数据结构
__CFRunLoopMode
struct __CFRunLoopMode { CFRuntimeBase _base; pthread_mutex_t _lock; /* must have the run loop locked before locking this *///mode名 CFStringRef _name; Boolean _stopped; char _padding[3];//source0 源 CFMutableSetRef _sources0;//source1 源 CFMutableSetRef _sources1;//observer 源 CFMutableArrayRef _observers;//timer 源 CFMutableArrayRef _timers; //mach port 到 mode的映射,为了在runloop主逻辑中过滤runloop自己的port消息。 CFMutableDictionaryRef _portToV1SourceMap; //记录了所有当前mode中需要监听的port，作为调用监听消息函数的参数。 __CFPortSet _portSet; CFIndex _observerMask;#if USE_DISPATCH_SOURCE_FOR_TIMERS dispatch_source_t _timerSource; dispatch_queue_t _queue; Boolean _timerFired; // set to true by the source when a timer has fired Boolean _dispatchTimerArmed;#endif#if USE_MK_TIMER_TOO//使用 mk timer， 用到的mach port，和source1类似，都依赖于mach port mach_port_t _timerPort; Boolean _mkTimerArmed;#endif//timer触发的理想时间 uint64_t _timerSoftDeadline; /* TSR *///timer触发的实际时间，理想时间加上tolerance（偏差） uint64_t _timerHardDeadline; /* TSR */};复制代码 __CFRunLoop
struct __CFRunLoop { CFRuntimeBase _base; pthread_mutex_t _lock; /* locked for accessing mode list */ //用于手动将当前runloop线程唤醒，通过调用CFRunLoopWakeUp完成，//CFRunLoopWakeUp会向_wakeUpPort发送一条消息 __CFPort _wakeUpPort; // used for CFRunLoopWakeUp Boolean _unused; volatile _per_run_data *_perRunData; // reset for runs of the run loop pthread_t _pthread; uint32_t _winthread;//记录了当前runloop中所有的mode名 CFMutableSetRef _commonModes;//记录了当前runloop中所有注册到commonMode中的源 CFMutableSetRef _commonModeItems; CFRunLoopModeRef _currentMode; CFMutableSetRef _modes;//记录了添加到runloop中的block，它也可以像其他源一样被runloop处理，//通过CFRunLoopPerformBlock可向runloop中添加block任务。 struct _block_item *_blocks_head; struct _block_item *_blocks_tail; CFTypeRef _counterpart;};复制代码 __CFRunLoops
//全局字典，保存线程和对应runloop之间的关系static CFMutableDictionaryRef __CFRunLoops = NULL;复制代码
函数：
__CFRunLoopRun
static int32_t __CFRunLoopRun(CFRunLoopRef rl, CFRunLoopModeRef rlm, CFTimeInterval seconds, Boolean stopAfterHandle, CFRunLoopModeRef previousMode) { //获取系统启动之后cpu嘀嗒数 uint64_t startTSR = mach_absolute_time(); if (__CFRunLoopIsStopped(rl)) { __CFRunLoopUnsetStopped(rl); return kCFRunLoopRunStopped; } else if (rlm->_stopped) { rlm->_stopped = false; return kCFRunLoopRunStopped; } //mach 端口, 线程之间通信的对象 mach_port_name_t dispatchPort = MACH_PORT_NULL; //这里主要是为了判断当前线程是否为主线程 Boolean libdispatchQSafe = pthread_main_np() && (( HANDLE_DISPATCH_ON_BASE_INVOCATION_ONLY && NULL == previousMode) || (! HANDLE_DISPATCH_ON_BASE_INVOCATION_ONLY && 0 == _CFGetTSD( __CFTSDKeyIsInGCDMainQ))); if (libdispatchQSafe && (CFRunLoopGetMain() == rl) && CFSetContainsValue(rl ->_commonModes, rlm->_name)) dispatchPort = _dispatch_get_main_queue_port_4CF(); //使用GCD实现runloop超时功能 dispatch_source_t timeout_timer = NULL; struct __timeout_context *timeout_context = (struct __timeout_context *) malloc(sizeof(*timeout_context)); //seconds是设置的runloop超时时间 if (seconds <= 0.0) { // instant timeout seconds = 0.0; timeout_context->termTSR = 0ULL; } else if (seconds <= TIMER_INTERVAL_LIMIT) { dispatch_queue_t queue = dispatch_get_global_queue( DISPATCH_QUEUE_PRIORITY_HIGH, DISPATCH_QUEUE_OVERCOMMIT); timeout_timer = dispatch_source_create(DISPATCH_SOURCE_TYPE_TIMER, 0, 0, queue); dispatch_retain(timeout_timer); timeout_context->ds = timeout_timer; timeout_context->rl = (CFRunLoopRef)CFRetain(rl); timeout_context->termTSR = startTSR + __CFTimeIntervalToTSR(seconds); dispatch_set_context(timeout_timer, timeout_context); // source gets //ownership of context dispatch_source_set_event_handler_f(timeout_timer, __CFRunLoopTimeout); dispatch_source_set_cancel_handler_f(timeout_timer, __CFRunLoopTimeoutCancel); uint64_t ns_at = (uint64_t)((__CFTSRToTimeInterval(startTSR) + seconds) * 1000000000ULL); dispatch_source_set_timer(timeout_timer, dispatch_time(1, ns_at), DISPATCH_TIME_FOREVER, 1000ULL); dispatch_resume(timeout_timer); } else { // infinite timeout seconds = 9999999999.0; timeout_context->termTSR = UINT64_MAX; } Boolean didDispatchPortLastTime = true; int32_t retVal = 0; do { uint8_t msg_buffer[3 * 1024]; mach_msg_header_t *msg = NULL; mach_port_t livePort = MACH_PORT_NULL; __CFPortSet waitSet = rlm->_portSet; __CFRunLoopUnsetIgnoreWakeUps(rl); //rl->_perRunData->ignoreWakeUps = 0x0; if (rlm->_observerMask & kCFRunLoopBeforeTimers) __CFRunLoopDoObservers (rl, rlm, kCFRunLoopBeforeTimers); if (rlm->_observerMask & kCFRunLoopBeforeSources) __CFRunLoopDoObservers(rl, rlm, kCFRunLoopBeforeSources);//Perform blocks queued by CFRunLoopPerformBlock; __CFRunLoopDoBlocks(rl, rlm); Boolean sourceHandledThisLoop = __CFRunLoopDoSources0(rl, rlm, stopAfterHandle); //如果rl中有source0消息 if (sourceHandledThisLoop) { //处理block Perform blocks newly queued by CFRunLoopPerformBlock; __CFRunLoopDoBlocks(rl, rlm); }//poll标志着有没有处理source0的消息，如果没有则为false，反之为true Boolean poll = sourceHandledThisLoop || (0ULL == timeout_context-> termTSR); //第一次进来不走这个逻辑，didDispatchPortLastTime是true if (MACH_PORT_NULL != dispatchPort && !didDispatchPortLastTime) { msg = (mach_msg_header_t *)msg_buffer; //__CFRunLoopServiceMachPort用于接受指定端口(一个也可以是多个) //的消息,最后一个参数代表当端口无消息的时候是否休眠,0是立刻返回不休眠, //TIMEOUT_INFINITY代表休眠 //处理通过GCD派发到主线程的任务,这些任务优先级最高会被最先处理 if (__CFRunLoopServiceMachPort(dispatchPort, &msg, sizeof( msg_buffer), &livePort, 0)) { goto handle_msg; } } didDispatchPortLastTime = false;//根据之前有没有处理过source0消息，来判断如果也没有source1消息的时候是否让线程进入睡眠，这里处//理observer源，如果睡眠则通知Observer进入睡眠。 if (!poll && (rlm->_observerMask & kCFRunLoopBeforeWaiting)) __CFRunLoopDoObservers(rl, rlm, kCFRunLoopBeforeWaiting); __CFRunLoopSetSleeping(rl); // do not do any user callouts after this point (after notifying of //sleeping) // Must push the local-to-this-activation ports in on every loop // iteration, as this mode could be run re-entrantly and we don't // want these ports to get serviced. __CFPortSetInsert(dispatchPort, waitSet); __CFRunLoopModeUnlock(rlm); __CFRunLoopUnlock(rl); if (kCFUseCollectableAllocator) { objc_clear_stack(0); memset(msg_buffer, 0, sizeof(msg_buffer)); } msg = (mach_msg_header_t *)msg_buffer; //如果poll为null，且waitset中无port有消息,线程进入休眠 __CFRunLoopServiceMachPort(waitSet, &msg, sizeof(msg_buffer), &livePort, poll ? 