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update atomic.h in lab6

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This commit is contained in:
chyyuu 2012-10-01 21:49:27 +08:00
parent d4c8e547d6
commit 6a1b22578e
1 changed files with 24 additions and 0 deletions
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24
code/lab6/libs/atomic.h
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@ -53,5 +53,29 @@ test_bit(int nr, volatile void *addr) {
return oldbit != 0; return oldbit != 0;
} }
/* *
* test_and_set_bit - Atomically set a bit and return its old value
* @nr: the bit to set
* @addr: the address to count from
* */
static inline bool
test_and_set_bit(int nr, volatile void *addr) {
int oldbit;
asm volatile ("btsl %2, %1; sbbl %0, %0" : "=r" (oldbit), "=m" (*(volatile long *)addr) : "Ir" (nr) : "memory");
return oldbit != 0;
}
/* *
* test_and_clear_bit - Atomically clear a bit and return its old value
* @nr: the bit to clear
* @addr: the address to count from
* */
static inline bool
test_and_clear_bit(int nr, volatile void *addr) {
int oldbit;
asm volatile ("btrl %2, %1; sbbl %0, %0" : "=r" (oldbit), "=m" (*(volatile long *)addr) : "Ir" (nr) : "memory");
return oldbit != 0;
}
#endif /* !__LIBS_ATOMIC_H__ */ #endif /* !__LIBS_ATOMIC_H__ */