Hello Everyone,
I'm encountering an issue while setting up a timer event in DriverKit and would appreciate any guidance.
Here's my current implementation:
void DRV_MAIN_CLASS_NAME::SetupEventTimer()
{
// 1. Create dispatch queue
kern_return_t ret = IODispatchQueue::Create("TimerQueue", 0, 0, &ivars->dispatchQueue);
if (ret != kIOReturnSuccess) {
LogErr("Failed to create dispatch queue: 0x%x", ret);
return;
}
// 2. Create timer source
ret = IOTimerDispatchSource::Create(ivars->dispatchQueue, &ivars->dispatchSource);
if (ret != kIOReturnSuccess) {
LogErr("Failed to create timer: 0x%x", ret);
OSSafeReleaseNULL(ivars->dispatchQueue);
return;
}
/*!
* @brief Create an instance of OSAction.
* @discussion Methods to allocate an OSAction instance are generated for each method defined in a class with
* a TYPE attribute, so there should not be any need to directly call OSAction::Create().
* @param target OSObject to receive the callback. This object will be retained until the OSAction is
* canceled or freed.
* @param targetmsgid Generated message ID for the target method.
* @param msgid Generated message ID for the method invoked by the receiver of the OSAction
* to generate the callback.
* @param referenceSize Size of additional state structure available to the creator of the OSAction
* with GetReference.
* @param action Created OSAction with +1 retain count to be released by the caller.
* @return kIOReturnSuccess on success. See IOReturn.h for error codes.
*/
// 3: Create an OSAction for the TimerOccurred method
// THIS IS WHERE I NEED HELP
OSAction* timerAction = nullptr;
ret = OSAction::Create(this, 0, 0, 0, &timerAction);
if (ret != kIOReturnSuccess) {
LogErr("Failed to create OSAction: 0x%x", ret);
goto cleanup;
}
// 4. Set handler
ret = ivars->dispatchSource->SetHandler(timerAction);
if (ret != kIOReturnSuccess) {
LogErr("Failed to set handler: 0x%x", ret);
goto cleanup;
}
// 5. Schedule timer (1 second)
uint64_t deadline = mach_absolute_time() + NSEC_PER_SEC;
ivars->dispatchSource->WakeAtTime(0, deadline, 0);
cleanup:
if (ret != kIOReturnSuccess) {
OSSafeReleaseNULL(timerAction);
OSSafeReleaseNULL(ivars->dispatchSource);
OSSafeReleaseNULL(ivars->dispatchQueue);
}
}
Problem:
The code runs but the OSAction callback binding seems incorrect (Step 3).
According to the OSAction documentation, I need to use the TYPE macro to properly bind the callback method. But I try to use
TYPE(DRV_MAIN_CLASS_NAME::TimerOccurred)
kern_return_t TimerOccurred() LOCALONLY;
TYPE(TimerOccurred)
kern_return_t TimerOccurred() LOCALONLY;
kern_return_t TimerOccurred() TYPE(DRV_MAIN_CLASS_NAME::TimerOccurred) LOCALONLY;
All results in Out-of-line definition of 'TimerOccurred' does not match any declaration in 'DRV_MAIN_CLASS_NAME'
Questions:
What is the correct way to declare a timer callback method using TYPE?
How to get the values targetmsgid & msgid generated by Xcode?
Any help would be greatly appreciated!
Best Regards, Charles