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Diffstat (limited to 'REORG.TODO/sysdeps/unix/sysv/linux/i386/lowlevellock.h')
| -rw-r--r-- | REORG.TODO/sysdeps/unix/sysv/linux/i386/lowlevellock.h | 267 |
1 files changed, 267 insertions, 0 deletions
diff --git a/REORG.TODO/sysdeps/unix/sysv/linux/i386/lowlevellock.h b/REORG.TODO/sysdeps/unix/sysv/linux/i386/lowlevellock.h new file mode 100644 index 0000000000..197bb1fcd9 --- /dev/null +++ b/REORG.TODO/sysdeps/unix/sysv/linux/i386/lowlevellock.h @@ -0,0 +1,267 @@ +/* Copyright (C) 2002-2017 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/>. */ + +#ifndef _LOWLEVELLOCK_H +#define _LOWLEVELLOCK_H 1 + +#include <stap-probe.h> + +#ifndef __ASSEMBLER__ +# include <time.h> +# include <sys/param.h> +# include <bits/pthreadtypes.h> +# include <kernel-features.h> +# include <tcb-offsets.h> + +# ifndef LOCK_INSTR +# ifdef UP +# define LOCK_INSTR /* nothing */ +# else +# define LOCK_INSTR "lock;" +# endif +# endif +#else +# ifndef LOCK +# ifdef UP +# define LOCK +# else +# define LOCK lock +# endif +# endif +#endif + +#include <lowlevellock-futex.h> + +/* XXX Remove when no assembler code uses futexes anymore. */ +#define SYS_futex __NR_futex + +#ifndef __ASSEMBLER__ + +/* Initializer for compatibility lock. */ +#define LLL_LOCK_INITIALIZER (0) +#define LLL_LOCK_INITIALIZER_LOCKED (1) +#define LLL_LOCK_INITIALIZER_WAITERS (2) + + +/* NB: in the lll_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. */ +#if !IS_IN (libc) || defined UP +# define __lll_trylock_asm LOCK_INSTR "cmpxchgl %2, %1" +#else +# define __lll_trylock_asm "cmpl $0, %%gs:%P5\n\t" \ + "je 0f\n\t" \ + "lock\n" \ + "0:\tcmpxchgl %2, %1" +#endif + +#define lll_trylock(futex) \ + ({ int ret; \ + __asm __volatile (__lll_trylock_asm \ + : "=a" (ret), "=m" (futex) \ + : "r" (LLL_LOCK_INITIALIZER_LOCKED), "m" (futex), \ + "0" (LLL_LOCK_INITIALIZER), \ + "i" (MULTIPLE_THREADS_OFFSET) \ + : "memory"); \ + ret; }) + + +#define lll_cond_trylock(futex) \ + ({ int ret; \ + __asm __volatile (LOCK_INSTR "cmpxchgl %2, %1" \ + : "=a" (ret), "=m" (futex) \ + : "r" (LLL_LOCK_INITIALIZER_WAITERS), \ + "m" (futex), "0" (LLL_LOCK_INITIALIZER) \ + : "memory"); \ + ret; }) + +#if !IS_IN (libc) || defined UP +# define __lll_lock_asm_start LOCK_INSTR "cmpxchgl %1, %2\n\t" +#else +# define __lll_lock_asm_start "cmpl $0, %%gs:%P6\n\t" \ + "je 0f\n\t" \ + "lock\n" \ + "0:\tcmpxchgl %1, %2\n\t" +#endif + +#define lll_lock(futex, private) \ + (void) \ + ({ int ignore1, ignore2; \ + if (__builtin_constant_p (private) && (private) == LLL_PRIVATE) \ + __asm __volatile (__lll_lock_asm_start \ + "jz 18f\n\t" \ + "1:\tleal %2, %%ecx\n" \ + "2:\tcall __lll_lock_wait_private\n" \ + "18:" \ + : "=a" (ignore1), "=c" (ignore2), "=m" (futex) \ + : "0" (0), "1" (1), "m" (futex), \ + "i" (MULTIPLE_THREADS_OFFSET) \ + : "memory"); \ + else \ + { \ + int ignore3; \ + __asm __volatile (__lll_lock_asm_start \ + "jz 18f\n\t" \ + "1:\tleal %2, %%edx\n" \ + "0:\tmovl %8, %%ecx\n" \ + "2:\tcall __lll_lock_wait\n" \ + "18:" \ + : "=a" (ignore1), "=c" (ignore2), \ + "=m" (futex), "=&d" (ignore3) \ + : "1" (1), "m" (futex), \ + "i" (MULTIPLE_THREADS_OFFSET), "0" (0), \ + "g" ((int) (private)) \ + : "memory"); \ + } \ + }) + + +/* Special version of lll_lock which causes the unlock function to + always wakeup waiters. */ +#define lll_cond_lock(futex, private) \ + (void) \ + ({ int ignore1, ignore2, ignore3; \ + __asm __volatile (LOCK_INSTR "cmpxchgl %1, %2\n\t" \ + "jz 18f\n\t" \ + "1:\tleal %2, %%edx\n" \ + "0:\tmovl %7, %%ecx\n" \ + "2:\tcall __lll_lock_wait\n" \ + "18:" \ + : "=a" (ignore1), "=c" (ignore2), "=m" (futex), \ + "=&d" (ignore3) \ + : "0" (0), "1" (2), "m" (futex), "g" ((int) (private))\ + : "memory"); \ + }) + + +#define lll_timedlock(futex, timeout, private) \ + ({ int result, ignore1, ignore2, ignore3; \ + __asm __volatile (LOCK_INSTR "cmpxchgl %1, %3\n\t" \ + "jz 18f\n\t" \ + "1:\tleal %3, %%ecx\n" \ + "0:\tmovl %8, %%edx\n" \ + "2:\tcall __lll_timedlock_wait\n" \ + "18:" \ + : "=a" (result), "=c" (ignore1), "=&d" (ignore2), \ + "=m" (futex), "=S" (ignore3) \ + : "0" (0), "1" (1), "m" (futex), "m" (timeout), \ + "4" ((int) (private)) \ + : "memory"); \ + result; }) + +extern int __lll_timedlock_elision (int *futex, short *adapt_count, + const struct timespec *timeout, + int private) attribute_hidden; + +#define lll_timedlock_elision(futex, adapt_count, timeout, private) \ + __lll_timedlock_elision(&(futex), &(adapt_count), timeout, private) + +#if !IS_IN (libc) || defined UP +# define __lll_unlock_asm LOCK_INSTR "subl $1, %0\n\t" +#else +# define __lll_unlock_asm "cmpl $0, %%gs:%P3\n\t" \ + "je 0f\n\t" \ + "lock\n" \ + "0:\tsubl $1,%0\n\t" +#endif + +#define lll_unlock(futex, private) \ + (void) \ + ({ int ignore; \ + if (__builtin_constant_p (private) && (private) == LLL_PRIVATE) \ + __asm __volatile (__lll_unlock_asm \ + "je 18f\n\t" \ + "1:\tleal %0, %%eax\n" \ + "2:\tcall __lll_unlock_wake_private\n" \ + "18:" \ + : "=m" (futex), "=&a" (ignore) \ + : "m" (futex), "i" (MULTIPLE_THREADS_OFFSET) \ + : "memory"); \ + else \ + { \ + int ignore2; \ + __asm __volatile (__lll_unlock_asm \ + "je 18f\n\t" \ + "1:\tleal %0, %%eax\n" \ + "0:\tmovl %5, %%ecx\n" \ + "2:\tcall __lll_unlock_wake\n" \ + "18:" \ + : "=m" (futex), "=&a" (ignore), "=&c" (ignore2) \ + : "i" (MULTIPLE_THREADS_OFFSET), "m" (futex), \ + "g" ((int) (private)) \ + : "memory"); \ + } \ + }) + + +#define lll_islocked(futex) \ + (futex != LLL_LOCK_INITIALIZER) + +/* The kernel notifies a process which uses CLONE_CHILD_CLEARTID via futex + wake-up when the clone terminates. The memory location contains the + thread ID while the clone is running and is reset to zero by the kernel + afterwards. The kernel up to version 3.16.3 does not use the private futex + operations for futex wake-up when the clone terminates. */ +#define lll_wait_tid(tid) \ + do { \ + __typeof (tid) __tid; \ + while ((__tid = (tid)) != 0) \ + lll_futex_wait (&(tid), __tid, LLL_SHARED);\ + } while (0) + +extern int __lll_timedwait_tid (int *tid, const struct timespec *abstime) + __attribute__ ((regparm (2))) attribute_hidden; + +/* As lll_wait_tid, but with a timeout. If the timeout occurs then return + ETIMEDOUT. If ABSTIME is invalid, return EINVAL. + XXX Note that this differs from the generic version in that we do the + error checking here and not in __lll_timedwait_tid. */ +#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; }) + + +extern int __lll_lock_elision (int *futex, short *adapt_count, int private) + attribute_hidden; + +extern int __lll_unlock_elision(int *lock, int private) + attribute_hidden; + +extern int __lll_trylock_elision(int *lock, short *adapt_count) + attribute_hidden; + +#define lll_lock_elision(futex, adapt_count, private) \ + __lll_lock_elision (&(futex), &(adapt_count), private) +#define lll_unlock_elision(futex, adapt_count, private) \ + __lll_unlock_elision (&(futex), private) +#define lll_trylock_elision(futex, adapt_count) \ + __lll_trylock_elision(&(futex), &(adapt_count)) + +#endif /* !__ASSEMBLER__ */ + +#endif /* lowlevellock.h */ |