alignment regardless of the requested alignment. If the requested memory block is 4 bytes or smaller, the block will be at least 4-byte aligned. If the requested block is greater than 4 bytes, the block will be at least 8-byte aligned.

    options

    Any optional information to use with this call. See Memory Allocation Option Constants for a list of possible values to pass.

    Return Value

    A pointer to the allocated memory. If the function cannot allocate the requested memory or the requested alignment, the returned address is NULL.

    Discussion

    The memory referenced by the returned address is guaranteed to be accessible by the application's cooperative task and any preemptive tasks that it creates, but not by other applications or their preemptive tasks. Any existing non-global heap blocks are freed when the application terminates. As with all shared memory, you must explicitly synchronize access to allocated heap blocks using a notification mechanism.

    You can replicate the effect of the older MPAllocate function by calling MPAllocateAligned with 32-byte alignment and no options.

    Also see the function MPFree.

    Special Considerations

    OS X does not support allocation of global (cross address space) or resident memory with this function. In addition, passing the kMPAllocateNoGrowthMask constant in the options parameter has no effect in OS X, since memory allocation is done with sparse heaps.

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

    Deprecated in OS X v10.7.

  • MPBlockClear MPBlockClear (OS X v10.7)

    Clears a block of memory.

    Declaration

    Objective-C

    void MPBlockClear ( LogicalAddress address, ByteCount size );

    Parameters

    address

    The starting address of the memory block you want to clear.

    size

    The number of bytes you want to clear.

    Discussion

    As with all shared memory, your application must synchronize access to the memory blocks to avoid data corruption. MPBlockClear ensures the clearing stays within the bounds of the area specified by size, but the calling task can be preempted during the copying process.

    Note that you can call this function from an interrupt handler.

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

    Deprecated in OS X v10.7.

  • MPBlockCopy MPBlockCopy (OS X v10.7)

    Copies a block of memory.

    Declaration

    Objective-C

    void MPBlockCopy ( LogicalAddress source, LogicalAddress destination, ByteCount size );

    Parameters

    source

    The starting address of the memory block you want to copy.

    destination

    The location to which you want to copy the memory block.

    size

    The number of bytes to copy.

    Discussion

    This function simply calls through to the Driver Services Library function BlockMoveData. Note that you should not make any assumptions about the state of the destination memory while this function is executing. In the intermediate state, values may be present that are neither the original nor the final ones. For example, this function may use the 'dcbz' instruction. If the underlying memory is not cacheable, if the memory is write-through instead of copy-back, or if the cache block is flushed for some reason, the 'dcbz' instruction will write zeros to the destination. You can avoid the use of the 'dcbz' instruction by calling BlockMoveDataUncached, but even that function makes no other guarantees about the memory block's intermediate state.

    As with all shared memory, your application must synchronize access to the memory blocks to avoid data corruption. MPBlockCopy ensures the copying stays within the bounds of the area specified by size, but the calling task can be preempted during the copying process.

    Note that you can call this function from an interrupt handler.

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

    Deprecated in OS X v10.7.

  • MPDataToCode MPDataToCode (OS X v10.7)

    Designates the specified block of memory as executable code.

    Declaration

    Objective-C

    void MPDataToCode ( LogicalAddress address, ByteCount size );

    Parameters

    address

    The starting address of the memory block you want to designate as code.

    size

    The size of the memory block.

    Discussion

    Since processors need to differentiate between code and data in memory, you should call this function to tag any executable code that your tasks may generate.

    Note that you can call this function from an interrupt handler.

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

    Deprecated in OS X v10.7.

    Not available to 64-bit applications.

  • MPFree MPFree (OS X v10.7)

    Frees memory allocated by MPAllocateAligned.

    Declaration

    Objective-C

    void MPFree ( LogicalAddress object );

    Parameters

    object

    A pointer to the memory you want to release.

    Discussion

    Also see the function MPAllocateAligned.

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

    Deprecated in OS X v10.7.

  • Returns the size of a memory block.

    Declaration

    Objective-C

    ByteCount MPGetAllocatedBlockSize ( LogicalAddress object );

    Parameters

    object

    The address of the memory block whose size you want to determine.

    Return Value

    The size of the allocated memory block, in bytes.

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

    Deprecated in OS X v10.7.

  • MPRemoteCall MPRemoteCall (OS X v10.7)

    Calls a non-reentrant function and blocks the current task.

    Declaration

    Objective-C

    void * MPRemoteCall ( MPRemoteProcedure remoteProc, void *parameter, MPRemoteContext context );

    Parameters

    remoteProc

    A pointer to the application-defined function you want to call. See MPRemoteProcedure for more information about the form of this function.

    parameter

    A pointer to a parameter to pass to the application-defined function. For example, this value could point to a data structure or a memory location.

    context

    This parameter is ignored; specify kMPOwningProcessRemoteContext.

    Return Value

    The value that your remote procedure callback returned.

    Discussion

    You use this function to execute code on your application’s main task. The remoteProc function is scheduled on the application’s main run loop and run in the default mode (kCFRunloopDefaultMode). If you call this function from your application’s main task, the remoteProc function is executed immediately in the current mode without blocking the task; otherwise, calling this function blocks the current task until the remote call completes.

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

    Deprecated in OS X v10.7.

  • Calls a non-reentrant function and blocks the current task.

    Declaration

    Objective-C

    void * MPRemoteCallCFM ( MPRemoteProcedure remoteProc, void *parameter, MPRemoteContext context );

    Parameters

    remoteProc

    A pointer to the application-defined CFM (Code Fragment Manager) function you want to call. See MPRemoteProcedure for more information about the form of this function.

    parameter

    A pointer to a parameter to pass to the application-defined function. For example, this value could point to a data structure or a memory location.

    context

    This parameter is ignored; specify kMPOwningProcessRemoteContext.

    Return Value

    The value that your remote procedure callback returned.

    Discussion

    You use this function to execute code on your application’s main task. The remoteProc function is scheduled on the application’s main run loop and run in the default mode (kCFRunloopDefaultMode). If you call this function from your application’s main task, the remoteProc function is executed immediately in the current mode without blocking the task; otherwise, calling this function blocks the current task until the remote call completes.

