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authorUlrich Drepper <drepper@redhat.com>2004-12-22 20:10:10 +0000
committerUlrich Drepper <drepper@redhat.com>2004-12-22 20:10:10 +0000
commita334319f6530564d22e775935d9c91663623a1b4 (patch)
treeb5877475619e4c938e98757d518bb1e9cbead751 /nptl/pthread_mutex_trylock.c
parent0ecb606cb6cf65de1d9fc8a919bceb4be476c602 (diff)
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(CFLAGS-tst-align.c): Add -mpreferred-stack-boundary=4.
Diffstat (limited to 'nptl/pthread_mutex_trylock.c')
-rw-r--r--nptl/pthread_mutex_trylock.c327
1 files changed, 11 insertions, 316 deletions
diff --git a/nptl/pthread_mutex_trylock.c b/nptl/pthread_mutex_trylock.c
index 66aca8e4b2..7008af3d97 100644
--- a/nptl/pthread_mutex_trylock.c
+++ b/nptl/pthread_mutex_trylock.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 2002, 2003, 2005, 2006, 2007 Free Software Foundation, Inc.
+/* Copyright (C) 2002, 2003 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
 
@@ -17,9 +17,7 @@
    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>
 
@@ -28,13 +26,13 @@ int
 __pthread_mutex_trylock (mutex)
      pthread_mutex_t *mutex;
 {
-  int oldval;
-  pid_t id = THREAD_GETMEM (THREAD_SELF, tid);
+  pid_t id;
 
   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)
 	{
@@ -58,323 +56,20 @@ __pthread_mutex_trylock (mutex)
       break;
 
     case PTHREAD_MUTEX_ERRORCHECK_NP:
-      /* Check whether we already hold the mutex.  */
-      if (__builtin_expect (mutex->__data.__owner == id, 0))
-	return EDEADLK;
-
-      /* FALLTHROUGH */
-
+      /* Error checking mutex.  We do not check for deadlocks.  */
+    default:
+      /* Correct code cannot set any other type.  */
     case PTHREAD_MUTEX_TIMED_NP:
     case PTHREAD_MUTEX_ADAPTIVE_NP:
       /* Normal mutex.  */
-      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_RECURSIVE_NP:
-    case PTHREAD_MUTEX_ROBUST_ERRORCHECK_NP:
-    case PTHREAD_MUTEX_ROBUST_NORMAL_NP:
-    case PTHREAD_MUTEX_ROBUST_ADAPTIVE_NP:
-      THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending,
-		     &mutex->__data.__list.__next);
-
-      oldval = mutex->__data.__lock;
-      do
+      if (lll_mutex_trylock (mutex->__data.__lock) == 0)
 	{
-	again:
-	  if ((oldval & FUTEX_OWNER_DIED) != 0)
-	    {
-	      /* The previous owner died.  Try locking the mutex.  */
-	      int newval = id | (oldval & FUTEX_WAITERS);
-
-	      newval
-		= atomic_compare_and_exchange_val_acq (&mutex->__data.__lock,
-						       newval, oldval);
-
-	      if (newval != oldval)
-		{
-		  oldval = newval;
-		  goto again;
-		}
-
-	      /* We got the mutex.  */
-	      mutex->__data.__count = 1;
-	      /* But it is inconsistent unless marked otherwise.  */
-	      mutex->__data.__owner = PTHREAD_MUTEX_INCONSISTENT;
-
-	      ENQUEUE_MUTEX (mutex);
-	      THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending, NULL);
-
-	      /* Note that we deliberately exist here.  If we fall
-		 through to the end of the function __nusers would be
-		 incremented which is not correct because the old
-		 owner has to be discounted.  */
-	      return EOWNERDEAD;
-	    }
-
-	  /* Check whether we already hold the mutex.  */
-	  if (__builtin_expect ((oldval & FUTEX_TID_MASK) == id, 0))
-	    {
-	      if (mutex->__data.__kind
-		  == PTHREAD_MUTEX_ROBUST_ERRORCHECK_NP)
-		{
-		  THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending,
-				 NULL);
-		  return EDEADLK;
-		}
-
-	      if (mutex->__data.__kind
-		  == PTHREAD_MUTEX_ROBUST_RECURSIVE_NP)
-		{
-		  THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending,
-				 NULL);
-
-		  /* Just bump the counter.  */
-		  if (__builtin_expect (mutex->__data.__count + 1 == 0, 0))
-		    /* Overflow of the counter.  */
-		    return EAGAIN;
-
-		  ++mutex->__data.__count;
-
-		  return 0;
-		}
-	    }
-
-	  oldval = lll_robust_mutex_trylock (mutex->__data.__lock, id);
-	  if (oldval != 0 && (oldval & FUTEX_OWNER_DIED) == 0)
-	    {
-	      THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending, NULL);
-
-	      return EBUSY;
-	    }
+	  /* Record the ownership.  */
+	  mutex->__data.__owner = THREAD_GETMEM (THREAD_SELF, tid);
+	  ++mutex->__data.__nusers;
 
