Kulexiu/KulexiuForStudent/Pods/SocketRocket/SocketRocket/Internal/RunLoop/SRRunLoopThread.m

//
// Copyright 2012 Square Inc.
// Portions Copyright (c) 2016-present, Facebook, Inc.
//
// All rights reserved.
//
// This source code is licensed under the BSD-style license found in the
// LICENSE file in the root directory of this source tree. An additional grant
// of patent rights can be found in the PATENTS file in the same directory.
//

#import "SRRunLoopThread.h"

@interface SRRunLoopThread ()
{
    dispatch_group_t _waitGroup;
}

@property (nonatomic, strong, readwrite) NSRunLoop *runLoop;

@end

@implementation SRRunLoopThread

+ (instancetype)sharedThread
{
    static SRRunLoopThread *thread;
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        thread = [[SRRunLoopThread alloc] init];
        thread.name = @"com.facebook.SocketRocket.NetworkThread";
        thread.qualityOfService = NSQualityOfServiceUserInitiated;
        [thread start];
    });
    return thread;
}

- (instancetype)init
{
    self = [super init];
    if (self) {
        _waitGroup = dispatch_group_create();
        dispatch_group_enter(_waitGroup);
    }
    return self;
}

- (void)main
{
    @autoreleasepool {
        _runLoop = [NSRunLoop currentRunLoop];
        dispatch_group_leave(_waitGroup);

        // Add an empty run loop source to prevent runloop from spinning.
        CFRunLoopSourceContext sourceCtx = {
            .version = 0,
            .info = NULL,
            .retain = NULL,
            .release = NULL,
            .copyDescription = NULL,
            .equal = NULL,
            .hash = NULL,
            .schedule = NULL,
            .cancel = NULL,
            .perform = NULL
        };
        CFRunLoopSourceRef source = CFRunLoopSourceCreate(NULL, 0, &sourceCtx);
        CFRunLoopAddSource(CFRunLoopGetCurrent(), source, kCFRunLoopDefaultMode);
        CFRelease(source);

        while ([_runLoop runMode:NSDefaultRunLoopMode beforeDate:[NSDate distantFuture]]) {

        }
        assert(NO);
    }
}

- (NSRunLoop *)runLoop
{
    dispatch_group_wait(_waitGroup, DISPATCH_TIME_FOREVER);
    return _runLoop;
}

@end