pthreads: Backed most of last pthread changes. Found the 'real' root poblem. A one like error in pthread_mutex.c.

libc/pthread/pthread_rwlock_rdlock.c

@@ -55,18 +55,7 @@ static void rdlock_cleanup(FAR void *arg)
 {
   FAR pthread_rwlock_t *rw_lock = (FAR pthread_rwlock_t *)arg;
 
-#ifndef CONFIG_PTHREAD_MUTEX_UNSAFE
-  /* Check if this is a robust mutex in an inconsistent state */
-
-  if ((rw_lock->lock.flags & _PTHREAD_MFLAGS_INCONSISTENT) != 0)
-    {
-      (void)pthread_mutex_consistent(&rw_lock->lock);
-    }
-  else
-#endif
-    {
-      (void)pthread_mutex_unlock(&rw_lock->lock);
-    }
+  (void)pthread_mutex_unlock(&rw_lock->lock);
 }
 #endif
 

libc/pthread/pthread_rwlock_wrlock.c

@@ -56,19 +56,7 @@ static void wrlock_cleanup(FAR void *arg)
   FAR pthread_rwlock_t *rw_lock = (FAR pthread_rwlock_t *)arg;
 
   rw_lock->num_writers--;
-
-#ifndef CONFIG_PTHREAD_MUTEX_UNSAFE
-  /* Check if this is a robust mutex in an inconsistent state */
-
-  if ((rw_lock->lock.flags & _PTHREAD_MFLAGS_INCONSISTENT) != 0)
-    {
-      (void)pthread_mutex_consistent(&rw_lock->lock);
-    }
-  else
-#endif
-    {
-      (void)pthread_mutex_unlock(&rw_lock->lock);
-    }
+  (void)pthread_mutex_unlock(&rw_lock->lock);
 }
 #endif
 

sched/pthread/pthread_cancel.c

@@ -145,12 +145,6 @@ int pthread_cancel(pthread_t thread)
       pthread_exit(PTHREAD_CANCELED);
     }
 
-#ifndef CONFIG_PTHREAD_MUTEX_UNSAFE
-  /* Recover any mutexes still held by the canceled thread */
-
-  pthread_mutex_inconsistent(tcb);
-#endif
-
 #ifdef CONFIG_PTHREAD_CLEANUP
   /* Perform any stack pthread clean-up callbacks.
    *
@@ -168,6 +162,12 @@ int pthread_cancel(pthread_t thread)
 
   (void)pthread_completejoin((pid_t)thread, PTHREAD_CANCELED);
 
+#ifndef CONFIG_PTHREAD_MUTEX_UNSAFE
+  /* Recover any mutexes still held by the canceled thread */
+
+  pthread_mutex_inconsistent(tcb);
+#endif
+
   /* Then let task_terminate do the real work */
 
   return task_terminate((pid_t)thread, false);

sched/pthread/pthread_exit.c

@@ -105,12 +105,6 @@ void pthread_exit(FAR void *exit_value)
    tcb->cpcount = 0;
 #endif
 
-#ifndef CONFIG_PTHREAD_MUTEX_UNSAFE
-  /* Recover any mutexes still held by the canceled thread */
-
-  pthread_mutex_inconsistent((FAR struct pthread_tcb_s *)tcb);
-#endif
-
 #ifdef CONFIG_PTHREAD_CLEANUP
    /* Perform any stack pthread clean-up callbacks */
 
@@ -129,6 +123,12 @@ void pthread_exit(FAR void *exit_value)
       exit(EXIT_FAILURE);
     }
 
+#ifndef CONFIG_PTHREAD_MUTEX_UNSAFE
+  /* Recover any mutexes still held by the canceled thread */
+
+  pthread_mutex_inconsistent((FAR struct pthread_tcb_s *)tcb);
+#endif
+
   /* Perform common task termination logic.  This will get called again later
    * through logic kicked off by _exit().  However, we need to call it before
    * calling _exit() in order certain operations if this is the last thread

sched/pthread/pthread_mutex.c

@@ -125,10 +125,12 @@ int pthread_mutex_take(FAR struct pthread_mutex_s *mutex, bool intr)
         }
       else
         {
-          /* Take semaphore underlying the mutex */
+          /* Take semaphore underlying the mutex.  pthread_takesemaphore
+           * returns zero on success and a positive errno value on failue.
+           */
 
           ret = pthread_takesemaphore(&mutex->sem, intr);
-          if (ret < OK)
+          if (ret != OK)
             {
               ret = get_errno();
             }