session-ios/Signal/src/util/ThreadManager.m

#import "ThreadManager.h"
#import "Util.h"

#define LOW_THREAD_NAME @"Audio Thread"
#define NORMAL_THREAD_NAME @"Background Thread"
#define HIGH_THREAD_NAME @"Blocking Working Thread"

@implementation RunningThreadRunLoopPair

@synthesize runLoop, thread;

+(RunningThreadRunLoopPair*) startNewWithThreadName:(NSString*)name {
    require(name != nil);
    
    RunningThreadRunLoopPair* instance = [RunningThreadRunLoopPair new];
    instance->thread = [[NSThread alloc] initWithTarget:instance selector:@selector(runLoopUntilCancelled) object:nil];
    [instance->thread setName:name];
    [instance->thread start];
    
    [Operation asyncRunAndWaitUntilDone:^{
        instance->runLoop = [NSRunLoop currentRunLoop];
    } onThread:instance->thread];
    
    return instance;
}
-(void) terminate {
    [thread cancel];
}
-(void) runLoopUntilCancelled {
    NSThread* curThread = [NSThread currentThread];
    NSRunLoop* curRunLoop = [NSRunLoop currentRunLoop];
    while (![curThread isCancelled]) {
        [curRunLoop runUntilDate:[NSDate dateWithTimeIntervalSinceNow:5]];
    }
}

@end

@implementation ThreadManager

static ThreadManager* sharedThreadManagerInternal;

+(ThreadManager*)sharedThreadManager {
    @synchronized(self) {
        if (sharedThreadManagerInternal == nil){
            sharedThreadManagerInternal = [ThreadManager new];
            sharedThreadManagerInternal->low = [RunningThreadRunLoopPair startNewWithThreadName:LOW_THREAD_NAME];
            sharedThreadManagerInternal->normal = [RunningThreadRunLoopPair startNewWithThreadName:NORMAL_THREAD_NAME];
            sharedThreadManagerInternal->high = [RunningThreadRunLoopPair startNewWithThreadName:HIGH_THREAD_NAME];
        }
    }
    return sharedThreadManagerInternal;
}

+(NSThread*)lowLatencyThread {
    return [self sharedThreadManager]->low.thread;
}
+(NSRunLoop*)lowLatencyThreadRunLoop {
    return [self sharedThreadManager]->low.runLoop;
}

+(NSThread*)normalLatencyThread {
    return [self sharedThreadManager]->normal.thread;
}
+(NSRunLoop *)normalLatencyThreadRunLoop {
    return [self sharedThreadManager]->normal.runLoop;
}

+(NSThread*)highLatencyThread {
    return [self sharedThreadManager]->high.thread;
}
+(NSRunLoop *)highLatencyThreadRunLoop {
    return [self sharedThreadManager]->high.runLoop;
}

+(void) terminate {
    @synchronized(self) {
        if (sharedThreadManagerInternal == nil) return;
        [sharedThreadManagerInternal->low terminate];
        [sharedThreadManagerInternal->normal terminate];
        [sharedThreadManagerInternal->high terminate];
        sharedThreadManagerInternal = nil;
    }
}

@end