From 03118dec509589007132be67e0c849e4545b383b Mon Sep 17 00:00:00 2001 From: Dio Date: Mon, 22 Jan 2024 11:57:18 +0800 Subject: [PATCH] =?UTF-8?q?ipc=E5=B0=BD=E6=95=B0=E6=8B=BF=E4=B8=8B?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- src/kernel_liteos_a/kernel/base/ipc/los_mux.c | 190 ++++++------- .../kernel/base/ipc/los_queue.c | 254 +++++++++--------- .../kernel/base/ipc/los_rwlock.c | 145 +++++----- src/kernel_liteos_a/kernel/base/ipc/los_sem.c | 116 ++++---- .../kernel/base/ipc/los_sem_debug.c | 24 +- .../kernel/base/ipc/los_signal.c | 234 ++++++++-------- 6 files changed, 492 insertions(+), 471 deletions(-) diff --git a/src/kernel_liteos_a/kernel/base/ipc/los_mux.c b/src/kernel_liteos_a/kernel/base/ipc/los_mux.c index fa4a67b8..45f43d6b 100644 --- a/src/kernel_liteos_a/kernel/base/ipc/los_mux.c +++ b/src/kernel_liteos_a/kernel/base/ipc/los_mux.c @@ -1,6 +1,6 @@ /* * Copyright (c) 2013-2019 Huawei Technologies Co., Ltd. All rights reserved. - * Copyright (c) 2020-2022 Huawei Device Co., Ltd. All rights reserved. + * Copyright (c) 2020-2021 Huawei Device Co., Ltd. All rights reserved. * * Redistribution and use in source and binary forms, with or without modification, * are permitted provided that the following conditions are met: @@ -40,19 +40,19 @@ #ifdef LOSCFG_BASE_IPC_MUX #define MUTEXATTR_TYPE_MASK 0x0FU - +///互斥属性初始化 LITE_OS_SEC_TEXT UINT32 LOS_MuxAttrInit(LosMuxAttr *attr) { if (attr == NULL) { return LOS_EINVAL; } - attr->protocol = LOS_MUX_PRIO_INHERIT; - attr->prioceiling = OS_TASK_PRIORITY_LOWEST; - attr->type = LOS_MUX_DEFAULT; + attr->protocol = LOS_MUX_PRIO_INHERIT; //协议默认用继承方式, A(4)task等B(19)释放锁时,B的调度优先级直接升到(4) + attr->prioceiling = OS_TASK_PRIORITY_LOWEST;//最低优先级 + attr->type = LOS_MUX_DEFAULT; //默认 LOS_MUX_RECURSIVE return LOS_OK; } - +/// ????? 销毁互斥属 ,这里啥也没干呀 LITE_OS_SEC_TEXT UINT32 LOS_MuxAttrDestroy(LosMuxAttr *attr) { if (attr == NULL) { @@ -61,7 +61,7 @@ LITE_OS_SEC_TEXT UINT32 LOS_MuxAttrDestroy(LosMuxAttr *attr) return LOS_OK; } - +///获取互斥锁的类型属性,由outType接走,不送! LITE_OS_SEC_TEXT UINT32 LOS_MuxAttrGetType(const LosMuxAttr *attr, INT32 *outType) { INT32 type; @@ -79,7 +79,7 @@ LITE_OS_SEC_TEXT UINT32 LOS_MuxAttrGetType(const LosMuxAttr *attr, INT32 *outTyp return LOS_OK; } - +///设置互斥锁的类型属性 LITE_OS_SEC_TEXT UINT32 LOS_MuxAttrSetType(LosMuxAttr *attr, INT32 type) { if ((attr == NULL) || (type < LOS_MUX_NORMAL) || (type > LOS_MUX_ERRORCHECK)) { @@ -89,7 +89,7 @@ LITE_OS_SEC_TEXT UINT32 LOS_MuxAttrSetType(LosMuxAttr *attr, INT32 type) attr->type = (UINT8)((attr->type & ~MUTEXATTR_TYPE_MASK) | (UINT32)type); return LOS_OK; } - +///获取互斥锁的类型属性 LITE_OS_SEC_TEXT UINT32 LOS_MuxAttrGetProtocol(const LosMuxAttr *attr, INT32 *protocol) { if ((attr != NULL) && (protocol != NULL)) { @@ -100,7 +100,7 @@ LITE_OS_SEC_TEXT UINT32 LOS_MuxAttrGetProtocol(const LosMuxAttr *attr, INT32 *pr return LOS_OK; } - +///设置互斥锁属性的协议 LITE_OS_SEC_TEXT UINT32 LOS_MuxAttrSetProtocol(LosMuxAttr *attr, INT32 protocol) { if (attr == NULL) { @@ -117,7 +117,7 @@ LITE_OS_SEC_TEXT UINT32 LOS_MuxAttrSetProtocol(LosMuxAttr *attr, INT32 protocol) return LOS_EINVAL; } } - +///获取互斥锁属性优先级 LITE_OS_SEC_TEXT UINT32 LOS_MuxAttrGetPrioceiling(const LosMuxAttr *attr, INT32 *prioceiling) { if (attr == NULL) { @@ -130,7 +130,7 @@ LITE_OS_SEC_TEXT UINT32 LOS_MuxAttrGetPrioceiling(const LosMuxAttr *attr, INT32 return LOS_OK; } - +///设置互斥锁属性的优先级的上限 LITE_OS_SEC_TEXT UINT32 LOS_MuxAttrSetPrioceiling(LosMuxAttr *attr, INT32 prioceiling) { if ((attr == NULL) || @@ -143,7 +143,7 @@ LITE_OS_SEC_TEXT UINT32 LOS_MuxAttrSetPrioceiling(LosMuxAttr *attr, INT32 prioce return LOS_OK; } - +///设置互斥锁的优先级的上限,老优先级由oldPrioceiling带走 LITE_OS_SEC_TEXT UINT32 LOS_MuxSetPrioceiling(LosMux *mutex, INT32 prioceiling, INT32 *oldPrioceiling) { INT32 ret; @@ -172,7 +172,7 @@ LITE_OS_SEC_TEXT UINT32 LOS_MuxSetPrioceiling(LosMux *mutex, INT32 prioceiling, return ret; } - +///获取互斥锁的优先级的上限 LITE_OS_SEC_TEXT UINT32 LOS_MuxGetPrioceiling(const LosMux *mutex, INT32 *prioceiling) { if ((mutex != NULL) && (prioceiling != NULL) && (mutex->magic == OS_MUX_MAGIC)) { @@ -182,7 +182,7 @@ LITE_OS_SEC_TEXT UINT32 LOS_MuxGetPrioceiling(const LosMux *mutex, INT32 *prioce return LOS_EINVAL; } - +///互斥锁是否有效 LITE_OS_SEC_TEXT BOOL LOS_MuxIsValid(const LosMux *mutex) { if ((mutex != NULL) && (mutex->magic == OS_MUX_MAGIC)) { @@ -191,7 +191,7 @@ LITE_OS_SEC_TEXT BOOL LOS_MuxIsValid(const LosMux *mutex) return FALSE; } - +///检查互斥锁属性是否OK,否则 no ok :|) STATIC UINT32 OsCheckMutexAttr(const LosMuxAttr *attr) { if (((INT8)(attr->type) < LOS_MUX_NORMAL) || (attr->type > LOS_MUX_ERRORCHECK)) { @@ -205,7 +205,7 @@ STATIC UINT32 OsCheckMutexAttr(const LosMuxAttr *attr) } return LOS_OK; } - +/// 初始化互斥锁 LITE_OS_SEC_TEXT UINT32 LOS_MuxInit(LosMux *mutex, const LosMuxAttr *attr) { UINT32 intSave; @@ -215,24 +215,24 @@ LITE_OS_SEC_TEXT UINT32 LOS_MuxInit(LosMux *mutex, const LosMuxAttr *attr) } if (attr == NULL) { - (VOID)LOS_MuxAttrInit(&mutex->attr); + (VOID)LOS_MuxAttrInit(&mutex->attr);//属性初始化 } else { - (VOID)memcpy_s(&mutex->attr, sizeof(LosMuxAttr), attr, sizeof(LosMuxAttr)); + (VOID)memcpy_s(&mutex->attr, sizeof(LosMuxAttr), attr, sizeof(LosMuxAttr));//把attr 拷贝到 mutex->attr } - if (OsCheckMutexAttr(&mutex->attr) != LOS_OK) { + if (OsCheckMutexAttr(&mutex->attr) != LOS_OK) {//检查属性 return LOS_EINVAL; } - SCHEDULER_LOCK(intSave); - mutex->muxCount = 0; - mutex->owner = NULL; - LOS_ListInit(&mutex->muxList); - mutex->magic = OS_MUX_MAGIC; - SCHEDULER_UNLOCK(intSave); + SCHEDULER_LOCK(intSave); //拿到调度自旋锁 + mutex->muxCount = 0; //锁定互斥量的次数 + mutex->owner = NULL; //谁持有该锁 + LOS_ListInit(&mutex->muxList); //互斥量双循环链表 + mutex->magic = OS_MUX_MAGIC; //固定标识,互斥锁的魔法数字 + SCHEDULER_UNLOCK(intSave); //释放调度自旋锁 return LOS_OK; } - +///销毁互斥锁 LITE_OS_SEC_TEXT UINT32 LOS_MuxDestroy(LosMux *mutex) { UINT32 intSave; @@ -241,22 +241,22 @@ LITE_OS_SEC_TEXT UINT32 LOS_MuxDestroy(LosMux *mutex) return LOS_EINVAL; } - SCHEDULER_LOCK(intSave); + SCHEDULER_LOCK(intSave); //保存调度自旋锁 if (mutex->magic != OS_MUX_MAGIC) { - SCHEDULER_UNLOCK(intSave); + SCHEDULER_UNLOCK(intSave);//释放调度自旋锁 return LOS_EBADF; } if (mutex->muxCount != 0) { - SCHEDULER_UNLOCK(intSave); + SCHEDULER_UNLOCK(intSave);//释放调度自旋锁 return LOS_EBUSY; } - (VOID)memset_s(mutex, sizeof(LosMux), 0, sizeof(LosMux)); - SCHEDULER_UNLOCK(intSave); + (VOID)memset_s(mutex, sizeof(LosMux), 0, sizeof(LosMux));//很简单,全部清0处理. + SCHEDULER_UNLOCK(intSave); //释放调度自旋锁 return LOS_OK; } - +///设置互斥锁位图 STATIC VOID OsMuxBitmapSet(const LosMux *mutex, const LosTaskCB *runTask) { if (mutex->attr.protocol != LOS_MUX_PRIO_INHERIT) { @@ -271,7 +271,7 @@ STATIC VOID OsMuxBitmapSet(const LosMux *mutex, const LosTaskCB *runTask) owner->ops->priorityInheritance(owner, ¶m); } } - +///恢复互斥锁位图 VOID OsMuxBitmapRestore(const LosMux *mutex, const LOS_DL_LIST *list, const LosTaskCB *runTask) { if (mutex->attr.protocol != LOS_MUX_PRIO_INHERIT) { @@ -284,20 +284,21 @@ VOID OsMuxBitmapRestore(const LosMux *mutex, const LOS_DL_LIST *list, const LosT owner->ops->priorityRestore(owner, list, ¶m); } +/// 最坏情况就是拿锁失败,让出CPU,变成阻塞任务,等别的任务释放锁后排到自己了接着执行. STATIC UINT32 OsMuxPendOp(LosTaskCB *runTask, LosMux *mutex, UINT32 timeout) { UINT32 ret; - if ((mutex->muxList.pstPrev == NULL) || (mutex->muxList.pstNext == NULL)) { + if ((mutex->muxList.pstPrev == NULL) || (mutex->muxList.pstNext == NULL)) {//列表为空时的处理 /* This is for mutex macro initialization. */ - mutex->muxCount = 0; - mutex->owner = NULL; - LOS_ListInit(&mutex->muxList); + mutex->muxCount = 0;//锁计数器清0 + mutex->owner = NULL;//锁没有归属任务 + LOS_ListInit(&mutex->muxList);//初始化锁的任务链表,后续申请这把锁任务都会挂上去 } - if (mutex->muxCount == 0) { - mutex->muxCount++; - mutex->owner = (VOID *)runTask; + if (mutex->muxCount == 0) {//无task用锁时,肯定能拿到锁了.在里面返回 + mutex->muxCount++; //互斥锁计数器加1 + mutex->owner = (VOID *)runTask; //当前任务拿到锁 LOS_ListTailInsert(&runTask->lockList, &mutex->holdList); if (mutex->attr.protocol == LOS_MUX_PRIO_PROTECT) { SchedParam param = { 0 }; @@ -307,23 +308,23 @@ STATIC UINT32 OsMuxPendOp(LosTaskCB *runTask, LosMux *mutex, UINT32 timeout) } return LOS_OK; } - - if (((LosTaskCB *)mutex->owner == runTask) && (mutex->attr.type == LOS_MUX_RECURSIVE)) { - mutex->muxCount++; - return LOS_OK; + //递归锁muxCount>0 如果是递归锁就要处理两种情况 1.runtask持有锁 2.锁被别的任务拿走了 + if (((LosTaskCB *)mutex->owner == runTask) && (mutex->attr.type == LOS_MUX_RECURSIVE)) {//第一种情况 runtask是锁持有方 + mutex->muxCount++; //递归锁计数器加1,递归锁的目的是防止死锁,鸿蒙默认用的就是递归锁(LOS_MUX_DEFAULT = LOS_MUX_RECURSIVE) + return LOS_OK; //成功退出 } - - if (!timeout) { - return LOS_EINVAL; + //到了这里说明锁在别的任务那里,当前任务只能被阻塞了. + if (!timeout) {//参数timeout表示等待多久再来拿锁 + return LOS_EINVAL;//timeout = 0表示不等了,没拿到锁就返回不纠结,返回错误.见于LOS_MuxTrylock } - - if (!OsPreemptableInSched()) { - return LOS_EDEADLK; + //自己要被阻塞,只能申请调度,让出CPU core 让别的任务上 + if (!OsPreemptableInSched()) {//不能申请调度 (不能调度的原因是因为没有持有调度任务自旋锁) + return LOS_EDEADLK;//返回错误,自旋锁被别的CPU core 持有 } - OsMuxBitmapSet(mutex, runTask); + OsMuxBitmapSet(mutex, runTask);//设置锁位图,尽可能的提高锁持有任务的优先级 - runTask->taskMux = (VOID *)mutex; + runTask->taskMux = (VOID *)mutex; //记下当前任务在等待这把锁 LOS_DL_LIST *node = OsSchedLockPendFindPos(runTask, &mutex->muxList); if (node == NULL) { ret = LOS_NOK; @@ -332,10 +333,10 @@ STATIC UINT32 OsMuxPendOp(LosTaskCB *runTask, LosMux *mutex, UINT32 timeout) OsTaskWaitSetPendMask(OS_TASK_WAIT_MUTEX, (UINTPTR)mutex, timeout); ret = runTask->ops->wait(runTask, node, timeout); - if (ret == LOS_ERRNO_TSK_TIMEOUT) { + if (ret == LOS_ERRNO_TSK_TIMEOUT) {//这行代码虽和OsTaskWait挨在一起,但要过很久才会执行到,因为在OsTaskWait中CPU切换了任务上下文 OsMuxBitmapRestore(mutex, NULL, runTask); - runTask->taskMux = NULL; - ret = LOS_ETIMEDOUT; + runTask->taskMux = NULL;// 所以重新回到这里时可能已经超时了 + ret = LOS_ETIMEDOUT;//返回超时 } return ret; @@ -343,7 +344,7 @@ STATIC UINT32 OsMuxPendOp(LosTaskCB *runTask, LosMux *mutex, UINT32 timeout) UINT32 OsMuxLockUnsafe(LosMux *mutex, UINT32 timeout) { - LosTaskCB *runTask = OsCurrTaskGet(); + LosTaskCB *runTask = OsCurrTaskGet();//获取当前任务 if (mutex->magic != OS_MUX_MAGIC) { return LOS_EBADF; @@ -352,23 +353,23 @@ UINT32 OsMuxLockUnsafe(LosMux *mutex, UINT32 timeout) if (OsCheckMutexAttr(&mutex->attr) != LOS_OK) { return LOS_EINVAL; } - + //LOS_MUX_ERRORCHECK 时 muxCount是要等于0 ,当前任务持有锁就不能再lock了. 