Rewrite Windows connect()

Our old code wasn't working with projects like Qt that call connect() in O_NONBLOCK mode multiple times. This change overhauls connect() to use a simpler WSAConnect() API and follows the same pattern as cosmo accept(). This change also reduces the binary footprint of read(), which no longer needs to depend on our enormous clock_gettime() function.
jart · Sep 13, 2024 · 694ba36 · 694ba36
1 parent 5469202
commit 694ba36
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Showing 25 changed files with 555 additions and 277 deletions.
diff --git a/libc/calls/clock_gettime_monotonic_nt.c b/libc/calls/clock_gettime_monotonic_nt.c
@@ -0,0 +1,26 @@
+/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
+│ vi: set et ft=c ts=2 sts=2 sw=2 fenc=utf-8                               :vi │
+╞══════════════════════════════════════════════════════════════════════════════╡
+│ Copyright 2024 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/calls/struct/timespec.internal.h"
+#include "libc/nt/time.h"
+
+textwindows struct timespec sys_clock_gettime_monotonic_nt(void) {
+  uint64_t hectons;
+  QueryUnbiasedInterruptTimePrecise(&hectons);
+  return timespec_fromnanos(hectons * 100);
+}
diff --git a/libc/calls/poll-nt.c b/libc/calls/poll-nt.c
@@ -21,6 +21,7 @@
 #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"
 #include "libc/intrin/atomic.h"
 #include "libc/intrin/fds.h"
@@ -58,14 +59,8 @@
 #define POLLPRI_    0x0400  // MSDN unsupported
 // </sync libc/sysv/consts.sh>
 
-textwindows dontinline static struct timespec sys_poll_nt_now(void) {
-  uint64_t hectons;
-  QueryUnbiasedInterruptTimePrecise(&hectons);
-  return timespec_fromnanos(hectons * 100);
-}
-
 textwindows static uint32_t sys_poll_nt_waitms(struct timespec deadline) {
-  struct timespec now = sys_poll_nt_now();
+  struct timespec now = sys_clock_gettime_monotonic_nt();
   if (timespec_cmp(now, deadline) < 0) {
     struct timespec remain = timespec_sub(deadline, now);
     int64_t millis = timespec_tomillis(remain);
@@ -340,7 +335,7 @@ textwindows int sys_poll_nt(struct pollfd *fds, uint64_t nfds, uint32_t *ms,
   int rc;
   struct timespec now, timeout, deadline;
   BLOCK_SIGNALS;
-  now = ms ? sys_poll_nt_now() : timespec_zero;
+  now = ms ? sys_clock_gettime_monotonic_nt() : timespec_zero;
   timeout = ms ? timespec_frommillis(*ms) : timespec_max;
   deadline = timespec_add(now, timeout);
   rc = sys_poll_nt_impl(fds, nfds, deadline, sigmask ? *sigmask : _SigMask);

diff --git a/libc/calls/read-nt.c b/libc/calls/read-nt.c
@@ -24,6 +24,7 @@
 #include "libc/calls/struct/iovec.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"
 #include "libc/cosmo.h"
 #include "libc/ctype.h"
@@ -837,7 +838,8 @@ textwindows static int CountConsoleInputBytesBlockingImpl(uint32_t ms,
   uint32_t wi;
   struct timespec now, deadline;
   InitConsole();
-  deadline = timespec_add(timespec_mono(), timespec_frommillis(ms));
+  deadline =
+      timespec_add(sys_clock_gettime_monotonic_nt(), timespec_frommillis(ms));
 RestartOperation:
   if (_check_cancel() == -1)
     return -1;
@@ -870,7 +872,7 @@ textwindows static int CountConsoleInputBytesBlockingImpl(uint32_t ms,
       // 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 = timespec_mono();
+      now = sys_clock_gettime_monotonic_nt();
       if (timespec_cmp(now, deadline) >= 0)
         return etimedout();
       ms = timespec_tomillis(timespec_sub(deadline, now));

diff --git a/libc/calls/struct/timespec.internal.h b/libc/calls/struct/timespec.internal.h
@@ -25,6 +25,7 @@ int sys_sem_timedwait(int64_t, const struct timespec *);
 int sys_utimensat(int, const char *, const struct timespec[2], int);
 int sys_utimensat_nt(int, const char *, const struct timespec[2], int);
 int sys_utimensat_old(int, const char *, const struct timespec[2], int);
+struct timespec sys_clock_gettime_monotonic_nt(void);
 
 const char *_DescribeTimespec(char[45], int, const struct timespec *);
 #define DescribeTimespec(rc, ts) _DescribeTimespec(alloca(45), rc, ts)

diff --git a/libc/intrin/fds.h b/libc/intrin/fds.h
@@ -28,6 +28,7 @@ struct Cursor {
 struct Fd {
   char kind;
   bool isbound;
+  char connecting;
   unsigned flags;
   unsigned mode;
   long handle;
@@ -38,7 +39,6 @@ struct Fd {
   unsigned sndtimeo; /* millis; 0 means wait forever */
   void *connect_op;
   struct Cursor *cursor;
-  struct sockaddr_storage peer;
 };
 
 struct Fds {

diff --git a/libc/sock/BUILD.mk b/libc/sock/BUILD.mk
@@ -34,6 +34,7 @@ LIBC_SOCK_A_DIRECTDEPS =			\
 	LIBC_NT_IPHLPAPI			\
 	LIBC_NT_KERNEL32			\
 	LIBC_NT_NTDLL				\
+	LIBC_NT_REALTIME			\
 	LIBC_NT_WS2_32				\
 	LIBC_RUNTIME				\
 	LIBC_STDIO				\

