[OC RunLoop_翻译]五、配置运行循环源

@interface RunLoopSource : NSObject
{
    CFRunLoopSourceRef runLoopSource;
    NSMutableArray* commands;
}
- (id)init;
- (void)addToCurrentRunLoop;
- (void)invalidate;
// Handler method 处理程序方法
- (void)sourceFired;
// Client interface for registering commands to process
//客户端接口，用于注册要处理的命令
- (void)addCommand:(NSInteger)command withData:(id)data;
- (void)fireAllCommandsOnRunLoop:(CFRunLoopRef)runloop;
@end
// These are the CFRunLoopSourceRef callback functions.
//这些是CFRunLoopSourceRef回调函数。
void RunLoopSourceScheduleRoutine (void *info, CFRunLoopRef rl, CFStringRef mode);
void RunLoopSourcePerformRoutine (void *info);
void RunLoopSourceCancelRoutine (void *info, CFRunLoopRef rl, CFStringRef mode);
// RunLoopContext is a container object used during registration of the input source.
//RunLoopContext是在注册输入源时使用的容器对象。
@interface RunLoopContext : NSObject
{
    CFRunLoopRef        runLoop;
    RunLoopSource*        source;
}
@property (readonly) CFRunLoopRef runLoop;
@property (readonly) RunLoopSource* source;
- (id)initWithSource:(RunLoopSource*)src andLoop:(CFRunLoopRef)loop;
@end

void RunLoopSourceScheduleRoutine (void *info, CFRunLoopRef rl, CFStringRef mode)
{
    RunLoopSource* obj = (RunLoopSource*)info;
    AppDelegate*   del = [AppDelegate sharedAppDelegate];
    RunLoopContext* theContext = [[RunLoopContext alloc] initWithSource:obj andLoop:rl];
    [del performSelectorOnMainThread:@selector(registerSource:)
                                withObject:theContext waitUntilDone:NO];
}

void RunLoopSourcePerformRoutine (void *info)
{
    RunLoopSource*  obj = (RunLoopSource*)info;
    [obj sourceFired];
}

//从runloop中删除输入源
void RunLoopSourceCancelRoutine (void *info, CFRunLoopRef rl, CFStringRef mode)
{
    //获取输入源
    RunLoopSource* obj = (RunLoopSource*)info;
    AppDelegate* del = [AppDelegate sharedAppDelegate];
    RunLoopContext* theContext = [[RunLoopContext alloc] initWithSource:obj andLoop:rl];
    //删除输入源
    [del performSelectorOnMainThread:@selector(removeSource:)
                                withObject:theContext waitUntilDone:YES];
}

//初始化
- (id)init
{
    CFRunLoopSourceContext    context = {0, self, NULL, NULL, NULL, NULL, NULL,
                                        &RunLoopSourceScheduleRoutine,
                                        RunLoopSourceCancelRoutine,
                                        RunLoopSourcePerformRoutine};
    runLoopSource = CFRunLoopSourceCreate(NULL, 0, &context);
    commands = [[NSMutableArray alloc] init];
    return self;
}
//添加到当前的runloop
- (void)addToCurrentRunLoop
{
    CFRunLoopRef runLoop = CFRunLoopGetCurrent();
    CFRunLoopAddSource(runLoop, runLoopSource, kCFRunLoopDefaultMode);
}

//注册输入源
- (void)registerSource:(RunLoopContext*)sourceInfo;
{
    [sourcesToPing addObject:sourceInfo];
}
//移除输入源
- (void)removeSource:(RunLoopContext*)sourceInfo
{
    id    objToRemove = nil;
    for (RunLoopContext* context in sourcesToPing)
    {
        if ([context isEqual:sourceInfo])
        {
            objToRemove = context;
            break;
        }
    }
    if (objToRemove)
        [sourcesToPing removeObject:objToRemove];
}

// 输入源处理缓存区中的命令
- (void)fireCommandsOnRunLoop:(CFRunLoopRef)runloop
{
    //客户端向输入源发送信号
    CFRunLoopSourceSignal(runLoopSource);
    // 唤醒runloop
    CFRunLoopWakeUp(runloop);
}

NSRunLoop* myRunLoop = [NSRunLoop currentRunLoop];
// Create and schedule the first timer. 手动调度定时器
NSDate* futureDate = [NSDate dateWithTimeIntervalSinceNow:1.0];
NSTimer* myTimer = [[NSTimer alloc] initWithFireDate:futureDate
                        interval:0.1
                        target:self
                        selector:@selector(myDoFireTimer1:)
                        userInfo:nil
                        repeats:YES];
[myRunLoop addTimer:myTimer forMode:NSDefaultRunLoopMode];
// Create and schedule the second timer. 默认模式创建定时器
[NSTimer scheduledTimerWithTimeInterval:0.2
                        target:self
                        selector:@selector(myDoFireTimer2:)
                        userInfo:nil
                        repeats:YES];

