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