-	  if (__builtin_expect (mutex->__data.__owner
-				== PTHREAD_MUTEX_NOTRECOVERABLE, 0))
-	    {
-	      /* This mutex is now not recoverable.  */
-	      mutex->__data.__count = 0;
-	      if (oldval == id)
-		lll_mutex_unlock (mutex->__data.__lock);
-	      THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending, NULL);
-	      return ENOTRECOVERABLE;
-	    }
+	  return 0;
 	}
-      while ((oldval & FUTEX_OWNER_DIED) != 0);
-
-      ENQUEUE_MUTEX (mutex);
-      THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending, NULL);
-
-      mutex->__data.__owner = id;
-      ++mutex->__data.__nusers;
-      mutex->__data.__count = 1;
-
-      return 0;
-
-    case PTHREAD_MUTEX_PI_RECURSIVE_NP:
-    case PTHREAD_MUTEX_PI_ERRORCHECK_NP:
-    case PTHREAD_MUTEX_PI_NORMAL_NP:
-    case PTHREAD_MUTEX_PI_ADAPTIVE_NP:
-    case PTHREAD_MUTEX_PI_ROBUST_RECURSIVE_NP:
-    case PTHREAD_MUTEX_PI_ROBUST_ERRORCHECK_NP:
-    case PTHREAD_MUTEX_PI_ROBUST_NORMAL_NP:
-    case PTHREAD_MUTEX_PI_ROBUST_ADAPTIVE_NP:
-      {
-	int kind = mutex->__data.__kind & PTHREAD_MUTEX_KIND_MASK_NP;
-	int robust = mutex->__data.__kind & PTHREAD_MUTEX_ROBUST_NORMAL_NP;
-
-	if (robust)
-	  /* Note: robust PI futexes are signaled by setting bit 0.  */
-	  THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending,
-			 (void *) (((uintptr_t) &mutex->__data.__list.__next)
-				   | 1));
-
-	oldval = mutex->__data.__lock;
-
-	/* Check whether we already hold the mutex.  */
-	if (__builtin_expect ((oldval & FUTEX_TID_MASK) == id, 0))
-	  {
-	    if (kind == PTHREAD_MUTEX_ERRORCHECK_NP)
-	      {
-		THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending, NULL);
-		return EDEADLK;
-	      }
-
-	    if (kind == PTHREAD_MUTEX_RECURSIVE_NP)
-	      {
-		THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending, NULL);
-
-		/* Just bump the counter.  */
-		if (__builtin_expect (mutex->__data.__count + 1 == 0, 0))
-		  /* Overflow of the counter.  */
-		  return EAGAIN;
-
-		++mutex->__data.__count;
-
-		return 0;
-	      }
-	  }
-
-	oldval
-	  = atomic_compare_and_exchange_val_acq (&mutex->__data.__lock,
-						 id, 0);
-
-	if (oldval != 0)
-	  {
-	    if ((oldval & FUTEX_OWNER_DIED) == 0)
-	      {
-		THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending, NULL);
-
-		return EBUSY;
-	      }
-
-	    assert (robust);
-
-	    /* The mutex owner died.  The kernel will now take care of
-	       everything.  */
-	    INTERNAL_SYSCALL_DECL (__err);
-	    int e = INTERNAL_SYSCALL (futex, __err, 4, &mutex->__data.__lock,
-				      FUTEX_TRYLOCK_PI, 0, 0);
-
-	    if (INTERNAL_SYSCALL_ERROR_P (e, __err)
-		&& INTERNAL_SYSCALL_ERRNO (e, __err) == EWOULDBLOCK)
-	      {
-		THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending, NULL);
-
-		return EBUSY;
-	      }
-
-	    oldval = mutex->__data.__lock;
-	  }
-
-	if (__builtin_expect (oldval & FUTEX_OWNER_DIED, 0))
-	  {
-	    atomic_and (&mutex->__data.__lock, ~FUTEX_OWNER_DIED);
-
-	    /* We got the mutex.  */
-	    mutex->__data.__count = 1;
