Loading...
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 | /* Copyright (C) 2002, 2003, 2004, 2005, 2006, 2007 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, see <http://www.gnu.org/licenses/>. */ #include <assert.h> #include <errno.h> #include <string.h> #include <bits/kernel-features.h> #include "pthreadP.h" static const struct pthread_mutexattr default_attr = { /* Default is a normal mutex, not shared between processes. */ .mutexkind = PTHREAD_MUTEX_NORMAL }; #ifndef __ASSUME_FUTEX_LOCK_PI static int tpi_supported; #endif int attribute_protected __pthread_mutex_init ( pthread_mutex_t *mutex, const pthread_mutexattr_t *mutexattr) { const struct pthread_mutexattr *imutexattr; assert (sizeof (pthread_mutex_t) <= __SIZEOF_PTHREAD_MUTEX_T); imutexattr = (const struct pthread_mutexattr *) mutexattr ?: &default_attr; /* Sanity checks. */ switch (__builtin_expect (imutexattr->mutexkind & PTHREAD_MUTEXATTR_PROTOCOL_MASK, PTHREAD_PRIO_NONE << PTHREAD_MUTEXATTR_PROTOCOL_SHIFT)) { case PTHREAD_PRIO_NONE << PTHREAD_MUTEXATTR_PROTOCOL_SHIFT: break; case PTHREAD_PRIO_INHERIT << PTHREAD_MUTEXATTR_PROTOCOL_SHIFT: #ifndef __ASSUME_FUTEX_LOCK_PI if (__builtin_expect (tpi_supported == 0, 0)) { int lock = 0; INTERNAL_SYSCALL_DECL (err); int ret = INTERNAL_SYSCALL (futex, err, 4, &lock, FUTEX_UNLOCK_PI, 0, 0); assert (INTERNAL_SYSCALL_ERROR_P (ret, err)); tpi_supported = INTERNAL_SYSCALL_ERRNO (ret, err) == ENOSYS ? -1 : 1; } if (__builtin_expect (tpi_supported < 0, 0)) return ENOTSUP; #endif break; default: /* XXX: For now we don't support robust priority protected mutexes. */ if (imutexattr->mutexkind & PTHREAD_MUTEXATTR_FLAG_ROBUST) return ENOTSUP; break; } /* Clear the whole variable. */ memset (mutex, '\0', __SIZEOF_PTHREAD_MUTEX_T); /* Copy the values from the attribute. */ mutex->__data.__kind = imutexattr->mutexkind & ~PTHREAD_MUTEXATTR_FLAG_BITS; if ((imutexattr->mutexkind & PTHREAD_MUTEXATTR_FLAG_ROBUST) != 0) { #ifndef __ASSUME_SET_ROBUST_LIST if ((imutexattr->mutexkind & PTHREAD_MUTEXATTR_FLAG_PSHARED) != 0 && __set_robust_list_avail < 0) return ENOTSUP; #endif mutex->__data.__kind |= PTHREAD_MUTEX_ROBUST_NORMAL_NP; } switch (imutexattr->mutexkind & PTHREAD_MUTEXATTR_PROTOCOL_MASK) { case PTHREAD_PRIO_INHERIT << PTHREAD_MUTEXATTR_PROTOCOL_SHIFT: mutex->__data.__kind |= PTHREAD_MUTEX_PRIO_INHERIT_NP; break; case PTHREAD_PRIO_PROTECT << PTHREAD_MUTEXATTR_PROTOCOL_SHIFT: mutex->__data.__kind |= PTHREAD_MUTEX_PRIO_PROTECT_NP; int ceiling = (imutexattr->mutexkind & PTHREAD_MUTEXATTR_PRIO_CEILING_MASK) >> PTHREAD_MUTEXATTR_PRIO_CEILING_SHIFT; if (! ceiling) { if (__sched_fifo_min_prio == -1) __init_sched_fifo_prio (); if (ceiling < __sched_fifo_min_prio) ceiling = __sched_fifo_min_prio; } mutex->__data.__lock = ceiling << PTHREAD_MUTEX_PRIO_CEILING_SHIFT; break; default: break; } /* The kernel when waking robust mutexes on exit never uses FUTEX_PRIVATE_FLAG FUTEX_WAKE. */ if ((imutexattr->mutexkind & (PTHREAD_MUTEXATTR_FLAG_PSHARED | PTHREAD_MUTEXATTR_FLAG_ROBUST)) != 0) mutex->__data.__kind |= PTHREAD_MUTEX_PSHARED_BIT; /* Default values: mutex not used yet. */ // mutex->__count = 0; already done by memset // mutex->__owner = 0; already done by memset // mutex->__nusers = 0; already done by memset // mutex->__spins = 0; already done by memset // mutex->__next = NULL; already done by memset return 0; } strong_alias (__pthread_mutex_init, pthread_mutex_init) INTDEF(__pthread_mutex_init) |