/* Copyright (C) 2002, 2003, 2004, 2005 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 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; } /* 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 */ 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; case PTHREAD_MUTEX_ROBUST_PRIVATE_RECURSIVE_NP: /* Check whether we already hold the mutex. */ if (abs (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; } /* 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; goto robust; 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: result = lll_mutex_timedlock (mutex->__data.__lock, abstime); if (result != 0) goto out; 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); if (__builtin_expect (mutex->__data.__owner == PTHREAD_MUTEX_OWNERDEAD, 0)) { result = EOWNERDEAD; /* We signal ownership of a not yet recovered robust mutex by storing the negative thread ID. */ mutex->__data.__owner = -id; ++mutex->__data.__nusers; } ENQUEUE_MUTEX (mutex); break; default: /* Correct code cannot set any other type. */ return EINVAL; } if (result == 0) { /* Record the ownership. */ mutex->__data.__owner = id; ++mutex->__data.__nusers; } out: return result; }