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.4 and later.

    Deprecated in OS X v10.7.

  • MPArmTimer MPArmTimer (OS X v10.7)

    Arms the timer to expire at a given time.

    Declaration

    Objective-C

    OSStatus MPArmTimer ( MPTimerID timerID, AbsoluteTime *expirationTime, OptionBits options );

    Parameters

    timerID

    The ID of the timer you want to arm.

    expirationTime

    A pointer to a value that specifies when you want the timer to expire. Note that if you arm the timer with a time that has already passed, the timer expires immediately.

    options

    Any optional actions. See Timer Option Masks for a list of possible values.

    Return Value

    A result code. See Multiprocessing Services Result Codes. If the timer has already expired, the reset does not take place and the function returns kMPInsufficientResourcesErr.

    Discussion

    The expiration time is an absolute time, which you can generate by calling the Driver Services Library function UpTime. When the timer expires, a notification is sent to the notification mechanism specified in the last MPSetTimerNotify call. If the specified notification ID has become invalid, no action is taken when the timer expires. The timer itself is deleted when it expires unless you specified the kMPPreserveTimerID option in the options parameter.

    Also see the function MPCancelTimer.

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

    Deprecated in OS X v10.7.

  • Cancels an armed timer.

    Declaration

    Objective-C

    OSStatus MPCancelTimer ( MPTimerID timerID, AbsoluteTime *timeRemaining );

    Parameters

    timerID

    The ID of the armed timer you want to cancel.

    timeRemaining

    On return, the timeRemaining contains the time remaining before the timer would have expired.

    Return Value

    A result code. See Multiprocessing Services Result Codes. If the timer has already expired, this function returns kMPInsufficientResourcesErr.

    Discussion

    Also see the function MPArmTimer.

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

    Deprecated in OS X v10.7.

  • Creates a timer.

    Declaration

    Objective-C

    OSStatus MPCreateTimer ( MPTimerID *timerID );

    Parameters

    timerID

    On return, the timerID contains the ID of the newly created timer.

    Return Value

    A result code. See Multiprocessing Services Result Codes.

    Discussion

    You can use a timer to notify an event, queue, or semaphore after a specified amount of time has elapsed.

    Timer objects are created from dynamically-allocated internal resources. Other tasks may be competing for these resources so it is possible this function may not be able to create one.

    To specify the notification mechanism to signal, use the function MPSetTimerNotify.

    Also see the functions MPDeleteTimer and MPArmTimer.

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

    Deprecated in OS X v10.7.

  • MPDelayUntil MPDelayUntil (OS X v10.7)

    Blocks the calling task until a specified time.

    Declaration

    Objective-C

    OSStatus MPDelayUntil ( AbsoluteTime *expirationTime );

    Parameters

    expirationTime

    The time to unblock the task.

    Return Value

    A result code. See Multiprocessing Services Result Codes.

    Discussion

    You cannot call this function from a cooperative task.

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

    Deprecated in OS X v10.7.

  • Removes a timer.

    Declaration

    Objective-C

    OSStatus MPDeleteTimer ( MPTimerID timerID );

    Parameters

    timerID

    The ID of the timer you want to remove.

    Return Value

    A result code. See Multiprocessing Services Result Codes.

    Discussion

    After deletion, the timer ID becomes invalid, and all internal resources associated with the timer are reclaimed.

    Also see the function MPCreateTimer.

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

    Deprecated in OS X v10.7.

  • Sets the notification information associated with a timer.

    Declaration

    Objective-C

    OSStatus MPSetTimerNotify ( MPTimerID timerID, MPOpaqueID anID, void *notifyParam1, void *notifyParam2, void *notifyParam3 );

    Parameters

    timerID

    The ID of the timer whose notification information you want to set.

    notificationID

    The ID of the notification mechanism to associate with the timer. This value should be the ID of an event group, a message queue, or a semaphore.

    notifyParam1

    If anID specifies an event group, this parameter should contain the flags to set in the event group when the timer expires. If anID specifies a message queue, this parameter should contain the first pointer-sized value of the message to be sent to the message queue when the timer expires.

    notifyParam2

    If anID specifies a message queue, this parameter should contain the second pointer-sized value of the message to be sent to the message queue when the timer expires. Pass NULL if you don’t need this parameter.

    notifyParam3

    If anID specifies a message queue, this parameter should contain the third pointer-sized value of the message sent to the message queue when the timer expires. Pass NULL if you don’t need this parameter.

    Return Value

    A result code. See Multiprocessing Services Result Codes.

    Discussion

    When the timer expires, Multiprocessing Services checks the notification ID, and if it is valid, notifies the related notification mechanisms (that is, event groups, queues, or semaphores) you had specified in your MPSetTimerNotify calls.

    You can specify multiple notification mechanisms by calling this function several times. For example, you can call MPSetTimerNotify to specify a message queue and then call it again to specify a semaphore. When the timer expires, a message is sent to the message queue and the appropriate semaphore is signaled. You cannot, however, specify more than one notification per notification mechanism (for example, if you call MPSetTimerNotify twice, specifying different messages or message queues in each call, the second call will overwrite the first). Note that if a call to MPSetTimerNotify returns an error, any previous calls specifying the same timer are still valid; previously set notifications will still be notified when the timer expires.

    You can set the notification information at any time. If the timer is armed, it will modify the notification parameters dynamically. If the timer is disarmed, it will modify the notification parameters to be used for the next MPArmTimer call.

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

    Deprecated in OS X v10.7.

  • Removes a task exception.

    Declaration

    Objective-C

    OSStatus MPDisposeTaskException ( MPTaskID task, OptionBits action );

    Parameters

    task

    The task whose exception you want to remove.

    action

    Any actions to perform on the task. For example, you can enable single-stepping when the task resumes, or you can pass the exception on to another handler. See Task Exception Disposal Constants for a listing of possible values.