//获取当前的runloop
CFRunLoopRef runLoop = CFRunLoopGetCurrent();
//CFRunLoopTimerContext 用于配置CFRunLoopTimer的行为
CFRunLoopTimerContext context = {0, NULL, NULL, NULL, NULL};
//使用Core Foundation 创建定时器
CFRunLoopTimerRef timer = CFRunLoopTimerCreate(kCFAllocatorDefault, 0.1, 0.3, 0, 0,
                                        &myCFTimerCallback, &context);
//将定时器加入到当前runloop
CFRunLoopAddTimer(runLoop, timer, kCFRunLoopCommonModes);

{
    //创建 端口对象
    NSPort* myPort = [NSMachPort port];
    if (myPort)
    {
        // This class handles incoming port messages.
        //端口对象处理传入的端口消息。
        [myPort setDelegate:self];
        // Install the port as an input source on the current run loop.
        //将端口添加为当前runloop的输入源。
        [[NSRunLoop currentRunLoop] addPort:myPort forMode:NSDefaultRunLoopMode];
        // Detach the thread. Let the worker release the port.
        //分离线程。并手动释放端口。
        [NSThread detachNewThreadSelector:@selector(LaunchThreadWithPort:)
               toTarget:[MyWorkerClass class] withObject:myPort];
    }
}

#define kCheckinMessage 100
// Handle responses from the worker thread.
// 处理来自工作线程的响应。
- (void)handlePortMessage:(NSPortMessage *)portMessage
{
    unsigned int message = [portMessage msgid];
    NSPort* distantPort = nil;
    if (message == kCheckinMessage)
    {
        // Get the worker thread’s communications port.
        // 获取工作线程的通信端口
        distantPort = [portMessage sendPort];
        // Retain and save the worker port for later use.
        // 保留并保存工作端口以供以后使用。
        [self storeDistantPort:distantPort];
    }
    else
    {
        // Handle other messages.处理其他消息
    }
}

// 使用Mach端口启动工作线程+(void)LaunchThreadWithPort:(id)inData
{
    //创建自动释放池
    NSAutoreleasePool*  pool = [[NSAutoreleasePool alloc] init];
    // Set up the connection between this thread and the main thread.   //设置此线程与主线程之间的连接。
    NSPort* distantPort = (NSPort*)inData;
    MyWorkerClass*  workerObj = [[self alloc] init];
    [workerObj sendCheckinMessage:distantPort];
    [distantPort release];
    // Let the run loop process things.
    // 让运行循环处理事情。
    do
    {
        [[NSRunLoop currentRunLoop] runMode:NSDefaultRunLoopMode
                            beforeDate:[NSDate distantFuture]];
    }
    while (![workerObj shouldExit]);
    [workerObj release];
    [pool release];
}

// Worker thread check-in method// 工作线程签入方法
- (void)sendCheckinMessage:(NSPort*)outPort
{
    // Retain and save the remote port for future use.
    //保留并保存远程端口以备将来使用
    [self setRemotePort:outPort];
    // Create and configure the worker thread port.
    // 创建并配置工作线程端口。
    NSPort* myPort = [NSMachPort port];
    [myPort setDelegate:self];
    [[NSRunLoop currentRunLoop] addPort:myPort forMode:NSDefaultRunLoopMode];
    // Create the check-in message.
    //创建签入消息
    NSPortMessage* messageObj = [[NSPortMessage alloc] initWithSendPort:outPort
                                         receivePort:myPort components:nil];
    if (messageObj)
    {
        // Finish configuring the message and send it immediately.
        // 完成消息配置并立即发送。
        [messageObj setMsgId:setMsgid:kCheckinMessage];
        [messageObj sendBeforeDate:[NSDate date]];
    }
}

//创建本地端口NSPort* localPort = [[NSMessagePort alloc] init];
// Configure the object and add it to the current run loop.
// 配置对象并将其添加到当前运行循环
[localPort setDelegate:self];
[[NSRunLoop currentRunLoop] addPort:localPort forMode:NSDefaultRunLoopMode];
// Register the port using a specific name. The name must be unique.
//使用特定名称注册本地端口，名称必须唯一。
NSString* localPortName = [NSString stringWithFormat:@“MyPortName"];
[[NSMessagePortNameServer sharedInstance] registerPort:localPort
                     name:localPortName];

#define kThreadStackSize        (8 *4096)
OSStatus MySpawnThread()
{
    // Create a local port for receiving responses.创建用于接收响应的本地端口
    CFStringRef myPortName;
    CFMessagePortRef myPort;
    CFRunLoopSourceRef rlSource;
    CFMessagePortContext context = {0, NULL, NULL, NULL, NULL};
    Boolean shouldFreeInfo;
    // Create a string with the port name.用端口名创建一个字符串
    myPortName = CFStringCreateWithFormat(NULL, NULL, CFSTR("com.myapp.MainThread"));
    // Create the port.创建端口
    myPort = CFMessagePortCreateLocal(NULL,
                myPortName,
                &MainThreadResponseHandler,
                &context,
                &shouldFreeInfo);
    if (myPort != NULL)
    {
        // The port was successfully created.已成功创建端口。
       // Now create a run loop source for it.现在为它创建一个运行循环源。
        rlSource = CFMessagePortCreateRunLoopSource(NULL, myPort, 0);
        if (rlSource)
        {
            // Add the source to the current run loop.
        // 将run loop source添加到当前runloop
            CFRunLoopAddSource(CFRunLoopGetCurrent(), rlSource, kCFRunLoopDefaultMode);
            // Once installed, these can be freed.安装后，即可释放它们。
            CFRelease(myPort);
            CFRelease(rlSource);
        }
    }
    // Create the thread and continue processing.创建线程并继续处理。
    MPTaskID        taskID;
    return(MPCreateTask(&ServerThreadEntryPoint,
                    (void*)myPortName,
                    kThreadStackSize,
                    NULL,
                    NULL,
                    NULL,
                    0,
                    &taskID));
}

