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Diffstat (limited to 'sysdeps/nptl/bits/libc-lockP.h')
| -rw-r--r-- | sysdeps/nptl/bits/libc-lockP.h | 424 |
1 files changed, 424 insertions, 0 deletions
diff --git a/sysdeps/nptl/bits/libc-lockP.h b/sysdeps/nptl/bits/libc-lockP.h new file mode 100644 index 0000000000..ec202713d6 --- /dev/null +++ b/sysdeps/nptl/bits/libc-lockP.h @@ -0,0 +1,424 @@ +/* Private libc-internal interface for mutex locks. NPTL version. + Copyright (C) 1996-2014 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + 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; see the file COPYING.LIB. If + not, see <http://www.gnu.org/licenses/>. */ + +#ifndef _BITS_LIBC_LOCKP_H +#define _BITS_LIBC_LOCKP_H 1 + +#include <pthread.h> +#define __need_NULL +#include <stddef.h> + + +/* Fortunately Linux now has a mean to do locking which is realtime + safe without the aid of the thread library. We also need no fancy + options like error checking mutexes etc. We only need simple + locks, maybe recursive. This can be easily and cheaply implemented + using futexes. We will use them everywhere except in ld.so since + ld.so might be used on old kernels with a different libc.so. */ +#include <lowlevellock.h> +#include <tls.h> +#include <pthread-functions.h> + +/* Mutex type. */ +#if defined NOT_IN_libc && !defined IS_IN_libpthread +typedef pthread_mutex_t __libc_lock_t; +#else +typedef int __libc_lock_t; +#endif +typedef struct { pthread_mutex_t mutex; } __rtld_lock_recursive_t; +typedef pthread_rwlock_t __libc_rwlock_t; + +/* Type for key to thread-specific data. */ +typedef pthread_key_t __libc_key_t; + +/* Define a lock variable NAME with storage class CLASS. The lock must be + initialized with __libc_lock_init before it can be used (or define it + with __libc_lock_define_initialized, below). Use `extern' for CLASS to + declare a lock defined in another module. In public structure + definitions you must use a pointer to the lock structure (i.e., NAME + begins with a `*'), because its storage size will not be known outside + of libc. */ +#define __libc_lock_define(CLASS,NAME) \ + CLASS __libc_lock_t NAME; +#define __libc_rwlock_define(CLASS,NAME) \ + CLASS __libc_rwlock_t NAME; +#define __rtld_lock_define_recursive(CLASS,NAME) \ + CLASS __rtld_lock_recursive_t NAME; + +/* Define an initialized lock variable NAME with storage class CLASS. + + For the C library we take a deeper look at the initializer. For + this implementation all fields are initialized to zero. Therefore + we don't initialize the variable which allows putting it into the + BSS section. (Except on PA-RISC and other odd architectures, where + initialized locks must be set to one due to the lack of normal + atomic operations.) */ + +#if !defined NOT_IN_libc || defined IS_IN_libpthread +# if LLL_LOCK_INITIALIZER == 0 +# define __libc_lock_define_initialized(CLASS,NAME) \ + CLASS __libc_lock_t NAME; +# else +# define __libc_lock_define_initialized(CLASS,NAME) \ + CLASS __libc_lock_t NAME = LLL_LOCK_INITIALIZER; +# endif +#else +# define __libc_lock_define_initialized(CLASS,NAME) \ + CLASS __libc_lock_t NAME; +#endif + +#define __libc_rwlock_define_initialized(CLASS,NAME) \ + CLASS __libc_rwlock_t NAME = PTHREAD_RWLOCK_INITIALIZER; + +#define __rtld_lock_define_initialized_recursive(CLASS,NAME) \ + CLASS __rtld_lock_recursive_t NAME = _RTLD_LOCK_RECURSIVE_INITIALIZER; +#define _RTLD_LOCK_RECURSIVE_INITIALIZER \ + {PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP} + +#define __rtld_lock_initialize(NAME) \ + (void) ((NAME) = (__rtld_lock_recursive_t) _RTLD_LOCK_RECURSIVE_INITIALIZER) + +/* If we check for a weakly referenced symbol and then perform a + normal jump to it te code generated for some platforms in