鸿蒙默认用的是递归锁LOS_MUX_RECURSIVE if ((mutex->attr.type == LOS_MUX_ERRORCHECK) && (mutex->owner == (VOID *)runTask)) { return LOS_EDEADLK; } return OsMuxPendOp(runTask, mutex, timeout); } - +/// 尝试加锁, UINT32 OsMuxTrylockUnsafe(LosMux *mutex, UINT32 timeout) { - LosTaskCB *runTask = OsCurrTaskGet(); + LosTaskCB *runTask = OsCurrTaskGet();//获取当前任务 - if (mutex->magic != OS_MUX_MAGIC) { + if (mutex->magic != OS_MUX_MAGIC) {//检查MAGIC有没有被改变 return LOS_EBADF; } - if (OsCheckMutexAttr(&mutex->attr) != LOS_OK) { + if (OsCheckMutexAttr(&mutex->attr) != LOS_OK) {//检查互斥锁属性 return LOS_EINVAL; } @@ -377,9 +378,9 @@ UINT32 OsMuxTrylockUnsafe(LosMux *mutex, UINT32 timeout) return LOS_EBUSY; } - return OsMuxPendOp(runTask, mutex, timeout); + return OsMuxPendOp(runTask, mutex, timeout);//当前任务去拿锁,拿不到就等timeout } - +/// 拿互斥锁, LITE_OS_SEC_TEXT UINT32 LOS_MuxLock(LosMux *mutex, UINT32 timeout) { LosTaskCB *runTask = NULL; @@ -394,19 +395,19 @@ LITE_OS_SEC_TEXT UINT32 LOS_MuxLock(LosMux *mutex, UINT32 timeout) return LOS_EINTR; } - runTask = (LosTaskCB *)OsCurrTaskGet(); + runTask = (LosTaskCB *)OsCurrTaskGet();//获取当前任务 /* DO NOT Call blocking API in system tasks */ - if (runTask->taskStatus & OS_TASK_FLAG_SYSTEM_TASK) { + if (runTask->taskStatus & OS_TASK_FLAG_SYSTEM_TASK) {//不要在内核任务里用mux锁 PRINTK("Warning: DO NOT call %s in system tasks.\n", __FUNCTION__); - OsBackTrace(); + OsBackTrace();//打印task信息 } - SCHEDULER_LOCK(intSave); - ret = OsMuxLockUnsafe(mutex, timeout); + SCHEDULER_LOCK(intSave);//调度自旋锁 + ret = OsMuxLockUnsafe(mutex, timeout);//如果任务没拿到锁,将进入阻塞队列一直等待,直到timeout或者持锁任务释放锁时唤醒它 SCHEDULER_UNLOCK(intSave); return ret; } - +///尝试要锁,没拿到也不等,直接返回,不纠结 LITE_OS_SEC_TEXT UINT32 LOS_MuxTrylock(LosMux *mutex) { LosTaskCB *runTask = NULL; @@ -421,39 +422,40 @@ LITE_OS_SEC_TEXT UINT32 LOS_MuxTrylock(LosMux *mutex) return LOS_EINTR; } - runTask = (LosTaskCB *)OsCurrTaskGet(); + runTask = (LosTaskCB *)OsCurrTaskGet();//获取当前执行的任务 /* DO NOT Call blocking API in system tasks */ - if (runTask->taskStatus & OS_TASK_FLAG_SYSTEM_TASK) { + if (runTask->taskStatus & OS_TASK_FLAG_SYSTEM_TASK) {//系统任务不能 PRINTK("Warning: DO NOT call %s in system tasks.\n", __FUNCTION__); OsBackTrace(); } SCHEDULER_LOCK(intSave); - ret = OsMuxTrylockUnsafe(mutex, 0); + ret = OsMuxTrylockUnsafe(mutex, 0);//timeout = 0,不等待,没拿到锁就算了 SCHEDULER_UNLOCK(intSave); return ret; } + STATIC UINT32 OsMuxPostOp(LosTaskCB *taskCB, LosMux *mutex, BOOL *needSched) { - if (LOS_ListEmpty(&mutex->muxList)) { - LOS_ListDelete(&mutex->holdList); + if (LOS_ListEmpty(&mutex->muxList)) {//如果互斥锁列表为空 + LOS_ListDelete(&mutex->holdList);//把持有互斥锁的节点摘掉 mutex->owner = NULL; return LOS_OK; } - LosTaskCB *resumedTask = OS_TCB_FROM_PENDLIST(LOS_DL_LIST_FIRST(&(mutex->muxList))); + LosTaskCB *resumedTask = OS_TCB_FROM_PENDLIST(LOS_DL_LIST_FIRST(&(mutex->muxList)));//拿到等待互斥锁链表的第一个任务实体,接下来要唤醒任务 OsMuxBitmapRestore(mutex, &mutex->muxList, resumedTask); - mutex->muxCount = 1; - mutex->owner = (VOID *)resumedTask; - LOS_ListDelete(&mutex->holdList); - LOS_ListTailInsert(&resumedTask->lockList, &mutex->holdList); + mutex->muxCount = 1;//互斥锁数量为1 + mutex->owner = (VOID *)resumedTask;//互斥锁的持有人换了 + LOS_ListDelete(&mutex->holdList);//自然要从等锁链表中把自己摘出去 + LOS_ListTailInsert(&resumedTask->lockList, &mutex->holdList);//把锁挂到恢复任务的锁链表上,lockList是任务持有的所有锁记录 OsTaskWakeClearPendMask(resumedTask); resumedTask->ops->wake(resumedTask); resumedTask->taskMux = NULL; - if (needSched != NULL) { - *needSched = TRUE; + if (needSched != NULL) {//如果不为空 + *needSched = TRUE;//就走起再次调度流程 } return LOS_OK; @@ -476,21 +478,21 @@ UINT32 OsMuxUnlockUnsafe(LosTaskCB *taskCB, LosMux *mutex, BOOL *needSched) if (mutex->muxCount == 0) { return LOS_EPERM; } - - if ((--mutex->muxCount != 0) && (mutex->attr.type == LOS_MUX_RECURSIVE)) { + //注意 --mutex->muxCount 先执行了-- 操作. + if ((--mutex->muxCount != 0) && (mutex->attr.type == LOS_MUX_RECURSIVE)) {//属性类型为LOS_MUX_RECURSIVE时,muxCount是可以不为0的 return LOS_OK; } - if (mutex->attr.protocol == LOS_MUX_PRIO_PROTECT) { + if (mutex->attr.protocol == LOS_MUX_PRIO_PROTECT) {//属性协议为保护时 SchedParam param = { 0 }; taskCB->ops->schedParamGet(taskCB, ¶m); taskCB->ops->priorityRestore(taskCB, NULL, ¶m); } - /* Whether a task block the mutex lock. */ - return OsMuxPostOp(taskCB, mutex, needSched); + /* Whether a task block the mutex lock. *///任务是否阻塞互斥锁 + return OsMuxPostOp(taskCB, mutex, needSched);//一个任务去唤醒另一个在等锁的任务 } - +///释放锁 LITE_OS_SEC_TEXT UINT32 LOS_MuxUnlock(LosMux *mutex) { LosTaskCB *runTask = NULL; @@ -506,9 +508,9 @@ LITE_OS_SEC_TEXT UINT32 LOS_MuxUnlock(LosMux *mutex) return LOS_EINTR; } - runTask = (LosTaskCB *)OsCurrTaskGet(); + runTask = (LosTaskCB *)OsCurrTaskGet();//获取当前任务 /* DO NOT Call blocking API in system tasks */ - if (runTask->taskStatus & OS_TASK_FLAG_SYSTEM_TASK) { + if (runTask->taskStatus & OS_TASK_FLAG_SYSTEM_TASK) {//不能在系统任务里调用,因为很容易让系统任务发生死锁 PRINTK("Warning: DO NOT call %s in system tasks.\n", __FUNCTION__); OsBackTrace(); } @@ -516,12 +518,12 @@ LITE_OS_SEC_TEXT UINT32 LOS_MuxUnlock(LosMux *mutex) SCHEDULER_LOCK(intSave); ret = OsMuxUnlockUnsafe(runTask, mutex, &needSched); SCHEDULER_UNLOCK(intSave); - if (needSched == TRUE) { - LOS_MpSchedule(OS_MP_CPU_ALL); - LOS_Schedule(); + if (needSched == TRUE) {//需要调度的情况 + LOS_MpSchedule(OS_MP_CPU_ALL);//向所有CPU发送调度指令 + LOS_Schedule();//发起调度 } return ret; } -#endif /* LOSCFG_BASE_IPC_MUX */ +#endif /* (LOSCFG_BASE_IPC_MUX == YES) */ diff --git a/src/kernel_liteos_a/kernel/base/ipc/los_queue.c b/src/kernel_liteos_a/kernel/base/ipc/los_queue.c index 8fe06ba2..40a4c197 100644 --- a/src/kernel_liteos_a/kernel/base/ipc/los_queue.c +++ b/src/kernel_liteos_a/kernel/base/ipc/los_queue.c @@ -1,6 +1,6 @@ /* * Copyright (c) 2013-2019 Huawei Technologies Co., Ltd. All rights reserved. - * Copyright (c) 2020-2023 Huawei Device Co., Ltd. All rights reserved. + * Copyright (c) 2020-2021 Huawei Device Co., Ltd. All rights reserved. * * Redistribution and use in source and binary forms, with or without modification, * are permitted provided that the following conditions are met: @@ -47,8 +47,8 @@ #endif /* LOSCFG_BASE_IPC_QUEUE_LIMIT <= 0 */ #ifndef LOSCFG_IPC_CONTAINER -LITE_OS_SEC_BSS LosQueueCB *g_allQueue = NULL; -LITE_OS_SEC_BSS STATIC LOS_DL_LIST g_freeQueueList; +LITE_OS_SEC_BSS LosQueueCB *g_allQueue = NULL;///< 消息队列池 +LITE_OS_SEC_BSS STATIC LOS_DL_LIST g_freeQueueList;///< 空闲队列链表,管分配的,需要队列从这里申请 #define FREE_QUEUE_LIST g_freeQueueList #endif @@ -83,10 +83,6 @@ LITE_OS_SEC_TEXT_INIT LosQueueCB *OsAllQueueCBInit(LOS_DL_LIST *freeQueueList) return allQueue; } -/* - * Description : queue initial - * Return : LOS_OK on success or error code on failure - */ LITE_OS_SEC_TEXT_INIT UINT32 OsQueueInit(VOID) { #ifndef LOSCFG_IPC_CONTAINER @@ -97,7 +93,7 @@ LITE_OS_SEC_TEXT_INIT UINT32 OsQueueInit(VOID) #endif return LOS_OK; } - +///创建一个队列,根据用户传入队列长度和消息节点大小来开辟相应的内存空间以供该队列使用，参数queueID带走队列ID LITE_OS_SEC_TEXT_INIT UINT32 LOS_QueueCreate(CHAR *queueName, UINT16 len, UINT32 *queueID, UINT32 flags, UINT16 maxMsgSize) { @@ -114,7 +110,7 @@ LITE_OS_SEC_TEXT_INIT UINT32 LOS_QueueCreate(CHAR *queueName, UINT16 len, UINT32 return LOS_ERRNO_QUEUE_CREAT_PTR_NULL; } - if (maxMsgSize > (OS_NULL_SHORT - sizeof(UINT32))) { + if (maxMsgSize > (OS_NULL_SHORT - sizeof(UINT32))) {// maxMsgSize上限 为啥要减去 sizeof(UINT32) ,因为前面存的是队列的大小 return LOS_ERRNO_QUEUE_SIZE_TOO_BIG; } @@ -122,83 +118,83 @@ LITE_OS_SEC_TEXT_INIT UINT32 LOS_QueueCreate(CHAR *queueName, UINT16 len, UINT32 return LOS_ERRNO_QUEUE_PARA_ISZERO; } - msgSize = maxMsgSize + sizeof(UINT32); + msgSize = maxMsgSize + sizeof(UINT32);//总size = 消息体内容长度 + 消息大小(UINT32) /* * Memory allocation is time-consuming, to shorten the time of disable interrupt, * move the memory allocation to here. - */ - queue = (UINT8 *)LOS_MemAlloc(m_aucSysMem1, (UINT32)len * msgSize); - if (queue == NULL) { - return LOS_ERRNO_QUEUE_CREATE_NO_MEMORY; + *///内存分配非常耗时，为了缩短禁用中断的时间，将内存分配移到此处,用的时候分配队列内存 + queue = (UINT8 *)LOS_MemAlloc(m_aucSysMem1, (UINT32)len * msgSize);//从系统内存池中分配,由这里提供读写队列的内存 + if (queue == NULL) {//这里是一次把队列要用到的所有最大内存都申请下来了,能保证不会出现后续使用过程中内存不够的问题出现 + return LOS_ERRNO_QUEUE_CREATE_NO_MEMORY;//调用处有 OsSwtmrInit sys_mbox_new DoMqueueCreate == } SCHEDULER_LOCK(intSave); - if (LOS_ListEmpty(&FREE_QUEUE_LIST)) { - SCHEDULER_UNLOCK(intSave); + if (LOS_ListEmpty(&FREE_QUEUE_LIST)) {//没有空余的队列ID的处理,注意软时钟定时器是由 g_swtmrCBArray统一管理的,里面有正在使用和可分配空闲的队列 + SCHEDULER_UNLOCK(intSave);//g_freeQueueList是管理可用于分配的队列链表,申请消息队列的ID需要向它要 OsQueueCheckHook(); - (VOID)LOS_MemFree(m_aucSysMem1, queue); + (VOID)LOS_MemFree(m_aucSysMem1, queue);//没有就要释放 queue申请的内存 return LOS_ERRNO_QUEUE_CB_UNAVAILABLE; } - unusedQueue = LOS_DL_LIST_FIRST(&FREE_QUEUE_LIST); - LOS_ListDelete(unusedQueue); - queueCB = GET_QUEUE_LIST(unusedQueue); - queueCB->queueLen = len; - queueCB->queueSize = msgSize; - queueCB->queueHandle = queue; - queueCB->queueState = OS_QUEUE_INUSED; - queueCB->readWriteableCnt[OS_QUEUE_READ] = 0; - queueCB->readWriteableCnt[OS_QUEUE_WRITE] = len; - queueCB->queueHead = 0; - queueCB->queueTail = 0; - LOS_ListInit(&queueCB->readWriteList[OS_QUEUE_READ]); - LOS_ListInit(&queueCB->readWriteList[OS_QUEUE_WRITE]); - LOS_ListInit(&queueCB->memList); - - OsQueueDbgUpdateHook(queueCB->queueID, OsCurrTaskGet()->taskEntry); + unusedQueue = LOS_DL_LIST_FIRST(&FREE_QUEUE_LIST);//找到一个没有被使用的队列 + LOS_ListDelete(unusedQueue);//将自己从g_freeQueueList中摘除, unusedQueue只是个 LOS_DL_LIST 结点. + queueCB = GET_QUEUE_LIST(unusedQueue);//通过unusedQueue找到整个消息队列(LosQueueCB) + queueCB->queueLen = len; //队列中消息的总个数,注意这个一旦创建是不能变的. + queueCB->queueSize = msgSize;//消息节点的大小,注意这个一旦创建也是不能变的. + queueCB->queueHandle = queue; //队列句柄,队列内容存储区. + queueCB->queueState = OS_QUEUE_INUSED; //队列状态使用中 + queueCB->readWriteableCnt[OS_QUEUE_READ] = 0;//可读资源计数，OS_QUEUE_READ(0):可读. + queueCB->readWriteableCnt[OS_QUEUE_WRITE] = len;//可些资源计数 OS_QUEUE_WRITE(1):可写, 默认len可写. + queueCB->queueHead = 0;//队列头节点 + queueCB->queueTail = 0;//队列尾节点 + LOS_ListInit(&queueCB->readWriteList[OS_QUEUE_READ]);//初始化可读队列任务链表 + LOS_ListInit(&queueCB->readWriteList[OS_QUEUE_WRITE]);//初始化可写队列任务链表 + LOS_ListInit(&queueCB->memList);// + + OsQueueDbgUpdateHook(queueCB->queueID, OsCurrTaskGet()->taskEntry);//在创建或删除队列调试信息时更新任务条目 