Support non-blocking i/o across platforms

This change introduces new tests for `O_NONBLOCK` and `SOCK_NONBLOCK` to
confirm that non-blocking i/o is now working on all supported platforms,
including Windows. For example, you can now say on Windows, MacOS, etc.:

    socket(AF_INET, SOCK_STREAM | SOCK_NONBLOCK, IPPROTO_TCP);

To create a non-blocking IPv4 TCP socket. Or you can enable non-blocking
i/o on an existing socket / pipe / etc. file descriptor by calling fcntl

    fcntl(fd, F_SETFL, fcntl(fd, F_GETFL) | O_NONBLOCK);

This functionality is polyfilled on older Linux kernels too, e.g. RHEL5.
Now that fcntl() support is much better the FIOCLEX / FIONCLEX polyfills
for ioctl() have been removed since they're ugly non-POSIX diameond APIs

This change fixes a weakness in kprintf() that was causing Windows trace
tools to frequently crash.

libc/calls/fcntl-nt.c

@@ -36,10 +36,13 @@
 #include "libc/nt/runtime.h"
 #include "libc/nt/struct/byhandlefileinformation.h"
 #include "libc/nt/struct/overlapped.h"
+#include "libc/nt/winsock.h"
+#include "libc/sock/internal.h"
 #include "libc/stdckdint.h"
 #include "libc/str/str.h"
 #include "libc/sysv/consts/f.h"
 #include "libc/sysv/consts/fd.h"
+#include "libc/sysv/consts/fio.h"
 #include "libc/sysv/consts/o.h"
 #include "libc/sysv/errfuns.h"
 #include "libc/thread/thread.h"
@@ -307,21 +310,49 @@ static textwindows int sys_fcntl_nt_dupfd(int fd, int cmd, int start) {
   return sys_dup_nt(fd, -1, (cmd == F_DUPFD_CLOEXEC ? O_CLOEXEC : 0), start);
 }
 
+static textwindows int sys_fcntl_nt_setfl(int fd, unsigned *flags, unsigned arg,
+                                          unsigned supported) {
+  unsigned old, neu, changed, other, allowed;
+  old = *flags & supported;
+  other = *flags & ~supported;
+  neu = arg & supported;
+  changed = old ^ neu;
+  // you may change the following access mode flags:
+  //
+  // - O_NONBLOCK     make read() raise EAGAIN
+  // - O_NDELAY       same thing as O_NONBLOCK
+  //
+  allowed = O_NONBLOCK;
+  if (changed & ~allowed) {
+    // the following access mode flags are supported, but it's currently
+    // not possible to change them on windows.
+    //
+    // - O_APPEND     tried to support but failed
+    // - O_RANDOM     use posix_fadvise() instead
+    // - O_SEQUENTIAL use posix_fadvise() instead
+    // - O_DIRECT     possibly in future?
+    // - O_DSYNC      possibly in future?
+    // - O_RSYNC      possibly in future?
+    // - O_SYNC       possibly in future?
+    //
+    return enotsup();
+  }
+  // 1. ignore flags that aren't access mode flags
+  // 2. return zero if nothing's changed
+  *flags = other | neu;
+  return 0;
+}
+
 textwindows int sys_fcntl_nt(int fd, int cmd, uintptr_t arg) {
   int rc;
   uint32_t flags;
+  int access_mode_flags = O_ACCMODE | O_APPEND | O_ASYNC | O_DIRECT |
+                          O_NOATIME | O_NONBLOCK | O_RANDOM | O_SEQUENTIAL;
   if (__isfdkind(fd, kFdFile) || __isfdkind(fd, kFdSocket)) {
     if (cmd == F_GETFL) {
-      rc = g_fds.p[fd].flags &
+      rc = g_fds.p[fd].flags & access_mode_flags;
-           (O_ACCMODE | O_APPEND | O_ASYNC | O_DIRECT | O_NOATIME | O_NONBLOCK |
-            O_RANDOM | O_SEQUENTIAL);
     } else if (cmd == F_SETFL) {
-      // O_APPEND doesn't appear to be tunable at cursory glance
+      rc = sys_fcntl_nt_setfl(fd, &g_fds.p[fd].flags, arg, access_mode_flags);
-      // O_NONBLOCK might require we start doing all i/o in threads
-      // O_DSYNC / O_RSYNC / O_SYNC maybe if we fsync() everything
-      // O_DIRECT | O_RANDOM | O_SEQUENTIAL | O_NDELAY possible but
-      // not worth it.
-      rc = enosys();
     } else if (cmd == F_GETFD) {
       if (g_fds.p[fd].flags & O_CLOEXEC) {
         rc = FD_CLOEXEC;

