Clean up more code

libc/calls/poll-nt.c

@@ -30,6 +30,7 @@
 #include "libc/nt/enum/filetype.h"
 #include "libc/nt/enum/wait.h"
 #include "libc/nt/errors.h"
+#include "libc/nt/events.h"
 #include "libc/nt/files.h"
 #include "libc/nt/ipc.h"
 #include "libc/nt/runtime.h"
@@ -114,7 +115,7 @@ textwindows static int sys_poll_nt_actual(struct pollfd *fds, uint64_t nfds,
         }
       } else if (kind == kFdFile || kind == kFdConsole) {
         // we can use WaitForMultipleObjects() for these fds
-        if (pn < ARRAYLEN(fileindices) - 1) {  // last slot for semaphore
+        if (pn < ARRAYLEN(fileindices) - 1) {  // last slot for signal event
           fileindices[pn] = i;
           filehands[pn] = g_fds.p[fds[i].fd].handle;
           ++pn;
@@ -230,8 +231,8 @@ textwindows static int sys_poll_nt_actual(struct pollfd *fds, uint64_t nfds,
       if (__sigcheck(waitmask, false))
         return -1;
       pt = _pthread_self();
-      filehands[pn] = pt->pt_semaphore = CreateSemaphore(0, 0, 1, 0);
-      atomic_store_explicit(&pt->pt_blocker, PT_BLOCKER_SEM,
+      filehands[pn] = pt->pt_event = CreateEvent(0, 0, 0, 0);
+      atomic_store_explicit(&pt->pt_blocker, PT_BLOCKER_EVENT,
                             memory_order_release);
       wi = WaitForMultipleObjects(pn + 1, filehands, 0, waitfor);
       atomic_store_explicit(&pt->pt_blocker, 0, memory_order_release);
@@ -240,7 +241,7 @@ textwindows static int sys_poll_nt_actual(struct pollfd *fds, uint64_t nfds,
         // win32 wait failure
         return __winerr();
       } else if (wi == pn) {
-        // our semaphore was signalled
+        // our signal event was signalled
         if (__sigcheck(waitmask, false))
           return -1;
       } else if ((wi ^ kNtWaitAbandoned) < pn) {

libc/calls/read-nt.c

@@ -47,6 +47,7 @@
 #include "libc/nt/enum/vk.h"
 #include "libc/nt/enum/wait.h"
 #include "libc/nt/errors.h"
+#include "libc/nt/events.h"
 #include "libc/nt/runtime.h"
 #include "libc/nt/struct/inputrecord.h"
 #include "libc/nt/synchronization.h"
@@ -833,25 +834,39 @@ textwindows static void RestoreProcessedInput(uint32_t inmode) {
 textwindows static int CountConsoleInputBytesBlockingImpl(uint32_t ms,
                                                           sigset_t waitmask,
                                                           bool restartable) {
-  int sig;
-  int64_t sem;
-  uint32_t wi;
-  struct timespec now, deadline;
   InitConsole();
-  deadline =
+  struct timespec deadline =
       timespec_add(sys_clock_gettime_monotonic_nt(), timespec_frommillis(ms));
-RestartOperation:
-  if (_check_cancel() == -1)
-    return -1;
-  if (_weaken(__sig_get) && (sig = _weaken(__sig_get)(waitmask)))
-    goto DeliverSignal;
+  for (;;) {
+    int sig = 0;
+    intptr_t sev;
+    if (!(sev = CreateEvent(0, 0, 0, 0)))
+      return __winerr();
     struct PosixThread *pt = _pthread_self();
+    pt->pt_event = sev;
     pt->pt_blkmask = waitmask;
-  pt->pt_semaphore = sem = CreateSemaphore(0, 0, 1, 0);
-  atomic_store_explicit(&pt->pt_blocker, PT_BLOCKER_SEM, memory_order_release);
-  wi = WaitForMultipleObjects(2, (int64_t[2]){__keystroke.cin, sem}, 0, ms);
+    atomic_store_explicit(&pt->pt_blocker, PT_BLOCKER_EVENT,
+                          memory_order_release);
+    if (_check_cancel() == -1) {
       atomic_store_explicit(&pt->pt_blocker, 0, memory_order_release);
-  CloseHandle(sem);
+      CloseHandle(sev);
+      return -1;
+    }
+    if (_weaken(__sig_get) && (sig = _weaken(__sig_get)(waitmask))) {
+      atomic_store_explicit(&pt->pt_blocker, 0, memory_order_release);
+      CloseHandle(sev);
+      goto DeliverSignal;
+    }
+    struct timespec now = sys_clock_gettime_monotonic_nt();
+    struct timespec remain = timespec_subz(deadline, now);
+    int64_t millis = timespec_tomillis(remain);
+    uint32_t waitms = MIN(millis, 0xffffffffu);
+    intptr_t hands[] = {__keystroke.cin, sev};
+    uint32_t wi = WaitForMultipleObjects(2, hands, 0, waitms);
+    atomic_store_explicit(&pt->pt_blocker, 0, memory_order_release);
+    CloseHandle(sev);
+    if (wi == -1u)
+      return __winerr();
 
