This commit is contained in:
gingerBill
2020-12-27 16:16:04 +00:00
parent 3558848da8
commit 98ad912509
+62 -1
View File
@@ -1,6 +1,7 @@
package sync
import "core:intrinsics"
import "intrinsics"
import "core:runtime"
cpu_relax :: inline proc "contextless" () {
intrinsics.cpu_relax();
@@ -61,3 +62,63 @@ benaphore_unlock :: proc(b: ^Benaphore) {
semaphore_post(&b.sema);
}
}
Recursive_Benaphore :: struct {
counter: int,
owner: int,
recursion: int,
sema: Semaphore,
}
recursive_benaphore_init :: proc(b: ^Recursive_Benaphore) {
intrinsics.atomic_store(&b.counter, 0);
semaphore_init(&b.sema);
}
recursive_benaphore_destroy :: proc(b: ^Recursive_Benaphore) {
semaphore_destroy(&b.sema);
}
recursive_benaphore_lock :: proc(b: ^Recursive_Benaphore) {
tid := runtime.current_thread_id();
if intrinsics.atomic_add_acq(&b.counter, 1) > 1 {
if tid != b.owner {
semaphore_wait_for(&b.sema);
}
}
// inside the lock
b.owner = tid;
b.recursion += 1;
}
recursive_benaphore_try_lock :: proc(b: ^Recursive_Benaphore) -> bool {
tid := runtime.current_thread_id();
if b.owner == tid {
intrinsics.atomic_add_acq(&b.counter, 1);
} else {
v, _ := intrinsics.atomic_cxchg_acq(&b.counter, 1, 0);
if v != 0 {
return false;
}
// inside the lock
b.owner = tid;
}
b.recursion += 1;
return true;
}
recursive_benaphore_unlock :: proc(b: ^Recursive_Benaphore) {
tid := runtime.current_thread_id();
assert(tid == b.owner);
b.recursion -= 1;
recursion := b.recursion;
if recursion == 0 {
b.owner = 0;
}
if intrinsics.atomic_sub_rel(&b.counter, 1) > 0 {
if recursion == 0 {
semaphore_post(&b.sema);
}
}
// outside the lock
}