case of + PIC is unnecessarily slow. What would happen is that the function + is first referenced as data and then it is called indirectly + through the PLT. We can make this a direct jump. */ +#ifdef __PIC__ +# define __libc_maybe_call(FUNC, ARGS, ELSE) \ + (__extension__ ({ __typeof (FUNC) *_fn = (FUNC); \ + _fn != NULL ? (*_fn) ARGS : ELSE; })) +#else +# define __libc_maybe_call(FUNC, ARGS, ELSE) \ + (FUNC != NULL ? FUNC ARGS : ELSE) +#endif + +/* Call thread functions through the function pointer table. */ +#if defined SHARED && !defined NOT_IN_libc +# define PTFAVAIL(NAME) __libc_pthread_functions_init +# define __libc_ptf_call(FUNC, ARGS, ELSE) \ + (__libc_pthread_functions_init ? PTHFCT_CALL (ptr_##FUNC, ARGS) : ELSE) +# define __libc_ptf_call_always(FUNC, ARGS) \ + PTHFCT_CALL (ptr_##FUNC, ARGS) +#else +# define PTFAVAIL(NAME) (NAME != NULL) +# define __libc_ptf_call(FUNC, ARGS, ELSE) \ + __libc_maybe_call (FUNC, ARGS, ELSE) +# define __libc_ptf_call_always(FUNC, ARGS) \ + FUNC ARGS +#endif + + +/* Initialize the named lock variable, leaving it in a consistent, unlocked + state. */ +#if !defined NOT_IN_libc || defined IS_IN_libpthread +# define __libc_lock_init(NAME) ((NAME) = LLL_LOCK_INITIALIZER, 0) +#else +# define __libc_lock_init(NAME) \ + __libc_maybe_call (__pthread_mutex_init, (&(NAME), NULL), 0) +#endif +#if defined SHARED && !defined NOT_IN_libc +/* ((NAME) = (__libc_rwlock_t) PTHREAD_RWLOCK_INITIALIZER, 0) is + inefficient. */ +# define __libc_rwlock_init(NAME) \ + (__builtin_memset (&(NAME), '\0', sizeof (NAME)), 0) +#else +# define __libc_rwlock_init(NAME) \ + __libc_maybe_call (__pthread_rwlock_init, (&(NAME), NULL), 0) +#endif + +/* Finalize the named lock variable, which must be locked. It cannot be + used again until __libc_lock_init is called again on it. This must be + called on a lock variable before the containing storage is reused. */ +#if !defined NOT_IN_libc || defined IS_IN_libpthread +# define __libc_lock_fini(NAME) ((void) 0) +#else +# define __libc_lock_fini(NAME) \ + __libc_maybe_call (__pthread_mutex_destroy, (&(NAME)), 0) +#endif +#if defined SHARED && !defined NOT_IN_libc +# define __libc_rwlock_fini(NAME) ((void) 0) +#else +# define __libc_rwlock_fini(NAME) \ + __libc_maybe_call (__pthread_rwlock_destroy, (&(NAME)), 0) +#endif + +/* Lock the named lock variable. */ +#if !defined NOT_IN_libc || defined IS_IN_libpthread +# ifndef __libc_lock_lock +# define __libc_lock_lock(NAME) \ + ({ lll_lock (NAME, LLL_PRIVATE); 0; }) +# endif +#else +# undef __libc_lock_lock +# define __libc_lock_lock(NAME) \ + __libc_maybe_call (__pthread_mutex_lock, (&(NAME)), 0) +#endif +#define __libc_rwlock_rdlock(NAME) \ + __libc_ptf_call (__pthread_rwlock_rdlock, (&(NAME)), 0) +#define __libc_rwlock_wrlock(NAME) \ + __libc_ptf_call (__pthread_rwlock_wrlock, (&(NAME)), 0) + +/* Try to lock the named lock variable. */ +#if !defined NOT_IN_libc || defined IS_IN_libpthread +# ifndef __libc_lock_trylock +# define __libc_lock_trylock(NAME) \ + lll_trylock (NAME) +# endif +#else +# undef __libc_lock_trylock +# define __libc_lock_trylock(NAME) \ + __libc_maybe_call (__pthread_mutex_trylock, (&(NAME)), 0) +#endif +#define __libc_rwlock_tryrdlock(NAME) \ + __libc_maybe_call (__pthread_rwlock_tryrdlock, (&(NAME)), 0) +#define __libc_rwlock_trywrlock(NAME) \ + __libc_maybe_call (__pthread_rwlock_trywrlock, (&(NAME)), 0) + +#define __rtld_lock_trylock_recursive(NAME) \ + __libc_maybe_call (__pthread_mutex_trylock, (&(NAME).mutex), 0) + +/* Unlock the named lock variable. */ +#if !defined NOT_IN_libc || defined IS_IN_libpthread +# define __libc_lock_unlock(NAME) \ + lll_unlock (NAME, LLL_PRIVATE) +#else +# define __libc_lock_unlock(NAME) \ + __libc_maybe_call (__pthread_mutex_unlock, (&(NAME)), 0) +#endif +#define __libc_rwlock_unlock(NAME) \ + __libc_ptf_call (__pthread_rwlock_unlock, (&(NAME)), 0) + +#ifdef SHARED +# define __rtld_lock_default_lock_recursive(lock) \ + ++((pthread_mutex_t *)(lock))->__data.