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https://github.com/checkpoint-restore/criu
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71f7f7546c
To switch to kernel's style. Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
140 lines
3.5 KiB
C
140 lines
3.5 KiB
C
#ifndef __CR_LOCK_H__
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#define __CR_LOCK_H__
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#include <linux/futex.h>
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#include <sys/time.h>
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#include <limits.h>
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#include <errno.h>
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#include "asm/types.h"
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#include "asm/atomic.h"
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#include "syscall.h"
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#include "bug.h"
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typedef struct {
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atomic_t raw;
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} futex_t;
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#define FUTEX_ABORT_FLAG (0x80000000)
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#define FUTEX_ABORT_RAW (-1U)
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/* Get current futex @f value */
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static inline u32 futex_get(futex_t *f)
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{
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return atomic_read(&f->raw);
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}
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/* Set futex @f value to @v */
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static inline void futex_set(futex_t *f, u32 v)
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{
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atomic_set(&f->raw, (int)v);
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}
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#define futex_init(f) futex_set(f, 0)
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/* Wait on futex @__f value @__v become in condition @__c */
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#define futex_wait_if_cond(__f, __v, __cond) \
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do { \
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int ret; \
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u32 tmp; \
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\
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while (1) { \
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tmp = (u32)atomic_read(&(__f)->raw); \
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if ((tmp & FUTEX_ABORT_FLAG) || \
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(tmp __cond (__v))) \
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break; \
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ret = sys_futex((u32 *)&(__f)->raw.counter, FUTEX_WAIT,\
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tmp, NULL, NULL, 0); \
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BUG_ON(ret < 0 && ret != -EWOULDBLOCK); \
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} \
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} while (0)
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/* Set futex @f to @v and wake up all waiters */
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static inline void futex_set_and_wake(futex_t *f, u32 v)
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{
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atomic_set(&f->raw, (int)v);
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BUG_ON(sys_futex((u32 *)&f->raw.counter, FUTEX_WAKE, INT_MAX, NULL, NULL, 0) < 0);
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}
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/* Mark futex @f as wait abort needed and wake up all waiters */
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static inline void futex_abort_and_wake(futex_t *f)
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{
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BUILD_BUG_ON(!(FUTEX_ABORT_RAW & FUTEX_ABORT_FLAG));
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futex_set_and_wake(f, FUTEX_ABORT_RAW);
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}
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/* Decrement futex @f value and wake up all waiters */
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static inline void futex_dec_and_wake(futex_t *f)
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{
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atomic_dec(&f->raw);
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BUG_ON(sys_futex((u32 *)&f->raw.counter, FUTEX_WAKE, INT_MAX, NULL, NULL, 0) < 0);
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}
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/* Increment futex @f value and wake up all waiters */
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static inline void futex_inc_and_wake(futex_t *f)
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{
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atomic_inc(&f->raw);
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BUG_ON(sys_futex((u32 *)&f->raw.counter, FUTEX_WAKE, INT_MAX, NULL, NULL, 0) < 0);
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}
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/* Plain increment futex @f value */
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static inline void futex_inc(futex_t *f) { atomic_inc(&f->raw); }
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/* Plain decrement futex @f value */
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static inline void futex_dec(futex_t *f) { atomic_dec(&f->raw); }
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/* Wait until futex @f value become @v */
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static inline void futex_wait_until(futex_t *f, u32 v)
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{ futex_wait_if_cond(f, v, ==); }
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/* Wait while futex @f value is greater than @v */
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static inline void futex_wait_while_gt(futex_t *f, u32 v)
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{ futex_wait_if_cond(f, v, <=); }
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/* Wait while futex @f value is less than @v */
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static inline void futex_wait_while_lt(futex_t *f, u32 v)
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{ futex_wait_if_cond(f, v, >=); }
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/* Wait while futex @f value is equal to @v */
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static inline void futex_wait_while_eq(futex_t *f, u32 v)
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{ futex_wait_if_cond(f, v, !=); }
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/* Wait while futex @f value is @v */
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static inline void futex_wait_while(futex_t *f, u32 v)
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{
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while ((u32)atomic_read(&f->raw) == v) {
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int ret = sys_futex((u32 *)&f->raw.counter, FUTEX_WAIT, v, NULL, NULL, 0);
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BUG_ON(ret < 0 && ret != -EWOULDBLOCK);
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}
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}
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typedef struct {
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atomic_t raw;
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} mutex_t;
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static inline void mutex_init(mutex_t *m)
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{
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u32 c = 0;
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atomic_set(&m->raw, (int)c);
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}
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static inline void mutex_lock(mutex_t *m)
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{
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u32 c;
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int ret;
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while ((c = (u32)atomic_inc_return(&m->raw)) != 1) {
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ret = sys_futex((u32 *)&m->raw.counter, FUTEX_WAIT, c, NULL, NULL, 0);
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BUG_ON(ret < 0 && ret != -EWOULDBLOCK);
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}
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}
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static inline void mutex_unlock(mutex_t *m)
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{
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u32 c = 0;
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atomic_set(&m->raw, (int)c);
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BUG_ON(sys_futex((u32 *)&m->raw.counter, FUTEX_WAKE, 1, NULL, NULL, 0) < 0);
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}
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#endif /* __CR_LOCK_H__ */
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