0 : TIMEOUT_INFINITY); __CFRunLoopLock(rl); __CFRunLoopModeLock(rlm); // Must remove the local-to-this-activation ports in on every loop // iteration, as this mode could be run re-entrantly and we don't // want these ports to get serviced. Also, we don't want them left // in there if this function returns. __CFPortSetRemove(dispatchPort, waitSet); __CFRunLoopSetIgnoreWakeUps(rl); // user callouts now OK again __CFRunLoopUnsetSleeping(rl); //处理observer源，线程醒来 if (!poll && (rlm->_observerMask & kCFRunLoopAfterWaiting)) __CFRunLoopDoObservers(rl, rlm, kCFRunLoopAfterWaiting); handle_msg:; __CFRunLoopSetIgnoreWakeUps(rl); if (MACH_PORT_NULL == livePort) { CFRUNLOOP_WAKEUP_FOR_NOTHING(); // handle nothing//通过CFRunloopWake将当前线程唤醒 } else if (livePort == rl->_wakeUpPort) { CFRUNLOOP_WAKEUP_FOR_WAKEUP(); // do nothing on Mac OS }//处理timer源 else if (rlm->_timerPort != MACH_PORT_NULL && livePort == rlm-> _timerPort) { CFRUNLOOP_WAKEUP_FOR_TIMER(); if (!__CFRunLoopDoTimers(rl, rlm, mach_absolute_time())) { // Re-arm the next timer __CFArmNextTimerInMode(rlm, rl); } }//通过GCD派发给主线程的任务 else if (livePort == dispatchPort) { CFRUNLOOP_WAKEUP_FOR_DISPATCH(); __CFRunLoopModeUnlock(rlm); __CFRunLoopUnlock(rl); _CFSetTSD(__CFTSDKeyIsInGCDMainQ, (void *)6, NULL); __CFRUNLOOP_IS_SERVICING_THE_MAIN_DISPATCH_QUEUE__(msg); _CFSetTSD(__CFTSDKeyIsInGCDMainQ, (void *)0, NULL); __CFRunLoopLock(rl); __CFRunLoopModeLock(rlm); sourceHandledThisLoop = true; didDispatchPortLastTime = true; } else {//通过macPort给当前线程派发消息,处理source1 CFRUNLOOP_WAKEUP_FOR_SOURCE(); // Despite the name, this works for windows handles as well //过滤macPort消息，有一些消息不一定是runloop中注册的，这里只处理runloop中注册的 //消息，在rlm->_portToV1SourceMap通过macPort找有没有对应的runloopMode CFRunLoopSourceRef rls = __CFRunLoopModeFindSourceForMachPort(rl, rlm, livePort); if (rls) { mach_msg_header_t *reply = NULL; sourceHandledThisLoop = __CFRunLoopDoSource1(rl, rlm, rls, msg, msg->msgh_size, &reply) || sourceHandledThisLoop; if (NULL != reply) { //当前线程处理完source1，给发消息的线程反馈消息, //MACH_SEND_MSG表示给replay端口发送消息 (void)mach_msg(reply, MACH_SEND_MSG, reply->msgh_size, 0, MACH_PORT_NULL, 0, MACH_PORT_NULL); CFAllocatorDeallocate(kCFAllocatorSystemDefault, reply); } } } if (msg && msg != (mach_msg_header_t *)msg_buffer) free(msg); __CFRunLoopDoBlocks(rl, rlm); if (sourceHandledThisLoop && stopAfterHandle) { retVal = kCFRunLoopRunHandledSource; } else if (timeout_context->termTSR < mach_absolute_time()) { //runloop超时时间到 retVal = kCFRunLoopRunTimedOut; } else if (__CFRunLoopIsStopped(rl)) { __CFRunLoopUnsetStopped(rl); retVal = kCFRunLoopRunStopped; } else if (rlm->_stopped) { rlm->_stopped = false; retVal = kCFRunLoopRunStopped; } else if (__CFRunLoopModeIsEmpty(rl, rlm, previousMode)) { retVal = kCFRunLoopRunFinished; } } while (0 == retVal); if (timeout_timer) { dispatch_source_cancel(timeout_timer); dispatch_release(timeout_timer); } else { free(timeout_context); } return retVal;}复制代码 CFRunLoopAddSource
