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Make win32 i/o signals atomic and longjmp() safe

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This commit is contained in:
Justine Tunney 2023-11-04 20:29:25 -07:00
parent 585c86e2a4
commit d7917ea076
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GPG key ID: BE714B4575D6E328
20 changed files with 381 additions and 263 deletions
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45
third_party/nsync/futex.c vendored
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@ -23,6 +23,8 @@
#include "libc/calls/internal.h"
#include "libc/calls/sig.internal.h"
#include "libc/calls/state.internal.h"
#include "libc/calls/struct/sigset.h"
#include "libc/calls/struct/sigset.internal.h"
#include "libc/calls/struct/timespec.h"
#include "libc/calls/struct/timespec.internal.h"
#include "libc/calls/syscall_support-nt.internal.h"
@ -40,6 +42,7 @@
#include "libc/nt/synchronization.h"
#include "libc/runtime/clktck.h"
#include "libc/sysv/consts/clock.h"
#include "libc/sysv/consts/sicode.h"
#include "libc/sysv/consts/timer.h"
#include "libc/sysv/errfuns.h"
#include "libc/thread/freebsd.internal.h"
@ -147,9 +150,11 @@ static int nsync_futex_polyfill_ (atomic_int *w, int expect, struct timespec *ab
static int nsync_futex_wait_win32_ (atomic_int *w, int expect, char pshare,
const struct timespec *timeout,
struct PosixThread *pt) {
struct PosixThread *pt,
sigset_t waitmask) {
int sig;
bool32 ok;
struct timespec deadline, interval, remain, wait, now;
struct timespec deadline, wait, now;
if (timeout) {
deadline = *timeout;
@ -162,16 +167,36 @@ static int nsync_futex_wait_win32_ (atomic_int *w, int expect, char pshare,
if (timespec_cmp (now, deadline) > 0) {
return etimedout();
}
remain = timespec_sub (deadline, now);
interval = timespec_frommillis (5000);
wait = timespec_cmp (remain, interval) > 0 ? interval : remain;
wait = timespec_sub (deadline, now);
if (atomic_load_explicit (w, memory_order_acquire) != expect) {
return 0;
}
if (pt) atomic_store_explicit (&pt->pt_blocker, w, memory_order_release);
if (_check_signal (false) == -1) return -1;
if (pt) {
if (_check_cancel () == -1) {
return -1; /* ECANCELED */
}
if ((sig = __sig_get (waitmask))) {
__sig_relay (sig, SI_KERNEL, waitmask);
if (_check_cancel () == -1) {
return -1; /* ECANCELED */
}
return eintr ();
}
pt->pt_blkmask = waitmask;
atomic_store_explicit (&pt->pt_blocker, w, memory_order_release);
}
ok = WaitOnAddress (w, &expect, sizeof(int), timespec_tomillis (wait));
if (_check_signal (false) == -1) return -1;
if (pt) {
/* __sig_cancel wakes our futex without changing `w` after enqueing signals */
atomic_store_explicit (&pt->pt_blocker, 0, memory_order_release);
if (ok && atomic_load_explicit (w, memory_order_acquire) == expect && (sig = __sig_get (waitmask))) {
__sig_relay (sig, SI_KERNEL, waitmask);
if (_check_cancel () == -1) {
return -1; /* ECANCELED */
}
return eintr ();
}
}
if (ok) {
return 0;
} else {
@ -233,7 +258,9 @@ int nsync_futex_wait_ (atomic_int *w, int expect, char pshare, const struct time
if (IsWindows ()) {
// Windows 8 futexes don't support multiple processes :(
if (pshare) goto Polyfill;
rc = nsync_futex_wait_win32_ (w, expect, pshare, timeout, pt);
sigset_t m = __sig_block ();
rc = nsync_futex_wait_win32_ (w, expect, pshare, timeout, pt, m);
__sig_unblock (m);
} else if (IsXnu ()) {
uint32_t op, us;
if (pshare) {