libc/calls/fixupnewfd.c

@@ -26,9 +26,15 @@
 // Applies file descriptor fixups on XNU or old Linux.
 // See __fixupnewsockfd() for socket file descriptors.
 int __fixupnewfd(int fd, int flags) {
+  int file_mode;
   if (fd != -1) {
     if (flags & O_CLOEXEC) {
-      _npassert(!__sys_fcntl(fd, F_SETFD, FD_CLOEXEC));
+      _unassert((file_mode = __sys_fcntl(fd, F_GETFD)) != -1);
+      _unassert(!__sys_fcntl(fd, F_SETFD, file_mode | FD_CLOEXEC));
+    }
+    if (flags & O_NONBLOCK) {
+      _unassert((file_mode = __sys_fcntl(fd, F_GETFL)) != -1);
+      _unassert(!__sys_fcntl(fd, F_SETFL, file_mode | O_NONBLOCK));
     }
   }
   return fd;

libc/calls/getdomainname.c

@@ -76,6 +76,6 @@ int getdomainname(char *name, size_t len) {
   if (!rc && len && !strcmp(name, "(none)")) {
     name[0] = 0;
   }
-  STRACE("getdomainname([%#.*s], %'zu) → %d% m", len, name, len, rc);
+  STRACE("getdomainname([%#.*s], %'zu) → %d% m", (int)len, name, len, rc);
   return rc;
 }

libc/calls/gethostname.c

@@ -71,6 +71,6 @@ int gethostname(char *name, size_t len) {
   } else {
     rc = enosys();
   }
-  STRACE("gethostname([%#.*s], %'zu) → %d% m", len, name, len, rc);
+  STRACE("gethostname([%#.*s], %'zu) → %d% m", (int)len, name, len, rc);
   return rc;
 }

