Simplify GNU Make build config

libc/calls/select-nt.c

@@ -0,0 +1,110 @@
+/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
+│ vi: set noet ft=c ts=2 sts=2 sw=2 fenc=utf-8                             :vi │
+╞══════════════════════════════════════════════════════════════════════════════╡
+│ Copyright 2020 Justine Alexandra Roberts Tunney                              │
+│                                                                              │
+│ Permission to use, copy, modify, and/or distribute this software for         │
+│ any purpose with or without fee is hereby granted, provided that the         │
+│ above copyright notice and this permission notice appear in all copies.      │
+│                                                                              │
+│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL                │
+│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED                │
+│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE             │
+│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL         │
+│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR        │
+│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER               │
+│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
+│ PERFORMANCE OF THIS SOFTWARE.                                                │
+╚─────────────────────────────────────────────────────────────────────────────*/
+#include "libc/assert.h"
+#include "libc/calls/internal.h"
+#include "libc/calls/state.internal.h"
+#include "libc/calls/struct/timeval.h"
+#include "libc/limits.h"
+#include "libc/macros.internal.h"
+#include "libc/sock/select.h"
+#include "libc/sock/sock.h"
+#include "libc/sock/struct/pollfd.h"
+#include "libc/sock/struct/pollfd.internal.h"
+#include "libc/stdckdint.h"
+#include "libc/sysv/consts/poll.h"
+#include "libc/sysv/errfuns.h"
+#ifdef __x86_64__
+
+int sys_select_nt(int nfds, fd_set *readfds, fd_set *writefds,
+                  fd_set *exceptfds, struct timeval *timeout,
+                  const sigset_t *sigmask) {
+  int i, pfds, events, fdcount;
+
+  // convert bitsets to pollfd
+  struct pollfd fds[64];
+  for (pfds = i = 0; i < nfds; ++i) {
+    events = 0;
+    if (readfds && FD_ISSET(i, readfds)) events |= POLLIN;
+    if (writefds && FD_ISSET(i, writefds)) events |= POLLOUT;
+    if (exceptfds && FD_ISSET(i, exceptfds)) events |= POLLERR;
+    if (events) {
+      if (pfds < ARRAYLEN(fds)) {
+        fds[pfds].fd = i;
+        fds[pfds].events = events;
+        fds[pfds].revents = 0;
+        pfds += 1;
+      } else {
+        return enomem();
+      }
+    }
+  }
+
+  // convert the wait time to a word
+  uint32_t millis;
+  if (!timeout) {
+    millis = -1;
+  } else {
+    int64_t ms = timeval_tomillis(*timeout);
+    if (ms < 0 || ms > UINT32_MAX) {
+      millis = -1u;
+    } else {
+      millis = ms;
+    }
+  }
+
+  // call our nt poll implementation
+  fdcount = sys_poll_nt(fds, pfds, &millis, sigmask);
+  unassert(fdcount < 64);
+  if (fdcount < 0) return -1;
+
+  // convert pollfd back to bitsets
+  if (readfds) FD_ZERO(readfds);
+  if (writefds) FD_ZERO(writefds);
+  if (exceptfds) FD_ZERO(exceptfds);
+  int bits = 0;
+  for (i = 0; i < pfds; ++i) {
+    if (fds[i].revents & POLLIN) {
+      if (readfds) {
+        FD_SET(fds[i].fd, readfds);
+        ++bits;
+      }
+    }
+    if (fds[i].revents & POLLOUT) {
+      if (writefds) {
+        FD_SET(fds[i].fd, writefds);
+        ++bits;
+      }
+    }
+    if (fds[i].revents & (POLLERR | POLLNVAL)) {
+      if (exceptfds) {
+        FD_SET(fds[i].fd, exceptfds);
+        ++bits;
+      }
+    }
+  }
+
+  // store remaining time back in caller's timeval
+  if (timeout) {
+    *timeout = timeval_frommillis(millis);
+  }
+
+  return bits;
+}
+
+#endif /* __x86_64__ */