void CFRunLoopAddSource(CFRunLoopRef rl, CFRunLoopSourceRef rls, CFStringRef modeName) { /* DOES CALLOUT */ CHECK_FOR_FORK(); if (__CFRunLoopIsDeallocating(rl)) return; if (!__CFIsValid(rls)) return; Boolean doVer0Callout = false; __CFRunLoopLock(rl); if (modeName == kCFRunLoopCommonModes) { //par1 : 处理commonModeItmes的逻辑/*rl->_commonModes的作用是记录了当前runloop中标记为commonMode的mode，rl->_commonModeItems记录了当前runloop中注册到commonMode中的源两者用来处理跟commonMode相关的逻辑，比如当一个mode被标记为commonMode的时候，会将rl->_commonModeItems中的源添加到新的mode当中去，在当前mode下这些源的消息就会被监听并处理。例如一个timer被注册到commonMode中，那么在所有被标记为commonMode的mode中都会处理该timer的消息。*/ CFSetRef set = rl->_commonModes ? CFSetCreateCopy(kCFAllocatorSystemDefault , rl->_commonModes) : NULL; if (NULL == rl->_commonModeItems) { rl->_commonModeItems = CFSetCreateMutable(kCFAllocatorSystemDefault, 0, &kCFTypeSetCallBacks); } CFSetAddValue(rl->_commonModeItems, rls); if (NULL != set) { CFTypeRef context[2] = {rl, rls}; /* add new item to all common-modes */ //对每一个mode，调用part2的逻辑 CFSetApplyFunction(set, (__CFRunLoopAddItemToCommonModes), (void *)context); CFRelease(set); } } else { //part2 : 处理某个具体的mode中addSource的逻辑 CFRunLoopModeRef rlm = __CFRunLoopFindMode(rl, modeName, true); if (NULL != rlm && NULL == rlm->_sources0) { rlm->_sources0 = CFSetCreateMutable(kCFAllocatorSystemDefault, 0, & kCFTypeSetCallBacks); rlm->_sources1 = CFSetCreateMutable(kCFAllocatorSystemDefault, 0, & kCFTypeSetCallBacks); rlm->_portToV1SourceMap = CFDictionaryCreateMutable( kCFAllocatorSystemDefault, 0, NULL, NULL); } if (NULL != rlm && !CFSetContainsValue(rlm->_sources0, rls) && ! CFSetContainsValue(rlm->_sources1, rls)) { if (0 == rls->_context.version0.version) { CFSetAddValue(rlm->_sources0, rls); } else if (1 == rls->_context.version0.version) { CFSetAddValue(rlm->_sources1, rls); __CFPort src_port = rls->_context.version1.getPort(rls->_context. version1.info); if (CFPORT_NULL != src_port) { //rlm->_portToV1SourceMap是port到source1的映射， //为了在runloop主逻辑中过滤runloop自己的port消息。 CFDictionarySetValue(rlm->_portToV1SourceMap, (const void *)( uintptr_t)src_port, rls); //rml->_portSet记录了所有当前mode中需要监听的port，作为调用监听消息函数的参数。 __CFPortSetInsert(src_port, rlm->_portSet); } } __CFRunLoopSourceLock(rls); if (NULL == rls->_runLoops) { rls->_runLoops = CFBagCreateMutable(kCFAllocatorSystemDefault, 0, & kCFTypeBagCallBacks); // sources retain run loops! } CFBagAddValue(rls->_runLoops, rl); __CFRunLoopSourceUnlock(rls); if (0 == rls->_context.version0.version) { if (NULL != rls->_context.version0.schedule) { doVer0Callout = true; } } } if (NULL != rlm) { __CFRunLoopModeUnlock(rlm); } } __CFRunLoopUnlock(rl); if (doVer0Callout) { // although it looses some protection for the source, we have no //choice but // to do this after unlocking the run loop and mode locks, to avoid //deadlocks // where the source wants to take a lock which is already held in //another // thread which is itself waiting for a run loop/mode lock rls->_context.version0.schedule(rls->_context.version0.info, rl, modeName); /* CALLOUT */ }}复制代码 CFRunLoopRemoveSource
