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aeb4d2e981
A new internal definition, __LIBC_LOCK_ALIGNMENT, is used to force the 4-byte alignment only for m68k, other architecture keep the natural alignment of the type used internally (and hppa does not require 16-byte alignment for kernel-assisted CAS). Reviewed-by: Florian Weimer <fweimer@redhat.com>
195 lines
6.8 KiB
C++
195 lines
6.8 KiB
C++
/* libc-internal interface for mutex locks. NPTL version.
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Copyright (C) 1996-2022 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public License as
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published by the Free Software Foundation; either version 2.1 of the
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License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; see the file COPYING.LIB. If
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not, see <https://www.gnu.org/licenses/>. */
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#ifndef _LIBC_LOCK_H
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#define _LIBC_LOCK_H 1
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#include <pthread.h>
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#define __need_NULL
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#include <stddef.h>
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#include <libc-lock-arch.h>
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/* Mutex type. */
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#if defined _LIBC || defined _IO_MTSAFE_IO
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# if (!IS_IN (libc) && !IS_IN (libpthread)) || !defined _LIBC
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typedef struct { pthread_mutex_t mutex; } __libc_lock_recursive_t;
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# else
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typedef struct
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{
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int lock __LIBC_LOCK_ALIGNMENT;
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int cnt;
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void *owner;
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} __libc_lock_recursive_t;
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# endif
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#else
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typedef struct __libc_lock_recursive_opaque__ __libc_lock_recursive_t;
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#endif
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/* Define a lock variable NAME with storage class CLASS. The lock must be
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initialized with __libc_lock_init before it can be used (or define it
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with __libc_lock_define_initialized, below). Use `extern' for CLASS to
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declare a lock defined in another module. In public structure
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definitions you must use a pointer to the lock structure (i.e., NAME
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begins with a `*'), because its storage size will not be known outside
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of libc. */
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#define __libc_lock_define_recursive(CLASS,NAME) \
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CLASS __libc_lock_recursive_t NAME;
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/* Define an initialized recursive lock variable NAME with storage
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class CLASS. */
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#if defined _LIBC && (IS_IN (libc) || IS_IN (libpthread))
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# define __libc_lock_define_initialized_recursive(CLASS, NAME) \
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CLASS __libc_lock_recursive_t NAME = _LIBC_LOCK_RECURSIVE_INITIALIZER;
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# define _LIBC_LOCK_RECURSIVE_INITIALIZER \
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{ LLL_LOCK_INITIALIZER, 0, NULL }
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#else
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# define __libc_lock_define_initialized_recursive(CLASS,NAME) \
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CLASS __libc_lock_recursive_t NAME = _LIBC_LOCK_RECURSIVE_INITIALIZER;
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# define _LIBC_LOCK_RECURSIVE_INITIALIZER \
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{PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP}
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#endif
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/* Initialize a recursive mutex. */
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#if defined _LIBC && (IS_IN (libc) || IS_IN (libpthread))
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# define __libc_lock_init_recursive(NAME) \
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((void) ((NAME) = (__libc_lock_recursive_t) _LIBC_LOCK_RECURSIVE_INITIALIZER))
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#else
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# define __libc_lock_init_recursive(NAME) \
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do { \
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if (__pthread_mutex_init != NULL) \
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{ \
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pthread_mutexattr_t __attr; \
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__pthread_mutexattr_init (&__attr); \
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__pthread_mutexattr_settype (&__attr, PTHREAD_MUTEX_RECURSIVE_NP); \
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__pthread_mutex_init (&(NAME).mutex, &__attr); \
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__pthread_mutexattr_destroy (&__attr); \
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} \
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} while (0)
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#endif
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/* Finalize recursive named lock. */
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#if defined _LIBC && (IS_IN (libc) || IS_IN (libpthread))
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# define __libc_lock_fini_recursive(NAME) ((void) 0)
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#else
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# define __libc_lock_fini_recursive(NAME) \
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__libc_maybe_call (__pthread_mutex_destroy, (&(NAME).mutex), 0)
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#endif
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/* Lock the recursive named lock variable. */
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#if defined _LIBC && (IS_IN (libc) || IS_IN (libpthread))
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# define __libc_lock_lock_recursive(NAME) \
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do { \