    Return Value

    A result code. See Multiprocessing Services Result Codes. If the specified action is invalid or unsupported, or if the specified task is not suspended, this function returns kMPInsufficientResourcesErr.

    Discussion

    This function removes the task exception and allows the task to resume operation. If desired, you can enable single-stepping or branch-stepping, or propagate the exception instead.

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

    Deprecated in OS X v10.7.

  • Extracts state information from a suspended task.

    Declaration

    Objective-C

    OSStatus MPExtractTaskState ( MPTaskID task, MPTaskStateKind kind, void *info );

    Parameters

    task

    The task whose state information you want to obtain.

    kind

    The kind of state information you want to obtain. See Task State Constants for a listing of possible values.

    info

    A pointer to a data structure to hold the state information. On return, the data structure holds the desired state information. The format of the data structure varies depending on the state information you want to retrieve. See the header file MachineExceptions.h for the formats of the various state information structures.

    Return Value

    A result code. See Multiprocessing Services Result Codes. If you attempt to extract state information for a running task, this function returns kMPInsufficientResourcesErr.

    Discussion

    You can use this function to obtain register contents or exception information about a particular task.

    Also see the function MPSetTaskState.

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

    Deprecated in OS X v10.7.

  • Sets an exception handler for a task.

    Declaration

    Objective-C

    OSStatus MPSetExceptionHandler ( MPTaskID task, MPQueueID exceptionQ );

    Parameters

    task

    The task to associate with the exception handler.

    exceptionQ

    The message queue to which an exception message will be sent.

    Return Value

    A result code. See Multiprocessing Services Result Codes.

    Discussion

    When an exception handler is set and an exception occurs, the task is suspended and a message is sent to the message queue specified by exceptionQ. The message contains the following information:

    • The first pointer-sized value contains the ID of the task in which the exception occurred.

    • The second pointer-sized value contains the type of exception that occurred. See the header file MachineExceptions.h for a listing of exception types.

    • The last pointer-sized value is set to NULL (reserved for future use).

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

    Deprecated in OS X v10.7.

  • Sets state information for a suspended task.

    Declaration

    Objective-C

    OSStatus MPSetTaskState ( MPTaskID task, MPTaskStateKind kind, void *info );

    Parameters

    task

    The task whose state information you want to set.

    kind

    The kind of state information you want to set. See Task State Constants for a listing of possible values. Note that some state information is read-only and cannot be changed using this function.

    info

    A pointer to a data structure holding the state information you want to set. The format of the data structure varies depending on the state information you want to set. See the header file MachineExceptions.h for the formats of the various state information structures.

    Return Value

    A result code. See Multiprocessing Services Result Codes. If you specify kMPTaskState32BitMemoryException for the state information, this function returns kMPInsufficientResourcesErr, since the exception state information is read-only. Attempting to set state information for a running task will also return kMPInsufficientResourcesErr.

    Discussion

    You can use this function to set register contents or exception information for a particular task. However, some state information, such as the exception information (as specified by kMPTaskState32BitMemoryException) as well as the MSR, ExceptKind, DSISR, and DAR machine registers (specified under kMPTaskStateMachine) are read-only. Attempting to set the read-only machine registers will do nothing, while attempting to set the exception information will return an error.

    Also see the function MPExtractTaskState.

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

    Deprecated in OS X v10.7.

  • Throws an exception to a specified task.

    Declaration

    Objective-C

    OSStatus MPThrowException ( MPTaskID task, MPExceptionKind kind );

    Parameters

    task

    The task to which the exception should be thrown.

    kind

    The type of exception to give to the task.

    Return Value

    A result code. See Multiprocessing Services Result Codes. If the task is already suspended or if the task is not defined to take thrown exceptions, the function returns kMPInsufficientResourcesErr.

    Discussion

    The exception is treated in the same manner as any other exception taken by a task. However, since it is asynchronous, it may not be presented immediately.

    By convention, you should set the exception kind to kMPTaskStoppedErr if you want to suspend a task. In general, you should do so only if you are debugging and wish to examine the state of the task. Otherwise you should block the task using one of the traditional notification mechanisms (such as a message queue).

    An exception can be thrown at any time, whether that task is running, eligible to be run (that is, ready), or blocked. The task is suspended and an exception message may be generated the next time the task is about to run. Note that this may never occur— for example, if the task is deadlocked or the resource it is waiting on is never released. If the task is currently blocked when this function is executed, kMPTaskBlockedErr is returned. If the task was suspended immediately at the conclusion of this function call the return value is kMPTaskStoppedErr.

    In OS X, this function is available but is not implemented.

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

    Deprecated in OS X v10.7.

  • Registers a debugger.

    Declaration

    Objective-C

    OSStatus MPRegisterDebugger ( MPQueueID queue, MPDebuggerLevel level );

    Parameters

    queue

    The ID of the queue to which you want exception messages and other information to be sent.

    level

    The level of this debugger with respect to other debuggers. Exceptions and informational messages are sent first to the debugger with the highest level. If more than one debugger attempts to register at a particular level, only the first debugger is registered. Other attempts return an error.

    Return Value

    A result code. See Multiprocessing Services Result Codes.

    Discussion

    In OS X, this function is available but is not implemented. Use system debugging services to write a debugger for OS X.

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

    Deprecated in OS X v10.7.

  • Unregisters a debugger.

    Declaration

    Objective-C

    OSStatus MPUnregisterDebugger ( MPQueueID queue );

    Parameters

    queue

    The ID of the queue whose debugger you want to unregister.

    Return Value

    A result code. See Multiprocessing Services Result Codes.

    Discussion

    In OS X, this function is available but is not implemented. Use system debugging services to write a debugger for OS X.

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

    Deprecated in OS X v10.7.

Callbacks

  • Defines a remote procedure call.

    Declaration

    Objective-C

    typedef void* (*MPRemoteProcedure) ( void *parameter );

    Parameters

    parameter

    A pointer to the application-defined value you passed to the function MPRemoteCallCFM. For example, this value could point to a data structure or a memory location.

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

  • Defines the entry point of a task.