SCHEDULER_UNLOCK(intSave); - *queueID = queueCB->queueID; + *queueID = queueCB->queueID;//带走队列ID OsHookCall(LOS_HOOK_TYPE_QUEUE_CREATE, queueCB); return LOS_OK; } - +///读队列参数检查 STATIC LITE_OS_SEC_TEXT UINT32 OsQueueReadParameterCheck(UINT32 queueID, const VOID *bufferAddr, const UINT32 *bufferSize, UINT32 timeout) { - if (GET_QUEUE_INDEX(queueID) >= LOSCFG_BASE_IPC_QUEUE_LIMIT) { + if (GET_QUEUE_INDEX(queueID) >= LOSCFG_BASE_IPC_QUEUE_LIMIT) {//队列ID不能超上限 return LOS_ERRNO_QUEUE_INVALID; } - if ((bufferAddr == NULL) || (bufferSize == NULL)) { + if ((bufferAddr == NULL) || (bufferSize == NULL)) {//缓存地址和大小参数判断 return LOS_ERRNO_QUEUE_READ_PTR_NULL; } - if ((*bufferSize == 0) || (*bufferSize > (OS_NULL_SHORT - sizeof(UINT32)))) { - return LOS_ERRNO_QUEUE_READSIZE_IS_INVALID; + if ((*bufferSize == 0) || (*bufferSize > (OS_NULL_SHORT - sizeof(UINT32)))) {//限制了读取数据的上限64K, sizeof(UINT32)代表的是队列的长度 + return LOS_ERRNO_QUEUE_READSIZE_IS_INVALID; //所以要减去 } OsQueueDbgTimeUpdateHook(queueID); - if (timeout != LOS_NO_WAIT) { - if (OS_INT_ACTIVE) { - return LOS_ERRNO_QUEUE_READ_IN_INTERRUPT; + if (timeout != LOS_NO_WAIT) {//等待一定时间再读取 + if (OS_INT_ACTIVE) {//如果碰上了硬中断 + return LOS_ERRNO_QUEUE_READ_IN_INTERRUPT;//意思是:硬中断发生时是不能读消息队列的 } } return LOS_OK; } - +///写队列参数检查 STATIC LITE_OS_SEC_TEXT UINT32 OsQueueWriteParameterCheck(UINT32 queueID, const VOID *bufferAddr, const UINT32 *bufferSize, UINT32 timeout) { - if (GET_QUEUE_INDEX(queueID) >= LOSCFG_BASE_IPC_QUEUE_LIMIT) { + if (GET_QUEUE_INDEX(queueID) >= LOSCFG_BASE_IPC_QUEUE_LIMIT) {//队列ID不能超上限 return LOS_ERRNO_QUEUE_INVALID; } - if (bufferAddr == NULL) { + if (bufferAddr == NULL) {//没有数据源 return LOS_ERRNO_QUEUE_WRITE_PTR_NULL; } - if (*bufferSize == 0) { + if (*bufferSize == 0) {//这里没有限制写队列的大小,如果写入一个很大buf 会怎样? return LOS_ERRNO_QUEUE_WRITESIZE_ISZERO; } @@ -211,128 +207,129 @@ STATIC LITE_OS_SEC_TEXT UINT32 OsQueueWriteParameterCheck(UINT32 queueID, const } return LOS_OK; } - +///队列buf操作,注意队列数据是按顺序来读取的,要不从头,要不从尾部,不会出现从中间读写,所有可由 head 和 tail 来管理队列. STATIC VOID OsQueueBufferOperate(LosQueueCB *queueCB, UINT32 operateType, VOID *bufferAddr, UINT32 *bufferSize) { UINT8 *queueNode = NULL; UINT32 msgDataSize; UINT16 queuePosition; - /* get the queue position */ - switch (OS_QUEUE_OPERATE_GET(operateType)) { - case OS_QUEUE_READ_HEAD: - queuePosition = queueCB->queueHead; - ((queueCB->queueHead + 1) == queueCB->queueLen) ? (queueCB->queueHead = 0) : (queueCB->queueHead++); + /* get the queue position | 先找到队列的位置*/ + switch (OS_QUEUE_OPERATE_GET(operateType)) {//获取操作类型 + case OS_QUEUE_READ_HEAD://从列队头开始读 + queuePosition = queueCB->queueHead;//拿到头部位置 + ((queueCB->queueHead + 1) == queueCB->queueLen) ? (queueCB->queueHead = 0) : (queueCB->queueHead++);//调整队列头部位置 break; - case OS_QUEUE_WRITE_HEAD: - (queueCB->queueHead == 0) ? (queueCB->queueHead = queueCB->queueLen - 1) : (--queueCB->queueHead); - queuePosition = queueCB->queueHead; + case OS_QUEUE_WRITE_HEAD://从列队头开始写 + (queueCB->queueHead == 0) ? (queueCB->queueHead = queueCB->queueLen - 1) : (--queueCB->queueHead);//调整队列头部位置 + queuePosition = queueCB->queueHead;//拿到头部位置 break; - case OS_QUEUE_WRITE_TAIL: - queuePosition = queueCB->queueTail; - ((queueCB->queueTail + 1) == queueCB->queueLen) ? (queueCB->queueTail = 0) : (queueCB->queueTail++); + case OS_QUEUE_WRITE_TAIL://从列队尾部开始写 + queuePosition = queueCB->queueTail;//设置队列位置为尾部位置 + ((queueCB->queueTail + 1) == queueCB->queueLen) ? (queueCB->queueTail = 0) : (queueCB->queueTail++);//调整队列尾部位置 break; default: /* read tail, reserved. */ PRINT_ERR("invalid queue operate type!\n"); return; } + //queueHandle是create队列时,由外界参数申请的一块内存. 用于copy 使用 + queueNode = &(queueCB->queueHandle[(queuePosition * (queueCB->queueSize))]);//拿到队列节点 - queueNode = &(queueCB->queueHandle[(queuePosition * (queueCB->queueSize))]); - - if (OS_QUEUE_IS_READ(operateType)) { + if (OS_QUEUE_IS_READ(operateType)) {//读操作处理,读队列分两步走 if (memcpy_s(&msgDataSize, sizeof(UINT32), queueNode + queueCB->queueSize - sizeof(UINT32), - sizeof(UINT32)) != EOK) { + sizeof(UINT32)) != EOK) {//1.先读出队列大小,由队列头四个字节表示 PRINT_ERR("get msgdatasize failed\n"); return; } msgDataSize = (*bufferSize < msgDataSize) ? *bufferSize : msgDataSize; - if (memcpy_s(bufferAddr, *bufferSize, queueNode, msgDataSize) != EOK) { + if (memcpy_s(bufferAddr, *bufferSize, queueNode, msgDataSize) != EOK) {//2.读表示读走已有数据,所以相当于bufferAddr接着了queueNode的数据 PRINT_ERR("copy message to buffer failed\n"); return; } - *bufferSize = msgDataSize; - } else { - if (memcpy_s(queueNode, queueCB->queueSize, bufferAddr, *bufferSize) != EOK) { - PRINT_ERR("store message failed\n"); + *bufferSize = msgDataSize;//通过入参 带走消息的大小 + } else {//只有读写两种操作,这里就是写队列了.写也分两步走 , @note_thinking 这里建议鸿蒙加上 OS_QUEUE_IS_WRITE 判断 + if (memcpy_s(queueNode, queueCB->queueSize, bufferAddr, *bufferSize) != EOK) {//1.写入消息内容 + PRINT_ERR("store message failed\n");//表示把外面数据写进来,所以相当于queueNode接着了bufferAddr的数据 return; } if (memcpy_s(queueNode + queueCB->queueSize - sizeof(UINT32), sizeof(UINT32), bufferSize, - sizeof(UINT32)) != EOK) { + sizeof(UINT32)) != EOK) {//2.写入消息数据的长度,sizeof(UINT32) PRINT_ERR("store message size failed\n"); return; } } } - +///队列操作参数检查 STATIC UINT32 OsQueueOperateParamCheck(const LosQueueCB *queueCB, UINT32 queueID, UINT32 operateType, const UINT32 *bufferSize) { - if ((queueCB->queueID != queueID) || (queueCB->queueState == OS_QUEUE_UNUSED)) { + if ((queueCB->queueID != queueID) || (queueCB->queueState == OS_QUEUE_UNUSED)) {//队列ID和状态判断 return LOS_ERRNO_QUEUE_NOT_CREATE; } - if (OS_QUEUE_IS_WRITE(operateType) && (*bufferSize > (queueCB->queueSize - sizeof(UINT32)))) { - return LOS_ERRNO_QUEUE_WRITE_SIZE_TOO_BIG; + if (OS_QUEUE_IS_WRITE(operateType) && (*bufferSize > (queueCB->queueSize - sizeof(UINT32)))) {//写时判断 + return LOS_ERRNO_QUEUE_WRITE_SIZE_TOO_BIG;//塞进来的数据太大,大于队列节点能承受的范围 } return LOS_OK; } + UINT32 OsQueueOperate(UINT32 queueID, UINT32 operateType, VOID *bufferAddr, UINT32 *bufferSize, UINT32 timeout) { UINT32 ret; - UINT32 readWrite = OS_QUEUE_READ_WRITE_GET(operateType); + UINT32 readWrite = OS_QUEUE_READ_WRITE_GET(operateType);//获取读/写操作标识 UINT32 intSave; OsHookCall(LOS_HOOK_TYPE_QUEUE_READ, (LosQueueCB *)GET_QUEUE_HANDLE(queueID), operateType, *bufferSize, timeout); SCHEDULER_LOCK(intSave); - LosQueueCB *queueCB = (LosQueueCB *)GET_QUEUE_HANDLE(queueID); - ret = OsQueueOperateParamCheck(queueCB, queueID, operateType, bufferSize); + LosQueueCB *queueCB = (LosQueueCB *)GET_QUEUE_HANDLE(queueID);//获取对应的队列控制块 + ret = OsQueueOperateParamCheck(queueCB, queueID, operateType, bufferSize);//参数检查 if (ret != LOS_OK) { goto QUEUE_END; } - if (queueCB->readWriteableCnt[readWrite] == 0) { - if (timeout == LOS_NO_WAIT) { + if (queueCB->readWriteableCnt[readWrite] == 0) {//根据readWriteableCnt判断队列是否有消息读/写 + if (timeout == LOS_NO_WAIT) {//不等待直接退出 ret = OS_QUEUE_IS_READ(operateType) ? LOS_ERRNO_QUEUE_ISEMPTY : LOS_ERRNO_QUEUE_ISFULL; goto QUEUE_END; } - if (!OsPreemptableInSched()) { + if (!OsPreemptableInSched()) {//不支持抢占式调度 ret = LOS_ERRNO_QUEUE_PEND_IN_LOCK; goto QUEUE_END; } - + //任务等待,这里很重要啊,将自己从就绪列表摘除,让出了CPU并发起了调度,并挂在readWriteList[readWrite]上,挂的都等待读/写消息的task LosTaskCB *runTask = OsCurrTaskGet(); OsTaskWaitSetPendMask(OS_TASK_WAIT_QUEUE, queueCB->queueID, timeout); ret = runTask->ops->wait(runTask, &queueCB->readWriteList[readWrite], timeout); - if (ret == LOS_ERRNO_TSK_TIMEOUT) { + if (ret == LOS_ERRNO_TSK_TIMEOUT) {//唤醒后如果超时了,返回读/写消息失败 ret = LOS_ERRNO_QUEUE_TIMEOUT; - goto QUEUE_END; + goto QUEUE_END;// } } else { - queueCB->readWriteableCnt[readWrite]--; + queueCB->readWriteableCnt[readWrite]--;//对应队列中计数器--,说明一条消息只能被读/写一次 } - OsQueueBufferOperate(queueCB, operateType, bufferAddr, bufferSize); + OsQueueBufferOperate(queueCB, operateType, bufferAddr, bufferSize);//发起读或写队列操作 - if (!LOS_ListEmpty(&queueCB->readWriteList[!readWrite])) { - LosTaskCB *resumedTask = OS_TCB_FROM_PENDLIST(LOS_DL_LIST_FIRST(&queueCB->readWriteList[!readWrite])); + if (!LOS_ListEmpty(&queueCB->readWriteList[!readWrite])) {//如果还有任务在排着队等待读/写入消息(当时不能读/写的原因有可能当时队列满了==) + LosTaskCB *resumedTask = OS_TCB_FROM_PENDLIST(LOS_DL_LIST_FIRST(&queueCB->readWriteList[!readWrite]));//取出要读/写消息的任务 OsTaskWakeClearPendMask(resumedTask); resumedTask->ops->wake(resumedTask); SCHEDULER_UNLOCK(intSave); - LOS_MpSchedule(OS_MP_CPU_ALL); - LOS_Schedule(); + LOS_MpSchedule(OS_MP_CPU_ALL);//让所有CPU发出调度申请,因为很可能那个要读/写消息的队列是由其他CPU执行 + LOS_Schedule();//申请调度 return LOS_OK; } else { - queueCB->readWriteableCnt[!readWrite]++; + queueCB->readWriteableCnt[!readWrite]++;//对应队列读/写中计数器++ } QUEUE_END: SCHEDULER_UNLOCK(intSave); return ret; } - +///接口函数定时读取消息队列 LITE_OS_SEC_TEXT UINT32 LOS_QueueReadCopy(UINT32 queueID, VOID *bufferAddr, UINT32 *bufferSize, @@ -341,15 +338,15 @@ LITE_OS_SEC_TEXT UINT32 LOS_QueueReadCopy(UINT32 queueID, UINT32 ret; UINT32 operateType; - ret = OsQueueReadParameterCheck(queueID, bufferAddr, bufferSize, timeout); + ret = OsQueueReadParameterCheck(queueID, bufferAddr, bufferSize, timeout);//参数检查 if (ret != LOS_OK) { return ret; } - operateType = OS_QUEUE_OPERATE_TYPE(OS_QUEUE_READ, OS_QUEUE_HEAD); - return OsQueueOperate(queueID, operateType, bufferAddr, bufferSize, timeout); + operateType = OS_QUEUE_OPERATE_TYPE(OS_QUEUE_READ, OS_QUEUE_HEAD);//从头开始读 + return OsQueueOperate(queueID, operateType, bufferAddr, bufferSize, timeout);//定时执行读操作 } - +///接口函数从队列头开始写 LITE_OS_SEC_TEXT UINT32 LOS_QueueWriteHeadCopy(UINT32 queueID, VOID *bufferAddr, UINT32 bufferSize, @@ -358,15 +355,15 @@ LITE_OS_SEC_TEXT UINT32 LOS_QueueWriteHeadCopy(UINT32 queueID, UINT32 ret; UINT32 operateType; - ret = OsQueueWriteParameterCheck(queueID, bufferAddr, &bufferSize, timeout); + ret = OsQueueWriteParameterCheck(queueID, bufferAddr, &bufferSize, timeout);//参数检查 if (ret != LOS_OK) { return ret; } - operateType = OS_QUEUE_OPERATE_TYPE(OS_QUEUE_WRITE, OS_QUEUE_HEAD); - return OsQueueOperate(queueID, operateType, bufferAddr, &bufferSize, timeout); + operateType = OS_QUEUE_OPERATE_TYPE(OS_QUEUE_WRITE, OS_QUEUE_HEAD);//从头开始写 + return OsQueueOperate(queueID, operateType, bufferAddr, &bufferSize, timeout);//执行写操作 } - +///接口函数 从队列尾部开始写 LITE_OS_SEC_TEXT UINT32 LOS_QueueWriteCopy(UINT32 queueID, VOID *bufferAddr, UINT32 bufferSize, @@ -375,15 +372,16 @@ LITE_OS_SEC_TEXT UINT32 LOS_QueueWriteCopy(UINT32 queueID, UINT32 ret; UINT32 operateType; - ret = OsQueueWriteParameterCheck(queueID, bufferAddr, &bufferSize, timeout); + ret = OsQueueWriteParameterCheck(queueID, bufferAddr, &bufferSize, timeout);//参数检查 if (ret != LOS_OK) { return ret; } - operateType = OS_QUEUE_OPERATE_TYPE(OS_QUEUE_WRITE, OS_QUEUE_TAIL); - return OsQueueOperate(queueID, operateType, bufferAddr, &bufferSize, timeout); + operateType = OS_QUEUE_OPERATE_TYPE(OS_QUEUE_WRITE, OS_QUEUE_TAIL);//从尾部开始写 + return OsQueueOperate(queueID, operateType, bufferAddr, &bufferSize, timeout);//执行写操作 } + LITE_OS_SEC_TEXT UINT32 LOS_QueueRead(UINT32 queueID, VOID *bufferAddr, UINT32 bufferSize, UINT32 timeout) { return LOS_QueueReadCopy(queueID, bufferAddr, &bufferSize, timeout); @@ -398,6 +396,7 @@ LITE_OS_SEC_TEXT UINT32 LOS_QueueWrite(UINT32 queueID, VOID *bufferAddr, UINT32 return LOS_QueueWriteCopy(queueID, &bufferAddr, bufferSize, timeout); } + LITE_OS_SEC_TEXT UINT32 LOS_QueueWriteHead(UINT32 queueID, VOID *bufferAddr, UINT32 bufferSize, @@ -410,6 +409,7 @@ LITE_OS_SEC_TEXT UINT32 LOS_QueueWriteHead(UINT32 queueID, return LOS_QueueWriteHeadCopy(queueID, &bufferAddr, bufferSize, timeout); } + LITE_OS_SEC_TEXT_INIT UINT32 LOS_QueueDelete(UINT32 queueID) { LosQueueCB *queueCB = NULL; @@ -422,50 +422,50 @@ LITE_OS_SEC_TEXT_INIT UINT32 LOS_QueueDelete(UINT32 queueID) } SCHEDULER_LOCK(intSave); - queueCB = (LosQueueCB *)GET_QUEUE_HANDLE(queueID); + queueCB = (LosQueueCB *)GET_QUEUE_HANDLE(queueID);//拿到队列实体 if ((queueCB->queueID != queueID) || (queueCB->queueState == OS_QUEUE_UNUSED)) { ret = LOS_ERRNO_QUEUE_NOT_CREATE; goto QUEUE_END; } - if (!LOS_ListEmpty(&queueCB->readWriteList[OS_QUEUE_READ])) { + if (!LOS_ListEmpty(&queueCB->readWriteList[OS_QUEUE_READ])) {//尚有任务要读数据 ret = LOS_ERRNO_QUEUE_IN_TSKUSE; goto QUEUE_END; } - if (!LOS_ListEmpty(&queueCB->readWriteList[OS_QUEUE_WRITE])) { + if (!LOS_ListEmpty(&queueCB->readWriteList[OS_QUEUE_WRITE])) {//尚有任务要写数据 ret = LOS_ERRNO_QUEUE_IN_TSKUSE; goto QUEUE_END; } - if (!LOS_ListEmpty(&queueCB->memList)) { + if (!LOS_ListEmpty(&queueCB->memList)) {// ret = LOS_ERRNO_QUEUE_IN_TSKUSE; goto QUEUE_END; } if ((queueCB->readWriteableCnt[OS_QUEUE_WRITE] + queueCB->readWriteableCnt[OS_QUEUE_READ]) != - queueCB->queueLen) { + queueCB->queueLen) {//读写队列的内容长度不等于总长度 ret = LOS_ERRNO_QUEUE_IN_TSKWRITE; goto QUEUE_END; } - queue = queueCB->queueHandle; - queueCB->queueHandle = NULL; - queueCB->queueState = OS_QUEUE_UNUSED; - queueCB->queueID = SET_QUEUE_ID(GET_QUEUE_COUNT(queueCB->queueID) + 1, GET_QUEUE_INDEX(queueCB->queueID)); + queue = queueCB->queueHandle; //队列buf + queueCB->queueHandle = NULL; // + queueCB->queueState = OS_QUEUE_UNUSED;//重置队列状态 + queueCB->queueID = SET_QUEUE_ID(GET_QUEUE_COUNT(queueCB->queueID) + 1, GET_QUEUE_INDEX(queueCB->queueID));//@note_why 这里需要这样做吗? OsQueueDbgUpdateHook(queueCB->queueID, NULL); - LOS_ListTailInsert(&FREE_QUEUE_LIST, &queueCB->readWriteList[OS_QUEUE_WRITE]); - SCHEDULER_UNLOCK(intSave); + LOS_ListTailInsert(&FREE_QUEUE_LIST, &queueCB->readWriteList[OS_QUEUE_WRITE]);//回收，将节点挂入可分配链表,等待重新被分配再利用 + SCHEDULER_UNLOCK(intSave); OsHookCall(LOS_HOOK_TYPE_QUEUE_DELETE, queueCB); - ret = LOS_MemFree(m_aucSysMem1, (VOID *)queue); + ret = LOS_MemFree(m_aucSysMem1, (VOID *)queue);//释放队列句柄 return ret; QUEUE_END: SCHEDULER_UNLOCK(intSave); return ret; } - +///外部接口, 获取队列信息,用queueInfo 把 LosQueueCB数据接走,QUEUE_INFO_S对内部数据的封装 LITE_OS_SEC_TEXT_MINOR UINT32 LOS_QueueInfoGet(UINT32 queueID, QUEUE_INFO_S *queueInfo) { UINT32 intSave; @@ -477,14 +477,14 @@ LITE_OS_SEC_TEXT_MINOR UINT32 LOS_QueueInfoGet(UINT32 queueID, QUEUE_INFO_S *que return LOS_ERRNO_QUEUE_PTR_NULL; } - if (GET_QUEUE_INDEX(queueID) >= LOSCFG_BASE_IPC_QUEUE_LIMIT) { + if (GET_QUEUE_INDEX(queueID) >= LOSCFG_BASE_IPC_QUEUE_LIMIT) {//1024 return LOS_ERRNO_QUEUE_INVALID; } - (VOID)memset_s((VOID *)queueInfo, sizeof(QUEUE_INFO_S), 0, sizeof(QUEUE_INFO_S)); + (VOID)memset_s((VOID *)queueInfo, sizeof(QUEUE_INFO_S), 0, sizeof(QUEUE_INFO_S));//接走数据之前先清0 SCHEDULER_LOCK(intSave); - queueCB = (LosQueueCB *)GET_QUEUE_HANDLE(queueID); + queueCB = (LosQueueCB *)GET_QUEUE_HANDLE(queueID);//通过队列ID获取 QCB if ((queueCB->queueID != queueID) || (queueCB->queueState == OS_QUEUE_UNUSED)) { ret = LOS_ERRNO_QUEUE_NOT_CREATE; goto QUEUE_END; @@ -495,19 +495,19 @@ LITE_OS_SEC_TEXT_MINOR UINT32 LOS_QueueInfoGet(UINT32 queueID, QUEUE_INFO_S *que queueInfo->usQueueSize = queueCB->queueSize; queueInfo->usQueueHead = queueCB->queueHead; queueInfo->usQueueTail = queueCB->queueTail; - queueInfo->usReadableCnt = queueCB->readWriteableCnt[OS_QUEUE_READ]; - queueInfo->usWritableCnt = queueCB->readWriteableCnt[OS_QUEUE_WRITE]; + queueInfo->usReadableCnt = queueCB->readWriteableCnt[OS_QUEUE_READ];//可读数 + queueInfo->usWritableCnt = queueCB->readWriteableCnt[OS_QUEUE_WRITE];//可写数 - LOS_DL_LIST_FOR_EACH_ENTRY(tskCB, &queueCB->readWriteList[OS_QUEUE_READ], LosTaskCB, pendList) { - queueInfo->uwWaitReadTask |= 1ULL << tskCB->taskID; - } + LOS_DL_LIST_FOR_EACH_ENTRY(tskCB, &queueCB->readWriteList[OS_QUEUE_READ], LosTaskCB, pendList) {//找出哪些task需要读消息 + queueInfo->uwWaitReadTask |= 1ULL << tskCB->taskID;//记录等待读消息的任务号, uwWaitReadTask 每一位代表一个任务编号 + }//0b..011011011 代表 0,1,3,4,6,7 号任务有数据等待读消息. - LOS_DL_LIST_FOR_EACH_ENTRY(tskCB, &queueCB->readWriteList[OS_QUEUE_WRITE], LosTaskCB, pendList) { - queueInfo->uwWaitWriteTask |= 1ULL << tskCB->taskID; - } + LOS_DL_LIST_FOR_EACH_ENTRY(tskCB, &queueCB->readWriteList[OS_QUEUE_WRITE], LosTaskCB, pendList) {//找出哪些task需要写消息 + queueInfo->uwWaitWriteTask |= 1ULL << tskCB->taskID;//记录等待写消息的任务号, uwWaitWriteTask 每一位代表一个任务编号 + }////0b..011011011 代表 0,1,3,4,6,7 号任务有数据等待写消息. - LOS_DL_LIST_FOR_EACH_ENTRY(tskCB, &queueCB->memList, LosTaskCB, pendList) { - queueInfo->uwWaitMemTask |= 1ULL << tskCB->taskID; + LOS_DL_LIST_FOR_EACH_ENTRY(tskCB, &queueCB->memList, LosTaskCB, pendList) {//同上 + queueInfo->uwWaitMemTask |= 1ULL << tskCB->taskID; //MailBox模块使用 } QUEUE_END: @@ -515,5 +515,5 @@ QUEUE_END: return ret; } -#endif /* LOSCFG_BASE_IPC_QUEUE */ +#endif /* (LOSCFG_BASE_IPC_QUEUE == YES) */ diff --git a/src/kernel_liteos_a/kernel/base/ipc/los_rwlock.c b/src/kernel_liteos_a/kernel/base/ipc/los_rwlock.c index 546fe831..5ddd3b81 100644 --- a/src/kernel_liteos_a/kernel/base/ipc/los_rwlock.c +++ b/src/kernel_liteos_a/kernel/base/ipc/los_rwlock.c @@ -1,6 +1,6 @@ /* * Copyright (c) 2013-2019 Huawei Technologies Co., Ltd. All rights reserved. - * Copyright (c) 2020-2022 Huawei Device Co., Ltd. All rights reserved. + * Copyright (c) 2020-2021 Huawei Device Co., Ltd. All rights reserved. * * Redistribution and use in source and binary forms, with or without modification, * are permitted provided that the following conditions are met: @@ -37,9 +37,10 @@ #include "los_exc.h" #include "los_sched_pri.h" + #ifdef LOSCFG_BASE_IPC_RWLOCK #define RWLOCK_COUNT_MASK 0x00FFFFFFU - +/// 判断读写锁有效性 BOOL LOS_RwlockIsValid(const LosRwlock *rwlock) { if ((rwlock != NULL) && ((rwlock->magic & RWLOCK_COUNT_MASK) == OS_RWLOCK_MAGIC)) { @@ -48,7 +49,7 @@ BOOL LOS_RwlockIsValid(const LosRwlock *rwlock) return FALSE; } - +/// 创建读写锁,初始化锁信息 UINT32 LOS_RwlockInit(LosRwlock *rwlock) { UINT32 intSave; @@ -71,7 +72,7 @@ UINT32 LOS_RwlockInit(LosRwlock *rwlock) SCHEDULER_UNLOCK(intSave); return LOS_OK; } - +/// 删除指定的读写锁 UINT32 LOS_RwlockDestroy(LosRwlock *rwlock) { UINT32 intSave; @@ -95,18 +96,18 @@ UINT32 LOS_RwlockDestroy(LosRwlock *rwlock) SCHEDULER_UNLOCK(intSave); return LOS_OK; } - +/// 读写锁检查 STATIC UINT32 OsRwlockCheck(const LosRwlock *rwlock) { if (rwlock == NULL) { return LOS_EINVAL; } - if (OS_INT_ACTIVE) { + if (OS_INT_ACTIVE) { // 读写锁不能在中断服务程序中使用。请想想为什么 ? return LOS_EINTR; } - /* DO NOT Call blocking API in system tasks */ + /* DO NOT Call blocking API in system tasks | 系统任务不能使用读写锁 */ LosTaskCB *runTask = (LosTaskCB *)OsCurrTaskGet(); if (runTask->taskStatus & OS_TASK_FLAG_SYSTEM_TASK) { return LOS_EPERM; @@ -114,19 +115,23 @@ STATIC UINT32 OsRwlockCheck(const LosRwlock *rwlock) return LOS_OK; } - +/// 指定任务优先级优先级是否低于 写锁任务最高优先级 STATIC BOOL OsRwlockPriCompare(LosTaskCB *runTask, LOS_DL_LIST *rwList) { if (!LOS_ListEmpty(rwList)) { - LosTaskCB *highestTask = OS_TCB_FROM_PENDLIST(LOS_DL_LIST_FIRST(rwList)); - if (OsSchedParamCompare(runTask, highestTask) < 0) { + LosTaskCB *highestTask = OS_TCB_FROM_PENDLIST(LOS_DL_LIST_FIRST(rwList));//首个写锁任务优先级是最高的 + if (OsSchedParamCompare(runTask, highestTask) < 0) {//如果当前任务优先级低于等待写锁任务 return TRUE; } return FALSE; } return TRUE; } - +/* 申请读模式下的锁,分三种情况： +1. 若无人持有锁，读任务可获得锁。 +2. 若有人持有锁，读任务可获得锁，读取顺序按照任务优先级。 +3. 若有人（非自己）持有写模式下的锁，则当前任务无法获得锁，直到写模式下的锁释放。 +*/ STATIC UINT32 OsRwlockRdPendOp(LosTaskCB *runTask, LosRwlock *rwlock, UINT32 timeout) { UINT32 ret; @@ -135,12 +140,12 @@ STATIC UINT32 OsRwlockRdPendOp(LosTaskCB *runTask, LosRwlock *rwlock, UINT32 tim * When the rwlock mode is read mode or free mode and the priority of the current read task * is higher than the first pended write task. current read task can obtain this rwlock. */ - if (rwlock->rwCount >= 0) { - if (OsRwlockPriCompare(runTask, &(rwlock->writeList))) { - if (rwlock->rwCount == INT8_MAX) { + if (rwlock->rwCount >= 0) {//第一和第二种情况 + if (OsRwlockPriCompare(runTask, &(rwlock->writeList))) {//读优先级低于写优先级,意思就是必须先写再读 + if (rwlock->rwCount == INT8_MAX) {//读锁任务达到上限 return LOS_EINVAL; } - rwlock->rwCount++; + rwlock->rwCount++;//拿读锁成功 return LOS_OK; } } @@ -149,45 +154,51 @@ STATIC UINT32 OsRwlockRdPendOp(LosTaskCB *runTask, LosRwlock *rwlock, UINT32 tim return LOS_EINVAL; } - if (!OsPreemptableInSched()) { + if (!OsPreemptableInSched()) {//不可抢占时 return LOS_EDEADLK; } - /* The current task is not allowed to obtain the write lock when it obtains the read lock. */ - if ((LosTaskCB *)(rwlock->writeOwner) == runTask) { + /* The current task is not allowed to obtain the write lock when it obtains the read lock. + | 当前任务在获得读锁时不允许获得写锁 */ + if ((LosTaskCB *)(rwlock->writeOwner) == runTask) { //拥有写锁任务是否为当前任务 return LOS_EINVAL; } /* * When the rwlock mode is write mode or the priority of the current read task * is lower than the first pended write task, current read task will be pended. + | 当 rwlock 模式为写模式或当前读任务的优先级低于第一个挂起的写任务时，当前读任务将被挂起。 + 反正就是写锁任务优先 */ - LOS_DL_LIST *node = OsSchedLockPendFindPos(runTask, &(rwlock->readList)); - ret = runTask->ops->wait(runTask, node, timeout); + LOS_DL_LIST *node = OsSchedLockPendFindPos(runTask, &(rwlock->readList));//找到要挂入的位置 + //例如现有链表内任务优先级为 0 3 8 9 23 当前为 10 时, 返回的是 9 这个节点 + ret = runTask->ops->wait(runTask, node, timeout);//从尾部插入读锁链表 由此变成了 0 3 8 9 10 23 if (ret == LOS_ERRNO_TSK_TIMEOUT) { return LOS_ETIMEDOUT; } return ret; } - +/// 申请写模式下的锁 STATIC UINT32 OsRwlockWrPendOp(LosTaskCB *runTask, LosRwlock *rwlock, UINT32 timeout) { UINT32 ret; - /* When the rwlock is free mode, current write task can obtain this rwlock. */ + /* When the rwlock is free mode, current write task can obtain this rwlock. + | 若该锁当前没有任务持有，或者持有该读模式下的锁的任务和申请该锁的任务为同一个任务，则申请成功，可立即获得写模式下的锁。*/ if (rwlock->rwCount == 0) { rwlock->rwCount = -1; - rwlock->writeOwner = (VOID *)runTask; + rwlock->writeOwner = (VOID *)runTask;//直接给当前进程锁 return LOS_OK; } - /* Current write task can use one rwlock once again if the rwlock owner is it. */ + /* Current write task can use one rwlock once again if the rwlock owner is it. + | 如果 rwlock 拥有者是当前写入任务，则它可以再次使用该锁。*/ if ((rwlock->rwCount < 0) && ((LosTaskCB *)(rwlock->writeOwner) == runTask)) { if (rwlock->rwCount == INT8_MIN) { return LOS_EINVAL; } - rwlock->rwCount--; + rwlock->rwCount--;//注意再次拥有算是两把写锁了. return LOS_OK; } @@ -201,9 +212,9 @@ STATIC UINT32 OsRwlockWrPendOp(LosTaskCB *runTask, LosRwlock *rwlock, UINT32 tim /* * When the rwlock is read mode or other write task obtains this rwlock, current - * write task will be pended. + * write task will be pended. | 当 rwlock 为读模式或其他写任务获得该 rwlock 时，当前的写任务将被挂起。直到读模式下的锁释放 */ - LOS_DL_LIST *node = OsSchedLockPendFindPos(runTask, &(rwlock->writeList)); + LOS_DL_LIST *node = OsSchedLockPendFindPos(runTask, &(rwlock->writeList));//找到要挂入的位置 ret = runTask->ops->wait(runTask, node, timeout); if (ret == LOS_ERRNO_TSK_TIMEOUT) { ret = LOS_ETIMEDOUT; @@ -265,20 +276,22 @@ UINT32 OsRwlockTryWrUnsafe(LosRwlock *rwlock, UINT32 timeout) return LOS_EBADF; } - /* When the rwlock is read mode, current write task will be pended. */ + /* When the rwlock is read mode, current write task will be pended. + | 当 rwlock 为读模式时，当前的写任务将被挂起。*/ if (rwlock->rwCount > 0) { return LOS_EBUSY; } - /* When other write task obtains this rwlock, current write task will be pended. */ + /* When other write task obtains this rwlock, current write task will be pended. + | 当其他写任务获得这个rwlock时，当前的写任务将被挂起。*/ LosTaskCB *runTask = OsCurrTaskGet(); if ((rwlock->rwCount < 0) && ((LosTaskCB *)(rwlock->writeOwner) != runTask)) { return LOS_EBUSY; } - return OsRwlockWrPendOp(runTask, rwlock, timeout); + return OsRwlockWrPendOp(runTask, rwlock, timeout);// } - +/// 申请指定的读模式下的锁 UINT32 LOS_RwlockRdLock(LosRwlock *rwlock, UINT32 timeout) { UINT32 intSave; @@ -293,7 +306,7 @@ UINT32 LOS_RwlockRdLock(LosRwlock *rwlock, UINT32 timeout) SCHEDULER_UNLOCK(intSave); return ret; } - +/// 尝试申请指定的读模式下的锁 UINT32 LOS_RwlockTryRdLock(LosRwlock *rwlock) { UINT32 intSave; @@ -304,11 +317,11 @@ UINT32 LOS_RwlockTryRdLock(LosRwlock *rwlock) } SCHEDULER_LOCK(intSave); - ret = OsRwlockTryRdUnsafe(rwlock, 0); + ret = OsRwlockTryRdUnsafe(rwlock, 0);//所谓尝试就是没锁爷就返回,不等待,不纠结.当前任务也不会被挂起 SCHEDULER_UNLOCK(intSave); return ret; } - +/// 申请指定的写模式下的锁 UINT32 LOS_RwlockWrLock(LosRwlock *rwlock, UINT32 timeout) { UINT32 intSave; @@ -323,7 +336,7 @@ UINT32 LOS_RwlockWrLock(LosRwlock *rwlock, UINT32 timeout) SCHEDULER_UNLOCK(intSave); return ret; } - +/// 尝试申请指定的写模式下的锁 UINT32 LOS_RwlockTryWrLock(LosRwlock *rwlock) { UINT32 intSave; @@ -334,32 +347,32 @@ UINT32 LOS_RwlockTryWrLock(LosRwlock *rwlock) } SCHEDULER_LOCK(intSave); - ret = OsRwlockTryWrUnsafe(rwlock, 0); + ret = OsRwlockTryWrUnsafe(rwlock, 0);//所谓尝试就是没锁爷就返回,不等待,不纠结.当前任务也不会被挂起 SCHEDULER_UNLOCK(intSave); return ret; } - +/// 获取读写锁模式 STATIC UINT32 OsRwlockGetMode(LOS_DL_LIST *readList, LOS_DL_LIST *writeList) { BOOL isReadEmpty = LOS_ListEmpty(readList); BOOL isWriteEmpty = LOS_ListEmpty(writeList); - if (isReadEmpty && isWriteEmpty) { - return RWLOCK_NONE_MODE; + if (isReadEmpty && isWriteEmpty) { //读写链表都没有内容 + return RWLOCK_NONE_MODE; //自由模式 } - if (!isReadEmpty && isWriteEmpty) { + if (!isReadEmpty && isWriteEmpty) { //读链表有数据,写链表没有数据 return RWLOCK_READ_MODE; } - if (isReadEmpty && !isWriteEmpty) { + if (isReadEmpty && !isWriteEmpty) { //写链表有数据,读链表没有数据 return RWLOCK_WRITE_MODE; } LosTaskCB *pendedReadTask = OS_TCB_FROM_PENDLIST(LOS_DL_LIST_FIRST(readList)); LosTaskCB *pendedWriteTask = OS_TCB_FROM_PENDLIST(LOS_DL_LIST_FIRST(writeList)); if (OsSchedParamCompare(pendedWriteTask, pendedReadTask) <= 0) { - return RWLOCK_WRITEFIRST_MODE; + return RWLOCK_WRITEFIRST_MODE; //写的优先级高时,为写优先模式 } - return RWLOCK_READFIRST_MODE; + return RWLOCK_READFIRST_MODE; //读的优先级高时,为读优先模式 } - +/// 释放锁 STATIC UINT32 OsRwlockPostOp(LosRwlock *rwlock, BOOL *needSched) { UINT32 rwlockMode; @@ -367,15 +380,15 @@ STATIC UINT32 OsRwlockPostOp(LosRwlock *rwlock, BOOL *needSched) rwlock->rwCount = 0; rwlock->writeOwner = NULL; - rwlockMode = OsRwlockGetMode(&(rwlock->readList), &(rwlock->writeList)); - if (rwlockMode == RWLOCK_NONE_MODE) { + rwlockMode = OsRwlockGetMode(&(rwlock->readList), &(rwlock->writeList));//先获取模式 + if (rwlockMode == RWLOCK_NONE_MODE) {//自由模式则正常返回 return LOS_OK; } - /* In this case, rwlock will wake the first pended write task. */ - if ((rwlockMode == RWLOCK_WRITE_MODE) || (rwlockMode == RWLOCK_WRITEFIRST_MODE)) { - resumedTask = OS_TCB_FROM_PENDLIST(LOS_DL_LIST_FIRST(&(rwlock->writeList))); - rwlock->rwCount = -1; - rwlock->writeOwner = (VOID *)resumedTask; + /* In this case, rwlock will wake the first pended write task. | 在这种情况下，rwlock 将唤醒第一个挂起的写任务。 */ + if ((rwlockMode == RWLOCK_WRITE_MODE) || (rwlockMode == RWLOCK_WRITEFIRST_MODE)) {//如果当前是写模式 (有任务在等写锁涅) + resumedTask = OS_TCB_FROM_PENDLIST(LOS_DL_LIST_FIRST(&(rwlock->writeList)));//获取任务实体 + rwlock->rwCount = -1;//直接干成-1,注意这里并不是 -- + rwlock->writeOwner = (VOID *)resumedTask;//有锁了则唤醒等锁的任务(写模式) resumedTask->ops->wake(resumedTask); if (needSched != NULL) { *needSched = TRUE; @@ -383,29 +396,30 @@ STATIC UINT32 OsRwlockPostOp(LosRwlock *rwlock, BOOL *needSched) return LOS_OK; } - rwlock->rwCount = 1; + rwlock->rwCount = 1; //直接干成1,因为是释放操作 resumedTask = OS_TCB_FROM_PENDLIST(LOS_DL_LIST_FIRST(&(rwlock->readList))); resumedTask->ops->wake(resumedTask); - while (!LOS_ListEmpty(&(rwlock->readList))) { + while (!LOS_ListEmpty(&(rwlock->readList))) {//遍历读链表,目的是要唤醒其他读模式的任务(优先级得要高于pendedWriteTaskPri才行) resumedTask = OS_TCB_FROM_PENDLIST(LOS_DL_LIST_FIRST(&(rwlock->readList))); if (rwlockMode == RWLOCK_READFIRST_MODE) { LosTaskCB *pendedWriteTask = OS_TCB_FROM_PENDLIST(LOS_DL_LIST_FIRST(&(rwlock->writeList))); if (OsSchedParamCompare(resumedTask, pendedWriteTask) >= 0) { - break; - } + break;//跳出循环 + } } if (rwlock->rwCount == INT8_MAX) { return EINVAL; } - rwlock->rwCount++; - resumedTask->ops->wake(resumedTask); + rwlock->rwCount++;//读锁任务数量增加 + resumedTask->ops->wake(resumedTask);//不断唤醒读锁任务,由此实现了允许多个读操作并发,因为在多核情况下resumedTask很大可能 + //与当前任务并不在同一个核上运行, 此处非常有意思,点赞! @note_good } if (needSched != NULL) { *needSched = TRUE; } return LOS_OK; } - +/// 释放锁,唤醒任务 UINT32 OsRwlockUnlockUnsafe(LosRwlock *rwlock, BOOL *needSched) { if ((rwlock->magic & RWLOCK_COUNT_MASK) != OS_RWLOCK_MAGIC) { @@ -417,27 +431,28 @@ UINT32 OsRwlockUnlockUnsafe(LosRwlock *rwlock, BOOL *needSched) } LosTaskCB *runTask = OsCurrTaskGet(); - if ((rwlock->rwCount < 0) && ((LosTaskCB *)(rwlock->writeOwner) != runTask)) { + if ((rwlock->rwCount < 0) && ((LosTaskCB *)(rwlock->writeOwner) != runTask)) {//写模式时,当前任务未持有锁 return LOS_EPERM; } /* * When the rwCount of the rwlock more than 1 or less than -1, the rwlock mode will * not changed after current unlock operation, so pended tasks can not be waken. + | 当 rwlock 的 rwCount 大于 1 或小于 -1 时，当前解锁操作后 rwlock 模式不会改变，因此挂起的任务不能被唤醒。 */ - if (rwlock->rwCount > 1) { + if (rwlock->rwCount > 1) {//读模式 rwlock->rwCount--; return LOS_OK; } - if (rwlock->rwCount < -1) { + if (rwlock->rwCount < -1) {//写模式 rwlock->rwCount++; return LOS_OK; } return OsRwlockPostOp(rwlock, needSched); } - +/// 释放指定读写锁 UINT32 LOS_RwlockUnLock(LosRwlock *rwlock) { UINT32 intSave; @@ -451,9 +466,9 @@ UINT32 LOS_RwlockUnLock(LosRwlock *rwlock) SCHEDULER_LOCK(intSave); ret = OsRwlockUnlockUnsafe(rwlock, &needSched); SCHEDULER_UNLOCK(intSave); - LOS_MpSchedule(OS_MP_CPU_ALL); - if (needSched == TRUE) { - LOS_Schedule(); + LOS_MpSchedule(OS_MP_CPU_ALL);//设置调度CPU的方式,所有CPU参与调度 + if (needSched == TRUE) {//是否需要调度 + LOS_Schedule();//产生调度,切换任务执行 } return ret; } diff --git a/src/kernel_liteos_a/kernel/base/ipc/los_sem.c b/src/kernel_liteos_a/kernel/base/ipc/los_sem.c index 31d484a1..a161a85c 100644 --- a/src/kernel_liteos_a/kernel/base/ipc/los_sem.c +++ b/src/kernel_liteos_a/kernel/base/ipc/los_sem.c @@ -1,6 +1,6 @@ /* * Copyright (c) 2013-2019 Huawei Technologies Co., Ltd. All rights reserved. - * Copyright (c) 2020-2022 Huawei Device Co., Ltd. All rights reserved. + * Copyright (c) 2020-2021 Huawei Device Co., Ltd. All rights reserved. * * Redistribution and use in source and binary forms, with or without modification, * are permitted provided that the following conditions are met: @@ -40,17 +40,18 @@ #include "los_percpu_pri.h" #include "los_hook.h" + #ifdef LOSCFG_BASE_IPC_SEM #if (LOSCFG_BASE_IPC_SEM_LIMIT <= 0) #error "sem maxnum cannot be zero" #endif /* LOSCFG_BASE_IPC_SEM_LIMIT <= 0 */ -LITE_OS_SEC_DATA_INIT STATIC LOS_DL_LIST g_unusedSemList; -LITE_OS_SEC_BSS LosSemCB *g_allSem = NULL; +LITE_OS_SEC_DATA_INIT STATIC LOS_DL_LIST g_unusedSemList; ///< 可用的信号量列表,干嘛不用freeList? 