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
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
|
//+private
package sync
import "base:intrinsics"
import "core:time"
import "core:c"
import "core:sys/unix"
foreign import libc "system:c"
FUTEX_PRIVATE_FLAG :: 128
FUTEX_WAIT_PRIVATE :: 0 | FUTEX_PRIVATE_FLAG
FUTEX_WAKE_PRIVATE :: 1 | FUTEX_PRIVATE_FLAG
EINTR :: 4 /* Interrupted system call */
EAGAIN :: 35 /* Resource temporarily unavailable */
ETIMEDOUT :: 60 /* Operation timed out */
Time_Spec :: struct {
time_sec: uint,
time_nsec: uint,
}
get_last_error :: proc "contextless" () -> int {
foreign libc {
__errno :: proc() -> ^c.int ---
}
return int(__errno()^)
}
_futex_wait :: proc "contextless" (futex: ^Futex, expected: u32) -> bool {
if cast(int) intrinsics.syscall(unix.SYS___futex, uintptr(futex), FUTEX_WAIT_PRIVATE, uintptr(expected), 0, 0, 0) == -1 {
switch get_last_error() {
case EINTR, EAGAIN:
return true
case:
_panic("futex_wait failure")
}
}
return true
}
_futex_wait_with_timeout :: proc "contextless" (futex: ^Futex, expected: u32, duration: time.Duration) -> bool {
if duration <= 0 {
return false
}
if cast(int) intrinsics.syscall(unix.SYS___futex, uintptr(futex), FUTEX_WAIT_PRIVATE, uintptr(expected), cast(uintptr) &Time_Spec{
time_sec = cast(uint)(duration / 1e9),
time_nsec = cast(uint)(duration % 1e9),
}, 0, 0) == -1 {
switch get_last_error() {
case EINTR, EAGAIN:
return true
case ETIMEDOUT:
return false
case:
_panic("futex_wait_with_timeout failure")
}
}
return true
}
_futex_signal :: proc "contextless" (futex: ^Futex) {
if cast(int) intrinsics.syscall(unix.SYS___futex, uintptr(futex), FUTEX_WAKE_PRIVATE, 1, 0, 0, 0) == -1 {
_panic("futex_wake_single failure")
}
}
_futex_broadcast :: proc "contextless" (futex: ^Futex) {
if cast(int) intrinsics.syscall(unix.SYS___futex, uintptr(futex), FUTEX_WAKE_PRIVATE, uintptr(max(i32)), 0, 0, 0) == -1 {
_panic("_futex_wake_all failure")
}
}
|