libc/calls/ioctl.c

@@ -558,34 +558,6 @@ static int ioctl_siocgifflags(int fd, void *arg) {
   }
 }
 
-/**
- * Sets "close on exec" on file descriptor the fast way.
- *
- * @see ioctl(fd, FIOCLEX, 0) dispatches here
- */
-static int ioctl_fioclex(int fd, int req) {
-  int rc;
-  if (fd >= 0) {
-    if (IsWindows() || (fd < g_fds.n && g_fds.p[fd].kind == kFdZip)) {
-      if (__isfdopen(fd)) {
-        if (req == FIOCLEX) {
-          g_fds.p[fd].flags |= O_CLOEXEC;
-        } else {
-          g_fds.p[fd].flags &= ~O_CLOEXEC;
-        }
-        rc = 0;
-      } else {
-        rc = ebadf();
-      }
-    } else {
-      rc = sys_ioctl(fd, req);
-    }
-  } else {
-    rc = einval();
-  }
-  return rc;
-}
-
 /**
  * Performs special i/o operation on file descriptor.
  *
@@ -618,17 +590,6 @@ static int ioctl_fioclex(int fd, int req) {
  *     - `TIOCNXCL` to give up exclusive mode on terminal. Only
  *       available on UNIX.
  *
- *     - `FIOCLEX` sets the `O_CLOEXEC` state (no arg) noting that this
- *       polyfill may be removed in the future, and code should migrate
- *       to the equivalent fcntl() api.
- *
- *     - `FIONBIO` sets the `O_NONBLOCK` state (arg is `int *enabled`)
- *       which is supported on Windows for sockets.
- *
- *     - `FIONCLEX` clears the `O_CLOEXEC` state (no arg) noting that
- *       this polyfill may be removed in the future, and code should
- *       migrate to the equivalent fcntl() api.
- *
  *     - `SIOCGIFCONF` takes an struct ifconf object of a given size,
  *       whose arg is `struct ifconf *`. It implements the Linux style
  *       and modifies the following:
@@ -647,6 +608,9 @@ static int ioctl_fioclex(int fd, int req) {
  *       network broadcast addr. This data structure should be obtained
  *       by calling `SIOCGIFCONF`.
  *
+ *     - `FIONBIO` isn't polyfilled; use `fcntl(F_SETFL, O_NONBLOCK)`
+ *     - `FIOCLEX` isn't polyfilled; use `fcntl(F_SETFD, FD_CLOEXEC)`
+ *     - `FIONCLEX` isn't polyfilled; use `fcntl(F_SETFD, 0)`
  *     - `TCGETS` isn't polyfilled; use tcgetattr()
  *     - `TCSETS` isn't polyfilled; use tcsetattr()
  *     - `TCSETSW` isn't polyfilled; use tcsetattr()
@@ -673,10 +637,6 @@ int ioctl(int fd, unsigned long request, ...) {
   va_end(va);
   if (request == FIONBIO) {
     rc = ioctl_default(fd, request, arg);
-  } else if (request == FIOCLEX) {
-    rc = ioctl_fioclex(fd, request);
-  } else if (request == FIONCLEX) {
-    rc = ioctl_fioclex(fd, request);
   } else if (request == TIOCGWINSZ) {
     rc = tcgetwinsize(fd, arg);
   } else if (request == TIOCSWINSZ) {

libc/calls/read-nt.c

@@ -33,6 +33,7 @@
 #include "libc/nt/runtime.h"
 #include "libc/nt/struct/overlapped.h"
 #include "libc/nt/synchronization.h"
+#include "libc/sysv/consts/o.h"
 #include "libc/sysv/errfuns.h"
 
 static textwindows ssize_t sys_read_nt_impl(struct Fd *fd, void *data,
@@ -51,6 +52,9 @@ static textwindows ssize_t sys_read_nt_impl(struct Fd *fd, void *data,
       if (SleepEx(__SIG_POLLING_INTERVAL_MS, true) == kNtWaitIoCompletion) {
         POLLTRACE("IOCP EINTR");
       }
+      if (fd->flags & O_NONBLOCK) {
+        return eagain();
+      }
       if (_check_interrupts(true, g_fds.p)) {
         POLLTRACE("sys_read_nt interrupted");
         return -1;

libc/calls/readlinkat.c

@@ -56,6 +56,6 @@ ssize_t readlinkat(int dirfd, const char *path, char *buf, size_t bufsiz) {
     bytes = sys_readlinkat_nt(dirfd, path, buf, bufsiz);
   }
   STRACE("readlinkat(%s, %#s, [%#.*s]) → %d% m", DescribeDirfd(dirfd), path,
-         MAX(0, bytes), buf, bytes);
+         (int)MAX(0, bytes), buf, bytes);
   return bytes;
 }

libc/calls/wincrash.c

@@ -42,6 +42,7 @@ unsigned __wincrash(struct NtExceptionPointers *ep) {
   ucontext_t ctx;
   struct CosmoTib *tib;
   static bool noreentry;
+  noreentry = true;
 
   if ((tib = __tls_enabled ? __get_tls_privileged() : 0)) {
     if (~tib->tib_flags & TIB_FLAG_WINCRASHING) {

libc/intrin/cancelioex.c

@@ -1,7 +1,7 @@
 /*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
 │vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8                                :vi│
 ╞══════════════════════════════════════════════════════════════════════════════╡
-│ Copyright 2020 Justine Alexandra Roberts Tunney                              │
+│ Copyright 2023 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         │
@@ -16,21 +16,23 @@
 │ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
-#include "libc/dce.h"
+#include "libc/calls/syscall_support-nt.internal.h"
-#include "libc/sock/internal.h"
+#include "libc/intrin/describentoverlapped.internal.h"
-#include "libc/sock/struct/sockaddr.internal.h"
+#include "libc/intrin/strace.internal.h"
+#include "libc/nt/struct/overlapped.h"
+#include "libc/nt/thread.h"
+#include "libc/nt/thunk/msabi.h"
 