可以看出这里是另一个人写的代码 +LITE_OS_SEC_BSS LosSemCB *g_allSem = NULL; ///< 信号池,一次分配 LOSCFG_BASE_IPC_SEM_LIMIT 个信号量 /* - * Description : Initialize the semaphore doubly linked list + * Description : Initialize the semaphore doubly linked list | 信号量初始化 * Return : LOS_OK on success, or error code on failure */ LITE_OS_SEC_TEXT_INIT UINT32 OsSemInit(VOID) @@ -58,18 +59,18 @@ LITE_OS_SEC_TEXT_INIT UINT32 OsSemInit(VOID) LosSemCB *semNode = NULL; UINT32 index; - LOS_ListInit(&g_unusedSemList); + LOS_ListInit(&g_unusedSemList);//初始化链表,链表上挂未使用的信号量,用于分配信号量,鸿蒙信号量的个数是有限的,默认1024个 /* system resident memory, don't free */ - g_allSem = (LosSemCB *)LOS_MemAlloc(m_aucSysMem0, (LOSCFG_BASE_IPC_SEM_LIMIT * sizeof(LosSemCB))); + g_allSem = (LosSemCB *)LOS_MemAlloc(m_aucSysMem0, (LOSCFG_BASE_IPC_SEM_LIMIT * sizeof(LosSemCB)));//分配信号池 if (g_allSem == NULL) { return LOS_ERRNO_SEM_NO_MEMORY; } for (index = 0; index < LOSCFG_BASE_IPC_SEM_LIMIT; index++) { - semNode = ((LosSemCB *)g_allSem) + index; - semNode->semID = SET_SEM_ID(0, index); - semNode->semStat = OS_SEM_UNUSED; - LOS_ListTailInsert(&g_unusedSemList, &semNode->semList); + semNode = ((LosSemCB *)g_allSem) + index;//拿信号控制块, 可以直接g_allSem[index]来嘛 + semNode->semID = SET_SEM_ID(0, index);//保存ID + semNode->semStat = OS_SEM_UNUSED;//标记未使用 + LOS_ListTailInsert(&g_unusedSemList, &semNode->semList);//通过semList把 信号块挂到空闲链表上 } if (OsSemDbgInitHook() != LOS_OK) { @@ -78,13 +79,7 @@ LITE_OS_SEC_TEXT_INIT UINT32 OsSemInit(VOID) return LOS_OK; } -/* - * Description : Create a semaphore, - * Input : count --- semaphore count, - * maxCount --- Max number of available semaphores, - * semHandle --- Index of semaphore, - * Return : LOS_OK on success ,or error code on failure - */ + LITE_OS_SEC_TEXT_INIT UINT32 OsSemCreate(UINT16 count, UINT16 maxCount, UINT32 *semHandle) { UINT32 intSave; @@ -97,45 +92,46 @@ LITE_OS_SEC_TEXT_INIT UINT32 OsSemCreate(UINT16 count, UINT16 maxCount, UINT32 * return LOS_ERRNO_SEM_PTR_NULL; } - if (count > maxCount) { + if (count > maxCount) {//信号量不能大于最大值,两参数都是外面给的 OS_GOTO_ERR_HANDLER(LOS_ERRNO_SEM_OVERFLOW); } - SCHEDULER_LOCK(intSave); + SCHEDULER_LOCK(intSave);//进入临界区,拿自旋锁 - if (LOS_ListEmpty(&g_unusedSemList)) { + if (LOS_ListEmpty(&g_unusedSemList)) {//没有可分配的空闲信号提供 SCHEDULER_UNLOCK(intSave); OsSemInfoGetFullDataHook(); OS_GOTO_ERR_HANDLER(LOS_ERRNO_SEM_ALL_BUSY); } - unusedSem = LOS_DL_LIST_FIRST(&g_unusedSemList); - LOS_ListDelete(unusedSem); + unusedSem = LOS_DL_LIST_FIRST(&g_unusedSemList);//从未使用信号量池中取首个 + LOS_ListDelete(unusedSem);//从空闲链表上摘除 SCHEDULER_UNLOCK(intSave); - semCreated = GET_SEM_LIST(unusedSem); - semCreated->semCount = count; - semCreated->semStat = OS_SEM_USED; - semCreated->maxSemCount = maxCount; - LOS_ListInit(&semCreated->semList); - *semHandle = semCreated->semID; + semCreated = GET_SEM_LIST(unusedSem);//通过semList挂到链表上的,这里也要通过它把LosSemCB头查到. 进程,线程等结构体也都是这么干的. + semCreated->semCount = count;//设置数量 + semCreated->semStat = OS_SEM_USED;//设置可用状态 + semCreated->maxSemCount = maxCount;//设置最大信号数量 + LOS_ListInit(&semCreated->semList);//初始化链表,后续阻塞任务通过task->pendList挂到semList链表上,就知道哪些任务在等它了. + *semHandle = semCreated->semID;//参数带走 semID OsHookCall(LOS_HOOK_TYPE_SEM_CREATE, semCreated); OsSemDbgUpdateHook(semCreated->semID, OsCurrTaskGet()->taskEntry, count); + return LOS_OK; ERR_HANDLER: OS_RETURN_ERROR_P2(errLine, errNo); } - +///对外接口 创建信号量 LITE_OS_SEC_TEXT_INIT UINT32 LOS_SemCreate(UINT16 count, UINT32 *semHandle) { return OsSemCreate(count, OS_SEM_COUNT_MAX, semHandle); } - +///对外接口 创建二值信号量，其计数值最大为1，可以当互斥锁用 LITE_OS_SEC_TEXT_INIT UINT32 LOS_BinarySemCreate(UINT16 count, UINT32 *semHandle) { return OsSemCreate(count, OS_SEM_BINARY_COUNT_MAX, semHandle); } - +///对外接口 删除指定的信号量,参数就是 semID LITE_OS_SEC_TEXT_INIT UINT32 LOS_SemDelete(UINT32 semHandle) { UINT32 intSave; @@ -147,23 +143,23 @@ LITE_OS_SEC_TEXT_INIT UINT32 LOS_SemDelete(UINT32 semHandle) OS_GOTO_ERR_HANDLER(LOS_ERRNO_SEM_INVALID); } - semDeleted = GET_SEM(semHandle); + semDeleted = GET_SEM(semHandle);//通过ID拿到信号量实体 SCHEDULER_LOCK(intSave); - if ((semDeleted->semStat == OS_SEM_UNUSED) || (semDeleted->semID != semHandle)) { + if ((semDeleted->semStat == OS_SEM_UNUSED) || (semDeleted->semID != semHandle)) {//参数判断 SCHEDULER_UNLOCK(intSave); OS_GOTO_ERR_HANDLER(LOS_ERRNO_SEM_INVALID); } - if (!LOS_ListEmpty(&semDeleted->semList)) { + if (!LOS_ListEmpty(&semDeleted->semList)) {//当前还有任务挂在这个信号上面,当然不能删除 SCHEDULER_UNLOCK(intSave); - OS_GOTO_ERR_HANDLER(LOS_ERRNO_SEM_PENDED); + OS_GOTO_ERR_HANDLER(LOS_ERRNO_SEM_PENDED);//这个宏很有意思,里面goto到ERR_HANDLER } - LOS_ListTailInsert(&g_unusedSemList, &semDeleted->semList); - semDeleted->semStat = OS_SEM_UNUSED; - semDeleted->semID = SET_SEM_ID(GET_SEM_COUNT(semDeleted->semID) + 1, GET_SEM_INDEX(semDeleted->semID)); + LOS_ListTailInsert(&g_unusedSemList, &semDeleted->semList);//通过semList从尾部插入空闲链表 + semDeleted->semStat = OS_SEM_UNUSED;//状态变成了未使用 + semDeleted->semID = SET_SEM_ID(GET_SEM_COUNT(semDeleted->semID) + 1, GET_SEM_INDEX(semDeleted->semID));//设置ID OsHookCall(LOS_HOOK_TYPE_SEM_DELETE, semDeleted); OsSemDbgUpdateHook(semDeleted->semID, NULL, 0); @@ -174,11 +170,11 @@ LITE_OS_SEC_TEXT_INIT UINT32 LOS_SemDelete(UINT32 semHandle) ERR_HANDLER: OS_RETURN_ERROR_P2(errLine, errNo); } - +///对外接口 申请指定的信号量，并设置超时时间 LITE_OS_SEC_TEXT UINT32 LOS_SemPend(UINT32 semHandle, UINT32 timeout) { UINT32 intSave; - LosSemCB *semPended = GET_SEM(semHandle); + LosSemCB *semPended = GET_SEM(semHandle);//通过ID拿到信号体 UINT32 retErr = LOS_OK; LosTaskCB *runTask = NULL; @@ -192,7 +188,7 @@ LITE_OS_SEC_TEXT UINT32 LOS_SemPend(UINT32 semHandle, UINT32 timeout) return LOS_ERRNO_SEM_PEND_INTERR; } - runTask = OsCurrTaskGet(); + runTask = OsCurrTaskGet();//获取当前任务 if (runTask->taskStatus & OS_TASK_FLAG_SYSTEM_TASK) { OsBackTrace(); return LOS_ERRNO_SEM_PEND_IN_SYSTEM_TASK; @@ -204,19 +200,20 @@ LITE_OS_SEC_TEXT UINT32 LOS_SemPend(UINT32 semHandle, UINT32 timeout) retErr = LOS_ERRNO_SEM_INVALID; goto OUT; } + /* Update the operate time, no matter the actual Pend success or not */ OsSemDbgTimeUpdateHook(semHandle); - if (semPended->semCount > 0) { - semPended->semCount--; + if (semPended->semCount > 0) {//还有资源可用,返回肯定得成功,semCount=0时代表没资源了,task会必须去睡眠了 + semPended->semCount--;//资源少了一个 OsHookCall(LOS_HOOK_TYPE_SEM_PEND, semPended, runTask, timeout); - goto OUT; + goto OUT;//注意这里 retErr = LOS_OK ,所以返回是OK的 } else if (!timeout) { retErr = LOS_ERRNO_SEM_UNAVAILABLE; goto OUT; } - if (!OsPreemptableInSched()) { + if (!OsPreemptableInSched()) {//不能申请调度 (不能调度的原因是因为没有持有调度任务自旋锁) PRINT_ERR("!!!LOS_ERRNO_SEM_PEND_IN_LOCK!!!\n"); OsBackTrace(); retErr = LOS_ERRNO_SEM_PEND_IN_LOCK; @@ -226,7 +223,7 @@ LITE_OS_SEC_TEXT UINT32 LOS_SemPend(UINT32 semHandle, UINT32 timeout) OsHookCall(LOS_HOOK_TYPE_SEM_PEND, semPended, runTask, timeout); OsTaskWaitSetPendMask(OS_TASK_WAIT_SEM, semPended->semID, timeout); retErr = runTask->ops->wait(runTask, &semPended->semList, timeout); - if (retErr == LOS_ERRNO_TSK_TIMEOUT) { + if (retErr == LOS_ERRNO_TSK_TIMEOUT) {//注意:这里是涉及到task切换的,把自己挂起,唤醒其他task retErr = LOS_ERRNO_SEM_TIMEOUT; } @@ -234,7 +231,7 @@ OUT: SCHEDULER_UNLOCK(intSave); return retErr; } - +///以不安全的方式释放指定的信号量,所谓不安全指的是不用自旋锁 LITE_OS_SEC_TEXT UINT32 OsSemPostUnsafe(UINT32 semHandle, BOOL *needSched) { LosTaskCB *resumedTask = NULL; @@ -246,23 +243,23 @@ LITE_OS_SEC_TEXT UINT32 OsSemPostUnsafe(UINT32 semHandle, BOOL *needSched) /* Update the operate time, no matter the actual Post success or not */ OsSemDbgTimeUpdateHook(semHandle); - if (semPosted->semCount == OS_SEM_COUNT_MAX) { + if (semPosted->semCount == OS_SEM_COUNT_MAX) {//当前信号资源不能大于最大资源量 return LOS_ERRNO_SEM_OVERFLOW; } - if (!LOS_ListEmpty(&semPosted->semList)) { - resumedTask = OS_TCB_FROM_PENDLIST(LOS_DL_LIST_FIRST(&(semPosted->semList))); + if (!LOS_ListEmpty(&semPosted->semList)) {//当前有任务挂在semList上,要去唤醒任务 + resumedTask = OS_TCB_FROM_PENDLIST(LOS_DL_LIST_FIRST(&(semPosted->semList)));//semList上面挂的都是task->pendlist节点,取第一个task下来唤醒 OsTaskWakeClearPendMask(resumedTask); resumedTask->ops->wake(resumedTask); - if (needSched != NULL) { - *needSched = TRUE; + if (needSched != NULL) {//参数不为空,就返回需要调度的标签 + *needSched = TRUE;//TRUE代表需要调度 } - } else { - semPosted->semCount++; + } else {//当前没有任务挂在semList上, + semPosted->semCount++;//信号资源多一个 } OsHookCall(LOS_HOOK_TYPE_SEM_POST, semPosted, resumedTask); return LOS_OK; } - +///对外接口 释放指定的信号量 LITE_OS_SEC_TEXT UINT32 LOS_SemPost(UINT32 semHandle) { UINT32 intSave; @@ -272,16 +269,15 @@ LITE_OS_SEC_TEXT UINT32 LOS_SemPost(UINT32 semHandle) if (GET_SEM_INDEX(semHandle) >= LOSCFG_BASE_IPC_SEM_LIMIT) { return LOS_ERRNO_SEM_INVALID; } - SCHEDULER_LOCK(intSave); ret = OsSemPostUnsafe(semHandle, &needSched); SCHEDULER_UNLOCK(intSave); - if (needSched) { - LOS_MpSchedule(OS_MP_CPU_ALL); - LOS_Schedule(); + if (needSched) {//需要调度的情况 + LOS_MpSchedule(OS_MP_CPU_ALL);//向所有CPU发送调度指令 + LOS_Schedule();////发起调度 } return ret; } -#endif /* LOSCFG_BASE_IPC_SEM */ +#endif /* (LOSCFG_BASE_IPC_SEM == YES) */ diff --git a/src/kernel_liteos_a/kernel/base/ipc/los_sem_debug.c b/src/kernel_liteos_a/kernel/base/ipc/los_sem_debug.c index 1ed42515..284a800d 100644 --- a/src/kernel_liteos_a/kernel/base/ipc/los_sem_debug.c +++ b/src/kernel_liteos_a/kernel/base/ipc/los_sem_debug.c @@ -78,11 +78,11 @@ STATIC VOID OsSemPendedTaskNamePrint(LosSemCB *semNode) #ifdef LOSCFG_DEBUG_SEMAPHORE typedef struct { - UINT16 origSemCount; /* Number of original available semaphores */ - UINT64 lastAccessTime; /* The last operation time */ - TSK_ENTRY_FUNC creator; /* The task entry who created this sem */ + UINT16 origSemCount; /* Number of orignal available semaphores *///原始可用信号量数 + UINT64 lastAccessTime; /* The last operation time */ //最后操作时间 + TSK_ENTRY_FUNC creator; /* The task entry who created this sem */ //由哪个task的入口函数创建了这个任务 } SemDebugCB; -STATIC SemDebugCB *g_semDebugArray = NULL; +STATIC SemDebugCB *g_semDebugArray = NULL;//默认1024个SemDebugCB debug信号量池 STATIC BOOL SemCompareValue(const IpcSortParam *sortParam, UINT32 left, UINT32 right) { @@ -102,23 +102,23 @@ UINT32 OsSemDbgInit(VOID) (VOID)memset_s(g_semDebugArray, size, 0, size); return LOS_OK; } - +///更新最后访问时间 VOID OsSemDbgTimeUpdate(UINT32 semID) { SemDebugCB *semDebug = &g_semDebugArray[GET_SEM_INDEX(semID)]; - semDebug->lastAccessTime = LOS_TickCountGet(); + semDebug->lastAccessTime = LOS_TickCountGet();//获取tick总数 return; } - +///更新信号量 VOID OsSemDbgUpdate(UINT32 semID, TSK_ENTRY_FUNC creator, UINT16 count) { SemDebugCB *semDebug = &g_semDebugArray[GET_SEM_INDEX(semID)]; - semDebug->creator = creator; - semDebug->lastAccessTime = LOS_TickCountGet(); - semDebug->origSemCount = count; + semDebug->creator = creator; //改为由参数入口函数创建了这个任务 + semDebug->lastAccessTime = LOS_TickCountGet();//获取tick总数 + semDebug->origSemCount = count;//原始信号量改变 return; } - +///按信号量访问时间排序 STATIC VOID OsSemSort(UINT32 *semIndexArray, UINT32 usedCount) { UINT32 i, intSave; @@ -296,6 +296,6 @@ LITE_OS_SEC_TEXT_MINOR UINT32 OsShellCmdSemInfoGet(UINT32 argc, const CHAR **arg return ret; } -SHELLCMD_ENTRY(sem_shellcmd, CMD_TYPE_EX, "sem", 1, (CmdCallBackFunc)OsShellCmdSemInfoGet); +SHELLCMD_ENTRY(sem_shellcmd, CMD_TYPE_EX, "sem", 1, (CmdCallBackFunc)OsShellCmdSemInfoGet);//采用shell命令静态注册方式 #endif diff --git a/src/kernel_liteos_a/kernel/base/ipc/los_signal.c b/src/kernel_liteos_a/kernel/base/ipc/los_signal.c index bb7bd2f7..55e34cd9 100644 --- a/src/kernel_liteos_a/kernel/base/ipc/los_signal.c +++ b/src/kernel_liteos_a/kernel/base/ipc/los_signal.c @@ -1,6 +1,6 @@ /* * Copyright (c) 2013-2019 Huawei Technologies Co., Ltd. All rights reserved. - * Copyright (c) 2020-2023 Huawei Device Co., Ltd. All rights reserved. + * Copyright (c) 2020-2021 Huawei Device Co., Ltd. All rights reserved. * * Redistribution and use in source and binary forms, with or without modification, * are permitted provided that the following conditions are met: @@ -53,15 +53,17 @@ int raise(int sig) #define GETUNMASKSET(procmask, pendFlag) ((~(procmask)) & (sigset_t)(pendFlag)) #define UINT64_BIT_SIZE 64 + int OsSigIsMember(const sigset_t *set, int signo) { int ret = LOS_NOK; - /* In musl, sig No bits 00000100 present sig No 3, but 1<< 3 = 00001000, so signo needs minus 1 */ + /* In musl, sig No bits 00000100 present sig No 3, but 1<< 3 = 00001000, so signo needs minus 1 */ + //在musl中，sig No bits 00000100表示sig No 3，但是在SIGNO2SET中 1<<3 = 00001000,因此signo需要减1 signo -= 1; /* Verify the signal */ - if (GOOD_SIGNO(signo)) { + if (GOOD_SIGNO(signo)) {//有效信号判断 /* Check if the signal is in the set */ - ret = ((*set & SIGNO2SET((unsigned int)signo)) != 0); + ret = ((*set & SIGNO2SET((unsigned int)signo)) != 0);//检查信号是否还在集合中 } return ret; @@ -120,7 +122,6 @@ VOID OsClearSigInfoTmpList(sig_cb *sigcb) (VOID)LOS_MemFree(m_aucSysMem0, tmpInfoNode); } } - STATIC INLINE VOID OsSigWaitTaskWake(LosTaskCB *taskCB, INT32 signo) { sig_cb *sigcb = &taskCB->sig; @@ -132,14 +133,14 @@ STATIC INLINE VOID OsSigWaitTaskWake(LosTaskCB *taskCB, INT32 signo) OsSigEmptySet(&sigcb->sigwaitmask); } } - +///< 唤醒被挂起的处于等待指定信号的任务 STATIC UINT32 OsPendingTaskWake(LosTaskCB *taskCB, INT32 signo) { if (!OsTaskIsPending(taskCB) || !OsProcessIsUserMode(OS_PCB_FROM_TCB(taskCB))) { return 0; } - if ((signo != SIGKILL) && (taskCB->waitFlag != OS_TASK_WAIT_SIGNAL)) { + if ((signo != SIGKILL) && (taskCB->waitFlag != OS_TASK_WAIT_SIGNAL)) { // @note_thinking 这个判断会不会有问题 ? return 0; } @@ -153,16 +154,16 @@ STATIC UINT32 OsPendingTaskWake(LosTaskCB *taskCB, INT32 signo) OsTaskWakeClearPendMask(taskCB); taskCB->ops->wake(taskCB); break; - case OS_TASK_WAIT_SIGNAL: + case OS_TASK_WAIT_SIGNAL://等待普通信号 OsSigWaitTaskWake(taskCB, signo); break; - case OS_TASK_WAIT_LITEIPC: - OsTaskWakeClearPendMask(taskCB); + case OS_TASK_WAIT_LITEIPC://等待liteipc信号 + OsTaskWakeClearPendMask(taskCB);//重置任务的等待信息 taskCB->ops->wake(taskCB); break; - case OS_TASK_WAIT_FUTEX: - OsFutexNodeDeleteFromFutexHash(&taskCB->futex, TRUE, NULL, NULL); - OsTaskWakeClearPendMask(taskCB); + case OS_TASK_WAIT_FUTEX://等待快锁信号 + OsFutexNodeDeleteFromFutexHash(&taskCB->futex, TRUE, NULL, NULL);//从哈希桶中删除快锁 + OsTaskWakeClearPendMask(taskCB);//重置任务的等待信息 taskCB->ops->wake(taskCB); break; default: @@ -171,7 +172,7 @@ STATIC UINT32 OsPendingTaskWake(LosTaskCB *taskCB, INT32 signo) return 0; } - +///给任务(线程)发送一个信号 int OsTcbDispatch(LosTaskCB *stcb, siginfo_t *info) { bool masked = FALSE; @@ -179,19 +180,19 @@ int OsTcbDispatch(LosTaskCB *stcb, siginfo_t *info) OS_RETURN_IF_NULL(sigcb); /* If signo is 0, not send signal, just check process or pthread exist */ - if (info->si_signo == 0) { + if (info->si_signo == 0) {//如果信号为0,则不发送信号,只是作为检查进程和线程是否还存在. return 0; } - masked = (bool)OsSigIsMember(&sigcb->sigprocmask, info->si_signo); - if (masked) { - /* If signal is in wait list and mask list, need unblock it */ + masked = (bool)OsSigIsMember(&sigcb->sigprocmask, info->si_signo);//@note_thinking 这里还有 masked= -1的情况要处理!!! + if (masked) {//如果信号被屏蔽了,要看等待信号集,sigwaitmask + /* If signal is in wait list and mask list, need unblock it */ //如果信号在等待列表和掩码列表中，需要解除阻止 if (LOS_ListEmpty(&sigcb->waitList) || - (!LOS_ListEmpty(&sigcb->waitList) && !OsSigIsMember(&sigcb->sigwaitmask, info->si_signo))) { - OsSigAddSet(&sigcb->sigPendFlag, info->si_signo); + (!LOS_ListEmpty(&sigcb->waitList) && !OsSigIsMember(&sigcb->sigwaitmask, info->si_signo))) { + OsSigAddSet(&sigcb->sigPendFlag, info->si_signo);//将信号加入挂起/待办集 } - } else { + } else {//信号没有被屏蔽的处理 /* unmasked signal actions */ - OsSigAddSet(&sigcb->sigFlag, info->si_signo); + OsSigAddSet(&sigcb->sigFlag, info->si_signo);//不屏蔽的信号集 } if (OsAddSigInfoToTmpList(sigcb, info) == LOS_NOK) { @@ -206,14 +207,15 @@ void OsSigMaskSwitch(LosTaskCB * const rtcb, sigset_t set) sigset_t unmaskset; rtcb->sig.sigprocmask = set; - unmaskset = GETUNMASKSET(rtcb->sig.sigprocmask, rtcb->sig.sigPendFlag); + unmaskset = GETUNMASKSET(rtcb->sig.sigprocmask, rtcb->sig.sigPendFlag);//过滤出没有被屏蔽的信号集 if (unmaskset != NULL_SIGNAL_SET) { /* pendlist do */ - rtcb->sig.sigFlag |= unmaskset; - rtcb->sig.sigPendFlag ^= unmaskset; + rtcb->sig.sigFlag |= unmaskset; //加入不屏蔽信号集 + rtcb->sig.sigPendFlag ^= unmaskset;//从挂起/待办集中去掉unmaskset } } + int OsSigprocMask(int how, const sigset_t_l *setl, sigset_t_l *oldsetl) { LosTaskCB *spcb = NULL; @@ -223,11 +225,11 @@ int OsSigprocMask(int how, const sigset_t_l *setl, sigset_t_l *oldsetl) SCHEDULER_LOCK(intSave); spcb = OsCurrTaskGet(); - /* If requested, copy the old mask to user. */ + /* If requested, copy the old mask to user. | 如果需要，请将旧掩码复制给用户*/ if (oldsetl != NULL) { *(sigset_t *)oldsetl = spcb->sig.sigprocmask; } - /* If requested, modify the current signal mask. */ + /* If requested, modify the current signal mask. | 如有要求，修改当前信号屏蔽*/ if (setl != NULL) { set = *(sigset_t *)setl; /* Okay, determine what we are supposed to do */ @@ -236,46 +238,46 @@ int OsSigprocMask(int how, const sigset_t_l *setl, sigset_t_l *oldsetl) * set pointed to by set as the new sigprocmask. */ case SIG_BLOCK: - spcb->sig.sigprocmask |= set; + spcb->sig.sigprocmask |= set;//增加信号屏蔽位 break; /* Set the intersection of the current set and the * signal set pointed to by set as the new sigprocmask. */ case SIG_UNBLOCK: - spcb->sig.sigprocmask &= ~(set); + spcb->sig.sigprocmask &= ~(set);//解除信号屏蔽位 break; /* Set the signal set pointed to by set as the new sigprocmask. */ case SIG_SETMASK: - spcb->sig.sigprocmask = set; + spcb->sig.sigprocmask = set;//设置一个新的屏蔽掩码 break; default: ret = -EINVAL; break; } /* If pending mask not in sigmask, need set sigflag. */ - OsSigMaskSwitch(spcb, spcb->sig.sigprocmask); + OsSigMaskSwitch(spcb, spcb->sig.sigprocmask);//更新与屏蔽信号相关的变量 } SCHEDULER_UNLOCK(intSave); return ret; } - +///让进程的每一个task执行参数函数 int OsSigProcessForeachChild(LosProcessCB *spcb, ForEachTaskCB handler, void *arg) { int ret; /* Visit the main thread last (if present) */ - LosTaskCB *taskCB = NULL; - LOS_DL_LIST_FOR_EACH_ENTRY(taskCB, &(spcb->threadSiblingList), LosTaskCB, threadList) { - ret = handler(taskCB, arg); - OS_RETURN_IF(ret != 0, ret); + LosTaskCB *taskCB = NULL;//遍历进程的 threadList 链表,里面存放的都是task节点 + LOS_DL_LIST_FOR_EACH_ENTRY(taskCB, &(spcb->threadSiblingList), LosTaskCB, threadList) {//遍历进程的任务列表 + ret = handler(taskCB, arg);//回调参数函数 + OS_RETURN_IF(ret != 0, ret);//这个宏的意思就是只有ret = 0时,啥也不处理.其余就返回 ret } return LOS_OK; } - +///信号处理函数,这里就是上面的 handler = SigProcessSignalHandler,见于 OsSigProcessSend static int SigProcessSignalHandler(LosTaskCB *tcb, void *arg) { - struct ProcessSignalInfo *info = (struct ProcessSignalInfo *)arg; + struct ProcessSignalInfo *info = (struct ProcessSignalInfo *)arg;//先把参数解出来 int ret; int isMember; @@ -283,128 +285,130 @@ static int SigProcessSignalHandler(LosTaskCB *tcb, void *arg) return 0; } - /* If the default tcb is not set, then set this one as default. */ - if (!info->defaultTcb) { + /* If the default tcb is not setted, then set this one as default. */ + if (!info->defaultTcb) {//如果没有默认发送方的任务,即默认参数任务. info->defaultTcb = tcb; } - isMember = OsSigIsMember(&tcb->sig.sigwaitmask, info->sigInfo->si_signo); - if (isMember && (!info->awakenedTcb)) { + isMember = OsSigIsMember(&tcb->sig.sigwaitmask, info->sigInfo->si_signo);//任务是否在等待这个信号 + if (isMember && (!info->awakenedTcb)) {//是在等待,并尚未向该任务时发送信号时 /* This means the task is waiting for this signal. Stop looking for it and use this tcb. * The requirement is: if more than one task in this task group is waiting for the signal, * then only one indeterminate task in the group will receive the signal. */ - ret = OsTcbDispatch(tcb, info->sigInfo); - OS_RETURN_IF(ret < 0, ret); + ret = OsTcbDispatch(tcb, info->sigInfo);//发送信号,注意这是给其他任务发送信号,tcb不是当前任务 + OS_RETURN_IF(ret < 0, ret);//这种写法很有意思 /* set this tcb as awakenedTcb */ info->awakenedTcb = tcb; OS_RETURN_IF(info->receivedTcb != NULL, SIG_STOP_VISIT); /* Stop search */ } /* Is this signal unblocked on this thread? */ - isMember = OsSigIsMember(&tcb->sig.sigprocmask, info->sigInfo->si_signo); - if ((!isMember) && (!info->receivedTcb) && (tcb != info->awakenedTcb)) { - /* if unblockedTcb of this signal is not set, then set it. */ + isMember = OsSigIsMember(&tcb->sig.sigprocmask, info->sigInfo->si_signo);//任务是否屏蔽了这个信号 + if ((!isMember) && (!info->receivedTcb) && (tcb != info->awakenedTcb)) {//没有屏蔽,有唤醒任务没有接收任务. + /* if unblockedTcb of this signal is not setted, then set it. */ if (!info->unblockedTcb) { info->unblockedTcb = tcb; } - ret = OsTcbDispatch(tcb, info->sigInfo); + ret = OsTcbDispatch(tcb, info->sigInfo);//向任务发送信号 OS_RETURN_IF(ret < 0, ret); /* set this tcb as receivedTcb */ - info->receivedTcb = tcb; + info->receivedTcb = tcb;//设置这个任务为接收任务 OS_RETURN_IF(info->awakenedTcb != NULL, SIG_STOP_VISIT); /* Stop search */ } return 0; /* Keep searching */ } - +///进程收到 SIGKILL 信号后,通知任务tcb处理. static int SigProcessKillSigHandler(LosTaskCB *tcb, void *arg) { - struct ProcessSignalInfo *info = (struct ProcessSignalInfo *)arg; + struct ProcessSignalInfo *info = (struct ProcessSignalInfo *)arg;//转参 return OsPendingTaskWake(tcb, info->sigInfo->si_signo); } +//处理信号发送 static void SigProcessLoadTcb(struct ProcessSignalInfo *info, siginfo_t *sigInfo) { LosTaskCB *tcb = NULL; - if (info->awakenedTcb == NULL && info->receivedTcb == NULL) { - if (info->unblockedTcb) { - tcb = info->unblockedTcb; - } else if (info->defaultTcb) { + if (info->awakenedTcb == NULL && info->receivedTcb == NULL) {//信号即没有指定接收task 也没有指定被唤醒task + if (info->unblockedTcb) {//如果进程信号信息体中有阻塞task + tcb = info->unblockedTcb;// + } else if (info->defaultTcb) {//如果有默认的发送方task tcb = info->defaultTcb; } else { return; } /* Deliver the signal to the selected task */ - (void)OsTcbDispatch(tcb, sigInfo); + (void)OsTcbDispatch(tcb, sigInfo);//向所选任务发送信号 } } - +///给参数进程发送参数信号 int OsSigProcessSend(LosProcessCB *spcb, siginfo_t *sigInfo) { int ret; struct ProcessSignalInfo info = { - .sigInfo = sigInfo, - .defaultTcb = NULL, + .sigInfo = sigInfo, //信号内容 + .defaultTcb = NULL, //以下四个值将在OsSigProcessForeachChild中根据条件完善 .unblockedTcb = NULL, .awakenedTcb = NULL, .receivedTcb = NULL }; - - if (info.sigInfo == NULL) { + //总之是要从进程中找个至少一个任务来接受这个信号,优先级 + //awakenedTcb > receivedTcb > unblockedTcb > defaultTcb + if (info.sigInfo == NULL){ return -EFAULT; } - - /* visit all taskcb and dispatch signal */ - if (info.sigInfo->si_signo == SIGKILL) { - OsSigAddSet(&spcb->sigShare, info.sigInfo->si_signo); + /* visit all taskcb and dispatch signal */ //访问所有任务和分发信号 + if (info.sigInfo->si_signo == SIGKILL) {//需要干掉进程时 SIGKILL = 9， #linux kill 9 14 + OsSigAddSet(&spcb->sigShare, info.sigInfo->si_signo);//信号集中增加信号 (void)OsSigProcessForeachChild(spcb, SigProcessKillSigHandler, &info); return 0; } else { - ret = OsSigProcessForeachChild(spcb, SigProcessSignalHandler, &info); + ret = OsSigProcessForeachChild(spcb, SigProcessSignalHandler, &info);//进程通知所有task处理信号 } if (ret < 0) { return ret; } - SigProcessLoadTcb(&info, sigInfo); + SigProcessLoadTcb(&info, sigInfo);//确保能给一个任务发送信号 return 0; } - +///信号集全部清0 int OsSigEmptySet(sigset_t *set) { *set = NULL_SIGNAL_SET; return 0; } -/* Privilege process can't send to kernel and privilege process */ +/* Privilege process can't send to kernel and privilege process */ //内核进程组和用户特权进程组无法发送 static int OsSignalPermissionToCheck(const LosProcessCB *spcb) { UINTPTR gid = (UINTPTR)OS_GET_PGROUP_LEADER(spcb->pgroup); - if (gid == OS_KERNEL_PROCESS_GROUP) { + + if (gid == OS_KERNEL_PROCESS_GROUP) {//内核进程组 return -EPERM; - } else if (gid == OS_USER_PRIVILEGE_PROCESS_GROUP) { + } else if (gid == OS_USER_PRIVILEGE_PROCESS_GROUP) {//用户特权进程组 return -EPERM; } return 0; } - +///信号分发,发送信号权限/进程组过滤. STATIC int SendSigPermissionCheck(LosProcessCB *spcb, int permission) { if (spcb == NULL) { return -ESRCH; } - if (OsProcessIsUnused(spcb)) { + if (OsProcessIsUnused(spcb)) {//进程是否还在使用,不一定是当前进程但必须是个有效进程 return -ESRCH; } -#ifdef LOSCFG_SECURITY_CAPABILITY - LosProcessCB *current = OsCurrProcessGet(); - /* Kernel process always has kill permission and user process should check permission */ - if (OsProcessIsUserMode(current) && !(current->processStatus & OS_PROCESS_FLAG_EXIT)) { +#ifdef LOSCFG_SECURITY_CAPABILITY //启用能力安全模式 + LosProcessCB *current = OsCurrProcessGet();//获取当前进程,检查当前进程是否有发送信号的权限. + /* Kernel process always has kill permission and user process should check permission *///内核进程总是有kill权限，用户进程需要检查权限 + if (OsProcessIsUserMode(current) && !(current->processStatus & OS_PROCESS_FLAG_EXIT)) {//用户进程检查能力范围 if ((current != spcb) && (!IsCapPermit(CAP_KILL)) && (current->user->userID != spcb->user->userID)) { return -EPERM; } @@ -437,7 +441,7 @@ int OsSendSigToProcess(LosProcessCB *spcb, int sig, int permission) info.si_code = SI_USER; info.si_value.sival_ptr = NULL; - return OsSigProcessSend(spcb, &info); + return OsSigProcessSend(spcb, &info);//给参数进程发送信号 } int OsDispatch(pid_t pid, siginfo_t *info, int permission) @@ -470,14 +474,14 @@ int OsKill(pid_t pid, int sig, int permission) return -EINVAL; } - /* Create the siginfo structure */ - info.si_signo = sig; - info.si_code = SI_USER; + /* Create the siginfo structure */ //创建信号结构体 + info.si_signo = sig; //信号编号 + info.si_code = SI_USER; //来自用户进程信号 info.si_value.sival_ptr = NULL; if (pid > 0) { /* Send the signal to the specify process */ - ret = OsDispatch(pid, &info, permission); + ret = OsDispatch(pid, &info, permission);//发送信号 } else if (pid == -1) { /* Send SIG to all processes */ ret = OsSendSignalToAllProcess(&info, permission); @@ -489,18 +493,17 @@ int OsKill(pid_t pid, int sig, int permission) } return ret; } - +///给发送信号过程加锁 int OsKillLock(pid_t pid, int sig) { int ret; unsigned int intSave; SCHEDULER_LOCK(intSave); - ret = OsKill(pid, sig, OS_USER_KILL_PERMISSION); + ret = OsKill(pid, sig, OS_USER_KILL_PERMISSION);//用户权限向进程发送信号 SCHEDULER_UNLOCK(intSave); return ret; } - INT32 OsTaskKillUnsafe(UINT32 taskID, INT32 signo) { siginfo_t info; @@ -519,7 +522,7 @@ INT32 OsTaskKillUnsafe(UINT32 taskID, INT32 signo) * dispatch rules. */ return OsTcbDispatch(taskCB, &info); } - +///发送信号 int OsPthreadKill(UINT32 tid, int signo) { int ret; @@ -537,7 +540,7 @@ int OsPthreadKill(UINT32 tid, int signo) SCHEDULER_UNLOCK(intSave); return ret; } - +///向信号集中加入signo信号 int OsSigAddSet(sigset_t *set, int signo) { /* Verify the signal */ @@ -545,13 +548,13 @@ int OsSigAddSet(sigset_t *set, int signo) return -EINVAL; } else { /* In musl, sig No bits 00000100 present sig No 3, but 1<< 3 = 00001000, so signo needs minus 1 */ - signo -= 1; + signo -= 1;// 信号范围是 [1 ~ 64 ],而保存变量位的范围是[0 ~ 63] /* Add the signal to the set */ - *set |= SIGNO2SET((unsigned int)signo); + *set |= SIGNO2SET((unsigned int)signo);//填充信号集 return LOS_OK; } } - +///获取阻塞当前任务的信号集 int OsSigPending(sigset_t *set) { LosTaskCB *tcb = NULL; @@ -563,7 +566,7 @@ int OsSigPending(sigset_t *set) SCHEDULER_LOCK(intSave); tcb = OsCurrTaskGet(); - *set = tcb->sig.sigPendFlag; + *set = tcb->sig.sigPendFlag;//被阻塞的信号集 SCHEDULER_UNLOCK(intSave); return LOS_OK; } @@ -578,7 +581,7 @@ STATIC int FindFirstSetedBit(UINT64 n) for (count = 0; (count < UINT64_BIT_SIZE) && (n ^ 1ULL); n >>= 1, count++) {} return (count < UINT64_BIT_SIZE) ? count : (-1); } - +///等待信号时间 int OsSigTimedWaitNoLock(sigset_t *set, siginfo_t *info, unsigned int timeout) { LosTaskCB *task = NULL; @@ -589,19 +592,19 @@ int OsSigTimedWaitNoLock(sigset_t *set, siginfo_t *info, unsigned int timeout) sigcb = &task->sig; if (sigcb->waitList.pstNext == NULL) { - LOS_ListInit(&sigcb->waitList); + LOS_ListInit(&sigcb->waitList);//初始化信号等待链表 } - /* If pendingflag & set > 0, should clear pending flag */ + /* If pendingflag & set > 0, shound clear pending flag */ sigset_t clear = sigcb->sigPendFlag & *set; if (clear) { sigcb->sigPendFlag ^= clear; ret = FindFirstSetedBit((UINT64)clear) + 1; OsMoveTmpInfoToUnbInfo(sigcb, ret); } else { - OsSigAddSet(set, SIGKILL); - OsSigAddSet(set, SIGSTOP); + OsSigAddSet(set, SIGKILL);//kill 9 14 必须要处理 + OsSigAddSet(set, SIGSTOP);//终止进程的信号也必须处理 - sigcb->sigwaitmask |= *set; + sigcb->sigwaitmask |= *set;//按位加到等待集上,也就是说sigwaitmask的信号来了都是要处理的. OsTaskWaitSetPendMask(OS_TASK_WAIT_SIGNAL, sigcb->sigwaitmask, timeout); ret = task->ops->wait(task, &sigcb->waitList, timeout); if (ret == LOS_ERRNO_TSK_TIMEOUT) { @@ -614,7 +617,7 @@ int OsSigTimedWaitNoLock(sigset_t *set, siginfo_t *info, unsigned int timeout) } return ret; } - +///让当前任务等待的信号 int OsSigTimedWait(sigset_t *set, siginfo_t *info, unsigned int timeout) { int ret; @@ -622,12 +625,12 @@ int OsSigTimedWait(sigset_t *set, siginfo_t *info, unsigned int timeout) SCHEDULER_LOCK(intSave); - ret = OsSigTimedWaitNoLock(set, info, timeout); + ret = OsSigTimedWaitNoLock(set, info, timeout);//以不加锁的方式等待 SCHEDULER_UNLOCK(intSave); return ret; } - +///通过信号挂起当前任务 int OsPause(void) { LosTaskCB *spcb = NULL; @@ -637,7 +640,7 @@ int OsPause(void) oldSigprocmask = spcb->sig.sigprocmask; return OsSigSuspend(&oldSigprocmask); } - +///用参数set代替进程的原有掩码，并暂停进程执行，直到收到信号再恢复原有掩码并继续执行进程。 int OsSigSuspend(const sigset_t *set) { unsigned int intSave; @@ -677,6 +680,7 @@ int OsSigSuspend(const sigset_t *set) return -EINTR; } + int OsSigAction(int sig, const sigaction_t *act, sigaction_t *oact) { UINTPTR addr; @@ -685,14 +689,17 @@ int OsSigAction(int sig, const sigaction_t *act, sigaction_t *oact) if (!GOOD_SIGNO(sig) || sig < 1 || act == NULL) { return -EINVAL; } - if (LOS_ArchCopyFromUser(&action, act, sizeof(sigaction_t)) != LOS_OK) { - return -EFAULT; - } - - if (sig == SIGSYS) { - addr = OsGetSigHandler(); - if (addr == 0) { - OsSetSigHandler((unsigned long)(UINTPTR)action.sa_handler); + //将数据从用户空间拷贝到内核空间 + if (LOS_ArchCopyFromUser(&action, act, sizeof(sigaction_t)) != LOS_OK) { + return -EFAULT; + } + + if (sig == SIGSYS) {//鸿蒙此处通过错误的系统调用 来安装信号处理函数,有点巧妙. + addr = OsGetSigHandler();//是否已存在信号处理函数 + if (addr == 0) {//进程没有设置信号处理函数时 + OsSetSigHandler((unsigned long)(UINTPTR)action.sa_handler);//设置进程信号处理函数 + //void (*sa_handler)(int); //信号处理函数——普通版 + //void (*sa_sigaction)(int, siginfo_t *, void *);//信号处理函数——高级版 return LOS_OK; } return -EINVAL; @@ -717,11 +724,11 @@ VOID OsSigIntUnlock(VOID) (VOID)LOS_AtomicSub((Atomic *)&sigcb->sigIntLock, 1); } + VOID *OsSaveSignalContext(VOID *sp, VOID *newSp) { UINTPTR sigHandler; UINT32 intSave; - LosTaskCB *task = OsCurrTaskGet(); LosProcessCB *process = OsCurrProcessGet(); sig_cb *sigcb = &task->sig; @@ -754,7 +761,7 @@ VOID *OsSaveSignalContext(VOID *sp, VOID *newSp) OsProcessExitCodeSignalSet(process, signo); sigcb->sigContext = sp; - OsInitSignalContext(sp, newSp, sigHandler, signo, sigVal); + OsInitSignalContext(sp, newSp, sigHandler, signo, sigVal);//初始化信号上下文 /* sig No bits 00000100 present sig No 3, but 1<< 3 = 00001000, so signo needs minus 1 */ sigcb->sigFlag ^= 1ULL << (signo - 1); @@ -767,6 +774,7 @@ VOID *OsSaveSignalContext(VOID *sp, VOID *newSp) return sp; } + VOID *OsRestorSignalContext(VOID *sp) { UINT32 intSave; @@ -785,8 +793,8 @@ VOID *OsRestorSignalContext(VOID *sp) VOID *saveContext = sigcb->sigContext; sigcb->sigContext = NULL; sigcb->count--; - process->sigShare = 0; - OsProcessExitCodeSignalClear(process); + process->sigShare = 0; //回到用户态,信号共享清0 + OsProcessExitCodeSignalClear(process);//清空进程退出码 SCHEDULER_UNLOCK(intSave); return saveContext; }