diff options
Diffstat (limited to 'sysdeps')
| -rw-r--r-- | sysdeps/nptl/lowlevellock-futex.h | 86 | ||||
| -rw-r--r-- | sysdeps/nptl/lowlevellock.h | 187 | ||||
| -rw-r--r-- | sysdeps/unix/sysv/linux/lowlevellock-futex.h | 137 |
3 files changed, 410 insertions, 0 deletions
diff --git a/sysdeps/nptl/lowlevellock-futex.h b/sysdeps/nptl/lowlevellock-futex.h new file mode 100644 index 0000000000..12f3876cd5 --- /dev/null +++ b/sysdeps/nptl/lowlevellock-futex.h @@ -0,0 +1,86 @@ +/* Low-level locking access to futex facilities. Stub 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 + +#include <errno.h> + + +/* Values for 'private' parameter of locking macros. Note pthreadP.h + optimizes for these exact values, though they are not required. */ +#define LLL_PRIVATE 0 +#define LLL_SHARED 128 + + +/* For most of these macros, the return value is never really used. + Nevertheless, the protocol is that each one returns a negated errno + code for failure or zero for success. (Note that the corresponding + Linux system calls can sometimes return positive values for success + cases too. We never use those values.) */ + + +/* Wait while *FUTEXP == VAL for an lll_futex_wake call on FUTEXP. */ +#define lll_futex_wait(futexp, val, private) \ + lll_futex_timed_wait (futexp, val, NULL, private) + +/* Wait until a lll_futex_wake call on FUTEXP, or TIMEOUT elapses. */ +#define lll_futex_timed_wait(futexp, val, timeout, private) \ + -ENOSYS + +/* This macro should be defined only if FUTEX_CLOCK_REALTIME is also defined. + If CLOCKBIT is zero, this is identical to lll_futex_timed_wait. + If CLOCKBIT has FUTEX_CLOCK_REALTIME set, then it's the same but + TIMEOUT is counted by CLOCK_REALTIME rather than CLOCK_MONOTONIC. */ +#define lll_futex_timed_wait_bitset(futexp, val, timeout, clockbit, private) \ + -ENOSYS + +/* Wake up up to NR waiters on FUTEXP. */ +#define lll_futex_wake(futexp, nr, private) \ + -ENOSYS + +/* Wake up up to NR_WAKE waiters on FUTEXP. Move up to NR_MOVE of the + rest from waiting on FUTEXP to waiting on MUTEX (a different futex). */ +#define lll_futex_requeue(futexp, nr_wake, nr_move, mutex, val, private) \ + -ENOSYS + +/* Wake up up to NR_WAKE waiters on FUTEXP and NR_WAKE2 on FUTEXP2. */ +#define lll_futex_wake_unlock(futexp, nr_wake, nr_wake2, futexp2, private) \ + -ENOSYS + + +/* Like lll_futex_wait (FUTEXP, VAL, PRIVATE) but with the expectation + that lll_futex_cmp_requeue_pi (FUTEXP, _, _, MUTEX, _, PRIVATE) will + be used to do the wakeup. Confers priority-inheritance behavior on + the waiter. */ +#define lll_futex_wait_requeue_pi(futexp, val, mutex, private) \ + lll_futex_timed_wait_requeue_pi (futexp, val, NULL, 0, mutex, private) + +/* Like lll_futex_wait_requeue_pi, but with a timeout. */ +#define lll_futex_timed_wait_requeue_pi(futexp, val, timeout, clockbit, \ + mutex, private) \ + -ENOSYS + +/* Like lll_futex_requeue, but pairs with lll_futex_wait_requeue_pi + and inherits priority from the waiter. */ +#define lll_futex_cmp_requeue_pi(futexp, nr_wake, nr_move, mutex, \ + val, private) \ + -ENOSYS + + +#endif /* lowlevellock-futex.h */ diff --git a/sysdeps/nptl/lowlevellock.h b/sysdeps/nptl/lowlevellock.h new file mode 100644 index 0000000000..548a9c842b --- /dev/null +++ b/sysdeps/nptl/lowlevellock.h @@ -0,0 +1,187 @@ +/* Low-level lock implementation. Generic futex-based version. + Copyright (C) 2005-2014 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_H +#define _LOWLEVELLOCK_H 1 + +#include <atomic.h> +#include <lowlevellock-futex.h> + +#define lll_trylock(lock) \ + atomic_compare_and_exchange_bool_acq (&(lock), 1, 0) + +#define lll_cond_trylock(lock) \ + atomic_compare_and_exchange_bool_acq (&(lock), 2, 0) + +extern void __lll_lock_wait_private (int *futex) attribute_hidden; +extern void __lll_lock_wait (int *futex, int private) attribute_hidden; +extern int __lll_robust_lock_wait (int *futex, int private) attribute_hidden; + +/* This is an expression rather than a statement even though its value is + void, so that it can be used in a comma expression or as an expression + that's cast to void. */ +#define __lll_lock(futex, private) \ + ((void) \ + ({ \ + int *__futex = (futex); \ + if (__glibc_unlikely \ + (atomic_compare_and_exchange_bool_acq (__futex, 1, 0))) \ + { \ + if (__builtin_constant_p (private) && (private) == LLL_PRIVATE) \ + __lll_lock_wait_private (__futex); \ + else \ + __lll_lock_wait (__futex, private); \ + } \ + })) +#define lll_lock(futex, private) \ + __lll_lock (&(futex), private) + + +#define __lll_robust_lock(futex, id, private) \ + ({ \ + int *__futex = (futex); \ + int __val = 0; \ + \ + if (__glibc_unlikely \ + (atomic_compare_and_exchange_bool_acq (__futex, id, 0))) \ + __val = __lll_robust_lock_wait (__futex, private); \ + __val; \ + }) +#define lll_robust_lock(futex, id, private) \ + __lll_robust_lock (&(futex), id, private) + + +/* This is an expression rather than a statement even though its value is + void, so that it can be used in a comma expression or as an expression + that's cast to void. */ +#define __lll_cond_lock(futex, private) \ + ((void) \ + ({ \ + int *__futex = (futex); \ + if (__glibc_unlikely (atomic_exchange_acq (__futex, 2) != 0)) \ + __lll_lock_wait (__futex, private); \ + })) +#define lll_cond_lock(futex, private) __lll_cond_lock (&(futex), private) + + +#define lll_robust_cond_lock(futex, id, private) \ + __lll_robust_lock (&(futex), (id) | FUTEX_WAITERS, private) + + +extern int __lll_timedlock_wait (int *futex, const struct timespec *, + int private) attribute_hidden; +extern int __lll_robust_timedlock_wait (int *futex, const struct timespec *, + int private) attribute_hidden; + +#define __lll_timedlock(futex, abstime, private) \ + ({ \ + int *__futex = (futex); \ + int __val = 0; \ + \ + if (__glibc_unlikely (atomic_exchange_acq (__futex, 1))) \ + __val = __lll_timedlock_wait (__futex, abstime, private); \ + __val; \ + }) +#define lll_timedlock(futex, abstime, private) \ + __lll_timedlock (&(futex), abstime, private) + + +#define __lll_robust_timedlock(futex, abstime, id, private) \ + ({ \ + int *__futex = (futex); \ + int __val = 0; \ + \ + if (__glibc_unlikely \ + (atomic_compare_and_exchange_bool_acq (__futex, id, 0))) \ + __val = __lll_robust_timedlock_wait (__futex, abstime, private); \ + __val; \ + }) +#define lll_robust_timedlock(futex, abstime, id, private) \ + __lll_robust_timedlock (&(futex), abstime, id, private) + + +/* This is an expression rather than a statement even though its value is + void, so that it can be used in a comma expression or as an expression + that's cast to void. */ +#define __lll_unlock(futex, private) \ + ((void) \ + ({ \ + int *__futex = (futex); \ + int __oldval = atomic_exchange_rel (__futex, 0); \ + if (__glibc_unlikely (__oldval > 1)) \ + lll_futex_wake (__futex, 1, private); \ + })) +#define lll_unlock(futex, private) \ + __lll_unlock (&(futex), private) + + +/* This is an expression rather than a statement even though its value is + void, so that it can be used in a comma expression or as an expression + that's cast to void. */ +#define __lll_robust_unlock(futex, private) \ + ((void) \ + ({ \ + int *__futex = (futex); \ + int __oldval = atomic_exchange_rel (__futex, 0); \ + if (__glibc_unlikely (__oldval & FUTEX_WAITERS)) \ + lll_futex_wake (__futex, 1, private); \ + })) +#define lll_robust_unlock(futex, private) \ + __lll_robust_unlock (&(futex), private) + + +#define lll_islocked(futex) \ + ((futex) != LLL_LOCK_INITIALIZER) + + +/* Our