Clean up some sleep code

This commit is contained in:
Justine Tunney 2022-10-08 02:40:44 -07:00
parent 9849b4c7ba
commit 672ccda37c
No known key found for this signature in database
GPG key ID: BE714B4575D6E328
35 changed files with 310 additions and 598 deletions

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@ -17,7 +17,9 @@
PERFORMANCE OF THIS SOFTWARE.
*/
#include "libc/atomic.h"
#include "libc/calls/calls.h"
#include "libc/calls/sig.internal.h"
#include "libc/calls/state.internal.h"
#include "libc/calls/struct/timespec.h"
#include "libc/calls/struct/timespec.internal.h"
#include "libc/dce.h"
@ -33,8 +35,10 @@
#include "libc/sysv/consts/timer.h"
#include "libc/thread/freebsd.internal.h"
#include "libc/thread/thread.h"
#include "libc/thread/tls.h"
#include "third_party/nsync/atomic.h"
#include "third_party/nsync/common.internal.h"
#include "third_party/nsync/mu_semaphore.internal.h"
#include "third_party/nsync/time.h"
// clang-format off
/* futex() polyfill w/ sched_yield() fallback */
@ -51,15 +55,15 @@ bool FUTEX_TIMEOUT_IS_ABSOLUTE;
__attribute__((__constructor__)) static void nsync_futex_init_ (void) {
int x = 0;
if (NSYNC_FUTEX_WIN32 && IsWindows ()) {
FUTEX_WAIT_ = FUTEX_WAIT;
if (IsWindows ()) {
FUTEX_IS_SUPPORTED = true;
FUTEX_WAIT_ = FUTEX_WAIT;
return;
}
if (IsFreebsd ()) {
FUTEX_IS_SUPPORTED = true;
FUTEX_WAIT_ = FUTEX_WAIT;
FUTEX_TIMEOUT_IS_ABSOLUTE = true;
FUTEX_PRIVATE_FLAG_ = FUTEX_PRIVATE_FLAG;
return;
@ -105,44 +109,41 @@ __attribute__((__constructor__)) static void nsync_futex_init_ (void) {
}
static int nsync_futex_polyfill_ (int *p, int expect, struct timespec *timeout) {
int rc;
atomic_int *w;
int64_t max, nanos;
int64_t nanos, maxnanos;
nsync_atomic_uint32_ *w;
struct timespec ts, deadline;
w = (atomic_int *)p;
if (atomic_load_explicit (p, memory_order_relaxed) != expect) {
w = (nsync_atomic_uint32_ *)p;
if (ATM_LOAD (p) != expect) {
return -EAGAIN;
}
ts = _timespec_real ();
ts = nsync_time_now ();
if (!timeout) {
deadline = nsync_time_no_deadline;
} else if (FUTEX_TIMEOUT_IS_ABSOLUTE) {
deadline = *timeout;
} else {
deadline = _timespec_add (ts, *timeout);
deadline = nsync_time_add (ts, *timeout);
}
nanos = 100;
max = __SIG_POLLING_INTERVAL_MS * 1000L * 1000;
while (_timespec_gt (deadline, ts)) {
if (atomic_load_explicit (p, memory_order_relaxed) != expect) {
maxnanos = __SIG_POLLING_INTERVAL_MS * 1000L * 1000;
while (nsync_time_cmp (deadline, ts) > 0) {
if (ATM_LOAD (p) != expect) {
return 0;
}
ts = _timespec_add (ts, _timespec_fromnanos (nanos));
if (_timespec_gt (ts, deadline)) {
ts = nsync_time_add (ts, _timespec_fromnanos (nanos));
if (nsync_time_cmp (ts, deadline) > 0) {
ts = deadline;
}
rc = clock_nanosleep (CLOCK_REALTIME, TIMER_ABSTIME, &ts, 0);
if (rc) {
ASSERT (rc == EINTR);
if (nsync_time_sleep_until (ts)) {
return -EINTR;
}
