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Add *NSYNC unit test suite

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This change also fixes the clock_nanosleep() api and polyfills futexes
on Windows, Mac, and NetBSD using exponential backoff.
This commit is contained in:
Justine Tunney 2022-10-07 21:29:40 -07:00
parent 3421b9a580
commit 9849b4c7ba
No known key found for this signature in database
GPG key ID: BE714B4575D6E328
51 changed files with 5505 additions and 1060 deletions
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107
third_party/nsync/futex.c vendored
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@ -16,10 +16,13 @@
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
│ PERFORMANCE OF THIS SOFTWARE. │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/atomic.h"
#include "libc/calls/sig.internal.h"
#include "libc/calls/struct/timespec.h"
#include "libc/calls/struct/timespec.internal.h"
#include "libc/calls/syscall_support-nt.internal.h"
#include "libc/dce.h"
#include "libc/errno.h"
#include "libc/intrin/atomic.h"
#include "libc/intrin/describeflags.internal.h"
#include "libc/intrin/strace.internal.h"
#include "libc/limits.h"
@ -27,10 +30,10 @@
#include "libc/nt/synchronization.h"
#include "libc/sysv/consts/clock.h"
#include "libc/sysv/consts/futex.h"
#include "libc/sysv/consts/timer.h"
#include "libc/thread/freebsd.internal.h"
#include "libc/thread/thread.h"
#include "third_party/nsync/common.internal.h"
#include "third_party/nsync/futex.internal.h"
#include "third_party/nsync/mu_semaphore.internal.h"
// clang-format off
@ -57,8 +60,8 @@ __attribute__((__constructor__)) static void nsync_futex_init_ (void) {
if (IsFreebsd ()) {
FUTEX_IS_SUPPORTED = true;
FUTEX_WAIT_ = FUTEX_WAIT;
FUTEX_PRIVATE_FLAG_ = FUTEX_PRIVATE_FLAG;
FUTEX_TIMEOUT_IS_ABSOLUTE = true;
FUTEX_PRIVATE_FLAG_ = FUTEX_PRIVATE_FLAG;
return;
}
@ -101,18 +104,58 @@ __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;
struct timespec ts, deadline;
w = (atomic_int *)p;
if (atomic_load_explicit (p, memory_order_relaxed) != expect) {
return -EAGAIN;
}
ts = _timespec_real ();
if (!timeout) {
deadline = nsync_time_no_deadline;
} else if (FUTEX_TIMEOUT_IS_ABSOLUTE) {
deadline = *timeout;
} else {
deadline = _timespec_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) {
return 0;
}
ts = _timespec_add (ts, _timespec_fromnanos (nanos));
if (_timespec_gt (ts, deadline)) {
ts = deadline;
}
rc = clock_nanosleep (CLOCK_REALTIME, TIMER_ABSTIME, &ts, 0);
if (rc) {
ASSERT (rc == EINTR);
return -EINTR;
}
if (nanos < max) {
nanos <<= 1;
if (nanos > max) {
nanos = max;
}
}
}
return -ETIMEDOUT;
}
int nsync_futex_wait_ (int *p, int expect, char pshare, struct timespec *timeout) {
size_t size;
uint32_t ms;
int rc, op, fop;
if (!FUTEX_IS_SUPPORTED || (IsWindows() && pshare)) {
nsync_yield_ ();
if (timeout) {
return -EINTR;
} else {
return 0;
}
if (!FUTEX_IS_SUPPORTED) {
return nsync_futex_polyfill_ (p, expect, timeout);
}
op = FUTEX_WAIT_;
@ -121,6 +164,10 @@ int nsync_futex_wait_ (int *p, int expect, char pshare, struct timespec *timeout
}
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);
} else {
@ -132,23 +179,7 @@ int nsync_futex_wait_ (int *p, int expect, char pshare, struct timespec *timeout
rc = -GetLastError ();
}
} else if (IsFreebsd ()) {
struct _umtx_time *put, ut;
if (!timeout) {
put = 0;
size = 0;
} else {
ut._flags = UMTX_ABSTIME;
ut._clockid = CLOCK_REALTIME;
ut._timeout = *timeout;
put = &ut;
size = sizeof(ut);
}
if (pshare) {
fop = UMTX_OP_WAIT_UINT;
} else {
fop = UMTX_OP_WAIT_UINT_PRIVATE;
}
rc = sys_umtx_op (p, fop, 0, &size, put);
rc = sys_umtx_timedwait_uint (p, expect, pshare, timeout);
} else {
rc = _futex (p, op, expect, timeout, 0, FUTEX_WAIT_BITS_);
if (IsOpenbsd() && rc > 0) {
@ -157,10 +188,10 @@ int nsync_futex_wait_ (int *p, int expect, char pshare, struct timespec *timeout
}
}
STRACE("futex(%t, %s, %d, %s) → %s",
p, DescribeFutexOp (op), expect,
DescribeTimespec (0, timeout),
DescribeErrnoResult (rc));
STRACE ("futex(%t, %s, %d, %s) → %s",
p, DescribeFutexOp (op), expect,
DescribeTimespec (0, timeout),
DescribeErrnoResult (rc));
return rc;
}
@ -171,7 +202,7 @@ int nsync_futex_wake_ (int *p, int count, char pshare) {
ASSERT (count == 1 || count == INT_MAX);
if (!FUTEX_IS_SUPPORTED || (IsWindows() && pshare)) {
if (!FUTEX_IS_SUPPORTED) {
nsync_yield_ ();
return 0;
}
@ -182,6 +213,10 @@ int nsync_futex_wake_ (int *p, int count, char pshare) {
}
if (NSYNC_FUTEX_WIN32 && IsWindows ()) {
if (pshare) {
nsync_yield_ ();
return 0;
}
if (count == 1) {
WakeByAddressSingle (p);
} else {
@ -199,9 +234,9 @@ int nsync_futex_wake_ (int *p, int count, char pshare) {
rc = wake (p, op, count);
}
STRACE("futex(%t, %s, %d) → %s", p,
DescribeFutexOp(op),
count, DescribeErrnoResult(rc));
STRACE ("futex(%t, %s, %d) → %s", p,
DescribeFutexOp(op),
count, DescribeErrnoResult(rc));
return rc;
}