From 0b3366f6a93ac0f7e2028745ea557c0acd8722c6 Mon Sep 17 00:00:00 2001 From: "\"Steven J. Hill\"" Date: Sat, 7 May 2005 02:04:55 +0000 Subject: Import in NPTL code from glibc. For further information please consult the 'README.NPTL' file. --- libpthread/nptl/pthread_mutex_timedlock.c | 118 ++++++++++++++++++++++++++++++ 1 file changed, 118 insertions(+) create mode 100644 libpthread/nptl/pthread_mutex_timedlock.c (limited to 'libpthread/nptl/pthread_mutex_timedlock.c') diff --git a/libpthread/nptl/pthread_mutex_timedlock.c b/libpthread/nptl/pthread_mutex_timedlock.c new file mode 100644 index 000000000..1cd2c7e60 --- /dev/null +++ b/libpthread/nptl/pthread_mutex_timedlock.c @@ -0,0 +1,118 @@ +/* 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 "pthreadP.h" +#include + + +int +pthread_mutex_timedlock (mutex, abstime) + pthread_mutex_t *mutex; + const struct timespec *abstime; +{ + pid_t id = THREAD_GETMEM (THREAD_SELF, tid); + int result = 0; + + /* We must not check ABSTIME here. If the thread does not block + abstime must not be checked for a valid value. */ + + switch (mutex->__data.__kind) + { + /* 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; + + goto out; + } + else + { + /* We have to get the mutex. */ + result = lll_mutex_timedlock (mutex->__data.__lock, abstime); + + if (result != 0) + goto out; + + /* Only locked once so far. */ + 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. */ + result = lll_mutex_timedlock (mutex->__data.__lock, abstime); + 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) + { + result = lll_mutex_timedlock (mutex->__data.__lock, abstime); + 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; + } + + if (result == 0) + { + /* Record the ownership. */ + mutex->__data.__owner = id; + ++mutex->__data.__nusers; + } + + out: + return result; +} -- cgit v1.2.3