-int sys_accept(int server, void *addr, uint32_t *addrsize) {
+__msabi extern typeof(CancelIoEx) *const __imp_CancelIoEx;
-  int client;
+
-  uint32_t size;
+/**
-  union sockaddr_storage_bsd bsd;
+ * Cancels Windows i/o operation.
-  if (!IsBsd()) {
+ */
-    client = __sys_accept(server, addr, addrsize, 0);
+bool32 CancelIoEx(int64_t hFile, struct NtOverlapped *opt_lpOverlapped) {
-  } else {
+  bool32 ok;
-    size = sizeof(bsd);
+  ok = __imp_CancelIoEx(hFile, opt_lpOverlapped);
-    if ((client = __sys_accept(server, &bsd, &size, 0)) != -1) {
+  if (!ok) __winerr();
-      sockaddr2linux(&bsd, size, addr, addrsize);
+  NTTRACE("CancelIoEx(%ld, %s) → %hhhd% m", hFile,
-    }
+          DescribeNtOverlapped(opt_lpOverlapped), ok);
-  }
+  return ok;
-  return client;
 }

libc/intrin/intrin.mk

@@ -146,6 +146,7 @@ o/$(MODE)/libc/intrin/exit1.greg.o			\
 o/$(MODE)/libc/intrin/wsarecv.o				\
 o/$(MODE)/libc/intrin/wsarecvfrom.o			\
 o/$(MODE)/libc/intrin/createfile.o			\
+o/$(MODE)/libc/intrin/cancelioex.o			\
 o/$(MODE)/libc/intrin/reopenfile.o			\
 o/$(MODE)/libc/intrin/deletefile.o			\
 o/$(MODE)/libc/intrin/createpipe.o			\
@@ -175,6 +176,7 @@ o/$(MODE)/libc/intrin/mapviewoffileexnuma.o		\
 o/$(MODE)/libc/intrin/createfilemapping.o		\
 o/$(MODE)/libc/intrin/createfilemappingnuma.o		\
 o/$(MODE)/libc/intrin/waitformultipleobjects.o		\
+o/$(MODE)/libc/intrin/wsagetoverlappedresult.o		\
 o/$(MODE)/libc/intrin/generateconsolectrlevent.o	\
 o/$(MODE)/libc/intrin/wsawaitformultipleevents.o: private\
 		CFLAGS +=				\

libc/intrin/kprintf.greg.c

@@ -26,12 +26,14 @@
 #include "libc/errno.h"
 #include "libc/fmt/divmod10.internal.h"
 #include "libc/fmt/fmt.h"
+#include "libc/fmt/itoa.h"
 #include "libc/fmt/magnumstrs.internal.h"
 #include "libc/intrin/asan.internal.h"
 #include "libc/intrin/asancodes.h"
 #include "libc/intrin/atomic.h"
 #include "libc/intrin/bits.h"
 #include "libc/intrin/cmpxchg.h"
+#include "libc/intrin/kprintf.h"
 #include "libc/intrin/likely.h"
 #include "libc/intrin/nomultics.internal.h"
 #include "libc/intrin/safemacros.internal.h"
@@ -259,6 +261,7 @@ privileged static size_t kformat(char *b, size_t n, const char *fmt,
                                  va_list va) {
   int si, y;
   wint_t t, u;
+  char errnum[12];
   const char *abet;
   signed char type;
   const char *s, *f;
@@ -539,6 +542,10 @@ privileged static size_t kformat(char *b, size_t n, const char *fmt,
           } else {
             type = 0;
             s = _strerrno(e);
+            if (!s) {
+              FormatInt32(errnum, e);
+              s = errnum;
+            }
             goto FormatString;
           }
         }
@@ -612,7 +619,7 @@ privileged static size_t kformat(char *b, size_t n, const char *fmt,
             if (cols) --cols;          // end quote
             p = kemitquote(p, e, type, hash);
           }
-          if (sign == ' ' && (!pdot || prec) && *s) {
+          if (sign == ' ' && (!pdot || prec) && s && *s) {
             if (p < e) *p = ' ';
             ++p;
           }