    Declaration

    Objective-C

    typedef OSStatus (*TaskProc) ( void *parameter );

    Parameters

    parameter

    A pointer to the application-defined value you passed to the function MPCreateTask. For example, this value could point to a data structure or a memory location.

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

Data Types

  • Declaration

    Objective-C

    typedef struct OpaqueMPAddressSpaceID * MPAddressSpaceID;

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

  • Declaration

    Objective-C

    struct MPAddressSpaceInfo { PBVersion version; MPProcessID processID; MPCoherenceID groupID; ItemCount nTasks; UInt32 vsid[16]; }; typedef struct MPAddressSpaceInfo MPAddressSpaceInfo;

    Availability

    Available in OS X v10.1 and later.

  • Declaration

    Objective-C

    typedef struct OpaqueMPAreaID * MPAreaID;

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

  • Represents a memory coherence group.

    Declaration

    Objective-C

    typedef struct OpaqueMPCoherenceID * MPCoherenceID;

    Discussion

    A coherence group is the set of processors and other bus controllers that have cache-coherent access to memory. Mac OS 9 defines only one coherence group, which is all the processors that can access internal memory (RAM). Other coherence groups are possible; for example, a PCI card with its own memory and processors can comprise a coherence group.

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

  • Declaration

    Objective-C

    typedef struct OpaqueMPConsoleID * MPConsoleID;

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

  • Represents a CPU ID.

    Declaration

    Objective-C

    typedef struct OpaqueMPCpuID * MPCpuID;

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

  • Represents a critical region ID, which Multiprocessing Services uses to manipulate critical regions.

    Declaration

    Objective-C

    typedef struct OpaqueMPCriticalRegionID * MPCriticalRegionID;

    Discussion

    You obtain a critical region ID by calling the function MPCreateCriticalRegion.

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

  • Declaration

    Objective-C

    struct MPCriticalRegionInfo { PBVersion version; MPProcessID processID; OSType regionName; ItemCount nWaiting; MPTaskID waitingTaskID; MPTaskID owningTask; ItemCount count; }; typedef struct MPCriticalRegionInfo MPCriticalRegionInfo;

    Availability

    Available in OS X v10.0 and later.

  • Represents event information for an event group.

    Declaration

    Objective-C

    typedef UInt32 MPEventFlags;

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

  • Represents an event group ID, which Multiprocessing Services uses to manipulate event groups.

    Declaration

    Objective-C

    typedef struct OpaqueMPEventID * MPEventID;

    Discussion

    You obtain an event group ID by calling the function MPCreateEvent.

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

  • Declaration

    Objective-C

    struct MPEventInfo { PBVersion version; MPProcessID processID; OSType eventName; ItemCount nWaiting; MPTaskID waitingTaskID; MPEventFlags events; }; typedef struct MPEventInfo MPEventInfo;

    Availability

    Available in OS X v10.0 and later.

  • Represents the kind of exception thrown.

    Declaration

    Objective-C

    typedef UInt32 MPExceptionKind;

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

  • Represents a notification ID, which Multiprocessing Services uses to manipulate kernel notifications.

    Declaration

    Objective-C

    typedef struct OpaqueMPNotificationID * MPNotificationID;

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

  • Declaration

    Objective-C

    struct MPNotificationInfo { PBVersion version; MPProcessID processID; OSType notificationName; MPQueueID queueID; void * p1; void * p2; void * p3; MPEventID eventID; MPEventFlags events; MPSemaphoreID semaphoreID; }; typedef struct MPNotificationInfo MPNotificationInfo;

    Availability

    Available in OS X v10.0 and later.

  • Represents a generic notification ID (that is, an ID that could be a queue ID, event ID, kernel notification ID, or semaphore ID).

    Declaration

    Objective-C

    typedef struct OpaqueMPOpaqueID * MPOpaqueID;

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

  • Declaration

    Objective-C

    typedef UInt32 MPOpaqueIDClass;

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

  • Declaration

    Objective-C

    typedef UInt32 MPPageSizeClass;

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

  • Represents a process ID.

    Declaration

    Objective-C

    typedef struct OpaqueMPProcessID * MPProcessID;

    Discussion

    Note that this process ID is identical to the process ID (or context ID) handled by the Code Fragment Manager.

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

  • Represents a queue ID, which Multiprocessing Services uses to manipulate message queues.

    Declaration

    Objective-C

    typedef struct OpaqueMPQueueID * MPQueueID;

    Discussion

    You obtain a queue ID by calling the function MPCreateQueue.

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

  • Declaration

    Objective-C

    struct MPQueueInfo { PBVersion version; MPProcessID processID; OSType queueName; ItemCount nWaiting; MPTaskID waitingTaskID; ItemCount nMessages; ItemCount nReserved; void * p1; void * p2; void * p3; }; typedef struct MPQueueInfo MPQueueInfo;

    Availability

    Available in OS X v10.0 and later.

  • Represents a semaphore count.

    Declaration

    Objective-C

    typedef ItemCount MPSemaphoreCount;

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

  • Represents a semaphore ID, which Multiprocessing Services uses to manipulate semaphores.

    Declaration

    Objective-C

    typedef struct OpaqueMPSemaphoreID * MPSemaphoreID;

    Discussion

    You obtain a semaphore ID by calling the function MPCreateSemaphore.

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

  • Declaration

    Objective-C

    struct MPSemaphoreInfo { PBVersion version; MPProcessID processID; OSType semaphoreName; ItemCount nWaiting; MPTaskID waitingTaskID; ItemCount maximum; ItemCount count; }; typedef struct MPSemaphoreInfo MPSemaphoreInfo;

    Availability

    Available in OS X v10.0 and later.

  • Represents a task ID.

    Declaration

    Objective-C

    typedef struct OpaqueMPTaskID * MPTaskID;

    Discussion

    You obtain a task ID by calling the function MPCreateTask.

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

  • Contains information about a task.