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void *self = THREAD_SELF; \
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if ((NAME).owner != self) \
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{ \
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lll_lock ((NAME).lock, LLL_PRIVATE); \
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(NAME).owner = self; \
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} \
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++(NAME).cnt; \
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} while (0)
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#else
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# define __libc_lock_lock_recursive(NAME) \
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__libc_maybe_call (__pthread_mutex_lock, (&(NAME).mutex), 0)
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#endif
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/* Try to lock the recursive named lock variable. */
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#if defined _LIBC && (IS_IN (libc) || IS_IN (libpthread))
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# define __libc_lock_trylock_recursive(NAME) \
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({ \
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int result = 0; \
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void *self = THREAD_SELF; \
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if ((NAME).owner != self) \
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{ \
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if (lll_trylock ((NAME).lock) == 0) \
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{ \
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(NAME).owner = self; \
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(NAME).cnt = 1; \
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} \
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else \
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result = EBUSY; \
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} \
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else \
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++(NAME).cnt; \
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result; \
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})
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#else
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# define __libc_lock_trylock_recursive(NAME) \
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__libc_maybe_call (__pthread_mutex_trylock, (&(NAME).mutex), 0)
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#endif
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/* Unlock the recursive named lock variable. */
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#if defined _LIBC && (IS_IN (libc) || IS_IN (libpthread))
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/* We do no error checking here. */
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# define __libc_lock_unlock_recursive(NAME) \
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do { \
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if (--(NAME).cnt == 0) \
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{ \
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(NAME).owner = NULL; \
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lll_unlock ((NAME).lock, LLL_PRIVATE); \
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} \
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} while (0)
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#else
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# define __libc_lock_unlock_recursive(NAME) \
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__libc_maybe_call (__pthread_mutex_unlock, (&(NAME).mutex), 0)
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#endif
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/* Put the unwind buffer BUFFER on the per-thread callback stack. The
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caller must fill BUFFER->__routine and BUFFER->__arg before calling
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this function. */
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void __libc_cleanup_push_defer (struct _pthread_cleanup_buffer *buffer);
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libc_hidden_proto (__libc_cleanup_push_defer)
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/* Remove BUFFER from the unwind callback stack. The caller must invoke
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the callback if desired. */
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void __libc_cleanup_pop_restore (struct _pthread_cleanup_buffer *buffer);
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libc_hidden_proto (__libc_cleanup_pop_restore)
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/* Start critical region with cleanup. */
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#define __libc_cleanup_region_start(DOIT, FCT, ARG) \
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{ bool _cleanup_start_doit; \
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struct _pthread_cleanup_buffer _buffer; \
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/* Non-addressable copy of FCT, so that we avoid indirect calls on \
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the non-unwinding path. */ \
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void (*_cleanup_routine) (void *) = (FCT); \
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_buffer.__arg = (ARG); \
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if (DOIT) \
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{ \
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_cleanup_start_doit = true; \
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_buffer.__routine = _cleanup_routine; \
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__libc_cleanup_push_defer (&_buffer); \
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} \
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else \
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_cleanup_start_doit = false;
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/* End critical region with cleanup. */
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#define __libc_cleanup_region_end(DOIT) \
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if (_cleanup_start_doit) \
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__libc_cleanup_pop_restore (&_buffer); \
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if (DOIT) \
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_cleanup_routine (_buffer.__arg); \
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} /* matches __libc_cleanup_region_start */
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/* Hide the definitions which are only supposed to be used inside libc in
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a separate file. This file is not present in the installation! */
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#ifdef _LIBC
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# include "libc-lockP.h"
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#endif
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#endif /* libc-lock.h */
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