libc/intrin/wsagetoverlappedresult.c

@@ -0,0 +1,59 @@
+/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
+│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8                                :vi│
+╞══════════════════════════════════════════════════════════════════════════════╡
+│ Copyright 2023 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/errno.h"
+#include "libc/intrin/describentoverlapped.internal.h"
+#include "libc/intrin/kprintf.h"
+#include "libc/intrin/strace.internal.h"
+#include "libc/mem/alloca.h"
+#include "libc/nt/thunk/msabi.h"
+#include "libc/nt/winsock.h"
+#include "libc/sock/internal.h"
+
+__msabi extern typeof(WSAGetOverlappedResult)
+    *const __imp_WSAGetOverlappedResult;
+
+static char *DescribeTransfer(char buf[16], bool32 ok, uint32_t *transfer) {
+  if (ok) {
+    ksnprintf(buf, 16, "%'u", *transfer);
+    return buf;
+  } else {
+    return "n/a";
+  }
+}
+
+/**
+ * Gets overlap i/o result.
+ *
+ * @return true on success, or false on failure
+ * @note this wrapper takes care of ABI, STRACE(), and __winsockerr()
+ */
+bool32 WSAGetOverlappedResult(uint64_t s,
+                              const struct NtOverlapped *lpOverlapped,
+                              uint32_t *out_lpcbTransfer, bool32 fWait,
+                              uint32_t *out_lpdwFlags) {
+  bool32 ok;
+  ok = __imp_WSAGetOverlappedResult(s, lpOverlapped, out_lpcbTransfer, fWait,
+                                    out_lpdwFlags);
+  if (!ok) __winsockerr();
+  NTTRACE("WSAGetOverlappedResult(%ld, %s, [%s], %hhhd, [%#x]) → %hhhd% lm", s,
+          DescribeNtOverlapped(lpOverlapped),
+          DescribeTransfer(alloca(16), ok, out_lpcbTransfer), fWait,
+          *out_lpdwFlags, ok);
+  return ok;
+}

libc/intrin/wsarecv.c

@@ -16,6 +16,7 @@
 │ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
+#include "libc/assert.h"
 #include "libc/calls/syscall_support-nt.internal.h"
 #include "libc/intrin/describeflags.internal.h"
 #include "libc/intrin/describentoverlapped.internal.h"
@@ -23,6 +24,7 @@
 #include "libc/intrin/strace.internal.h"
 #include "libc/nt/thunk/msabi.h"
 #include "libc/nt/winsock.h"
+#include "libc/sock/internal.h"
 
 __msabi extern typeof(WSARecv) *const __imp_WSARecv;
 
@@ -38,6 +40,12 @@ textwindows int WSARecv(
     struct NtOverlapped *opt_inout_lpOverlapped,
     const NtWsaOverlappedCompletionRoutine opt_lpCompletionRoutine) {
   int rc;
+  if (opt_inout_lpOverlapped) {
+    // Use NULL for this parameter if the lpOverlapped parameter is not
+    // NULL to avoid potentially erroneous results. This parameter can
+    // be NULL only if the lpOverlapped parameter is not NULL.
+    _unassert(!opt_out_lpNumberOfBytesRecvd);
+  }
 #if defined(SYSDEBUG) && _NTTRACE
   uint32_t NumberOfBytesRecvd;
   if (opt_out_lpNumberOfBytesRecvd) {
@@ -50,7 +58,7 @@ textwindows int WSARecv(
     *opt_out_lpNumberOfBytesRecvd = NumberOfBytesRecvd;
   }
   if (rc == -1) {
-    __winerr();
+    __winsockerr();
   }
   if (UNLIKELY(__strace > 0) && strace_enabled(0) > 0) {
     kprintf(STRACE_PROLOGUE "WSARecv(%lu, [", s);
@@ -66,7 +74,7 @@ textwindows int WSARecv(
                      opt_out_lpNumberOfBytesRecvd, inout_lpFlags,
                      opt_inout_lpOverlapped, opt_lpCompletionRoutine);
   if (rc == -1) {
-    __winerr();
+    __winsockerr();
   }
 #endif
   return rc;

