Introduce sigtimedwait() on Windows

libc/calls/ppoll.c

@@ -35,80 +35,14 @@
 #include "libc/sysv/consts/sig.h"
 #include "libc/sysv/errfuns.h"
 
-/**
- * Checks status on multiple file descriptors at once.
- *
- * This function is the same as saying:
- *
- *     sigset_t old;
- *     sigprocmask(SIG_SETMASK, sigmask, &old);
- *     poll(fds, nfds, timeout);
- *     sigprocmask(SIG_SETMASK, old, 0);
- *
- * Except it happens atomically when the kernel supports doing that. On
- * kernels such as XNU and NetBSD which don't, this wrapper will fall
- * back to using the example above. If you need ironclad assurances of
- * signal mask atomicity, then consider using pselect() which Cosmo Libc
- * guarantees to be atomic on all supported platforms.
- *
- * Servers that need to handle an unbounded number of client connections
- * should just create a separate thread for each client. poll(), ppoll()
- * and select() aren't scalable i/o solutions on any platform.
- *
- * On Windows it's only possible to poll 64 file descriptors at a time;
- * it's a limitation imposed by WSAPoll(). Cosmopolitan Libc's ppoll()
- * polyfill can go higher in some cases; for example, It's possible to
- * poll 64 sockets and 64 pipes/terminals at the same time. Furthermore,
- * elements whose fd field is set to a negative number are ignored and
- * will not count against this limit.
- *
- * One of the use cases for poll() is to quickly check if a number of
- * file descriptors are valid. The canonical way to do this is to set
- * events to 0 which prevents blocking and causes only the invalid,
- * hangup, and error statuses to be checked.
- *
- * On XNU, the POLLHUP and POLLERR statuses aren't checked unless either
- * POLLIN, POLLOUT, or POLLPRI are specified in the events field. Cosmo
- * will however polyfill the checking of POLLNVAL on XNU with the events
- * doesn't specify any of the above i/o events.
- *
- * When XNU and BSD OSes report POLLHUP, they will always set POLLIN too
- * when POLLIN is requested, even in cases when there isn't unread data.
- *
- * @param fds[𝑖].fd should be a socket, input pipe, or conosle input
- *     and if it's a negative number then the entry is ignored, plus
- *     revents will be set to zero
- * @param fds[𝑖].events flags can have POLLIN, POLLOUT, POLLPRI,
- *     POLLRDNORM, POLLWRNORM, POLLRDBAND, POLLWRBAND as well as
- *     POLLERR, POLLHUP, and POLLNVAL although the latter are
- *     always implied (assuming fd≥0) so they're ignored here
- * @param timeout_ms if 0 means don't wait and negative waits forever
- * @return number of `fds` whose revents field has been set to a nonzero
- *     number, 0 if the timeout elapsed without events, or -1 w/ errno
- * @return fds[𝑖].revents is always zero initializaed and then will
- *     be populated with POLL{IN,OUT,PRI,HUP,ERR,NVAL} if something
- *     was determined about the file descriptor
- * @param timeout if null will block indefinitely
- * @param sigmask may be null in which case no mask change happens
- * @raise EINVAL if we exceeded the 64 socket limit on Windows
- * @raise ECANCELED if thread was cancelled in masked mode
- * @raise EINVAL if `nfds` exceeded `RLIMIT_NOFILE`
- * @raise ENOMEM on failure to allocate memory
- * @raise EINVAL if `*timeout` is invalid
- * @raise EINTR if signal was delivered
- * @cancelationpoint
- * @asyncsignalsafe
- * @norestart
- */
-int ppoll(struct pollfd *fds, size_t nfds, const struct timespec *timeout,
-          const sigset_t *sigmask) {
+static int ppoll_impl(struct pollfd *fds, size_t nfds,
+                      const struct timespec *timeout, const sigset_t *sigmask) {
   int e, fdcount;
   sigset_t oldmask;
   struct timespec ts, *tsp;
-  BEGIN_CANCELATION_POINT;
 
   // validate timeout
-  if (timeout && timeout->tv_nsec >= 1000000000)
+  if (timeout && timeout->tv_nsec >= 1000000000ull)
     return einval();
 
