diff options
Diffstat (limited to 'sysdeps/unix/sysv/linux/i386/lowlevellock-futex.h')
| -rw-r--r-- | sysdeps/unix/sysv/linux/i386/lowlevellock-futex.h | 137 |
1 files changed, 137 insertions, 0 deletions
diff --git a/sysdeps/unix/sysv/linux/i386/lowlevellock-futex.h b/sysdeps/unix/sysv/linux/i386/lowlevellock-futex.h new file mode 100644 index 0000000000..d7f8728689 --- /dev/null +++ b/sysdeps/unix/sysv/linux/i386/lowlevellock-futex.h @@ -0,0 +1,137 @@ +/* Low-level locking access to futex facilities. Linux/i386 version. + Copyright (C) 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; if not, see + <http://www.gnu.org/licenses/>. */ + +#ifndef _LOWLEVELLOCK_FUTEX_H +#define _LOWLEVELLOCK_FUTEX_H 1 + +#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 + + +#if IS_IN (libc) || 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 %%gs:%P1, %0" : "+r" (__fl) \ + : "i" (offsetof (struct pthread, header.private_futex))); \ + __fl | (fl); })) +# endif +#endif + + +#ifndef __ASSEMBLER__ + +/* To avoid naming conflicts with lowlevellock.h, use a different prefix + here. */ +#ifdef PIC +# define LLLF_EBX_LOAD "xchgl %2, %%ebx\n" +# define LLLF_EBX_REG "D" +#else +# define LLLF_EBX_LOAD +# define LLLF_EBX_REG "b" +#endif + +#ifdef I386_USE_SYSENTER +# ifdef SHARED +# define LLLF_ENTER_KERNEL "call *%%gs:%P6\n\t" +# else +# define LLLF_ENTER_KERNEL "call *_dl_sysinfo\n\t" +# endif +#else +# define LLLF_ENTER_KERNEL "int $0x80\n\t" +#endif + + +#define lll_futex_wait(futex, val, private) \ + lll_futex_timed_wait (futex, val, NULL, private) + + +#define lll_futex_timed_wait(futex, val, timeout, private) \ + ({ \ + int __status; \ + register __typeof (val) _val asm ("edx") = (val); \ + __asm __volatile (LLLF_EBX_LOAD \ + LLLF_ENTER_KERNEL \ + LLLF_EBX_LOAD \ + : "=a" (__status) \ + : "0" (SYS_futex), LLLF_EBX_REG (futex), "S" (timeout), \ + "c" (__lll_private_flag (FUTEX_WAIT, private)), \ + "d" (_val), "i" (offsetof (tcbhead_t, sysinfo)) \ + : "memory"); \ + __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 (LLLF_EBX_LOAD \ + LLLF_ENTER_KERNEL \ + LLLF_EBX_LOAD \ + : "=a" (__status) \ + : "0" (SYS_futex), LLLF_EBX_REG (futex), \ + "c" (__lll_private_flag (FUTEX_WAKE, private)), \ + "d" (_nr), \ + "i" (0) /* phony, to align next arg's number */, \ + "i" (offsetof (tcbhead_t, sysinfo))); \ + __status; \ + }) + + +#endif /* !__ASSEMBLER__ */ + +#endif /* lowlevellock-futex.h */ |