From c68d0fa2d88fc2134a38d99e7e944828384a7671 Mon Sep 17 00:00:00 2001 From: Austin Foxley Date: Sat, 17 Oct 2009 12:26:24 -0700 Subject: libpthread/nptl: core of the "Native Posix Threading Library" for uClibc targetting arm,sh,i386,mips,sparc for now Signed-off-by: Austin Foxley --- libpthread/nptl/pthread_mutex_lock.c | 119 +++++++++++++++++++++++++++++++++++ 1 file changed, 119 insertions(+) create mode 100644 libpthread/nptl/pthread_mutex_lock.c (limited to 'libpthread/nptl/pthread_mutex_lock.c') diff --git a/libpthread/nptl/pthread_mutex_lock.c b/libpthread/nptl/pthread_mutex_lock.c new file mode 100644 index 000000000..ee39f2082 --- /dev/null +++ b/libpthread/nptl/pthread_mutex_lock.c @@ -0,0 +1,119 @@ +/* Copyright (C) 2002, 2003, 2004 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Ulrich Drepper , 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 +#include +#include "pthreadP.h" +#include + + +#ifndef LLL_MUTEX_LOCK +# define LLL_MUTEX_LOCK(mutex) lll_mutex_lock (mutex) +# define LLL_MUTEX_TRYLOCK(mutex) lll_mutex_trylock (mutex) +#endif + + +int +__pthread_mutex_lock (mutex) + pthread_mutex_t *mutex; +{ + assert (sizeof (mutex->__size) >= sizeof (mutex->__data)); + + 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: + /* 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; + } + + /* We have to get the mutex. */ + LLL_MUTEX_LOCK (mutex->__data.__lock); + + mutex->__data.__count = 1; + break; + + /* Error checking mutex. */ + case PTHREAD_MUTEX_ERRORCHECK_NP: + /* Check whether we already hold the mutex. */ + if (mutex->__data.__owner == id) + return EDEADLK; + + /* FALLTHROUGH */ + + default: + /* Correct code cannot set any other type. */ + case PTHREAD_MUTEX_TIMED_NP: + simple: + /* Normal mutex. */ + LLL_MUTEX_LOCK (mutex->__data.__lock); + break; + + case PTHREAD_MUTEX_ADAPTIVE_NP: + if (! __is_smp) + goto simple; + + if (LLL_MUTEX_TRYLOCK (mutex->__data.__lock) != 0) + { + int cnt = 0; + int max_cnt = MIN (MAX_ADAPTIVE_COUNT, + mutex->__data.__spins * 2 + 10); + do + { + if (cnt++ >= max_cnt) + { + LLL_MUTEX_LOCK (mutex->__data.__lock); + break; + } + +#ifdef BUSY_WAIT_NOP + BUSY_WAIT_NOP; +#endif + } + while (LLL_MUTEX_TRYLOCK (mutex->__data.__lock) != 0); + + mutex->__data.__spins += (cnt - mutex->__data.__spins) / 8; + } + break; + } + + /* Record the ownership. */ + assert (mutex->__data.__owner == 0); + mutex->__data.__owner = id; +#ifndef NO_INCR + ++mutex->__data.__nusers; +#endif + + return 0; +} +#ifndef __pthread_mutex_lock +strong_alias (__pthread_mutex_lock, pthread_mutex_lock) +strong_alias (__pthread_mutex_lock, __pthread_mutex_lock_internal) +#endif -- cgit v1.2.3