void CFRunLoopRemoveSource(CFRunLoopRef rl, CFRunLoopSourceRef rls, CFStringRef modeName) { /* DOES CALLOUT */ CHECK_FOR_FORK(); Boolean doVer0Callout = false, doRLSRelease = false; __CFRunLoopLock(rl); if (modeName == kCFRunLoopCommonModes) { if (NULL != rl->_commonModeItems && CFSetContainsValue(rl-> _commonModeItems, rls)) { CFSetRef set = rl->_commonModes ? CFSetCreateCopy( kCFAllocatorSystemDefault, rl->_commonModes) : NULL; CFSetRemoveValue(rl->_commonModeItems, rls); if (NULL != set) { CFTypeRef context[2] = {rl, rls}; /* remove new item from all common-modes */ CFSetApplyFunction(set, (__CFRunLoopRemoveItemFromCommonModes), ( void *)context); CFRelease(set); } } } else { CFRunLoopModeRef rlm = __CFRunLoopFindMode(rl, modeName, false); if (NULL != rlm && ((NULL != rlm->_sources0 && CFSetContainsValue(rlm-> _sources0, rls)) || (NULL != rlm->_sources1 && CFSetContainsValue(rlm-> _sources1, rls)))) { //source0或者source1中的一种 CFRetain(rls); if (1 == rls->_context.version0.version) { __CFPort src_port = rls->_context.version1.getPort(rls->_context. version1.info); if (CFPORT_NULL != src_port) { CFDictionaryRemoveValue(rlm->_portToV1SourceMap, (const void *)( uintptr_t)src_port); __CFPortSetRemove(src_port, rlm->_portSet); } } CFSetRemoveValue(rlm->_sources0, rls); CFSetRemoveValue(rlm->_sources1, rls); __CFRunLoopSourceLock(rls); if (NULL != rls->_runLoops) { CFBagRemoveValue(rls->_runLoops, rl); } __CFRunLoopSourceUnlock(rls); if (0 == rls->_context.version0.version) { if (NULL != rls->_context.version0.cancel) { doVer0Callout = true; } } doRLSRelease = true; } if (NULL != rlm) { __CFRunLoopModeUnlock(rlm); } } __CFRunLoopUnlock(rl); if (doVer0Callout) { // although it looses some protection for the source, we have no choice but // to do this after unlocking the run loop and mode locks, to avoid deadlocks // where the source wants to take a lock which is already held in another // thread which is itself waiting for a run loop/mode lock rls->_context.version0.cancel(rls->_context.version0.info, rl, modeName); /* CALLOUT */ } if (doRLSRelease) CFRelease(rls);}复制代码 CFRunLoopAddTimer
void CFRunLoopAddTimer(CFRunLoopRef rl, CFRunLoopTimerRef rlt, CFStringRef modeName) { CHECK_FOR_FORK(); if (__CFRunLoopIsDeallocating(rl)) return; if (!__CFIsValid(rlt) || (NULL != rlt->_runLoop && rlt->_runLoop != rl)) return; __CFRunLoopLock(rl); if (modeName == kCFRunLoopCommonModes) { CFSetRef set = rl->_commonModes ? CFSetCreateCopy(kCFAllocatorSystemDefault , rl->_commonModes) : NULL; if (NULL == rl->_commonModeItems) { rl->_commonModeItems = CFSetCreateMutable(kCFAllocatorSystemDefault, 0, &kCFTypeSetCallBacks); } CFSetAddValue(rl->_commonModeItems, rlt); if (NULL != set) { CFTypeRef context[2] = {rl, rlt}; /* add new item to all common-modes */ CFSetApplyFunction(set, (__CFRunLoopAddItemToCommonModes), (void *) context); CFRelease(set); } } else { CFRunLoopModeRef rlm = __CFRunLoopFindMode(rl, modeName, true); if (NULL != rlm) { if (NULL == rlm->_timers) { CFArrayCallBacks cb = kCFTypeArrayCallBacks; cb.equal = NULL; rlm->_timers = CFArrayCreateMutable(kCFAllocatorSystemDefault, 0, &cb); } } if (NULL != rlm && !CFSetContainsValue(rlt->_rlModes, rlm->_name)) { __CFRunLoopTimerLock(rlt); if (NULL == rlt->_runLoop) { rlt->_runLoop = rl; } else if (rl != rlt->_runLoop) { __CFRunLoopTimerUnlock(rlt); __CFRunLoopModeUnlock(rlm); __CFRunLoopUnlock(rl); return; } CFSetAddValue(rlt->_rlModes, rlm->_name); __CFRunLoopTimerUnlock(rlt); __CFRunLoopTimerFireTSRLock(); //__CFRepositionTimerInMode是添加或者删除timer, //这里是往rlm->_timers添加timer __CFRepositionTimerInMode(rlm, rlt, false); __CFRunLoopTimerFireTSRUnlock(); if (!