Why is my CFRunLoopTimer not firing?
c++, cocoa, core-foundation, ios, objective-c
Solution
Quote from the docs
A timer needs to be added to a run loop mode before it will fire. To add the timer to a run loop, use CFRunLoopAddTimer. A timer can be registered to only one run loop at a time, although it can be in multiple modes within that run loop.
Also make sure your run loop doesn't die before the timer fires.
Problem
I have a `CFRunLoopTimer` created within a C++ class as shown below: ``` #import <CoreFoundation/CoreFoundation.h> void cClass::StartTimer() { if(!mActiveSenseTimer) { CFTimeInterval TIMER_INTERVAL = 5; CFRunLoopTimerContext TimerContext = {0, this, NULL, NULL, NULL}; CFAbsoluteTime FireTime = CFAbsoluteTimeGetCurrent() + TIMER_INTERVAL; mTimer = CFRunLoopTimerCreate(kCFAllocatorDefault, FireTime, 0, 0, 0, ActiveSenseTimerCallback, &TimerContext); NSLog(@"RunLoop:0x%x, TimerIsValid:%d, TimeIsNow:%f, TimerWillFireAt:%f", CFRunLoopGetCurrent(), CFRunLoopTimerIsValid(mActiveSenseTimer), CFAbsoluteTimeGetCurrent(), FireTime); } } void ActiveSenseTimerCallback(CFRunLoopTimerRef timer, void *info) { NSLog(@"Timeout"); CFRunLoopTimerContext TimerContext; TimerContext.version = 0; CFRunLoopTimerGetContext(timer, &TimerContext); ((cClass *)TimerContext.info)->Timeout(); } ``` Calling `cClass::StartTimer()` results in the following log output: RunLoop:0x7655d60, TimerIsValid:1, TimeIsNow:389196910.537962, TimerWillFireAt:389196915.537956 However, my timer never fires. Any ideas why?