blob: 8153b4b373d20541d45b0c6c29987fe168b5890a (
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
|
package sync
import "core:sys/darwin"
import "core:c"
// 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: darwin.semaphore_t,
}
// TODO(tetra): Only marked with alignment because we cannot mark distinct integers with alignments.
// See core/sys/unix/pthread_linux.odin/pthread_t.
semaphore_init :: proc(s: ^Semaphore, initial_count := 0) {
ct := darwin.mach_task_self();
res := darwin.semaphore_create(ct, &s.handle, 0, c.int(initial_count));
assert(res == 0);
}
semaphore_destroy :: proc(s: ^Semaphore) {
ct := darwin.mach_task_self();
res := darwin.semaphore_destroy(ct, s.handle);
assert(res == 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-1 {
res := darwin.semaphore_signal(s.handle);
assert(res == 0);
}
}
semaphore_wait_for :: proc(s: ^Semaphore) {
res := darwin.semaphore_wait(s.handle);
assert(res == 0);
}
|
