diff options
Diffstat (limited to 'libpthread/nptl/sysdeps/unix/sysv/linux/i386/lowlevellock.h')
| -rw-r--r-- | libpthread/nptl/sysdeps/unix/sysv/linux/i386/lowlevellock.h | 365 |
1 files changed, 365 insertions, 0 deletions
diff --git a/libpthread/nptl/sysdeps/unix/sysv/linux/i386/lowlevellock.h b/libpthread/nptl/sysdeps/unix/sysv/linux/i386/lowlevellock.h new file mode 100644 index 000000000..97f3b09e2 --- /dev/null +++ b/libpthread/nptl/sysdeps/unix/sysv/linux/i386/lowlevellock.h @@ -0,0 +1,365 @@ +/* Copyright (C) 2002, 2003, 2004 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, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ + +#ifndef _LOWLEVELLOCK_H +#define _LOWLEVELLOCK_H 1 + +#include <time.h> +#include <sys/param.h> +#include <bits/pthreadtypes.h> +#include <atomic.h> +#include <sysdep.h> + +/* We have a separate internal lock implementation which is not tied + to binary compatibility. */ + +/* Type for lock object. */ +typedef int lll_lock_t; + +/* Initializers for lock. */ +#define LLL_LOCK_INITIALIZER (0) +#define LLL_LOCK_INITIALIZER_LOCKED (1) + +#include <tls.h> + +#ifndef LOCK_INSTR +# define LOCK_INSTR "lock;" +#endif + +#define FUTEX_WAIT 0 +#define FUTEX_WAKE 1 + + +/* Initializer for compatibility lock. */ +#define LLL_MUTEX_LOCK_INITIALIZER (0) +#define LLL_MUTEX_LOCK_INITIALIZER_LOCKED (1) +#define LLL_MUTEX_LOCK_INITIALIZER_WAITERS (2) + + +#ifdef __PIC__ +# define LLL_EBX_LOAD "xchgl %2, %%ebx\n" +# define LLL_EBX_REG "D" +#else +# define LLL_EBX_LOAD +# define LLL_EBX_REG "b" +#endif + +#define LLL_ENTER_KERNEL "int $0x80\n\t" + +/* Delay in spinlock loop. */ +#define BUSY_WAIT_NOP __asm__ ("rep; nop") + +#define lll_futex_wait(futex, val) \ + lll_futex_timed_wait (futex, val, NULL) + +#define lll_futex_timed_wait(futex, val, timeout) \ + ({ \ + int __ret; \ + register __typeof (val) _val __asm__ ("edx") = (val); \ + __asm__ __volatile (LLL_EBX_LOAD \ + LLL_ENTER_KERNEL \ + LLL_EBX_LOAD \ + : "=a" (__ret) \ + : "0" (SYS_futex), LLL_EBX_REG (futex), "S" (timeout), \ + "c" (FUTEX_WAIT), "d" (_val), \ + "i" (offsetof (tcbhead_t, sysinfo))); \ + __ret; }) + + +#define lll_futex_wake(futex, nr) \ + ({ \ + int __ret; \ + register __typeof (nr) _nr __asm__ ("edx") = (nr); \ + __asm__ __volatile (LLL_EBX_LOAD \ + LLL_ENTER_KERNEL \ + LLL_EBX_LOAD \ + : "=a" (__ret) \ + : "0" (SYS_futex), LLL_EBX_REG (futex), \ + "c" (FUTEX_WAKE), "d" (_nr), \ + "i" (0) /* phony, to align next arg's number */, \ + "i" (offsetof (tcbhead_t, sysinfo))); \ + __ret; }) + + +/* Does not preserve %eax and %ecx. */ +extern int __lll_mutex_lock_wait (int val, int *__futex) + __attribute ((regparm (2))) attribute_hidden; +/* Does not preserve %eax, %ecx, and %edx. */ +extern int __lll_mutex_timedlock_wait (int val, int *__futex, + const struct timespec *abstime) + __attribute ((regparm (3))) attribute_hidden; +/* Preserves all registers but %eax. */ +extern int __lll_mutex_unlock_wake (int *__futex) + __attribute ((regparm (1))) attribute_hidden; + + +/* NB: in the lll_mutex_trylock macro we simply return the value in %eax + after the cmpxchg instruction. In case the operation succeded this + value is zero. In case the operation failed, the cmpxchg instruction + has loaded the current value of the memory work which is guaranteed + to be nonzero. */ +#define lll_mutex_trylock(futex) \ + ({ int ret; \ + __asm__ __volatile (LOCK_INSTR "cmpxchgl %2, %1" \ + : "=a" (ret), "=m" (futex) \ + : "r" (LLL_MUTEX_LOCK_INITIALIZER_LOCKED), "m" (futex),\ + "0" (LLL_MUTEX_LOCK_INITIALIZER) \ + : "memory"); \ + ret; }) + + +#define lll_mutex_cond_trylock(futex) \ + ({ int ret; \ + __asm__ __volatile (LOCK_INSTR "cmpxchgl %2, %1" \ + : "=a" (ret), "=m" (futex) \ + : "r" (LLL_MUTEX_LOCK_INITIALIZER_WAITERS), \ + "m" (futex), "0" (LLL_MUTEX_LOCK_INITIALIZER) \ + : "memory"); \ + ret; }) + + +#define lll_mutex_lock(futex) \ + (void) ({ int ignore1, ignore2; \ + __asm__ __volatile (LOCK_INSTR "cmpxchgl %1, %2\n\t" \ + "jnz _L_mutex_lock_%=\n\t" \ + ".subsection 1\n\t" \ + ".type _L_mutex_lock_%=,@function\n" \ + "_L_mutex_lock_%=:\n\t" \ + "leal %2, %%ecx\n\t" \ + "call __lll_mutex_lock_wait\n\t" \ + "jmp 1f\n\t" \ + ".size _L_mutex_lock_%=,.-_L_mutex_lock_%=\n" \ + ".previous\n" \ + "1:" \ + : "=a" (ignore1), "=c" (ignore2), "=m" (futex) \ + : "0" (0), "1" (1), "m" (futex) \ + : "memory"); }) + + +/* Special version of lll_mutex_lock which causes the unlock function to + always wakeup waiters. */ +#define lll_mutex_cond_lock(futex) \ + (void) ({ int ignore1, ignore2; \ + __asm__ __volatile (LOCK_INSTR "cmpxchgl %1, %2\n\t" \ + "jnz _L_mutex_cond_lock_%=\n\t" \ + ".subsection 1\n\t" \ + ".type _L_mutex_cond_lock_%=,@function\n" \ + "_L_mutex_cond_lock_%=:\n\t" \ + "leal %2, %%ecx\n\t" \ + "call __lll_mutex_lock_wait\n\t" \ + "jmp 1f\n\t" \ + ".size _L_mutex_cond_lock_%=,.-_L_mutex_cond_lock_%=\n" \ + ".previous\n" \ + "1:" \ + : "=a" (ignore1), "=c" (ignore2), "=m" (futex) \ + : "0" (0), "1" (2), "m" (futex) \ + : "memory"); }) + + +#define lll_mutex_timedlock(futex, timeout) \ + ({ int _result, ignore1, ignore2; \ + __asm__ __volatile (LOCK_INSTR "cmpxchgl %1, %3\n\t" \ + "jnz _L_mutex_timedlock_%=\n\t" \ + ".subsection 1\n\t" \ + ".type _L_mutex_timedlock_%=,@function\n" \ + "_L_mutex_timedlock_%=:\n\t" \ + "leal %3, %%ecx\n\t" \ + "movl %7, %%edx\n\t" \ + "call __lll_mutex_timedlock_wait\n\t" \ + "jmp 1f\n\t" \ + ".size _L_mutex_timedlock_%=,.-_L_mutex_timedlock_%=\n"\ + ".previous\n" \ + "1:" \ + : "=a" (_result), "=c" (ignore1), "=&d" (ignore2), \ + "=m" (futex) \ + : "0" (0), "1" (1), "m" (futex), "m" (timeout) \ + : "memory"); \ + _result; }) + + +#define lll_mutex_unlock(futex) \ + (void) ({ int ignore; \ + __asm__ __volatile (LOCK_INSTR "subl $1,%0\n\t" \ + "jne _L_mutex_unlock_%=\n\t" \ + ".subsection 1\n\t" \ + ".type _L_mutex_unlock_%=,@function\n" \ + "_L_mutex_unlock_%=:\n\t" \ + "leal %0, %%eax\n\t" \ + "call __lll_mutex_unlock_wake\n\t" \ + "jmp 1f\n\t" \ + ".size _L_mutex_unlock_%=,.-_L_mutex_unlock_%=\n" \ + ".previous\n" \ + "1:" \ + : "=m" (futex), "=&a" (ignore) \ + : "m" (futex) \ + : "memory"); }) + + +#define lll_mutex_islocked(futex) \ + (futex != 0) + + +extern int __lll_lock_wait (int val, int *__futex) + __attribute ((regparm (2))) attribute_hidden; +extern int __lll_unlock_wake (int *__futex) + __attribute ((regparm (1))) attribute_hidden; +extern int lll_unlock_wake_cb (int *__futex) attribute_hidden; + + +/* The states of a lock are: + 0 - untaken + 1 - taken by one user + 2 - taken by more users */ + + +#if defined NOT_IN_libc +# define lll_trylock(futex) lll_mutex_trylock (futex) +# define lll_lock(futex) lll_mutex_lock (futex) +# define lll_unlock(futex) lll_mutex_unlock (futex) +#else +/* Special versions of the macros for use in libc itself. They avoid + the lock prefix when the thread library is not used. */ + + + +# define lll_trylock(futex) \ + ({ unsigned char ret; \ + __asm__ __volatile ("cmpl $0, %%gs:%P5\n\t" \ + "je,pt 0f\n\t" \ + "lock\n" \ + "0:\tcmpxchgl %2, %1; setne %0" \ + : "=a" (ret), "=m" (futex) \ + : "r" (LLL_MUTEX_LOCK_INITIALIZER_LOCKED), "m" (futex),\ + "0" (LLL_MUTEX_LOCK_INITIALIZER), \ + "i" (offsetof (tcbhead_t, multiple_threads)) \ + : "memory"); \ + ret; }) + + +# define lll_lock(futex) \ + (void) ({ int ignore1, ignore2; \ + __asm__ __volatile ("cmpl $0, %%gs:%P6\n\t" \ + "je,pt 0f\n\t" \ + "lock\n" \ + "0:\tcmpxchgl %1, %2\n\t" \ + "jnz _L_mutex_lock_%=\n\t" \ + ".subsection 1\n\t" \ + ".type _L_mutex_lock_%=,@function\n" \ + "_L_mutex_lock_%=:\n\t" \ + "leal %2, %%ecx\n\t" \ + "call __lll_mutex_lock_wait\n\t" \ + "jmp 1f\n\t" \ + ".size _L_mutex_lock_%=,.-_L_mutex_lock_%=\n" \ + ".previous\n" \ + "1:" \ + : "=a" (ignore1), "=c" (ignore2), "=m" (futex) \ + : "0" (0), "1" (1), "m" (futex), \ + "i" (offsetof (tcbhead_t, multiple_threads)) \ + : "memory"); }) + + +# define lll_unlock(futex) \ + (void) ({ int ignore; \ + __asm__ __volatile ("cmpl $0, %%gs:%P3\n\t" \ + "je,pt 0f\n\t" \ + "lock\n" \ + "0:\tsubl $1,%0\n\t" \ + "jne _L_mutex_unlock_%=\n\t" \ + ".subsection 1\n\t" \ + ".type _L_mutex_unlock_%=,@function\n" \ + "_L_mutex_unlock_%=:\n\t" \ + "leal %0, %%eax\n\t" \ + "call __lll_mutex_unlock_wake\n\t" \ + "jmp 1f\n\t" \ + ".size _L_mutex_unlock_%=,.-_L_mutex_unlock_%=\n" \ + ".previous\n" \ + "1:" \ + : "=m" (futex), "=&a" (ignore) \ + : "m" (futex), \ + "i" (offsetof (tcbhead_t, multiple_threads)) \ + : "memory"); }) +#endif + + +#define lll_islocked(futex) \ + (futex != LLL_LOCK_INITIALIZER) + + +/* The kernel notifies a process with uses CLONE_CLEARTID via futex + wakeup when the clone terminates. The memory location contains the + thread ID while the clone is running and is reset to zero + afterwards. + + The macro parameter must not have any side effect. */ +#define lll_wait_tid(tid) \ + ({ \ + int __ret; \ + register __typeof (tid) _tid __asm__ ("edx") = (tid); \ + if (_tid != 0) \ + __asm__ __volatile (LLL_EBX_LOAD \ + "1:\tmovl %1, %%eax\n\t" \ + LLL_ENTER_KERNEL \ + "cmpl $0, (%%ebx)\n\t" \ + "jne,pn 1b\n\t" \ + LLL_EBX_LOAD \ + : "=&a" (__ret) \ + : "i" (SYS_futex), LLL_EBX_REG (&tid), "S" (0), \ + "c" (FUTEX_WAIT), "d" (_tid), \ + "i" (offsetof (tcbhead_t, sysinfo))); \ + __ret; }) + +extern int __lll_timedwait_tid (int *tid, const struct timespec *abstime) + __attribute__ ((regparm (2))) attribute_hidden; +#define lll_timedwait_tid(tid, abstime) \ + ({ \ + int __result = 0; \ + if (tid != 0) \ + { \ + if (abstime->tv_nsec < 0 || abstime->tv_nsec >= 1000000000) \ + __result = EINVAL; \ + else \ + __result = __lll_timedwait_tid (&tid, abstime); \ + } \ + __result; }) + + +/* Conditional variable handling. */ + +extern void __lll_cond_wait (pthread_cond_t *cond) + __attribute ((regparm (1))) attribute_hidden; +extern int __lll_cond_timedwait (pthread_cond_t *cond, + const struct timespec *abstime) + __attribute ((regparm (2))) attribute_hidden; +extern void __lll_cond_wake (pthread_cond_t *cond) + __attribute ((regparm (1))) attribute_hidden; +extern void __lll_cond_broadcast (pthread_cond_t *cond) + __attribute ((regparm (1))) attribute_hidden; + + +#define lll_cond_wait(cond) \ + __lll_cond_wait (cond) +#define lll_cond_timedwait(cond, abstime) \ + __lll_cond_timedwait (cond, abstime) +#define lll_cond_wake(cond) \ + __lll_cond_wake (cond) +#define lll_cond_broadcast(cond) \ + __lll_cond_broadcast (cond) + + +#endif /* lowlevellock.h */ |