     // check for wait timeout
     if (wi == kNtWaitTimeout)
@@ -863,35 +878,27 @@ RestartOperation:
     // raised. so we need to check for pending signals again and handle it
     if (wi == 0) {
       int got = CountConsoleInputBytes();
+      // we might have read a keystroke that generated a signal
       if (_weaken(__sig_get) && (sig = _weaken(__sig_get)(waitmask)))
         goto DeliverSignal;
       if (got == -1)
         // this is a bona fide eof and console errors are logged to strace
         return 0;
-    if (got == 0) {
+      if (got == 0)
         // this can happen for multiple reasons. first our driver controls
         // user interactions in canonical mode. secondly we could lose the
         // race with another thread that's reading input.
-      now = sys_clock_gettime_monotonic_nt();
-      if (timespec_cmp(now, deadline) >= 0)
-        return etimedout();
-      ms = timespec_tomillis(timespec_sub(deadline, now));
-      ms = ms > -1u ? -1u : ms;
-      goto RestartOperation;
-    }
+        continue;
       return got;
     }
 
-  // handle wait itself failing
-  if (wi != 1)
-    return __winerr();
-
+    if (wi == 1 && _weaken(__sig_get) && (sig = _weaken(__sig_get)(waitmask))) {
       // handle event on throwaway semaphore, it is poked by signal delivery
-  if (_weaken(__sig_get)) {
-    if (!(sig = _weaken(__sig_get)(waitmask)))
-      return eintr();
-  DeliverSignal:
-    int handler_was_called = _weaken(__sig_relay)(sig, SI_KERNEL, waitmask);
+    DeliverSignal:;
+      int handler_was_called = 0;
+      do {
+        handler_was_called |= _weaken(__sig_relay)(sig, SI_KERNEL, waitmask);
+      } while ((sig = _weaken(__sig_get)(waitmask)));
       if (_check_cancel() == -1)
         return -1;
       if (handler_was_called & SIG_HANDLED_NO_RESTART)
@@ -900,7 +907,7 @@ RestartOperation:
         if (!restartable)
           return eintr();
     }
-  goto RestartOperation;
+  }
 }
 
 textwindows static int CountConsoleInputBytesBlocking(uint32_t ms,
@@ -911,7 +918,7 @@ textwindows static int CountConsoleInputBytesBlocking(uint32_t ms,
   if (got > 0)
     return got;
   uint32_t inmode = DisableProcessedInput();
-  int rc = CountConsoleInputBytesBlockingImpl(ms, waitmask, false);
+  int rc = CountConsoleInputBytesBlockingImpl(ms, waitmask, true);
   RestoreProcessedInput(inmode);
   return rc;
 }

libc/calls/readwrite-nt.c

@@ -104,13 +104,13 @@ sys_readwrite_nt(int fd, void *data, size_t size, ssize_t offset,
         // atomic block on i/o completion, signal, or cancel
         // it's not safe to acknowledge cancelation from here
         // it's not safe to call any signal handlers from here
-        intptr_t sem;
-        if ((sem = CreateSemaphore(0, 0, 1, 0))) {
+        intptr_t sigev;
+        if ((sigev = CreateEvent(0, 0, 0, 0))) {
           // installing semaphore before sig get makes wait atomic
           struct PosixThread *pt = _pthread_self();
-          pt->pt_semaphore = sem;
+          pt->pt_event = sigev;
           pt->pt_blkmask = waitmask;
-          atomic_store_explicit(&pt->pt_blocker, PT_BLOCKER_SEM,
+          atomic_store_explicit(&pt->pt_blocker, PT_BLOCKER_EVENT,
                                 memory_order_release);
           if (_is_canceled()) {
             CancelIoEx(handle, &overlap);
@@ -118,9 +118,9 @@ sys_readwrite_nt(int fd, void *data, size_t size, ssize_t offset,
                      (got_sig = _weaken(__sig_get)(waitmask))) {
             CancelIoEx(handle, &overlap);
           } else {
-            intptr_t hands[] = {event, sem};
+            intptr_t hands[] = {event, sigev};
             uint32_t wi = WaitForMultipleObjects(2, hands, 0, -1u);
-            if (wi == 1) {  // semaphore was signaled by signal enqueue
+            if (wi == 1) {  // event was signaled by signal enqueue
               CancelIoEx(handle, &overlap);
               if (_weaken(__sig_get))
                 got_sig = _weaken(__sig_get)(waitmask);
@@ -130,7 +130,7 @@ sys_readwrite_nt(int fd, void *data, size_t size, ssize_t offset,
             }
           }
           atomic_store_explicit(&pt->pt_blocker, 0, memory_order_release);
-          CloseHandle(sem);
+          CloseHandle(sigev);
         } else {
           other_error = GetLastError();
           CancelIoEx(handle, &overlap);

