From 948332ca343f596acf7af0b434812a2bb7f90079 Mon Sep 17 00:00:00 2001
From: Gregory Nutt <gnutt@nuttx.org>
Date: Mon, 10 Apr 2017 09:51:03 -0600
Subject: [PATCH] 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 | 13 +------------
 libc/pthread/pthread_rwlock_wrlock.c | 14 +-------------
 sched/pthread/pthread_cancel.c       | 12 ++++++------
 sched/pthread/pthread_exit.c         | 12 ++++++------
 sched/pthread/pthread_mutex.c        |  6 ++++--
 5 files changed, 18 insertions(+), 39 deletions(-)

diff --git a/libc/pthread/pthread_rwlock_rdlock.c b/libc/pthread/pthread_rwlock_rdlock.c
index 29dcf7daae1..4eadfedccb5 100644
--- a/libc/pthread/pthread_rwlock_rdlock.c
+++ b/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
 
diff --git a/libc/pthread/pthread_rwlock_wrlock.c b/libc/pthread/pthread_rwlock_wrlock.c
index 93a6a238582..c9f4f3a7c56 100644
--- a/libc/pthread/pthread_rwlock_wrlock.c
+++ b/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
 
diff --git a/sched/pthread/pthread_cancel.c b/sched/pthread/pthread_cancel.c
index f68d272e03a..e2cad60ebbf 100644
--- a/sched/pthread/pthread_cancel.c
+++ b/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);
diff --git a/sched/pthread/pthread_exit.c b/sched/pthread/pthread_exit.c
index 4929db94cb5..bcc8e79c855 100644
--- a/sched/pthread/pthread_exit.c
+++ b/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
diff --git a/sched/pthread/pthread_mutex.c b/sched/pthread/pthread_mutex.c
index f11a5b01f6f..afd296407ef 100644
--- a/sched/pthread/pthread_mutex.c
+++ b/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();
             }