   // The OpenBSD poll() man pages claims it'll ignore POLLERR, POLLHUP,
@@ -192,6 +126,78 @@ int ppoll(struct pollfd *fds, size_t nfds, const struct timespec *timeout,
     }
   }
 
+  return fdcount;
+}
+
+/**
+ * Checks status on multiple file descriptors at once.
+ *
+ * This function is the same as saying:
+ *
+ *     sigset_t old;
+ *     sigprocmask(SIG_SETMASK, sigmask, &old);
+ *     poll(fds, nfds, timeout);
+ *     sigprocmask(SIG_SETMASK, old, 0);
+ *
+ * Except it happens atomically when the kernel supports doing that. On
+ * kernels such as XNU and NetBSD which don't, this wrapper will fall
+ * back to using the example above. If you need ironclad assurances of
+ * signal mask atomicity, then consider using pselect() which Cosmo Libc
+ * guarantees to be atomic on all supported platforms.
+ *
+ * Servers that need to handle an unbounded number of client connections
+ * should just create a separate thread for each client. poll(), ppoll()
+ * and select() aren't scalable i/o solutions on any platform.
+ *
+ * On Windows it's only possible to poll 64 file descriptors at a time;
+ * it's a limitation imposed by WSAPoll(). Cosmopolitan Libc's ppoll()
+ * polyfill can go higher in some cases; for example, It's possible to
+ * poll 64 sockets and 64 pipes/terminals at the same time. Furthermore,
+ * elements whose fd field is set to a negative number are ignored and
+ * will not count against this limit.
+ *
+ * One of the use cases for poll() is to quickly check if a number of
+ * file descriptors are valid. The canonical way to do this is to set
+ * events to 0 which prevents blocking and causes only the invalid,
+ * hangup, and error statuses to be checked.
+ *
+ * On XNU, the POLLHUP and POLLERR statuses aren't checked unless either
+ * POLLIN, POLLOUT, or POLLPRI are specified in the events field. Cosmo
+ * will however polyfill the checking of POLLNVAL on XNU with the events
+ * doesn't specify any of the above i/o events.
+ *
+ * When XNU and BSD OSes report POLLHUP, they will always set POLLIN too
+ * when POLLIN is requested, even in cases when there isn't unread data.
+ *
+ * @param fds[𝑖].fd should be a socket, input pipe, or conosle input
+ *     and if it's a negative number then the entry is ignored, plus
+ *     revents will be set to zero
+ * @param fds[𝑖].events flags can have POLLIN, POLLOUT, POLLPRI,
+ *     POLLRDNORM, POLLWRNORM, POLLRDBAND, POLLWRBAND as well as
+ *     POLLERR, POLLHUP, and POLLNVAL although the latter are
+ *     always implied (assuming fd≥0) so they're ignored here
+ * @param timeout_ms if 0 means don't wait and negative waits forever
+ * @return number of `fds` whose revents field has been set to a nonzero
+ *     number, 0 if the timeout elapsed without events, or -1 w/ errno
+ * @return fds[𝑖].revents is always zero initializaed and then will
+ *     be populated with POLL{IN,OUT,PRI,HUP,ERR,NVAL} if something
+ *     was determined about the file descriptor
+ * @param timeout if null will block indefinitely
+ * @param sigmask may be null in which case no mask change happens
+ * @raise ECANCELED if thread was cancelled in masked mode
+ * @raise EINVAL if `nfds` exceeded `RLIMIT_NOFILE`
+ * @raise ENOMEM on failure to allocate memory
+ * @raise EINVAL if `*timeout` is invalid
+ * @raise EINTR if signal was delivered
+ * @cancelationpoint
+ * @asyncsignalsafe
+ * @norestart
+ */
+int ppoll(struct pollfd *fds, size_t nfds, const struct timespec *timeout,
+          const sigset_t *sigmask) {
+  int fdcount;
+  BEGIN_CANCELATION_POINT;
+  fdcount = ppoll_impl(fds, nfds, timeout, sigmask);
   END_CANCELATION_POINT;
   STRACE("ppoll(%s, %'zu, %s, %s) → %d% lm",
          DescribePollFds(fdcount, fds, nfds), nfds,