    Declaration

    Objective-C

    struct MPTaskInfo { PBVersion version; OSType name; OSType queueName; UInt16 runState; UInt16 lastCPU; UInt32 weight; MPProcessID processID; AbsoluteTime cpuTime; AbsoluteTime schedTime; AbsoluteTime creationTime; ItemCount codePageFaults; ItemCount dataPageFaults; ItemCount preemptions; MPCpuID cpuID; MPOpaqueID blockedObject; MPAddressSpaceID spaceID; LogicalAddress stackBase; LogicalAddress stackLimit; LogicalAddress stackCurr; }; typedef struct MPTaskInfo MPTaskInfo;

    Fields

    version

    The version of this data structure.

    name

    The name of the task.

    queueName

    A four-byte code indicating the status of the queue waiting on the task.

    runState

    The current state of the task (running, ready, or blocked).

    lastCPU

    The address of the last processor that ran this task.

    weight

    The weighting assigned to this task.

    processID

    The ID of the process that owns this task.

    cpuTime

    The accumulated CPU time used by the task.

    schedTime

    The time when the task was last scheduled.

    creationTime

    The time when the task was created.

    codePageFaults

    The number of page faults that occurred during code execution.

    dataPageFaults

    The number of page faults that occurred during data access.

    preemptions

    The number of times this task was preempted.

    cpuID

    The ID of the last processor that ran this task.

    blockedObject

    Reserved for use by OS X.

    spaceID

    Address space ID of this task.

    stackBase

    The lowest memory address of the task’s stack.

    stackLimit

    The highest memory address of the task’s stack.

    stackCurr

    The current stack address.

    Discussion

    If you specify the kMPTaskStateTaskInfo constant when calling the function MPExtractTaskState , Multiprocessing Services returns state information in an MPTaskInfo structure.

    Availability

    Available in OS X v10.0 and later.

  • Declaration

    Objective-C

    struct MPTaskInfoVersion2 { PBVersion version; OSType name; OSType queueName; UInt16 runState; UInt16 lastCPU; UInt32 weight; MPProcessID processID; AbsoluteTime cpuTime; AbsoluteTime schedTime; AbsoluteTime creationTime; ItemCount codePageFaults; ItemCount dataPageFaults; ItemCount preemptions; MPCpuID cpuID; }; typedef struct MPTaskInfoVersion2 MPTaskInfoVersion2;

    Availability

    Available in OS X v10.0 and later.

  • Declaration

    Objective-C

    typedef UInt32 MPTaskStateKind;

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

  • Represents the relative processor weighting of a task.

    Declaration

    Objective-C

    typedef UInt32 MPTaskWeight;

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

  • Represents a timer ID.

    Declaration

    Objective-C

    typedef struct OpaqueMPTimerID * MPTimerID;

    Discussion

    You obtain a timer ID by calling the function MPCreateTimer.

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

  • Represents a task storage index value used by functions described in “Accessing Per-Task Storage Variables.”

    Declaration

    Objective-C

    typedef ItemCount TaskStorageIndex;

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

  • Represents a task storage value used by functions described in “Accessing Per-Task Storage Variables.”

    Declaration

    Objective-C

    typedef LogicalAddress TaskStorageValue;

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

Constants

  • The maximum memory allocation size.

    Declaration

    Objective-C

    enum { kMPMaxAllocSize = 1024L * 1024 * 1024 };

    Constants

    • kMPMaxAllocSize

      kMPMaxAllocSize

      The maximum allocation size: 1GB.

      Available in OS X v10.0 and later.

  • Use to specify no task ID.

    Declaration

    Objective-C

    enum { kMPNoID = kInvalidID };

    Constants

    • kMPNoID

      kMPNoID

      No task ID.

      Available in OS X v10.0 and later.

    Discussion

    Used when calling MPTaskIsPreemptive if you want to specify the current task.

  • Data structure version information constants.

    Declaration

    Objective-C

    enum { kMPQueueInfoVersion = 1L | (kOpaqueQueueID << 16), kMPSemaphoreInfoVersion = 1L | (kOpaqueSemaphoreID << 16), kMPEventInfoVersion = 1L | (kOpaqueEventID << 16), kMPCriticalRegionInfoVersion = 1L | (kOpaqueCriticalRegionID << 16), kMPNotificationInfoVersion = 1L | (kOpaqueNotificationID << 16), kMPAddressSpaceInfoVersion = 1L | (kOpaqueAddressSpaceID << 16) };

    Constants

    • kMPQueueInfoVersion

      kMPQueueInfoVersion

      The MPQueueInfo structure version.

      Available in OS X v10.0 and later.

    • kMPSemaphoreInfoVersion

      kMPSemaphoreInfoVersion

      The MPSemaphoreInfo structure version.

      Available in OS X v10.0 and later.

    • kMPEventInfoVersion

      kMPEventInfoVersion

      The MPEventInfo structure version.

      Available in OS X v10.0 and later.

    • kMPCriticalRegionInfoVersion

      kMPCriticalRegionInfoVersion

      The MPCriticalRegionInfo structure version.

      Available in OS X v10.0 and later.

    • kMPNotificationInfoVersion

      kMPNotificationInfoVersion

      The MPNotificationInfo structure version.

      Available in OS X v10.0 and later.

    • kMPAddressSpaceInfoVersion

      kMPAddressSpaceInfoVersion

      The MPAddressSpaceInfo structure version.

      Available in OS X v10.1 and later.

  • Constants indicating the source of a generic notification.

    Declaration

    Objective-C

    enum { kOpaqueAnyID = 0, kOpaqueProcessID = 1, kOpaqueTaskID = 2, kOpaqueTimerID = 3, kOpaqueQueueID = 4, kOpaqueSemaphoreID = 5, kOpaqueCriticalRegionID = 6, kOpaqueCpuID = 7, kOpaqueAddressSpaceID = 8, kOpaqueEventID = 9, kOpaqueCoherenceID = 10, kOpaqueAreaID = 11, kOpaqueNotificationID = 12, kOpaqueConsoleID = 13 };

    Constants

    • kOpaqueAnyID

      kOpaqueAnyID

      Any source.

      Available in OS X v10.0 and later.

    • kOpaqueProcessID

      kOpaqueProcessID

      A process.