internal lock implementation is identical to the binary-compatible + mutex implementation. */ + +/* Initializers for lock. */ +#define LLL_LOCK_INITIALIZER (0) +#define LLL_LOCK_INITIALIZER_LOCKED (1) + +/* The states of a lock are: + 0 - untaken + 1 - taken by one user + >1 - taken by more users */ + +/* 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. */ +#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 *, const struct timespec *) + attribute_hidden; + +#define lll_timedwait_tid(tid, abstime) \ + ({ \ + int __res = 0; \ + if ((tid) != 0) \ + __res = __lll_timedwait_tid (&(tid), (abstime)); \ + __res; \ + }) + + +#endif /* lowlevellock.h */ diff --git a/sysdeps/unix/sysv/linux/lowlevellock-futex.h b/sysdeps/unix/sysv/linux/lowlevellock-futex.h new file mode 100644 index 0000000000..343afd6ddd --- /dev/null +++ b/sysdeps/unix/sysv/linux/lowlevellock-futex.h @@ -0,0 +1,137 @@ +/* Low-level locking access to futex facilities. Linux version. + Copyright (C) 2005-2014 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 + +#include <sysdep.h> +#include <tls.h> +#include <kernel-features.h> + + +#define FUTEX_WAIT 0 +#define FUTEX_WAKE 1 +#define FUTEX_REQUEUE 3 +#define FUTEX_CMP_REQUEUE 4 +#define FUTEX_WAKE_OP 5 +#define FUTEX_OP_CLEAR_WAKE_IF_GT_ONE ((4 << 24) | 1) +#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 + +/* 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 !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)) \ + : ((fl) | (((private) ^ FUTEX_PRIVATE_FLAG) \ + & THREAD_GETMEM (THREAD_SELF, header.private_futex)))) +# endif +#endif + +#define lll_futex_syscall(nargs, futexp, op, ...) \ + ({ \ + INTERNAL_SYSCALL_DECL (__err); \ + long int __ret = INTERNAL_SYSCALL (futex, __err, nargs, futexp, op, \ + __VA_ARGS__); \ + (__glibc_unlikely (INTERNAL_SYSCALL_ERROR_P (__ret, __err)) \ + ? -INTERNAL_SYSCALL_ERRNO (__ret, __err) : 0); \ + }) + +#define lll_futex_wait(futexp, val, private) \ + lll_futex_timed_wait (futexp, val, NULL, private) + +#define lll_futex_timed_wait(futexp, val, timeout, private) \ + lll_futex_syscall (4, futexp, \ + __lll_private_flag (FUTEX_WAIT, private), \ + val, timeout) + +#define lll_futex_timed_wait_bitset(futexp, val, timeout, clockbit, private) \ + lll_futex_syscall (6, futexp, \ + __lll_private_flag (FUTEX_WAIT_BITSET | (clockbit), \ + private), \ + val, timeout, NULL /* Unused. */, \ + FUTEX_BITSET_MATCH_ANY) + +#define lll_futex_wake(futexp, nr, private) \ + lll_futex_syscall (4, futexp, \ + __lll_private_flag (FUTEX_WAKE, private), nr, 0) + +/* Returns non-zero if error happened, zero if success. */ +#define lll_futex_requeue(futexp, nr_wake, nr_move, mutex, val, private) \ + lll_futex_syscall (6, futexp, \ + __lll_private_flag (FUTEX_CMP_REQUEUE, private), \ + nr_wake, nr_move, mutex, val) + +/* Returns non-zero if error happened, zero if success. */ +#define lll_futex_wake_unlock(futexp, nr_wake, nr_wake2, futexp2, private) \ + lll_futex_syscall (6, futexp, \ + __lll_private_flag (FUTEX_WAKE_OP, private), \ + nr_wake, nr_wake2, futexp2, \ + FUTEX_OP_CLEAR_WAKE_IF_GT_ONE) + +/* Priority Inheritance support. */ +#define lll_futex_wait_requeue_pi(futexp, val, mutex, private) \ + lll_futex_timed_wait_requeue_pi (futexp, val, NULL, 0, mutex, private) + +#define lll_futex_timed_wait_requeue_pi(futexp, val, timeout, clockbit, \ + mutex, private) \ + lll_futex_syscall (5, futexp, \ + __lll_private_flag (FUTEX_WAIT_REQUEUE_PI \ + | (clockbit), private), \ + val, timeout, mutex) + + +#define lll_futex_cmp_requeue_pi(futexp, nr_wake, nr_move, mutex, \ + val, private) \ + lll_futex_syscall (6, futexp, \ + __lll_private_flag (FUTEX_CMP_REQUEUE_PI, \ + private), \ + nr_wake, nr_move, mutex, val) + + +#endif /* lowlevellock-futex.h */ |