libc/nt/kernel32/CancelIoEx.S

@@ -3,7 +3,7 @@
 
 	.text.windows
         .ftrace1
-CancelIoEx:
+__CancelIoEx:
         .ftrace2
 #ifdef __x86_64__
 	push	%rbp
@@ -14,5 +14,5 @@ CancelIoEx:
 	mov	x0,#0
 	ret
 #endif
-	.endfn	CancelIoEx,globl
+	.endfn	__CancelIoEx,globl
 	.previous

libc/nt/master.sh

@@ -98,7 +98,6 @@ imp	'CallNamedPipeA'					CallNamedPipeA						kernel32	110	7
 imp	'CallbackMayRunLong'					CallbackMayRunLong					kernel32	0
 imp	'CancelDeviceWakeupRequest'				CancelDeviceWakeupRequest				kernel32	113
 imp	'CancelIo'						CancelIo						kernel32	0	1
-imp	'CancelIoEx'						CancelIoEx						kernel32	0	2
 imp	'CancelSynchronousIo'					CancelSynchronousIo					kernel32	0	1
 imp	'CancelTimerQueueTimer'					CancelTimerQueueTimer					kernel32	118
 imp	'CancelWaitableTimer'					CancelWaitableTimer					kernel32	0
@@ -1097,6 +1096,7 @@ imp	'WriteProfileString'					WriteProfileStringW					kernel32	1575
 imp	'WriteTapemark'						WriteTapemark						kernel32	1576
 imp	'ZombifyActCtx'						ZombifyActCtx						kernel32	0
 imp	'ZombifyActCtxWorker'					ZombifyActCtxWorker					kernel32	1578
+imp	'__CancelIoEx'						CancelIoEx						kernel32	0	2
 imp	'__CloseHandle'						CloseHandle						kernel32	0	1
 imp	'__CreateDirectory'					CreateDirectoryW					kernel32	0	2
 imp	'__CreateFile'						CreateFileW						kernel32	0	7
@@ -3228,7 +3228,6 @@ imp	'WSAEnumNetworkEvents'					WSAEnumNetworkEvents					ws2_32		64	3
 imp	'WSAEnumProtocols'					WSAEnumProtocolsW					ws2_32		66	3
 imp	'WSAEventSelect'					WSAEventSelect						ws2_32		67	3
 imp	'WSAGetLastError'					WSAGetLastError						ws2_32		111	0
-imp	'WSAGetOverlappedResult'				WSAGetOverlappedResult					ws2_32		68	5
 imp	'WSAGetQOSByName'					WSAGetQOSByName						ws2_32		69	3
 imp	'WSAGetServiceClassInfo'				WSAGetServiceClassInfoW					ws2_32		71	4
 imp	'WSAGetServiceClassNameByClassId'			WSAGetServiceClassNameByClassIdW			ws2_32		73	3
@@ -3329,6 +3328,7 @@ imp	'__WSARecvFrom'						WSARecvFrom						ws2_32		93	9
 imp	'__WSAWaitForMultipleEvents'				WSAWaitForMultipleEvents				ws2_32		124	5
 imp	'__sys_recv_nt'						recv							ws2_32		16	4	# we're using WSARecvFrom()
 imp	'__sys_send_nt'						send							ws2_32		19	4	# we're using WSASendTo()
+imp	'__WSAGetOverlappedResult'				WSAGetOverlappedResult					ws2_32		68	5
 
