blob: ac0ee8fe8aff2e0a0c0676f8b43c5f7aa5929831 (
plain) (
blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
|
#include <mutex.h>
static uint32_t atomic_exchange(uint32_t* ptr, uint32_t newval) {
uint32_t r;
asm volatile("xchg (%%ecx), %%eax" : "=a"(r) : "c"(ptr), "a"(newval));
return r;
}
void mutex_lock(uint32_t* mutex) {
while (atomic_exchange(mutex, MUTEX_LOCKED) == MUTEX_LOCKED) {
thread_sleep(1);
}
}
int mutex_lockE(uint32_t* mutex) {
if (atomic_exchange(mutex, MUTEX_LOCKED) == MUTEX_LOCKED) return 0;
return 1;
}
void mutex_unlock(uint32_t* mutex) {
*mutex = MUTEX_UNLOCKED;
}
|