libc/calls/sig.c

@@ -40,6 +40,7 @@
 #include "libc/nt/enum/exceptionhandleractions.h"
 #include "libc/nt/enum/signal.h"
 #include "libc/nt/enum/status.h"
+#include "libc/nt/events.h"
 #include "libc/nt/runtime.h"
 #include "libc/nt/signals.h"
 #include "libc/nt/struct/ntexceptionpointers.h"
@@ -230,16 +231,10 @@ textwindows void __sig_cancel(struct PosixThread *pt, int sig, unsigned flags) {
     STRACE("%G sent to %d asynchronously", sig, _pthread_tid(pt));
     return;
   }
-  // we can cancel another thread's overlapped i/o op after the freeze
-  if (blocker == PT_BLOCKER_IO) {
-    STRACE("%G canceling %d's i/o", sig, _pthread_tid(pt));
-    CancelIoEx(pt->pt_iohandle, pt->pt_ioverlap);
-    return;
-  }
   // threads can create semaphores on an as-needed basis
-  if (blocker == PT_BLOCKER_SEM) {
-    STRACE("%G releasing %d's semaphore", sig, _pthread_tid(pt));
-    ReleaseSemaphore(pt->pt_semaphore, 1, 0);
+  if (blocker == PT_BLOCKER_EVENT) {
+    STRACE("%G set %d's event object", sig, _pthread_tid(pt));
+    SetEvent(pt->pt_event);
     return;
   }
   // all other blocking ops that aren't overlap should use futexes

libc/calls/sigtimedwait-nt.c

@@ -25,6 +25,7 @@
 #include "libc/calls/syscall_support-nt.internal.h"
 #include "libc/intrin/atomic.h"
 #include "libc/macros.h"
+#include "libc/nt/events.h"
 #include "libc/nt/runtime.h"
 #include "libc/nt/synchronization.h"
 #include "libc/str/str.h"
@@ -85,7 +86,7 @@ textwindows static int sys_sigtimedwait_nt_impl(sigset_t syncsigs,
 textwindows int sys_sigtimedwait_nt(const sigset_t *set, siginfo_t *opt_info,
                                     const struct timespec *opt_timeout) {
   int rc;
-  intptr_t sem;
+  intptr_t sev;
   struct PosixThread *pt;
   struct timespec deadline;
   sigset_t syncsigs, waitmask;
@@ -95,17 +96,17 @@ textwindows int sys_sigtimedwait_nt(const sigset_t *set, siginfo_t *opt_info,
   } else {
     deadline = timespec_max;
   }
-  if ((sem = CreateSemaphore(0, 0, 1, 0))) {
+  if ((sev = CreateEvent(0, 0, 0, 0))) {
     syncsigs = *set & ~(1ull << (SIGTHR - 1));  // internal to pthreads
     waitmask = ~syncsigs & _SigMask;
     pt = _pthread_self();
+    pt->pt_event = sev;
     pt->pt_blkmask = waitmask;
-    pt->pt_semaphore = sem = CreateSemaphore(0, 0, 1, 0);
-    atomic_store_explicit(&pt->pt_blocker, PT_BLOCKER_SEM,
+    atomic_store_explicit(&pt->pt_blocker, PT_BLOCKER_EVENT,
                           memory_order_release);
-    rc = sys_sigtimedwait_nt_impl(syncsigs, opt_info, deadline, waitmask, sem);
+    rc = sys_sigtimedwait_nt_impl(syncsigs, opt_info, deadline, waitmask, sev);
     atomic_store_explicit(&pt->pt_blocker, 0, memory_order_release);
-    CloseHandle(sem);
+    CloseHandle(sev);
   } else {
     rc = __winerr();
   }

libc/proc/wait4-nt.c

@@ -131,15 +131,15 @@ static textwindows int __proc_wait(int pid, int *wstatus, int options,
 
