blob: 6474cd900af839ea53d58cb36f78c6adeb68de84 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
|
package sync
import "core:sys/unix"
foreign import libc "system:c"
current_thread_id :: proc "contextless" () -> int {
foreign libc {
syscall :: proc(number: i32, #c_vararg args: ..any) -> i32 ---
}
SYS_GETTID :: 186;
return int(syscall(SYS_GETTID));
}
// The Darwin docs say it best:
// A semaphore is much like a lock, except that a finite number of threads can hold it simultaneously.
// Semaphores can be thought of as being much like piles of tokens; multiple threads can take these tokens,
// but when there are none left, a thread must wait until another thread returns one.
Semaphore :: struct #align 16 {
handle: unix.sem_t,
}
semaphore_init :: proc(s: ^Semaphore, initial_count := 0) {
assert(unix.sem_init(&s.handle, 0, u32(initial_count)) == 0);
}
semaphore_destroy :: proc(s: ^Semaphore) {
assert(unix.sem_destroy(&s.handle) == 0);
s.handle = {};
}
semaphore_post :: proc(s: ^Semaphore, count := 1) {
// NOTE: SPEED: If there's one syscall to do this, we should use it instead of the loop.
for in 0..<count {
assert(unix.sem_post(&s.handle) == 0);
}
}
semaphore_wait_for :: proc(s: ^Semaphore) {
assert(unix.sem_wait(&s.handle) == 0);
}
|