      Available in OS X v10.0 and later.

    • kOpaqueTaskID

      kOpaqueTaskID

      A task.

      Available in OS X v10.0 and later.

    • kOpaqueTimerID

      kOpaqueTimerID

      A timer.

      Available in OS X v10.0 and later.

    • kOpaqueQueueID

      kOpaqueQueueID

      A queue.

      Available in OS X v10.0 and later.

    • kOpaqueSemaphoreID

      kOpaqueSemaphoreID

      A semaphore.

      Available in OS X v10.0 and later.

    • kOpaqueCriticalRegionID

      kOpaqueCriticalRegionID

      A critical region.

      Available in OS X v10.0 and later.

    • kOpaqueCpuID

      kOpaqueCpuID

      A CPU.

      Available in OS X v10.0 and later.

    • kOpaqueAddressSpaceID

      kOpaqueAddressSpaceID

      An address space.

      Available in OS X v10.0 and later.

    • kOpaqueEventID

      kOpaqueEventID

      An event.

      Available in OS X v10.0 and later.

    • kOpaqueCoherenceID

      kOpaqueCoherenceID

      A coherence group.

      Available in OS X v10.0 and later.

    • kOpaqueAreaID

      kOpaqueAreaID

      An area.

      Available in OS X v10.0 and later.

    • kOpaqueNotificationID

      kOpaqueNotificationID

      A notification.

      Available in OS X v10.0 and later.

    • kOpaqueConsoleID

      kOpaqueConsoleID

      A console.

      Available in OS X v10.0 and later.

  • Specify the alignment of the desired memory block when calling the MPAllocateAligned function.

    Declaration

    Objective-C

    enum { kMPAllocateDefaultAligned = 0, kMPAllocate8ByteAligned = 3, kMPAllocate16ByteAligned = 4, kMPAllocate32ByteAligned = 5, kMPAllocate1024ByteAligned = 10, kMPAllocate4096ByteAligned = 12, kMPAllocateMaxAlignment = 16, kMPAllocateAltiVecAligned = kMPAllocate16ByteAligned, kMPAllocateVMXAligned = kMPAllocateAltiVecAligned, kMPAllocateVMPageAligned = 254, kMPAllocateInterlockAligned = 255 };

    Constants

    • kMPAllocateDefaultAligned

      kMPAllocateDefaultAligned

      Use the default alignment.

      Available in OS X v10.0 and later.

    • kMPAllocate8ByteAligned

      kMPAllocate8ByteAligned

      Use 8-byte alignment.

      Available in OS X v10.0 and later.

    • kMPAllocate16ByteAligned

      kMPAllocate16ByteAligned

      Use 16-byte alignment.

      Available in OS X v10.0 and later.

    • kMPAllocate32ByteAligned

      kMPAllocate32ByteAligned

      Use 32-byte alignment.

      Available in OS X v10.0 and later.

    • kMPAllocate1024ByteAligned

      kMPAllocate1024ByteAligned

      Use 1024-byte alignment.

      Available in OS X v10.0 and later.

    • kMPAllocate4096ByteAligned

      kMPAllocate4096ByteAligned

      Use 4096-byte alignment.

      Available in OS X v10.0 and later.

    • kMPAllocateMaxAlignment

      kMPAllocateMaxAlignment

      Use the maximum alignment (65536 byte).

      Available in OS X v10.0 and later.

    • kMPAllocateAltiVecAligned

      kMPAllocateAltiVecAligned

      Use AltiVec alignment.

      Available in OS X v10.0 and later.

    • kMPAllocateVMXAligned

      kMPAllocateVMXAligned

      Use VMX (now called AltiVec) alignment.

      Available in OS X v10.0 and later.

    • kMPAllocateVMPageAligned

      kMPAllocateVMPageAligned

      Use virtual memory page alignment. This alignment is set at runtime.

      Available in OS X v10.0 and later.

    • kMPAllocateInterlockAligned

      kMPAllocateInterlockAligned

      Use interlock alignment, which is the alignment needed to allow the use of CPU interlock instructions (that is, lwarx and stwcx.) on the returned memory address. This alignment is set at runtime. In most cases you would never need to use this alignment.

      Available in OS X v10.0 and later.

  • Specify optional actions when calling the MPAllocateAligned function.

    Declaration

    Objective-C

    enum { kMPAllocateClearMask = 0x0001, kMPAllocateGloballyMask = 0x0002, kMPAllocateResidentMask = 0x0004, kMPAllocateNoGrowthMask = 0x0010, kMPAllocateNoCreateMask = 0x0020 };

    Constants

    • kMPAllocateClearMask

      kMPAllocateClearMask

      Zero out the allocated memory block.

      Available in OS X v10.0 and later.

    • kMPAllocateGloballyMask

      kMPAllocateGloballyMask

      Allocate memory from in memory space that is visible to all processes. Note that such globally-allocated space is not automatically reclaimed when the allocating process terminates. By default, MPAllocateAligned allocates memory from process-specific (that is, not global) memory.

      Available in OS X v10.0 and later.

    • kMPAllocateResidentMask

      kMPAllocateResidentMask

      Allocate memory from resident memory only (that is, the allocated memory is not pageable).

      Available in OS X v10.0 and later.

    • kMPAllocateNoGrowthMask

      kMPAllocateNoGrowthMask

      Do not attempt to grow the pool of available memory. Specifying this option is useful, as attempting to grow memory may cause your task to block until such memory becomes available.

      Available in OS X v10.0 and later.

    • kMPAllocateNoCreateMask

      kMPAllocateNoCreateMask

      Do not attempt to create the pool if it does not yet exist.

      Available in OS X v10.1 and later.

  • Indicates the debugger level.

    Declaration

    Objective-C

    typedef UInt32 MPDebuggerLevel; enum { kMPLowLevelDebugger = 0x00000000, kMPMidLevelDebugger = 0x10000000, kMPHighLevelDebugger = 0x20000000 };

    Constants

    • kMPLowLevelDebugger

      kMPLowLevelDebugger

      The low-level debugger.

      Available in OS X v10.1 and later.