     // perform blocking operation
     uint32_t wi;
-    uintptr_t sem;
+    uintptr_t event;
     struct PosixThread *pt = _pthread_self();
     pt->pt_blkmask = waitmask;
-    pt->pt_semaphore = sem = CreateSemaphore(0, 0, 1, 0);
-    atomic_store_explicit(&pt->pt_blocker, PT_BLOCKER_SEM,
+    pt->pt_event = event = CreateEvent(0, 0, 0, 0);
+    atomic_store_explicit(&pt->pt_blocker, PT_BLOCKER_EVENT,
                           memory_order_release);
-    wi = WaitForMultipleObjects(2, (intptr_t[2]){hWaitObject, sem}, 0, -1u);
+    wi = WaitForMultipleObjects(2, (intptr_t[2]){hWaitObject, event}, 0, -1u);
     atomic_store_explicit(&pt->pt_blocker, 0, memory_order_release);
-    CloseHandle(sem);
+    CloseHandle(event);
 
     // log warning if handle unexpectedly closed
     if (wi & kNtWaitAbandoned) {

libc/sock/winsockblock.c

@@ -27,6 +27,7 @@
 #include "libc/intrin/weaken.h"
 #include "libc/nt/enum/wait.h"
 #include "libc/nt/errors.h"
+#include "libc/nt/events.h"
 #include "libc/nt/runtime.h"
 #include "libc/nt/struct/overlapped.h"
 #include "libc/nt/synchronization.h"
@@ -75,13 +76,13 @@ __winsock_block(int64_t handle, uint32_t flags, bool nonblock,
         // atomic block on i/o completion, signal, or cancel
         // it's not safe to acknowledge cancelation from here
         // it's not safe to call any signal handlers from here
-        intptr_t sem;
-        if ((sem = CreateSemaphore(0, 0, 1, 0))) {
+        intptr_t sev;
+        if ((sev = CreateEvent(0, 0, 0, 0))) {
           // installing semaphore before sig get makes wait atomic
           struct PosixThread *pt = _pthread_self();
-          pt->pt_semaphore = sem;
+          pt->pt_event = sev;
           pt->pt_blkmask = waitmask;
-          atomic_store_explicit(&pt->pt_blocker, PT_BLOCKER_SEM,
+          atomic_store_explicit(&pt->pt_blocker, PT_BLOCKER_EVENT,
                                 memory_order_release);
           if (_is_canceled()) {
             got_cancel = true;
@@ -94,7 +95,7 @@ __winsock_block(int64_t handle, uint32_t flags, bool nonblock,
             struct timespec remain = timespec_subz(deadline, now);
             int64_t millis = timespec_tomillis(remain);
             uint32_t waitms = MIN(millis, 0xffffffffu);
-            intptr_t hands[] = {event, sem};
+            intptr_t hands[] = {event, sev};
             uint32_t wi = WSAWaitForMultipleEvents(2, hands, 0, waitms, 0);
             if (wi == 1) {  // semaphore was signaled by signal enqueue
               CancelIoEx(handle, &overlap);
@@ -109,7 +110,7 @@ __winsock_block(int64_t handle, uint32_t flags, bool nonblock,
             }
           }
           atomic_store_explicit(&pt->pt_blocker, 0, memory_order_release);
-          CloseHandle(sem);
+          CloseHandle(sev);
         } else {
           other_error = GetLastError();
           CancelIoEx(handle, &overlap);

libc/thread/posixthread.internal.h

@@ -9,8 +9,7 @@
 #include "libc/thread/thread.h"
 #include "libc/thread/tls.h"
 
-#define PT_BLOCKER_SEM ((atomic_int *)-1)
-#define PT_BLOCKER_IO  ((atomic_int *)-2)
+#define PT_BLOCKER_EVENT ((atomic_int *)-1)
 
 COSMOPOLITAN_C_START_
 
@@ -86,10 +85,8 @@ struct PosixThread {
   struct _pthread_cleanup_buffer *pt_cleanup;
   _Atomic(atomic_int *) pt_blocker;
   uint64_t pt_blkmask;
-  int64_t pt_semaphore;
-  intptr_t pt_iohandle;
+  int64_t pt_event;
   locale_t pt_locale;
-  void *pt_ioverlap;
   jmp_buf pt_exiter;
   pthread_attr_t pt_attr;
 };

third_party/python/Modules/selectmodule.c

@@ -9,7 +9,6 @@
 #include "libc/errno.h"
 #include "libc/mem/gc.h"
 #include "libc/mem/mem.h"
-#include "libc/nt/efi.h"
 #include "libc/sock/select.h"
 #include "libc/sock/sock.h"
 #include "libc/sock/struct/pollfd.h"