diff options
Diffstat (limited to 'sysdeps/unix/sysv/linux/x86_64/lowlevellock.h')
| -rw-r--r-- | sysdeps/unix/sysv/linux/x86_64/lowlevellock.h | 476 |
1 files changed, 476 insertions, 0 deletions
diff --git a/sysdeps/unix/sysv/linux/x86_64/lowlevellock.h b/sysdeps/unix/sysv/linux/x86_64/lowlevellock.h new file mode 100644 index 0000000000..c13ca084df --- /dev/null +++ b/sysdeps/unix/sysv/linux/x86_64/lowlevellock.h @@ -0,0 +1,476 @@ +/* Copyright (C) 2002-2014 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 + +#define SYS_futex __NR_futex +#define FUTEX_WAIT 0 +#define FUTEX_WAKE 1 +#define FUTEX_CMP_REQUEUE 4 +#define FUTEX_WAKE_OP 5 +#define FUTEX_LOCK_PI 6 +#define FUTEX_UNLOCK_PI 7 +#define FUTEX_TRYLOCK_PI 8 +#define FUTEX_WAIT_BITSET 9 +#define FUTEX_WAKE_BITSET 10 +#define FUTEX_WAIT_REQUEUE_PI 11 +#define FUTEX_CMP_REQUEUE_PI 12 +#define FUTEX_PRIVATE_FLAG 128 +#define FUTEX_CLOCK_REALTIME 256 + +#define FUTEX_BITSET_MATCH_ANY 0xffffffff + +#define FUTEX_OP_CLEAR_WAKE_IF_GT_ONE ((4 << 24) | 1) + +/* Values for 'private' parameter of locking macros. Yes, the + definition seems to be backwards. But it is not. The bit will be + reversed before passing to the system call. */ +#define LLL_PRIVATE 0 +#define LLL_SHARED FUTEX_PRIVATE_FLAG + +#ifndef __ASSEMBLER__ + +#if !defined NOT_IN_libc || defined IS_IN_rtld +/* In libc.so or ld.so all futexes are private. */ +# ifdef __ASSUME_PRIVATE_FUTEX +# define __lll_private_flag(fl, private) \ + ((fl) | FUTEX_PRIVATE_FLAG) +# else +# define __lll_private_flag(fl, private) \ + ((fl) | THREAD_GETMEM (THREAD_SELF, header.private_futex)) +# endif +#else +# ifdef __ASSUME_PRIVATE_FUTEX +# define __lll_private_flag(fl, private) \ + (((fl) | FUTEX_PRIVATE_FLAG) ^ (private)) +# else +# define __lll_private_flag(fl, private) \ + (__builtin_constant_p (private) \ + ? ((private) == 0 \ + ? ((fl) | THREAD_GETMEM (THREAD_SELF, header.private_futex)) \ + : (fl)) \ + : ({ unsigned int __fl = ((private) ^ FUTEX_PRIVATE_FLAG); \ + asm ("andl %%fs:%P1, %0" : "+r" (__fl) \ + : "i" (offsetof (struct pthread, header.private_futex))); \ + __fl | (fl); })) +# endif +#endif + +/* Initializer for lock. */ +#define LLL_LOCK_INITIALIZER (0) +#define LLL_LOCK_INITIALIZER_LOCKED (1) +#define LLL_LOCK_INITIALIZER_WAITERS (2) + +/* Delay in spinlock loop. */ +#define BUSY_WAIT_NOP asm ("rep; nop") + +#define lll_futex_wait(futex, val, private) \ + lll_futex_timed_wait(futex, val, NULL, private) + + +#define lll_futex_timed_wait(futex, val, timeout, private) \ + ({ \ + register const struct timespec *__to __asm ("r10") = timeout; \ + int __status; \ + register __typeof (val) _val __asm ("edx") = (val); \ + __asm __volatile ("syscall" \ + : "=a" (__status) \ + : "0" (SYS_futex), "D" (futex), \ + "S" (__lll_private_flag (FUTEX_WAIT, private)), \ + "d" (_val), "r" (__to) \ + : "memory", "cc", "r11", "cx"); \ + __status; \ + }) + + +#define lll_futex_wake(futex, nr, private) \ + ({ \ + int __status; \ + register __typeof (nr) _nr __asm ("edx") = (nr); \ + LIBC_PROBE (lll_futex_wake, 3, futex, nr, private); \ + __asm __volatile ("syscall" \ + : "=a" (__status) \ + : "0" (SYS_futex), "D" (futex), \ + "S" (__lll_private_flag (FUTEX_WAKE, private)), \ + "d" (_nr) \ + : "memory", "cc", "r10", "r11", "cx"); \ + __status; \ + }) + + +/* 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 defined NOT_IN_libc || defined UP +# define __lll_trylock_asm LOCK_INSTR "cmpxchgl %2, %1" +#else +# define __lll_trylock_asm "cmpl $0, __libc_multiple_threads(%%rip)\n\t" \ + "je 0f\n\t" \ + "lock; cmpxchgl %2, %1\n\t" \ + "jmp 1f\n\t" \ + "0:\tcmpxchgl %2, %1\n\t" \ + "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) \ + : "memory"); \ + ret; }) + +#define lll_robust_trylock(futex, id) \ + ({ int ret; \ + __asm __volatile (LOCK_INSTR "cmpxchgl %2, %1" \ + : "=a" (ret), "=m" (futex) \ + : "r" (id), "m" (futex), "0" (LLL_LOCK_INITIALIZER) \ + : "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 defined NOT_IN_libc || defined UP +# define __lll_lock_asm_start LOCK_INSTR "cmpxchgl %4, %2\n\t" \ + "jz 24f\n\t" +#else +# define __lll_lock_asm_start "cmpl $0, __libc_multiple_threads(%%rip)\n\t" \ + "je 0f\n\t" \ + "lock; cmpxchgl %4, %2\n\t" \ + "jnz 1f\n\t" \ + "jmp 24f\n" \ + "0:\tcmpxchgl %4, %2\n\t" \ + "jz 24f\n\t" +#endif + +#define lll_lock(futex, private) \ + (void) \ + ({ int ignore1, ignore2, ignore3; \ + if (__builtin_constant_p (private) && (private) == LLL_PRIVATE) \ + __asm __volatile (__lll_lock_asm_start \ + "1:\tlea %2, %%" RDI_LP "\n" \ + "2:\tsub $128, %%" RSP_LP "\n" \ + ".cfi_adjust_cfa_offset 128\n" \ + "3:\tcallq __lll_lock_wait_private\n" \ + "4:\tadd $128, %%" RSP_LP "\n" \ + ".cfi_adjust_cfa_offset -128\n" \ + "24:" \ + : "=S" (ignore1), "=&D" (ignore2), "=m" (futex), \ + "=a" (ignore3) \ + : "0" (1), "m" (futex), "3" (0) \ + : "cx", "r11", "cc", "memory"); \ + else \ + __asm __volatile (__lll_lock_asm_start \ + "1:\tlea %2, %%" RDI_LP "\n" \ + "2:\tsub $128, %%" RSP_LP "\n" \ + ".cfi_adjust_cfa_offset 128\n" \ + "3:\tcallq __lll_lock_wait\n" \ + "4:\tadd $128, %%" RSP_LP "\n" \ + ".cfi_adjust_cfa_offset -128\n" \ + "24:" \ + : "=S" (ignore1), "=D" (ignore2), "=m" (futex), \ + "=a" (ignore3) \ + : "1" (1), "m" (futex), "3" (0), "0" (private) \ + : "cx", "r11", "cc", "memory"); \ + }) \ + +#define lll_robust_lock(futex, id, private) \ + ({ int result, ignore1, ignore2; \ + __asm __volatile (LOCK_INSTR "cmpxchgl %4, %2\n\t" \ + "jz 24f\n" \ + "1:\tlea %2, %%" RDI_LP "\n" \ + "2:\tsub $128, %%" RSP_LP "\n" \ + ".cfi_adjust_cfa_offset 128\n" \ + "3:\tcallq __lll_robust_lock_wait\n" \ + "4:\tadd $128, %%" RSP_LP "\n" \ + ".cfi_adjust_cfa_offset -128\n" \ + "24:" \ + : "=S" (ignore1), "=D" (ignore2), "=m" (futex), \ + "=a" (result) \ + : "1" (id), "m" (futex), "3" (0), "0" (private) \ + : "cx", "r11", "cc", "memory"); \ + result; }) + +#define lll_cond_lock(futex, private) \ + (void) \ + ({ int ignore1, ignore2, ignore3; \ + __asm __volatile (LOCK_INSTR "cmpxchgl %4, %2\n\t" \ + "jz 24f\n" \ + "1:\tlea %2, %%" RDI_LP "\n" \ + "2:\tsub $128, %%" RSP_LP "\n" \ + ".cfi_adjust_cfa_offset 128\n" \ + "3:\tcallq __lll_lock_wait\n" \ + "4:\tadd $128, %%" RSP_LP "\n" \ + ".cfi_adjust_cfa_offset -128\n" \ + "24:" \ + : "=S" (ignore1), "=D" (ignore2), "=m" (futex), \ + "=a" (ignore3) \ + : "1" (2), "m" (futex), "3" (0), "0" (private) \ + : "cx", "r11", "cc", "memory"); \ + }) + +#define lll_robust_cond_lock(futex, id, private) \ + ({ int result, ignore1, ignore2; \ + __asm __volatile (LOCK_INSTR "cmpxchgl %4, %2\n\t" \ + "jz 24f\n" \ + "1:\tlea %2, %%" RDI_LP "\n" \ + "2:\tsub $128, %%" RSP_LP "\n" \ + ".cfi_adjust_cfa_offset 128\n" \ + "3:\tcallq __lll_robust_lock_wait\n" \ + "4:\tadd $128, %%" RSP_LP "\n" \ + ".cfi_adjust_cfa_offset -128\n" \ + "24:" \ + : "=S" (ignore1), "=D" (ignore2), "=m" (futex), \ + "=a" (result) \ + : "1" (id | FUTEX_WAITERS), "m" (futex), "3" (0), \ + "0" (private) \ + : "cx", "r11", "cc", "memory"); \ + result; }) + +#define lll_timedlock(futex, timeout, private) \ + ({ int result, ignore1, ignore2, ignore3; \ + __asm __volatile (LOCK_INSTR "cmpxchgl %1, %4\n\t" \ + "jz 24f\n" \ + "1:\tlea %4, %%" RDI_LP "\n" \ + "0:\tmov %8, %%" RDX_LP "\n" \ + "2:\tsub $128, %%" RSP_LP "\n" \ + ".cfi_adjust_cfa_offset 128\n" \ + "3:\tcallq __lll_timedlock_wait\n" \ + "4:\tadd $128, %%" RSP_LP "\n" \ + ".cfi_adjust_cfa_offset -128\n" \ + "24:" \ + : "=a" (result), "=D" (ignore1), "=S" (ignore2), \ + "=&d" (ignore3), "=m" (futex) \ + : "0" (0), "1" (1), "m" (futex), "m" (timeout), \ + "2" (private) \ + : "memory", "cx", "cc", "r10", "r11"); \ + 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) + +#define lll_robust_timedlock(futex, timeout, id, private) \ + ({ int result, ignore1, ignore2, ignore3; \ + __asm __volatile (LOCK_INSTR "cmpxchgl %1, %4\n\t" \ + "jz 24f\n\t" \ + "1:\tlea %4, %%" RDI_LP "\n" \ + "0:\tmov %8, %%" RDX_LP "\n" \ + "2:\tsub $128, %%" RSP_LP "\n" \ + ".cfi_adjust_cfa_offset 128\n" \ + "3:\tcallq __lll_robust_timedlock_wait\n" \ + "4:\tadd $128, %%" RSP_LP "\n" \ + ".cfi_adjust_cfa_offset -128\n" \ + "24:" \ + : "=a" (result), "=D" (ignore1), "=S" (ignore2), \ + "=&d" (ignore3), "=m" (futex) \ + : "0" (0), "1" (id), "m" (futex), "m" (timeout), \ + "2" (private) \ + : "memory", "cx", "cc", "r10", "r11"); \ + result; }) + +#if defined NOT_IN_libc || defined UP +# define __lll_unlock_asm_start LOCK_INSTR "decl %0\n\t" \ + "je 24f\n\t" +#else +# define __lll_unlock_asm_start "cmpl $0, __libc_multiple_threads(%%rip)\n\t" \ + "je 0f\n\t" \ + "lock; decl %0\n\t" \ + "jne 1f\n\t" \ + "jmp 24f\n\t" \ + "0:\tdecl %0\n\t" \ + "je 24f\n\t" +#endif + +#define lll_unlock(futex, private) \ + (void) \ + ({ int ignore; \ + if (__builtin_constant_p (private) && (private) == LLL_PRIVATE) \ + __asm __volatile (__lll_unlock_asm_start \ + "1:\tlea %0, %%" RDI_LP "\n" \ + "2:\tsub $128, %%" RSP_LP "\n" \ + ".cfi_adjust_cfa_offset 128\n" \ + "3:\tcallq __lll_unlock_wake_private\n" \ + "4:\tadd $128, %%" RSP_LP "\n" \ + ".cfi_adjust_cfa_offset -128\n" \ + "24:" \ + : "=m" (futex), "=&D" (ignore) \ + : "m" (futex) \ + : "ax", "cx", "r11", "cc", "memory"); \ + else \ + __asm __volatile (__lll_unlock_asm_start \ + "1:\tlea %0, %%" RDI_LP "\n" \ + "2:\tsub $128, %%" RSP_LP "\n" \ + ".cfi_adjust_cfa_offset 128\n" \ + "3:\tcallq __lll_unlock_wake\n" \ + "4:\tadd $128, %%" RSP_LP "\n" \ + ".cfi_adjust_cfa_offset -128\n" \ + "24:" \ + : "=m" (futex), "=&D" (ignore) \ + : "m" (futex), "S" (private) \ + : "ax", "cx", "r11", "cc", "memory"); \ + }) + +#define lll_robust_unlock(futex, private) \ + do \ + { \ + int ignore; \ + __asm __volatile (LOCK_INSTR "andl %2, %0\n\t" \ + "je 24f\n\t" \ + "1:\tlea %0, %%" RDI_LP "\n" \ + "2:\tsub $128, %%" RSP_LP "\n" \ + ".cfi_adjust_cfa_offset 128\n" \ + "3:\tcallq __lll_unlock_wake\n" \ + "4:\tadd $128, %%" RSP_LP "\n" \ + ".cfi_adjust_cfa_offset -128\n" \ + "24:" \ + : "=m" (futex), "=&D" (ignore) \ + : "i" (FUTEX_WAITERS), "m" (futex), \ + "S" (private) \ + : "ax", "cx", "r11", "cc", "memory"); \ + } \ + while (0) + +#define lll_robust_dead(futex, private) \ + do \ + { \ + int ignore; \ + __asm __volatile (LOCK_INSTR "orl %3, (%2)\n\t" \ + "syscall" \ + : "=m" (futex), "=a" (ignore) \ + : "D" (&(futex)), "i" (FUTEX_OWNER_DIED), \ + "S" (__lll_private_flag (FUTEX_WAKE, private)), \ + "1" (__NR_futex), "d" (1) \ + : "cx", "r11", "cc", "memory"); \ + } \ + while (0) + +/* Returns non-zero if error happened, zero if success. */ +#define lll_futex_requeue(ftx, nr_wake, nr_move, mutex, val, private) \ + ({ int __res; \ + register int __nr_move __asm ("r10") = nr_move; \ + register void *__mutex __asm ("r8") = mutex; \ + register int __val __asm ("r9") = val; \ + __asm __volatile ("syscall" \ + : "=a" (__res) \ + : "0" (__NR_futex), "D" ((void *) ftx), \ + "S" (__lll_private_flag (FUTEX_CMP_REQUEUE, \ + private)), "d" (nr_wake), \ + "r" (__nr_move), "r" (__mutex), "r" (__val) \ + : "cx", "r11", "cc", "memory"); \ + __res < 0; }) + +#define lll_islocked(futex) \ + (futex != LLL_LOCK_INITIALIZER) + + +/* The kernel notifies a process which uses CLONE_CHILD_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) \ + do { \ + int __ignore; \ + register __typeof (tid) _tid asm ("edx") = (tid); \ + if (_tid != 0) \ + __asm __volatile ("xorq %%r10, %%r10\n\t" \ + "1:\tmovq %2, %%rax\n\t" \ + "syscall\n\t" \ + "cmpl $0, (%%rdi)\n\t" \ + "jne 1b" \ + : "=&a" (__ignore) \ + : "S" (FUTEX_WAIT), "i" (SYS_futex), "D" (&tid), \ + "d" (_tid) \ + : "memory", "cc", "r10", "r11", "cx"); \ + } while (0) + +extern int __lll_timedwait_tid (int *tid, const struct timespec *abstime) + 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; }) + +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, private) \ + __lll_unlock_elision (&(futex), private) +#define lll_trylock_elision(futex, adapt_count) \ + __lll_trylock_elision (&(futex), &(adapt_count)) + +#endif /* !__ASSEMBLER__ */ + +#endif /* lowlevellock.h */ |