-	    /* But it is inconsistent unless marked otherwise.  */
-	    mutex->__data.__owner = PTHREAD_MUTEX_INCONSISTENT;
-
-	    ENQUEUE_MUTEX (mutex);
-	    THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending, NULL);
-
-	    /* Note that we deliberately exit here.  If we fall
-	       through to the end of the function __nusers would be
-	       incremented which is not correct because the old owner
-	       has to be discounted.  */
-	    return EOWNERDEAD;
-	  }
-
-	if (robust
-	    && __builtin_expect (mutex->__data.__owner
-				 == PTHREAD_MUTEX_NOTRECOVERABLE, 0))
-	  {
-	    /* This mutex is now not recoverable.  */
-	    mutex->__data.__count = 0;
-
-	    INTERNAL_SYSCALL_DECL (__err);
-	    INTERNAL_SYSCALL (futex, __err, 4, &mutex->__data.__lock,
-			      FUTEX_UNLOCK_PI, 0, 0);
-
-	    THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending, NULL);
-	    return ENOTRECOVERABLE;
-	  }
-
-	if (robust)
-	  {
-	    ENQUEUE_MUTEX_PI (mutex);
-	    THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending, NULL);
-	  }
-
-	mutex->__data.__owner = id;
-	++mutex->__data.__nusers;
-	mutex->__data.__count = 1;
-
-	return 0;
-      }
-
-    case PTHREAD_MUTEX_PP_RECURSIVE_NP:
-    case PTHREAD_MUTEX_PP_ERRORCHECK_NP:
-    case PTHREAD_MUTEX_PP_NORMAL_NP:
-    case PTHREAD_MUTEX_PP_ADAPTIVE_NP:
-      {
-	int kind = mutex->__data.__kind & PTHREAD_MUTEX_KIND_MASK_NP;
-
-	oldval = mutex->__data.__lock;
-
-	/* Check whether we already hold the mutex.  */
-	if (mutex->__data.__owner == id)
-	  {
-	    if (kind == PTHREAD_MUTEX_ERRORCHECK_NP)
-	      return EDEADLK;
-
-	    if (kind == PTHREAD_MUTEX_RECURSIVE_NP)
-	      {
-		/* Just bump the counter.  */
-		if (__builtin_expect (mutex->__data.__count + 1 == 0, 0))
-		  /* Overflow of the counter.  */
-		  return EAGAIN;
-
-		++mutex->__data.__count;
-
-		return 0;
-	      }
-	  }
-
-	int oldprio = -1, ceilval;
-	do
-	  {
-	    int ceiling = (oldval & PTHREAD_MUTEX_PRIO_CEILING_MASK)
-			  >> PTHREAD_MUTEX_PRIO_CEILING_SHIFT;
-
-	    if (__pthread_current_priority () > ceiling)
-	      {
-		if (oldprio != -1)
-		  __pthread_tpp_change_priority (oldprio, -1);
-		return EINVAL;
-	      }
-
-	    int retval = __pthread_tpp_change_priority (oldprio, ceiling);
-	    if (retval)
-	      return retval;
-
-	    ceilval = ceiling << PTHREAD_MUTEX_PRIO_CEILING_SHIFT;
-	    oldprio = ceiling;
-
-	    oldval
-	      = atomic_compare_and_exchange_val_acq (&mutex->__data.__lock,
-						     ceilval | 1, ceilval);
-
-	    if (oldval == ceilval)
-	      break;
-	  }
-	while ((oldval & PTHREAD_MUTEX_PRIO_CEILING_MASK) != ceilval);
-
-	if (oldval != ceilval)
-	  {
-	    __pthread_tpp_change_priority (oldprio, -1);
-	    break;
-	  }
-
-	assert (mutex->__data.__owner == 0);
-	/* Record the ownership.  */
-	mutex->__data.__owner = id;
-	++mutex->__data.__nusers;
-	mutex->__data.__count = 1;
-
-	return 0;
-      }
-      break;
-
-    default:
-      /* Correct code cannot set any other type.  */
-      return EINVAL;
     }
 
   return EBUSY;