if (nanos < max) {
if (nanos < maxnanos) {
nanos <<= 1;
if (nanos > max) {
nanos = max;
if (nanos > maxnanos) {
nanos = maxnanos;
}
}
}
@ -154,38 +155,42 @@ int nsync_futex_wait_ (int *p, int expect, char pshare, struct timespec *timeout
uint32_t ms;
int rc, op, fop;
if (!FUTEX_IS_SUPPORTED) {
return nsync_futex_polyfill_ (p, expect, timeout);
}
op = FUTEX_WAIT_;
if (pshare == PTHREAD_PROCESS_PRIVATE) {
op |= FUTEX_PRIVATE_FLAG_;
}
if (NSYNC_FUTEX_WIN32 && IsWindows ()) {
// Windows 8 futexes don't support multiple processes :(
if (pshare) {
return nsync_futex_polyfill_ (p, expect, timeout);
}
if (timeout) {
ms = _timespec_tomillis (*timeout);
if (FUTEX_IS_SUPPORTED) {
if (IsWindows ()) {
// Windows 8 futexes don't support multiple processes :(
if (pshare) {
goto Polyfill;
}
if (timeout) {
ms = _timespec_tomillis (*timeout);
} else {
ms = -1;
}
if (WaitOnAddress (p, &expect, sizeof(int), ms)) {
rc = 0;
} else {
rc = -GetLastError ();
}
} else if (IsFreebsd ()) {
rc = sys_umtx_timedwait_uint (
p, expect, pshare, timeout);
} else {
ms = -1;
rc = _futex (p, op, expect, timeout, 0,
FUTEX_WAIT_BITS_);
if (IsOpenbsd() && rc > 0) {
rc = -rc;
}
}
if (WaitOnAddress (p, &expect, sizeof(int), ms)) {
rc = 0;
} else {
rc = -GetLastError ();
}
} else if (IsFreebsd ()) {
rc = sys_umtx_timedwait_uint (p, expect, pshare, timeout);
} else {
rc = _futex (p, op, expect, timeout, 0, FUTEX_WAIT_BITS_);
if (IsOpenbsd() && rc > 0) {
// [jart] openbsd does this without setting carry flag
rc = -rc;
}
Polyfill:
__get_tls()->tib_flags |= TIB_FLAG_TIME_CRITICAL;
rc = nsync_futex_polyfill_ (p, expect, timeout);
__get_tls()->tib_flags &= ~TIB_FLAG_TIME_CRITICAL;
}
STRACE ("futex(%t, %s, %d, %s) → %s",
@ -202,40 +207,40 @@ int nsync_futex_wake_ (int *p, int count, char pshare) {
ASSERT (count == 1 || count == INT_MAX);
if (!FUTEX_IS_SUPPORTED) {
nsync_yield_ ();
return 0;
}
op = FUTEX_WAKE;
if (pshare == PTHREAD_PROCESS_PRIVATE) {
op |= FUTEX_PRIVATE_FLAG_;
}
if (NSYNC_FUTEX_WIN32 && IsWindows ()) {
if (pshare) {
nsync_yield_ ();
return 0;
}
if (count == 1) {
WakeByAddressSingle (p);
if (FUTEX_IS_SUPPORTED) {
if (IsWindows ()) {
if (pshare) {
goto Polyfill;
}
if (count == 1) {
WakeByAddressSingle (p);
} else {
WakeByAddressAll (p);
}
rc = 0;
} else if (IsFreebsd ()) {
if (pshare) {
fop = UMTX_OP_WAKE;
} else {
fop = UMTX_OP_WAKE_PRIVATE;
}
rc = sys_umtx_op (p, fop, count, 0, 0);
} else {
WakeByAddressAll (p);
rc = wake (p, op, count);
}
rc = 0;
} else if (IsFreebsd ()) {
if (pshare) {
fop = UMTX_OP_WAKE;
} else {
fop = UMTX_OP_WAKE_PRIVATE;
}
rc = sys_umtx_op (p, fop, count, 0, 0);
} else {
rc = wake (p, op, count);
Polyfill:
sched_yield ();
rc = 0;
}
STRACE ("futex(%t, %s, %d) → %s", p,
DescribeFutexOp(op),
STRACE ("futex(%t, %s, %d) → %s",
p, DescribeFutexOp(op),
count, DescribeErrnoResult(rc));
return rc;