diff options
Diffstat (limited to 'libpthread/nptl/pthread_mutex_trylock.c')
| -rw-r--r-- | libpthread/nptl/pthread_mutex_trylock.c | 76 | 
1 files changed, 76 insertions, 0 deletions
| diff --git a/libpthread/nptl/pthread_mutex_trylock.c b/libpthread/nptl/pthread_mutex_trylock.c new file mode 100644 index 000000000..2eb88db53 --- /dev/null +++ b/libpthread/nptl/pthread_mutex_trylock.c @@ -0,0 +1,76 @@ +/* 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. + +   The GNU C Library is free software; you can redistribute it and/or +   modify it under the terms of the GNU Lesser General Public +   License as published by the Free Software Foundation; either +   version 2.1 of the License, or (at your option) any later version. + +   The GNU C Library is distributed in the hope that it will be useful, +   but WITHOUT ANY WARRANTY; without even the implied warranty of +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU +   Lesser General Public License for more details. + +   You should have received a copy of the GNU Lesser General Public +   License along with the GNU C Library; if not, write to the Free +   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA +   02111-1307 USA.  */ + +#include <errno.h> +#include "pthreadP.h" +#include <lowlevellock.h> + + +int +__pthread_mutex_trylock (pthread_mutex_t *mutex) +{ +  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) +	{ +	  /* Just bump the counter.  */ +	  if (__builtin_expect (mutex->__data.__count + 1 == 0, 0)) +	    /* Overflow of the counter.  */ +	    return EAGAIN; + +	  ++mutex->__data.__count; +	  return 0; +	} + +      if (lll_mutex_trylock (mutex->__data.__lock) == 0) +	{ +	  /* Record the ownership.  */ +	  mutex->__data.__owner = id; +	  mutex->__data.__count = 1; +	  ++mutex->__data.__nusers; +	  return 0; +	} +      break; + +    case PTHREAD_MUTEX_ERRORCHECK_NP: +      /* 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) +	{ +	  /* Record the ownership.  */ +	  mutex->__data.__owner = THREAD_GETMEM (THREAD_SELF, tid); +	  ++mutex->__data.__nusers; + +	  return 0; +	} +    } + +  return EBUSY; +} +strong_alias (__pthread_mutex_trylock, pthread_mutex_trylock) | 