diff --git a/libc/sock/accept-nt.c b/libc/sock/accept-nt.c
@@ -18,15 +18,12 @@
 ╚─────────────────────────────────────────────────────────────────────────────*/
 #include "libc/calls/internal.h"
 #include "libc/calls/struct/sigset.internal.h"
-#include "libc/calls/syscall_support-nt.internal.h"
 #include "libc/errno.h"
-#include "libc/intrin/kprintf.h"
 #include "libc/nt/errors.h"
 #include "libc/nt/struct/pollfd.h"
 #include "libc/nt/thunk/msabi.h"
 #include "libc/nt/winsock.h"
 #include "libc/sock/internal.h"
-#include "libc/sock/struct/sockaddr.h"
 #include "libc/sock/syscall_fd.internal.h"
 #include "libc/sysv/consts/fio.h"
 #include "libc/sysv/consts/o.h"
@@ -38,8 +35,6 @@
 
 #define POLL_INTERVAL_MS 10
 
-__msabi extern typeof(__sys_setsockopt_nt) *const __imp_setsockopt;
-__msabi extern typeof(__sys_closesocket_nt) *const __imp_closesocket;
 __msabi extern typeof(__sys_ioctlsocket_nt) *const __imp_ioctlsocket;
 
 textwindows static int sys_accept_nt_impl(struct Fd *f,
@@ -61,7 +56,6 @@ textwindows static int sys_accept_nt_impl(struct Fd *f,
   for (;;) {
 
     // perform non-blocking accept
-    // we assume listen() put f->handle in non-blocking mode
     int32_t addrsize = sizeof(*addr);
     struct sockaddr *paddr = (struct sockaddr *)addr;
     if ((handle = WSAAccept(f->handle, paddr, &addrsize, 0, 0)) != -1)
@@ -76,7 +70,7 @@ textwindows static int sys_accept_nt_impl(struct Fd *f,
       return -1;
     }
 
-    // we're done if user wants non-blocking
+    // check for non-blocking
     if (f->flags & O_NONBLOCK)
       return eagain();
 
@@ -91,13 +85,6 @@ textwindows static int sys_accept_nt_impl(struct Fd *f,
       return __winsockerr();
   }
 
-  // inherit properties of listening socket
-  // errors ignored as if f->handle was created before forking
-  // this fails with WSAENOTSOCK, see
-  // https://github.com/jart/cosmopolitan/issues/1174
-  __imp_setsockopt(handle, SOL_SOCKET, kNtSoUpdateAcceptContext, &f->handle,
-                   sizeof(f->handle));
-
   // create file descriptor for new socket
   // don't inherit the file open mode bits
   int oflags = 0;

diff --git a/libc/sock/accept.c b/libc/sock/accept.c
@@ -22,6 +22,9 @@
 /**
  * Creates client socket file descriptor for incoming connection.
  *
+ * On Windows, when this function blocks, there may be a 10 millisecond
+ * delay on the handling of signals or thread cancelation.
+ *
  * @param fd is the server socket file descriptor
  * @param opt_out_addr will receive the remote address
  * @param opt_inout_addrsize provides and receives addr's byte length

diff --git a/libc/sock/accept4.c b/libc/sock/accept4.c
@@ -30,12 +30,23 @@
 /**
  * Creates client socket file descriptor for incoming connection.
  *
+ * When `fd` is in `O_NONBLOCK` mode, this function will raise `EAGAIN`
+ * when no client is available to accept. To wait until a client exists
+ * the poll() function may be called using `POLLIN`.
+ *
+ * On Linux, your `SO_RCVTIMEO` will timeout accept4(). Other OSes (i.e.
+ * Windows, MacOS, and BSDs) do not support this and will block forever.
+ *
+ * On Windows, when this function blocks, there may be a 10 millisecond
+ * delay on the handling of signals or thread cancelation.
+ *
  * @param fd is the server socket file descriptor
  * @param opt_out_addr will receive the remote address
  * @param opt_inout_addrsize provides and receives out_addr's byte length
  * @param flags can have SOCK_{CLOEXEC,NONBLOCK}, which may apply to
  *     both the newly created socket and the server one
  * @return client fd which needs close(), or -1 w/ errno
+ * @raise EAGAIN if `O_NONBLOCK` and no clients pending
  * @cancelationpoint
  * @asyncsignalsafe
  * @restartable (unless SO_RCVTIMEO)

diff --git a/libc/sock/closesocket-nt.c b/libc/sock/closesocket-nt.c
@@ -16,8 +16,6 @@
 │ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
-#include "libc/intrin/weaken.h"
-#include "libc/mem/mem.h"
 #include "libc/nt/thunk/msabi.h"
 #include "libc/nt/winsock.h"
 #include "libc/sock/internal.h"
@@ -32,9 +30,6 @@ __msabi extern typeof(__sys_closesocket_nt) *const __imp_closesocket;
  * This function should only be called by close().
  */
 textwindows int sys_closesocket_nt(struct Fd *f) {
-  if (_weaken(sys_connect_nt_cleanup)) {
-    _weaken(sys_connect_nt_cleanup)(f, true);
-  }
   if (!__imp_closesocket(f->handle)) {
     return 0;
   } else {