From 1bcfb5a5eb1c25b64a329c1edf6bcfb440cdbc93 Mon Sep 17 00:00:00 2001
From: Ulrich Drepper <drepper@redhat.com>
Date: Tue, 27 Dec 2005 01:04:06 +0000
Subject: * Versions.def: Add GLIBC_2.4 for libpthread.

---
 nptl/pthread_mutex_trylock.c | 88 ++++++++++++++++++++++++++++++++++++++++----
 1 file changed, 81 insertions(+), 7 deletions(-)

(limited to 'nptl/pthread_mutex_trylock.c')

diff --git a/nptl/pthread_mutex_trylock.c b/nptl/pthread_mutex_trylock.c
index 8213f90da9..ae73ecc39b 100644
--- a/nptl/pthread_mutex_trylock.c
+++ b/nptl/pthread_mutex_trylock.c
@@ -17,7 +17,9 @@
    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
    02111-1307 USA.  */
 
+#include <assert.h>
 #include <errno.h>
+#include <stdlib.h>
 #include "pthreadP.h"
 #include <lowlevellock.h>
 
@@ -26,13 +28,12 @@ int
 __pthread_mutex_trylock (mutex)
      pthread_mutex_t *mutex;
 {
-  pid_t id;
+  pid_t id = THREAD_GETMEM (THREAD_SELF, tid);
 
   switch (__builtin_expect (mutex->__data.__kind, PTHREAD_MUTEX_TIMED_NP))
     {
       /* Recursive mutex.  */
     case PTHREAD_MUTEX_RECURSIVE_NP:
-      id = THREAD_GETMEM (THREAD_SELF, tid);
       /* Check whether we already hold the mutex.  */
       if (mutex->__data.__owner == id)
 	{
@@ -56,20 +57,93 @@ __pthread_mutex_trylock (mutex)
       break;
 
     case PTHREAD_MUTEX_ERRORCHECK_NP:
-      /* Error checking mutex.  We do not check for deadlocks.  */
+      /* Check whether we already hold the mutex.  */
+      if (__builtin_expect (mutex->__data.__owner == id, 0))
+	return EDEADLK;
+
+      /* FALLTHROUGH */
+
     case PTHREAD_MUTEX_TIMED_NP:
     case PTHREAD_MUTEX_ADAPTIVE_NP:
       /* Normal mutex.  */
-      if (lll_mutex_trylock (mutex->__data.__lock) == 0)
+      if (lll_mutex_trylock (mutex->__data.__lock) != 0)
+	break;
+
+      /* Record the ownership.  */
+      mutex->__data.__owner = id;
+      ++mutex->__data.__nusers;
+
+      return 0;
+
+
+    case PTHREAD_MUTEX_ROBUST_PRIVATE_RECURSIVE_NP:
+      /* Check whether we already hold the mutex.  */
+      if (abs (mutex->__data.__owner) == id)
 	{
-	  /* Record the ownership.  */
-	  mutex->__data.__owner = THREAD_GETMEM (THREAD_SELF, tid);
-	  ++mutex->__data.__nusers;
+	  /* Just bump the counter.  */
+	  if (__builtin_expect (mutex->__data.__count + 1 == 0, 0))
+	    /* Overflow of the counter.  */
+	    return EAGAIN;
+
+	  ++mutex->__data.__count;
 
 	  return 0;
 	}
+
+      /* We have to get the mutex.  */
+      if (lll_mutex_trylock (mutex->__data.__lock) == 0)
+	{
+	  mutex->__data.__count = 1;
+
+	  goto robust;
+	}
+
       break;
 
+    case PTHREAD_MUTEX_ROBUST_PRIVATE_ERRORCHECK_NP:
+      /* Check whether we already hold the mutex.  */
+      if (__builtin_expect (abs (mutex->__data.__owner) == id, 0))
+	return EDEADLK;
+
+      /* FALLTHROUGH */
+
+    case PTHREAD_MUTEX_ROBUST_PRIVATE_NP:
+    case PTHREAD_MUTEX_ROBUST_PRIVATE_ADAPTIVE_NP:
+      if (lll_mutex_trylock (mutex->__data.__lock) != 0)
+	break;
+
+    robust:
+      if (__builtin_expect (mutex->__data.__owner
+			    == PTHREAD_MUTEX_NOTRECOVERABLE, 0))
+	{
+	  /* This mutex is now not recoverable.  */
+	  mutex->__data.__count = 0;
+	  lll_mutex_unlock (mutex->__data.__lock);
+	  return ENOTRECOVERABLE;
+	}
+
+      /* This mutex is either healthy or we can try to recover it.  */
+      assert (mutex->__data.__owner == 0
+	      || mutex->__data.__owner == PTHREAD_MUTEX_OWNERDEAD);
+
+      /* Record the ownership.  */
+      int retval = 0;
+      if (__builtin_expect (mutex->__data.__owner
+			    == PTHREAD_MUTEX_OWNERDEAD, 0))
+	{
+	  retval = EOWNERDEAD;
+	  /* We signal ownership of a not yet recovered robust
+	     mutex by storing the negative thread ID.  */
+	  id = -id;
+	}
+
+      ENQUEUE_MUTEX (mutex);
+
+      mutex->__data.__owner = id;
+      ++mutex->__data.__nusers;
+
+      return retval
+;
     default:
       /* Correct code cannot set any other type.  */
       return EINVAL;
-- 
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