diff options
Diffstat (limited to 'nptl/sysdeps/pthread/bits/libc-lock.h')
| -rw-r--r-- | nptl/sysdeps/pthread/bits/libc-lock.h | 122 |
1 files changed, 94 insertions, 28 deletions
diff --git a/nptl/sysdeps/pthread/bits/libc-lock.h b/nptl/sysdeps/pthread/bits/libc-lock.h index 0001676a3b..9536d0c909 100644 --- a/nptl/sysdeps/pthread/bits/libc-lock.h +++ b/nptl/sysdeps/pthread/bits/libc-lock.h @@ -24,9 +24,24 @@ #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. */ +#ifdef _LIBC +# include <lowlevellock.h> +#endif + /* Mutex type. */ -#if defined(_LIBC) || defined(_IO_MTSAFE_IO) +#if defined _LIBC || defined _IO_MTSAFE_IO +# if defined NOT_IN_libc || !defined _LIBC typedef pthread_mutex_t __libc_lock_t; +# else +typedef int __libc_lock_t; +# endif typedef struct { pthread_mutex_t mutex; } __libc_lock_recursive_t; # ifdef __USE_UNIX98 typedef pthread_rwlock_t __libc_rwlock_t; @@ -65,12 +80,22 @@ typedef pthread_key_t __libc_key_t; initialized locks must be set to one due to the lack of normal atomic operations.) */ -#if __LT_SPINLOCK_INIT == 0 +#if defined _LIBC && !defined NOT_IN_libc +# 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 +# if __LT_SPINLOCK_INIT == 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 = PTHREAD_MUTEX_INITIALIZER; +# endif #endif #define __libc_rwlock_define_initialized(CLASS,NAME) \ @@ -83,12 +108,32 @@ typedef pthread_key_t __libc_key_t; #define _LIBC_LOCK_RECURSIVE_INITIALIZER \ {PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP} + +/* 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 + + /* Initialize the named lock variable, leaving it in a consistent, unlocked state. */ -#define __libc_lock_init(NAME) \ - (__pthread_mutex_init != NULL ? __pthread_mutex_init (&(NAME), NULL) : 0); +#if defined _LIBC && !defined NOT_IN_libc +# define __libc_lock_init(NAME) (NAME) = LLL_LOCK_INITIALIZER; +#else +# define __libc_lock_init(NAME) \ + __libc_maybe_call (__pthread_mutex_init, (&(NAME), NULL), 0) +#endif #define __libc_rwlock_init(NAME) \ - (__pthread_rwlock_init != NULL ? __pthread_rwlock_init (&(NAME), NULL) : 0); + __libc_maybe_call (__pthread_rwlock_init, (&(NAME), NULL), 0) /* Same as last but this time we initialize a recursive mutex. */ #define __libc_lock_init_recursive(NAME) \ @@ -106,46 +151,67 @@ typedef pthread_key_t __libc_key_t; /* 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. */ -#define __libc_lock_fini(NAME) \ - (__pthread_mutex_destroy != NULL ? __pthread_mutex_destroy (&(NAME)) : 0); +#if defined _LIBC && !defined NOT_IN_libc +# define __libc_lock_fini(NAME) (0) +#else +# define __libc_lock_fini(NAME) \ + __libc_maybe_call (__pthread_mutex_destroy, (&(NAME)), 0) +#endif #define __libc_rwlock_fini(NAME) \ - (__pthread_rwlock_destroy != NULL ? __pthread_rwlock_destroy (&(NAME)) : 0); + __libc_maybe_call (__pthread_rwlock_destroy, (&(NAME)), 0) /* Finalize recursive named lock. */ -#define __libc_lock_fini_recursive(NAME) __libc_lock_fini ((NAME).mutex) +#define __libc_lock_fini_recursive(NAME) \ + __libc_maybe_call (__pthread_mutex_destroy, (&(NAME)), 0) /* Lock the named lock variable. */ -#define __libc_lock_lock(NAME) \ - (__pthread_mutex_lock != NULL ? __pthread_mutex_lock (&(NAME)) : 0); +#if defined _LIBC && !defined NOT_IN_libc +# define __libc_lock_lock(NAME) \ + lll_lock (NAME); +#else +# define __libc_lock_lock(NAME) \ + __libc_maybe_call (__pthread_mutex_lock, (&(NAME)), 0) +#endif #define __libc_rwlock_rdlock(NAME) \ - (__pthread_rwlock_rdlock != NULL ? __pthread_rwlock_rdlock (&(NAME)) : 0); + __libc_maybe_call (__pthread_rwlock_rdlock, (&(NAME)), 0) #define __libc_rwlock_wrlock(NAME) \ - (__pthread_rwlock_wrlock != NULL ? __pthread_rwlock_wrlock (&(NAME)) : 0); + __libc_maybe_call (__pthread_rwlock_wrlock, (&(NAME)), 0) /* Lock the recursive named lock variable. */ -#define __libc_lock_lock_recursive(NAME) __libc_lock_lock ((NAME).mutex) +#define __libc_lock_lock_recursive(NAME) \ + __libc_maybe_call (__pthread_mutex_lock, (&(NAME)), 0) /* Try to lock the named lock variable. */ -#define __libc_lock_trylock(NAME) \ - (__pthread_mutex_trylock != NULL ? __pthread_mutex_trylock (&(NAME)) : 0) +#if defined _LIBC && !defined NOT_IN_libc +# define __libc_lock_trylock(NAME) \ + lll_trylock (NAME) +#else +# define __libc_lock_trylock(NAME) \ + __libc_maybe_call (__pthread_mutex_trylock, (&(NAME)), 0) +#endif #define __libc_rwlock_tryrdlock(NAME) \ - (__pthread_rwlock_tryrdlock != NULL \ - ? __pthread_rwlock_tryrdlock (&(NAME)) : 0) + __libc_maybe_call (__pthread_rwlock_tryrdlock, (&(NAME)), 0) #define __libc_rwlock_trywrlock(NAME) \ - (__pthread_rwlock_trywrlock != NULL \ - ? __pthread_rwlock_trywrlock (&(NAME)) : 0) + __libc_maybe_call (__pthread_rwlock_trywrlock, (&(NAME)), 0) /* Try to lock the recursive named lock variable. */ -#define __libc_lock_trylock_recursive(NAME) __libc_lock_trylock ((NAME).mutex) +#define __libc_lock_trylock_recursive(NAME) \ + __libc_maybe_call (__pthread_mutex_trylock, (&(NAME)), 0) /* Unlock the named lock variable. */ -#define __libc_lock_unlock(NAME) \ - (__pthread_mutex_unlock != NULL ? __pthread_mutex_unlock (&(NAME)) : 0); +#if defined _LIBC && !defined NOT_IN_libc +# define __libc_lock_unlock(NAME) \ + lll_unlock (NAME); +#else +# define __libc_lock_unlock(NAME) \ + __libc_maybe_call (__pthread_mutex_unlock, (&(NAME)), 0) +#endif #define __libc_rwlock_unlock(NAME) \ - (__pthread_rwlock_unlock != NULL ? __pthread_rwlock_unlock (&(NAME)) : 0); + __libc_maybe_call (__pthread_rwlock_unlock, (&(NAME)), 0) /* Unlock the recursive named lock variable. */ -#define __libc_lock_unlock_recursive(NAME) __libc_lock_unlock ((NAME).mutex) +#define __libc_lock_unlock_recursive(NAME) \ + __libc_maybe_call (__pthread_mutex_unlock, (&(NAME)), 0) /* Define once control variable. */ @@ -194,15 +260,15 @@ typedef pthread_key_t __libc_key_t; /* Create thread-specific key. */ #define __libc_key_create(KEY, DESTRUCTOR) \ - (__pthread_key_create != NULL ? __pthread_key_create (KEY, DESTRUCTOR) : 1) + __libc_maybe_call (__pthread_key_create, (KEY, DESTRUCTOR), 1) /* Get thread-specific data. */ #define __libc_getspecific(KEY) \ - (__pthread_getspecific != NULL ? __pthread_getspecific (KEY) : NULL) + __libc_maybe_call (__pthread_getspecific, (KEY), NULL) /* Set thread-specific data. */ #define __libc_setspecific(KEY, VALUE) \ - (__pthread_setspecific != NULL ? __pthread_setspecific (KEY, VALUE) : 0) + __libc_maybe_call (__pthread_setspecific, (KEY, VALUE), 0) /* Register handlers to execute before and after `fork'. Note that the |