    • kMPMidLevelDebugger

      kMPMidLevelDebugger

      The mid-level debugger.

      Available in OS X v10.1 and later.

    • kMPHighLevelDebugger

      kMPHighLevelDebugger

      The high-level debugger.

      Available in OS X v10.1 and later.

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

  • Identifies the current library version.

    Declaration

    Objective-C

    enum { MPLibrary_MajorVersion = 2, MPLibrary_MinorVersion = 3, MPLibrary_Release = 1, MPLibrary_DevelopmentRevision = 1 };

    Constants

    • MPLibrary_MajorVersion

      MPLibrary_MajorVersion

      Major version number.

      Available in OS X v10.0 and later.

    • MPLibrary_MinorVersion

      MPLibrary_MinorVersion

      Minor version number.

      Available in OS X v10.0 and later.

    • MPLibrary_Release

      MPLibrary_Release

      Release number.

      Available in OS X v10.0 and later.

    • MPLibrary_DevelopmentRevision

      MPLibrary_DevelopmentRevision

      Development revision number.

      Available in OS X v10.0 and later.

  • Specify which contexts are allowed to execute the callback function when using MPRemoteCall.

    Declaration

    Objective-C

    enum { kMPAnyRemoteContext = 0, kMPOwningProcessRemoteContext = 1, kMPInterruptRemoteContext = 2, kMPAsyncInterruptRemoteContext = 3 }; typedef UInt8 MPRemoteContext;

    Constants

    • kMPAnyRemoteContext

      kMPAnyRemoteContext

      Any cooperative context can execute the function. Note that the called function may not have access to any of the owning context’s process-specific low-memory values.

      Available in OS X v10.0 and later.

    • kMPOwningProcessRemoteContext

      kMPOwningProcessRemoteContext

      Only the context that owns the task can execute the function.

      Available in OS X v10.0 and later.

    • kMPInterruptRemoteContext

      kMPInterruptRemoteContext

      Unsupported in OS X.

      Available in OS X v10.1 and later.

    • kMPAsyncInterruptRemoteContext

      kMPAsyncInterruptRemoteContext

      Unsupported in OS X.

      Available in OS X v10.1 and later.

    Discussion

    These constants are used to support older versions of Mac OS and are ignored in OS X.

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

  • Specify optional actions when calling the MPCreateTask function.

    Declaration

    Objective-C

    enum { kMPCreateTaskSuspendedMask = 1L << 0, kMPCreateTaskTakesAllExceptionsMask = 1L << 1, kMPCreateTaskNotDebuggableMask = 1L << 2, kMPCreateTaskValidOptionsMask = kMPCreateTaskSuspendedMask | kMPCreateTaskTakesAllExceptionsMask | kMPCreateTaskNotDebuggableMask }; typedef OptionBits MPTaskOptions;

    Constants

    • kMPCreateTaskSuspendedMask

      kMPCreateTaskSuspendedMask

      Unsupported in OS X.

      Available in OS X v10.0 and later.

    • kMPCreateTaskTakesAllExceptionsMask

      kMPCreateTaskTakesAllExceptionsMask

      The task will take all exceptions, including those normally handled by the system, such as page faults.

      Available in OS X v10.0 and later.

    • kMPCreateTaskNotDebuggableMask

      kMPCreateTaskNotDebuggableMask

      Unsupported in OS X.

      Available in OS X v10.1 and later.

    • kMPCreateTaskValidOptionsMask

      kMPCreateTaskValidOptionsMask

      Include all valid options for this task.

      Available in OS X v10.0 and later.

    Import Statement

    Objective-C

    @import CoreServices;

    Availability

    Available in OS X v10.0 and later.

  • Specify actions to take on an exception when passed in the action parameter of the MPDisposeTaskException function.

    Declaration

    Objective-C

    enum { kMPTaskPropagate = 0, kMPTaskResumeStep = 1, kMPTaskResumeBranch = 2, kMPTaskResumeMask = 0x0000, kMPTaskPropagateMask = 1 << kMPTaskPropagate, kMPTaskResumeStepMask = 1 << kMPTaskResumeStep, kMPTaskResumeBranchMask = 1 << kMPTaskResumeBranch };

    Constants

    • kMPTaskPropagate

      kMPTaskPropagate

      The exception is propagated.

      Available in OS X v10.0 and later.

    • kMPTaskResumeStep

      kMPTaskResumeStep

      The task is resumed and single step is enabled.

      Available in OS X v10.0 and later.

    • kMPTaskResumeBranch

      kMPTaskResumeBranch

      The task is resumed and branch stepping is enabled.

      Available in OS X v10.0 and later.

    • kMPTaskResumeMask

      kMPTaskResumeMask

      Resume the task.

      Available in OS X v10.0 and later.

    • kMPTaskPropagateMask

      kMPTaskPropagateMask

      Propagate the exception to the next debugger level.

      Available in OS X v10.0 and later.

    • kMPTaskResumeStepMask

      kMPTaskResumeStepMask

      Resume the task and enable single stepping.

      Available in OS X v10.0 and later.

    • kMPTaskResumeBranchMask

      kMPTaskResumeBranchMask

      Resume the task and enable branch stepping.

      Available in OS X v10.0 and later.

  • Indicates the current version of the MPTaskInfo structure (returned as the first field).

    Declaration

    Objective-C

    enum { kMPTaskInfoVersion = 3 };

    Constants

    • kMPTaskInfoVersion

      kMPTaskInfoVersion

      The current version of the task information structure.

      Available in OS X v10.0 and later.

  • Indicate the state of the task when returned as part of the MPTaskInfo data structure.

    Declaration

    Objective-C

    enum { kMPTaskBlocked = 0, kMPTaskReady = 1, kMPTaskRunning = 2 };

    Constants

    • kMPTaskBlocked

      kMPTaskBlocked

      The task is blocked..

      Available in OS X v10.0 and later.

    • kMPTaskReady

      kMPTaskReady

      The task is ready for execution.

      Available in OS X v10.0 and later.

