mirror of
https://github.com/TomHarte/CLK.git
synced 2024-11-23 18:31:53 +00:00
46 lines
1.1 KiB
Objective-C
46 lines
1.1 KiB
Objective-C
//
|
|
// CSHighPrecisionTimer.m
|
|
// Clock Signal
|
|
//
|
|
// Created by Thomas Harte on 07/03/2019.
|
|
// Copyright © 2019 Thomas Harte. All rights reserved.
|
|
//
|
|
|
|
#import "CSHighPrecisionTimer.h"
|
|
|
|
@implementation CSHighPrecisionTimer {
|
|
dispatch_source_t _timer;
|
|
dispatch_queue_t _queue;
|
|
}
|
|
|
|
- (instancetype)initWithTask:(dispatch_block_t)task interval:(uint64_t)interval {
|
|
self = [super init];
|
|
if(self) {
|
|
_queue = dispatch_queue_create("High precision timer queue", DISPATCH_QUEUE_SERIAL);
|
|
_timer = dispatch_source_create(DISPATCH_SOURCE_TYPE_TIMER, 0, 0, _queue);
|
|
if(_timer) {
|
|
dispatch_source_set_timer(_timer, dispatch_walltime(NULL, 0), interval, 0);
|
|
dispatch_source_set_event_handler(_timer, task);
|
|
|
|
// TODO: dispatch_activate is preferred to dispatch_resume, but arrives only
|
|
// as of macOS 10.12. So switch if/when upping the OS requirements.
|
|
dispatch_resume(_timer);
|
|
}
|
|
}
|
|
return self;
|
|
}
|
|
|
|
- (void)invalidate {
|
|
NSConditionLock *lock = [[NSConditionLock alloc] initWithCondition:0];
|
|
|
|
dispatch_source_set_cancel_handler(_timer, ^{
|
|
[lock lock];
|
|
[lock unlockWithCondition:1];
|
|
});
|
|
|
|
dispatch_source_cancel(_timer);
|
|
[lock lockWhenCondition:1];
|
|
}
|
|
|
|
@end
|