_CFExecutableLinkedOnOrAfter(CFSystemVersionLion)) { // Normally we don't do this on behalf of clients, but for // backwards compatibility due to the change in timer handling... if (rl != CFRunLoopGetCurrent()) CFRunLoopWakeUp(rl); } } if (NULL != rlm) { __CFRunLoopModeUnlock(rlm); } } __CFRunLoopUnlock(rl);}复制代码 __CFRunLoopFindMode
static CFRunLoopModeRef __CFRunLoopFindMode(CFRunLoopRef rl, CFStringRef modeName, Boolean create) { CHECK_FOR_FORK(); CFRunLoopModeRef rlm; struct __CFRunLoopMode srlm; memset(&srlm, 0, sizeof(srlm)); _CFRuntimeSetInstanceTypeIDAndIsa(&srlm, __kCFRunLoopModeTypeID); srlm._name = modeName; rlm = (CFRunLoopModeRef)CFSetGetValue(rl->_modes, &srlm); if (NULL != rlm) { __CFRunLoopModeLock(rlm); return rlm; } if (!create) { return NULL; } rlm = (CFRunLoopModeRef)_CFRuntimeCreateInstance(kCFAllocatorSystemDefault, __kCFRunLoopModeTypeID, sizeof(struct __CFRunLoopMode) - sizeof( CFRuntimeBase), NULL); if (NULL == rlm) { return NULL; } __CFRunLoopLockInit(&rlm->_lock); rlm->_name = CFStringCreateCopy(kCFAllocatorSystemDefault, modeName); rlm->_stopped = false; rlm->_portToV1SourceMap = NULL; rlm->_sources0 = NULL; rlm->_sources1 = NULL; rlm->_observers = NULL; rlm->_timers = NULL; rlm->_observerMask = 0; rlm->_portSet = __CFPortSetAllocate(); rlm->_timerSoftDeadline = UINT64_MAX; rlm->_timerHardDeadline = UINT64_MAX; kern_return_t ret = KERN_SUCCESS; //1#if USE_DISPATCH_SOURCE_FOR_TIMERS rlm->_timerFired = false; rlm->_queue = _dispatch_runloop_root_queue_create_4CF("Run Loop Mode Queue" , 0); mach_port_t queuePort = _dispatch_runloop_root_queue_get_port_4CF(rlm-> _queue); if (queuePort == MACH_PORT_NULL) CRASH("*** Unable to create run loop mode queue port. (%d) ***", -1); rlm->_timerSource = dispatch_source_create(DISPATCH_SOURCE_TYPE_TIMER, 0, 0 , rlm->_queue); __block Boolean *timerFiredPointer = &(rlm->_timerFired); dispatch_source_set_event_handler(rlm->_timerSource, ^{ *timerFiredPointer = true; }); // Set timer to far out there. The unique leeway makes this timer easy to spot in debug output. _dispatch_source_set_runloop_timer_4CF(rlm->_timerSource, DISPATCH_TIME_FOREVER, DISPATCH_TIME_FOREVER, 321); dispatch_resume(rlm->_timerSource); ret = __CFPortSetInsert(queuePort, rlm->_portSet); if (KERN_SUCCESS != ret) CRASH("*** Unable to insert timer port into port set. (%d) ***", ret); #endif //1#if USE_MK_TIMER_TOO rlm->_timerPort = mk_timer_create(); ret = __CFPortSetInsert(rlm->_timerPort, rlm->_portSet); if (KERN_SUCCESS != ret) CRASH("*** Unable to insert timer port into port set. (%d) ***", ret);#endif ret = __CFPortSetInsert(rl->_wakeUpPort, rlm->_portSet); if (KERN_SUCCESS != ret) CRASH("*** Unable to insert wake up port into port set. (%d) ***", ret); CFSetAddValue(rl->_modes, rlm); CFRelease(rlm); __CFRunLoopModeLock(rlm); /* return mode locked */ return rlm;} ``return` `rlm;``}`复制代码 __CFRepositionTimerInMode