__count; + +# define __rtld_lock_default_unlock_recursive(lock) \ + --((pthread_mutex_t *)(lock))->__data.__count; + +# define __rtld_lock_lock_recursive(NAME) \ + GL(dl_rtld_lock_recursive) (&(NAME).mutex) + +# define __rtld_lock_unlock_recursive(NAME) \ + GL(dl_rtld_unlock_recursive) (&(NAME).mutex) +#else +# define __rtld_lock_lock_recursive(NAME) \ + __libc_maybe_call (__pthread_mutex_lock, (&(NAME).mutex), 0) + +# define __rtld_lock_unlock_recursive(NAME) \ + __libc_maybe_call (__pthread_mutex_unlock, (&(NAME).mutex), 0) +#endif + +/* Define once control variable. */ +#if PTHREAD_ONCE_INIT == 0 +/* Special case for static variables where we can avoid the initialization + if it is zero. */ +# define __libc_once_define(CLASS, NAME) \ + CLASS pthread_once_t NAME +#else +# define __libc_once_define(CLASS, NAME) \ + CLASS pthread_once_t NAME = PTHREAD_ONCE_INIT +#endif + +/* Call handler iff the first call. */ +#define __libc_once(ONCE_CONTROL, INIT_FUNCTION) \ + do { \ + if (PTFAVAIL (__pthread_once)) \ + __libc_ptf_call_always (__pthread_once, (&(ONCE_CONTROL), \ + INIT_FUNCTION)); \ + else if ((ONCE_CONTROL) == PTHREAD_ONCE_INIT) { \ + INIT_FUNCTION (); \ + (ONCE_CONTROL) |= 2; \ + } \ + } while (0) + +/* Get once control variable. */ +#define __libc_once_get(ONCE_CONTROL) ((ONCE_CONTROL) != PTHREAD_ONCE_INIT) + +/* Note that for I/O cleanup handling we are using the old-style + cancel handling. It does not have to be integrated with C++ snce + no C++ code is called in the middle. The old-style handling is + faster and the support is not going away. */ +extern void _pthread_cleanup_push (struct _pthread_cleanup_buffer *buffer, + void (*routine) (void *), void *arg); +extern void _pthread_cleanup_pop (struct _pthread_cleanup_buffer *buffer, + int execute); +extern void _pthread_cleanup_push_defer (struct _pthread_cleanup_buffer *buffer, + void (*routine) (void *), void *arg); +extern void _pthread_cleanup_pop_restore (struct _pthread_cleanup_buffer *buffer, + int execute); + +/* Sometimes we have to exit the block in the middle. */ +#define __libc_cleanup_end(DOIT) \ + if (_avail) { \ + __libc_ptf_call_always (_pthread_cleanup_pop_restore, (&_buffer, DOIT));\ + } else if (DOIT) \ + _buffer.__routine (_buffer.__arg) + + +/* Normal cleanup handling, based on C cleanup attribute. */ +__extern_inline void +__libc_cleanup_routine (struct __pthread_cleanup_frame *f) +{ + if (f->__do_it) + f->__cancel_routine (f->__cancel_arg); +} + +#define __libc_cleanup_push(fct, arg) \ + do { \ + struct __pthread_cleanup_frame __clframe \ + __attribute__ ((__cleanup__ (__libc_cleanup_routine))) \ + = { .__cancel_routine = (fct), .__cancel_arg = (arg), \ + .__do_it = 1 }; + +#define __libc_cleanup_pop(execute) \ + __clframe.__do_it = (execute); \ + } while (0) + + +/* Create thread-specific key. */ +#define __libc_key_create(KEY, DESTRUCTOR) \ + __libc_ptf_call (__pthread_key_create, (KEY, DESTRUCTOR), 1) + +/* Get thread-specific data. */ +#define __libc_getspecific(KEY) \ + __libc_ptf_call (__pthread_getspecific, (KEY), NULL) + +/* Set thread-specific data. */ +#define __libc_setspecific(KEY, VALUE) \ + __libc_ptf_call (__pthread_setspecific, (KEY, VALUE), 0) + + +/* Register handlers to execute before and after `fork'. Note that the + last parameter is NULL. The handlers registered by the libc are + never removed so this is OK. */ +#define __libc_atfork(PREPARE, PARENT, CHILD) \ + __register_atfork (PREPARE, PARENT, CHILD, NULL) +extern int __register_atfork (void (*__prepare) (void), + void (*__parent) (void), + void (*__child) (void), + void *__dso_handle); + +/* Functions that are used by this file and are internal to the GNU C + library. */ + +extern int __pthread_mutex_init (pthread_mutex_t *__mutex, + const pthread_mutexattr_t *__mutex_attr); + +extern int __pthread_mutex_destroy (pthread_mutex_t *__mutex); + +extern int __pthread_mutex_trylock (pthread_mutex_t *__mutex); + +extern int __pthread_mutex_lock (pthread_mutex_t *__mutex); + +extern int __pthread_mutex_unlock (pthread_mutex_t *__mutex); + +extern int __pthread_mutexattr_init (pthread_mutexattr_t *__attr); + +extern int __pthread_mutexattr_destroy (pthread_mutexattr_t *__attr); + +extern int __pthread_mutexattr_settype (pthread_mutexattr_t *__attr, + int __kind); + +extern int __pthread_rwlock_init (pthread_rwlock_t *__rwlock, + const pthread_rwlockattr_t *__attr); + +extern int __pthread_rwlock_destroy (pthread_rwlock_t *__rwlock); + +extern int __pthread_rwlock_rdlock (pthread_rwlock_t *__rwlock); + +extern int __pthread_rwlock_tryrdlock (pthread_rwlock_t *__rwlock); + +extern int __pthread_rwlock_wrlock (pthread_rwlock_t *__rwlock); + +extern int __pthread_rwlock_trywrlock (pthread_rwlock_t *__rwlock); + +extern int __pthread_rwlock_unlock (pthread_rwlock_t *__rwlock); + +extern int __pthread_key_create (pthread_key_t *__key, + void (*__destr_function) (void *)); + +extern int __pthread_setspecific (pthread_key_t __key, + const void *__pointer); + +extern void *__pthread_getspecific (pthread_key_t __key); + +extern int __pthread_once (pthread_once_t *__once_control, + void (*__init_routine) (void)); + +extern int __pthread_atfork (void (*__prepare) (void), + void (*__parent) (void), + void (*__child) (void)); + + + +/* Make the pthread functions weak so that we can elide them from + single-threaded processes. */ +#ifndef __NO_WEAK_PTHREAD_ALIASES +# ifdef weak_extern +weak_extern (__pthread_mutex_init) +weak_extern (__pthread_mutex_destroy) +weak_extern (__pthread_mutex_lock) +weak_extern (__pthread_mutex_trylock) +weak_extern (__pthread_mutex_unlock) +weak_extern (__pthread_mutexattr_init) +weak_extern (__pthread_mutexattr_destroy) +weak_extern (__pthread_mutexattr_settype) +weak_extern (__pthread_rwlock_init) +weak_extern (__pthread_rwlock_destroy) +weak_extern (__pthread_rwlock_rdlock) +weak_extern (__pthread_rwlock_tryrdlock) +weak_extern (__pthread_rwlock_wrlock) +weak_extern (__pthread_rwlock_trywrlock) +weak_extern (__pthread_rwlock_unlock) +weak_extern (__pthread_key_create) +weak_extern (__pthread_setspecific) +weak_extern (__pthread_getspecific) +weak_extern (__pthread_once) +weak_extern (__pthread_initialize) +weak_extern (__pthread_atfork) +weak_extern (_pthread_cleanup_push_defer) +weak_extern (_pthread_cleanup_pop_restore) +weak_extern (pthread_setcancelstate) +# else +# pragma weak __pthread_mutex_init +# pragma weak __pthread_mutex_destroy +# pragma weak __pthread_mutex_lock +# pragma weak __pthread_mutex_trylock +# pragma weak __pthread_mutex_unlock +# pragma weak __pthread_mutexattr_init +# pragma weak __pthread_mutexattr_destroy +# pragma weak __pthread_mutexattr_settype +# pragma weak __pthread_rwlock_destroy +# pragma weak __pthread_rwlock_rdlock +# pragma weak __pthread_rwlock_tryrdlock +# pragma weak __pthread_rwlock_wrlock +# pragma weak __pthread_rwlock_trywrlock +# pragma weak __pthread_rwlock_unlock +# pragma weak __pthread_key_create +# pragma weak __pthread_setspecific +# pragma weak __pthread_getspecific +# pragma weak __pthread_once +# pragma weak __pthread_initialize +# pragma weak __pthread_atfork +# pragma weak _pthread_cleanup_push_defer +# pragma weak _pthread_cleanup_pop_restore +# pragma weak pthread_setcancelstate +# endif +#endif + +#endif /* bits/libc-lockP.h */ |