    • kMPTaskRunning

      kMPTaskRunning

      The task is currently running.

      Available in OS X v10.0 and later.

  • Specify what states you want to set or obtain when calling the MPExtractTaskState or MPSetTaskState functions.

    Declaration

    Objective-C

    enum { kMPTaskStateRegisters = 0, kMPTaskStateFPU = 1, kMPTaskStateVectors = 2, kMPTaskStateMachine = 3, kMPTaskState32BitMemoryException = 4, kMPTaskStateTaskInfo = 5 };

    Constants

    • kMPTaskStateRegisters

      kMPTaskStateRegisters

      The task’s general-purpose (GP) registers. The RegisterInformationPowerPC structure in MachineExceptions.h defines the format of this information.

      Available in OS X v10.0 and later.

    • kMPTaskStateFPU

      kMPTaskStateFPU

      The task’s floating point registers. The FPUInformationPowerPC structure in MachineExceptions.h defines the format of this information.

      Available in OS X v10.0 and later.

    • kMPTaskStateVectors

      kMPTaskStateVectors

      The task’s vector registers. The VectorInformationPowerPC structure in MachineExceptions.h defines the format of this information.

      Available in OS X v10.0 and later.

    • kMPTaskStateMachine

      kMPTaskStateMachine

      The task’s machine registers. The MachineInformationPowerPC structure in MachineExceptions.h defines the format of this information. Note that the MSR, ExceptKind, DSISR, and DAR registers are read-only.

      Available in OS X v10.0 and later.

    • kMPTaskState32BitMemoryException

      kMPTaskState32BitMemoryException

      The task’s exception information for older 32-bit memory exceptions (that is, memory exceptions on 32-bit CPUs). The MemoryExceptionInformation structure in MachineExceptions.h defines the format of this information. This exception information is read-only.

      Available in OS X v10.0 and later.

    • kMPTaskStateTaskInfo

      kMPTaskStateTaskInfo

      Static and dynamic information about the task, as described by the data structure MPTaskInfo. This task information is read-only.

      Available in OS X v10.0 and later.

  • Specify the maximum time a task should wait for an event to occur.

    Declaration

    Objective-C

    enum { kDurationImmediate = 0, kDurationForever = 0x7FFFFFFF, kDurationMillisecond = 1, kDurationMicrosecond = -1 };

    Constants

    • kDurationImmediate

      kDurationImmediate

      The task times out immediately, whether or not the event has occurred. If the event occurred, the return status is noErr. If the event did not occur, the return status is kMPTimeoutErr (assuming no other errors occurred).

      Available in OS X v10.0 and later.

    • kDurationForever

      kDurationForever

      The task waits forever. The blocking call waits until either the event occurs, or until the object being waited upon (such as a message queue) is deleted.

      Available in OS X v10.0 and later.

    • kDurationMillisecond

      kDurationMillisecond

      The task waits one millisecond before timing out.

      Available in OS X v10.0 and later.

    • kDurationMicrosecond

      kDurationMicrosecond

      The task waits one microsecond before timing out.

      Available in OS X v10.0 and later.

    Discussion

    You can use these constants in conjunction with other values to indicate specific wait intervals. For example, to wait 1 second, you can pass kDurationMillisecond * 1000.

  • Indicate optional actions when calling MPArmTimer.

    Declaration

    Objective-C

    enum { kMPPreserveTimerIDMask = 1L << 0, kMPTimeIsDeltaMask = 1L << 1, kMPTimeIsDurationMask = 1L << 2 };

    Constants

    • kMPPreserveTimerIDMask

      kMPPreserveTimerIDMask

      Specifying this mask prevents the timer from being deleted when it expires.

      Available in OS X v10.0 and later.

    • kMPTimeIsDeltaMask

      kMPTimeIsDeltaMask

      Specifying this mask indicates that the specified time should be added to the previous expiration time to form the new expiration time. You can use this mask to compensate for timing drift caused by the finite amount of time required to arm the timer, receive the notification, and so on.

      Available in OS X v10.0 and later.

    • kMPTimeIsDurationMask

      kMPTimeIsDurationMask

      Specifying this mask indicates that the specified expiration time is of type Duration. You can use this mask to avoid having to call time conversion routines when specifying an expiration time.

      Available in OS X v10.0 and later.

Result Codes

Result codes defined for Multiprocessing Services are listed below.

  • Value

    -29275

    Description

    Available in OS X v10.0 and later.

  • Value

    -29276

    Description

    Available in OS X v10.0 and later.

  • Value

    -29288

    Description

    Available in OS X v10.0 and later.

  • Value

    -29289

    Description

    Available in OS X v10.0 and later.

  • Value

    -29290

    Description

    Available in OS X v10.0 and later.

  • The desired task is blocked.

    Value

    -29291

    Description

    The desired task is blocked.

    Available in OS X v10.0 and later.

  • The desired task is stopped.

    Value

    -29292

    Description

    The desired task is stopped.

    Available in OS X v10.0 and later.

  • The desired notification the function was waiting upon was deleted.

    Value

    -29295

    Description

    The desired notification the function was waiting upon was deleted.

    Available in OS X v10.0 and later.

  • The designated timeout interval passed before the function could take action.

    Value

    -29296

    Description

    The designated timeout interval passed before the function could take action.

    Available in OS X v10.0 and later.

  • Could not complete task due to unavailable Multiprocessing Services resources. Note that many functions return this value as a general error when the desired action could not be performed.

    Value

    -29298

    Description

    Could not complete task due to unavailable Multiprocessing Services resources. Note that many functions return this value as a general error when the desired action could not be performed.

    Available in OS X v10.0 and later.

  • Invalid ID value. For example, an invalid message queue ID was passed to MPNotifyQueue.

    Value

    -29299

    Description

    Invalid ID value. For example, an invalid message queue ID was passed to MPNotifyQueue.

    Available in OS X v10.0 and later.

Gestalt Constants

You can determine which system software calls are preemptively-safe for Multiprocessing Services by using the preemptive function attribute selectors defined in the Gestalt Manager. For more information, see Gestalt Manager Reference.