pthread: remove enter_critical_section in pthread_mutex

reason: We would like to replace the critical section with a small lock. Signed-off-by: hujun5 <[email protected]>
apache · Jan 12, 2025 · 5f4a15b · 5f4a15b
1 parent 19bca74
commit 5f4a15b
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Showing 9 changed files with 73 additions and 96 deletions.
diff --git a/include/nuttx/sched.h b/include/nuttx/sched.h
@@ -48,6 +48,7 @@
 #include <nuttx/net/net.h>
 #include <nuttx/mm/map.h>
 #include <nuttx/tls.h>
+#include <nuttx/spinlock_type.h>
 
 #include <arch/arch.h>
 
@@ -737,6 +738,10 @@ struct tcb_s
   size_t level_deepest;
   size_t level;
 #endif
+
+#ifndef CONFIG_PTHREAD_MUTEX_UNSAFE
+  spinlock_t mutex_lock;
+#endif
 };
 
 /* struct task_tcb_s ********************************************************/

diff --git a/sched/init/nx_start.c b/sched/init/nx_start.c
@@ -469,6 +469,10 @@ static void idle_group_initialize(void)
 
       nxtask_joininit(tcb);
 
+#ifndef CONFIG_PTHREAD_MUTEX_UNSAFE
+      spin_lock_init(&tcb->mutex_lock);
+#endif
+
 #ifdef CONFIG_SMP
       /* Create a stack for all CPU IDLE threads (except CPU0 which already
        * has a stack).

diff --git a/sched/pthread/CMakeLists.txt b/sched/pthread/CMakeLists.txt
@@ -46,8 +46,7 @@ if(NOT CONFIG_DISABLE_PTHREAD)
       pthread_setschedprio.c)
 
   if(NOT CONFIG_PTHREAD_MUTEX_UNSAFE)
-    list(APPEND SRCS pthread_mutex.c pthread_mutexconsistent.c
-         pthread_mutexinconsistent.c)
+    list(APPEND SRCS pthread_mutex.c pthread_mutexconsistent.c)
   endif()
 
   if(CONFIG_SMP)

diff --git a/sched/pthread/Make.defs b/sched/pthread/Make.defs
@@ -32,7 +32,7 @@ CSRCS += pthread_completejoin.c pthread_findjoininfo.c
 CSRCS += pthread_release.c pthread_setschedprio.c
 
 ifneq ($(CONFIG_PTHREAD_MUTEX_UNSAFE),y)
-CSRCS += pthread_mutex.c pthread_mutexconsistent.c pthread_mutexinconsistent.c
+CSRCS += pthread_mutex.c pthread_mutexconsistent.c
 endif
 
 ifeq ($(CONFIG_SMP),y)

diff --git a/sched/pthread/pthread_create.c b/sched/pthread/pthread_create.c
@@ -222,6 +222,10 @@ int nx_pthread_create(pthread_trampoline_t trampoline, FAR pthread_t *thread,
 
   nxtask_joininit(&ptcb->cmn);
 
+#ifndef CONFIG_PTHREAD_MUTEX_UNSAFE
+  spin_lock_init(&ptcb->cmn.mutex_lock);
+#endif
+
   /* Bind the parent's group to the new TCB (we have not yet joined the
    * group).
    */

diff --git a/sched/pthread/pthread_mutex.c b/sched/pthread/pthread_mutex.c
@@ -65,10 +65,10 @@ static void pthread_mutex_add(FAR struct pthread_mutex_s *mutex)
 
   /* Add the mutex to the list of mutexes held by this pthread */
 
-  flags        = enter_critical_section();
+  flags        = spin_lock_irqsave(&rtcb->mutex_lock);
   mutex->flink = rtcb->mhead;
   rtcb->mhead  = mutex;
-  leave_critical_section(flags);
+  spin_unlock_irqrestore(&rtcb->mutex_lock, flags);
 }
 
 /****************************************************************************
@@ -92,7 +92,7 @@ static void pthread_mutex_remove(FAR struct pthread_mutex_s *mutex)
   FAR struct pthread_mutex_s *prev;
   irqstate_t flags;
 
-  flags = enter_critical_section();
+  flags = spin_lock_irqsave(&rtcb->mutex_lock);
 
   /* Remove the mutex from the list of mutexes held by this task */
 
@@ -118,7 +118,7 @@ static void pthread_mutex_remove(FAR struct pthread_mutex_s *mutex)
     }
 
   mutex->flink = NULL;
-  leave_critical_section(flags);
+  spin_unlock_irqrestore(&rtcb->mutex_lock, flags);
 }
 
 /****************************************************************************
@@ -346,3 +346,49 @@ int pthread_mutex_restorelock(FAR struct pthread_mutex_s *mutex,
 
   return ret;
 }
+
+/****************************************************************************
+ * Name: pthread_mutex_inconsistent
+ *
+ * Description:
+ *   This function is called when a pthread is terminated via either
+ *   pthread_exit() or pthread_cancel().  It will check for any mutexes
+ *   held by exitting thread.  It will mark them as inconsistent and
+ *   then wake up the highest priority waiter for the mutex.  That
+ *   instance of pthread_mutex_lock() will then return EOWNERDEAD.
+ *
+ * Input Parameters:
+ *   tcb -- a reference to the TCB of the exitting pthread.
+ *
+ * Returned Value:
+ *   None.
+ *
+ ****************************************************************************/
+
+void pthread_mutex_inconsistent(FAR struct tcb_s *tcb)
+{
+  FAR struct pthread_mutex_s *mutex;
+  irqstate_t flags;
+
+  DEBUGASSERT(tcb != NULL);
+
+  flags = spin_lock_irqsave(&tcb->mutex_lock);
+
+  /* Remove and process each mutex held by this task */
+
+  while (tcb->mhead != NULL)
+    {
+      /* Remove the mutex from the TCB list */
+
+      mutex        = tcb->mhead;
+      tcb->mhead   = mutex->flink;
+      mutex->flink = NULL;
+
+      /* Mark the mutex as INCONSISTENT and wake up any waiting thread */
+
+      mutex->flags |= _PTHREAD_MFLAGS_INCONSISTENT;
+      mutex_unlock(&mutex->mutex);
+    }
+
+  spin_unlock_irqrestore(&tcb->mutex_lock, flags);
+}
diff --git a/sched/pthread/pthread_mutexinconsistent.c b/sched/pthread/pthread_mutexinconsistent.c
diff --git a/sched/task/task_fork.c b/sched/task/task_fork.c
@@ -164,6 +164,10 @@ FAR struct task_tcb_s *nxtask_setup_fork(start_t retaddr)
 
   nxtask_joininit(&child->cmn);
 
+#ifndef CONFIG_PTHREAD_MUTEX_UNSAFE
+  spin_lock_init(&child->cmn.mutex_lock);
+#endif
+
   /* Allocate a new task group with the same privileges as the parent */
 
   ret = group_initialize(child, ttype);

diff --git a/sched/task/task_init.c b/sched/task/task_init.c
@@ -126,6 +126,10 @@ int nxtask_init(FAR struct task_tcb_s *tcb, const char *name, int priority,
   nxtask_joininit(&tcb->cmn);
 #endif
 
+#ifndef CONFIG_PTHREAD_MUTEX_UNSAFE
+  spin_lock_init(&tcb->cmn.mutex_lock);
+#endif
+
   /* Duplicate the parent tasks environment */
 
   ret = env_dup(tcb->cmn.group, envp);