#define kCheckinMessage 100
// Main thread port message handler 主线程端口消息处理程序
CFDataRef MainThreadResponseHandler(CFMessagePortRef local, SInt32 msgid, CFDataRef data, void* info)
{
    if (msgid == kCheckinMessage) //如果是check-in消息
    {
        CFMessagePortRef messagePort;
        CFStringRef threadPortName;
        CFIndex bufferLength = CFDataGetLength(data);
        UInt8* buffer = CFAllocatorAllocate(NULL, bufferLength, 0);
        CFDataGetBytes(data, CFRangeMake(0, bufferLength), buffer);
        threadPortName = CFStringCreateWithBytes (NULL, buffer, bufferLength, kCFStringEncodingASCII, FALSE);
        // You must obtain a remote message port by name.必须通过远程端口名获取消息
        messagePort = CFMessagePortCreateRemote(NULL, (CFStringRef)threadPortName);
        if (messagePort)
        {
            // Retain and save the thread’s comm port for future reference.
        //保留并保存线程的comm端口以备将来参考
            AddPortToListOfActiveThreads(messagePort);
            // Since the port is retained by the previous function, release
            // it here.由于该端口由先前的功能保留，因此在此处释放
            CFRelease(messagePort);
        }
        // Clean up. 释放
        CFRelease(threadPortName);
        CFAllocatorDeallocate(NULL, buffer);
    }
    else
    {
        // Process other messages. 处理其他消息
    }
    return NULL;
}

//工作线程的入口点函数OSStatus ServerThreadEntryPoint(void* param)
{
    // Create the remote port to the main thread.
    //创建到主线程的远程端口。
    CFMessagePortRef mainThreadPort;
    CFStringRef portName = (CFStringRef)param;
    mainThreadPort = CFMessagePortCreateRemote(NULL, portName);
    // Free the string that was passed in param.释放在param中传递的字符串
    CFRelease(portName);
    // Create a port for the worker thread.为工作线程创建端口。
    CFStringRef myPortName = CFStringCreateWithFormat(NULL, NULL, CFSTR("com.MyApp.Thread-%d"), MPCurrentTaskID());
    // Store the port in this thread’s context info for later reference.
    // 将端口存储在此线程的上下文信息中，以供以后参考。
    CFMessagePortContext context = {0, mainThreadPort, NULL, NULL, NULL};
    Boolean shouldFreeInfo;
    Boolean shouldAbort = TRUE;
    CFMessagePortRef myPort = CFMessagePortCreateLocal(NULL,
                myPortName,
                &ProcessClientRequest,
                &context,
                &shouldFreeInfo);
  if (shouldFreeInfo)
    {
        // Couldn't create a local port, so kill the thread.
        //无法创建本地端口，所以终止线程。
        MPExit(0);
    }
    CFRunLoopSourceRef rlSource = CFMessagePortCreateRunLoopSource(NULL, myPort, 0);
      if (!rlSource)
    {
        // Couldn't create a local port, so kill the thread.
        //无法创建本地端口，所以终止线程。
        MPExit(0);
    }
    // Add the source to the current run loop.将源添加到当前运行循环。
    CFRunLoopAddSource(CFRunLoopGetCurrent(), rlSource, kCFRunLoopDefaultMode);
    // Once installed, these can be freed.释放
    CFRelease(myPort);
    CFRelease(rlSource);
    // Package up the port name and send the check-in message.
    //打包端口名并发送签入消息。
    CFDataRef returnData = nil;
    CFDataRef outData;
    CFIndex stringLength = CFStringGetLength(myPortName);
    UInt8* buffer = CFAllocatorAllocate(NULL, stringLength, 0);
    CFStringGetBytes(myPortName,
                CFRangeMake(0,stringLength),
                kCFStringEncodingASCII,
                0,
                FALSE,
                buffer,
                stringLength,
                NULL);
    outData = CFDataCreate(NULL, buffer, stringLength);
    CFMessagePortSendRequest(mainThreadPort, kCheckinMessage, outData, 0.1, 0.0, NULL, NULL);
    // Clean up thread data structures.清理线程数据结构。
    CFRelease(outData);
    CFAllocatorDeallocate(NULL, buffer);
    // Enter the run loop.进入运行循环
    CFRunLoopRun();
}