static void __CFRepositionTimerInMode(CFRunLoopModeRef rlm, CFRunLoopTimerRef rlt, Boolean isInArray) { if (!rlt) return; CFMutableArrayRef timerArray = rlm->_timers; if (!timerArray) return; Boolean found = false; // If we know in advance that the timer is not in the array (just being added now) then we can skip this search if (isInArray) { CFIndex idx = CFArrayGetFirstIndexOfValue(timerArray, CFRangeMake(0, CFArrayGetCount(timerArray)), rlt); if (kCFNotFound != idx) { CFRetain(rlt); CFArrayRemoveValueAtIndex(timerArray, idx); found = true; } } if (!found && isInArray) return; CFIndex newIdx = __CFRunLoopInsertionIndexInTimerArray(timerArray, rlt); //timer开始计时 CFArrayInsertValueAtIndex(timerArray, newIdx, rlt); __CFArmNextTimerInMode(rlm, rlt->_runLoop); if (isInArray) CFRelease(rlt);}复制代码 __CFArmNextTimerInMode
static void __CFArmNextTimerInMode(CFRunLoopModeRef rlm, CFRunLoopRef rl) { uint64_t nextHardDeadline = UINT64_MAX; uint64_t nextSoftDeadline = UINT64_MAX; if (rlm->_timers) { // Look at the list of timers. We will calculate two TSR values; the //next soft and next hard deadline. // The next soft deadline is the first time we can fire any timer. //This is the fire date of the first timer in our sorted list of timers. // The next hard deadline is the last time at which we can fire the //timer before we've moved out of the allowable tolerance of the timers in our list. for (CFIndex idx = 0, cnt = CFArrayGetCount(rlm->_timers); idx < cnt; idx++) { CFRunLoopTimerRef t = (CFRunLoopTimerRef)CFArrayGetValueAtIndex(rlm ->_timers , idx); // discount timers currently firing if (__CFRunLoopTimerIsFiring(t)) continue; int32_t err = CHECKINT_NO_ERROR; uint64_t oneTimerSoftDeadline = t->_fireTSR; uint64_t oneTimerHardDeadline = check_uint64_add(t->_fireTSR, __CFTimeIntervalToTSR(t->_tolerance), &err); if (err != CHECKINT_NO_ERROR) oneTimerHardDeadline = UINT64_MAX; // We can stop searching if the soft deadline for this timer exceeds the current hard deadline. Otherwise, later timers with lower tolerance could still have earlier hard deadlines. if (oneTimerSoftDeadline > nextHardDeadline) { break; } if (oneTimerSoftDeadline < nextSoftDeadline) { nextSoftDeadline = oneTimerSoftDeadline; } if (oneTimerHardDeadline < nextHardDeadline) { nextHardDeadline = oneTimerHardDeadline; } } if (nextSoftDeadline < UINT64_MAX && (nextHardDeadline != rlm-> _timerHardDeadline || nextSoftDeadline != rlm->_timerSoftDeadline)) { if (CFRUNLOOP_NEXT_TIMER_ARMED_ENABLED()) { CFRUNLOOP_NEXT_TIMER_ARMED((unsigned long)(nextSoftDeadline - mach_absolute_time())); }#if USE_DISPATCH_SOURCE_FOR_TIMERS // We're going to hand off the range of allowable timer fire date //to dispatch and let it fire when appropriate for the system. uint64_t leeway = __CFTSRToNanoseconds(nextHardDeadline - nextSoftDeadline); dispatch_time_t deadline = __CFTSRToDispatchTime(nextSoftDeadline);#if USE_MK_TIMER_TOO//leeway表示timer的偏差，如果_tolerance(>=0)为0，则leeway等于0 if (leeway > 0) {//GCD timer // Only use the dispatch timer if we have any leeway // // Cancel the mk timer if (rlm->_mkTimerArmed && rlm->_timerPort) { AbsoluteTime dummy; mk_timer_cancel(rlm->_timerPort, &dummy); rlm->_mkTimerArmed = false; } // Arm the dispatch timer _dispatch_source_set_runloop_timer_4CF(rlm->_timerSource, deadline, DISPATCH_TIME_FOREVER, leeway); rlm->_dispatchTimerArmed = true; } else {//mk timer，实际中是这种情况 // Cancel the dispatch timer if (rlm->_dispatchTimerArmed) { // Cancel the dispatch timer _dispatch_source_set_runloop_timer_4CF(rlm->_timerSource, DISPATCH_TIME_FOREVER, DISPATCH_TIME_FOREVER, 888); rlm->_dispatchTimerArmed = false; } // Arm the mk timer if (rlm->_timerPort) {//timer开始运行 mk_timer_arm(rlm->_timerPort, __CFUInt64ToAbsoluteTime( nextSoftDeadline)); rlm->_mkTimerArmed = true; } }#else _dispatch_source_set_runloop_timer_4CF(rlm->_timerSource, deadline, DISPATCH_TIME_FOREVER, leeway);#endif#else if (rlm->_timerPort) { mk_timer_arm(rlm->_timerPort, __CFUInt64ToAbsoluteTime( nextSoftDeadline)); }#endif } else if (nextSoftDeadline == UINT64_MAX) { // Disarm the timers - there is no timer scheduled if (rlm->_mkTimerArmed && rlm->_timerPort) { AbsoluteTime dummy; mk_timer_cancel(rlm->_timerPort, &dummy); rlm->_mkTimerArmed = false; } #if USE_DISPATCH_SOURCE_FOR_TIMERS if (rlm->_dispatchTimerArmed) { _dispatch_source_set_runloop_timer_4CF(rlm->_timerSource, DISPATCH_TIME_FOREVER, DISPATCH_TIME_FOREVER, 333); rlm->_dispatchTimerArmed = false; }#endif } } rlm->_timerHardDeadline = nextHardDeadline; rlm->_timerSoftDeadline = nextSoftDeadline;}复制代码 _CFRunLoopGet0
CF_EXPORT CFRunLoopRef _CFRunLoopGet0(pthread_t t) { //判断t是否是传的空，如果是当成主线程处理 if (pthread_equal(t, kNilPthreadT)) { t = pthread_main_thread_np(); } __CFSpinLock(&loopsLock);//__CFRunLoops是全局存储线程和runloop关系的字典 if (!__CFRunLoops) {//__CFRunLoop第一次初始化 __CFSpinUnlock(&loopsLock);//初始化__CFRunLoop CFMutableDictionaryRef dict = CFDictionaryCreateMutable( kCFAllocatorSystemDefault, 0, NULL, &kCFTypeDictionaryValueCallBacks);//生成主线程对应runloop CFRunLoopRef mainLoop = __CFRunLoopCreate(pthread_main_thread_np());//存储到__CFRunLoop字典中 CFDictionarySetValue(dict, pthreadPointer(pthread_main_thread_np()), mainLoop); if (!OSAtomicCompareAndSwapPtrBarrier(NULL, dict, (void * volatile *)& __CFRunLoops)) { CFRelease(dict); } CFRelease(mainLoop); __CFSpinLock(&loopsLock); }//找到线程t对应的runloop CFRunLoopRef loop = (CFRunLoopRef)CFDictionaryGetValue(__CFRunLoops, pthreadPointer(t)); __CFSpinUnlock(&loopsLock); if (!loop) {//没有找到，创建一个 CFRunLoopRef newLoop = __CFRunLoopCreate(t); __CFSpinLock(&loopsLock);//?????? loop = (CFRunLoopRef)CFDictionaryGetValue(__CFRunLoops, pthreadPointer(t)); if (!loop) {//保存到全局字典中 CFDictionarySetValue(__CFRunLoops, pthreadPointer(t), newLoop); loop = newLoop; } // don't release run loops inside the loopsLock, because //CFRunLoopDeallocate may end up taking it --> --> __CFSpinUnlock(&loopsLock); CFRelease(newLoop); } if (pthread_equal(t, pthread_self())) { _CFSetTSD(__CFTSDKeyRunLoop, (void *)loop, NULL); if (0 == _CFGetTSD(__CFTSDKeyRunLoopCntr)) { _CFSetTSD(__CFTSDKeyRunLoopCntr, (void *)( PTHREAD_DESTRUCTOR_ITERATIONS-1), (void (*)(void *)) __CFFinalizeRunLoop); } } return loop;}复制代码