 # IPHLPAPI.DLL
 #

libc/nt/winsock.h

@@ -294,7 +294,7 @@ int32_t WSAStartup(uint16_t wVersionRequested, struct NtWsaData *lpWSAData)
     paramsnonnull() dontdiscard;
 
 int WSACleanup(void);
-int WSAGetLastError(void);
+int WSAGetLastError(void) nosideeffect;
 void WSASetLastError(int);
 
 int __sys_bind_nt(uint64_t, const void *, int);
@@ -343,6 +343,12 @@ int64_t WSAAccept(uint64_t s, struct sockaddr *out_addr,
                   const uint32_t *opt_dwCallbackData)
     paramsnonnull((2)) dontdiscard;
 
+bool32 AcceptEx(int64_t sListenSocket, int64_t sAcceptSocket,
+                void *out_lpOutputBuffer /*[recvlen+local+remoteaddrlen]*/,
+                uint32_t dwReceiveDataLength, uint32_t dwLocalAddressLength,
+                uint32_t dwRemoteAddressLength, uint32_t *out_lpdwBytesReceived,
+                struct NtOverlapped *inout_lpOverlapped);
+
 int WSASend(uint64_t s, const struct NtIovec *lpBuffers, uint32_t dwBufferCount,
             uint32_t *opt_out_lpNumberOfBytesSent, uint32_t dwFlags,
             struct NtOverlapped *opt_inout_lpOverlapped,

libc/nt/ws2_32/WSAGetOverlappedResult.S

@@ -3,7 +3,7 @@
 
 	.text.windows
         .ftrace1
-WSAGetOverlappedResult:
+__WSAGetOverlappedResult:
         .ftrace2
 #ifdef __x86_64__
 	push	%rbp
@@ -14,5 +14,5 @@ WSAGetOverlappedResult:
 	mov	x0,#0
 	ret
 #endif
-	.endfn	WSAGetOverlappedResult,globl
+	.endfn	__WSAGetOverlappedResult,globl
 	.previous

libc/runtime/inflate.c

@@ -58,8 +58,8 @@ int __inflate(void *out, size_t outsize, const void *in, size_t insize) {
   } else {
     rc = _puff(out, &outsize, in, &insize);
   }
-  STRACE("inflate([%#.*hhs%s], %'zu, %#.*hhs%s, %'zu) → %d", MIN(40, outsize),
+  STRACE("inflate([%#.*hhs%s], %'zu, %#.*hhs%s, %'zu) → %d",
-         out, outsize > 40 ? "..." : "", outsize, MIN(40, insize), in,
+         (int)MIN(40, outsize), out, outsize > 40 ? "..." : "", outsize,
-         insize > 40 ? "..." : "", insize, rc);
+         (int)MIN(40, insize), in, insize > 40 ? "..." : "", insize, rc);
   return rc;
 }

libc/sock/accept-nt.c

@@ -17,58 +17,109 @@
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
 #include "libc/calls/internal.h"
-#include "libc/calls/sig.internal.h"
 #include "libc/calls/state.internal.h"
+#include "libc/macros.internal.h"
 #include "libc/mem/mem.h"
 #include "libc/nt/winsock.h"
 #include "libc/sock/internal.h"
+#include "libc/sock/struct/sockaddr.h"
+#include "libc/sock/struct/sockaddr.internal.h"
+#include "libc/sock/struct/sockaddr6.h"
 #include "libc/sock/syscall_fd.internal.h"
-#include "libc/sysv/consts/fio.h"
+#include "libc/str/str.h"
+#include "libc/sysv/consts/af.h"
 #include "libc/sysv/consts/o.h"
-#include "libc/sysv/consts/poll.h"
 #include "libc/sysv/consts/sock.h"
-#include "libc/sysv/errfuns.h"
 
-textwindows int sys_accept_nt(struct Fd *fd, void *addr, uint32_t *addrsize,
+union AcceptExAddr {
-                              int flags) {
+  union sockaddr_storage_linux addr;
-  int64_t h;
+  char buf[sizeof(struct sockaddr_storage) + 16];
-  int rc, client, oflags;
+};
-  struct SockFd *sockfd, *sockfd2;
+
-  sockfd = (struct SockFd *)fd->extra;
+struct AcceptExBuffer {
-  if (_check_interrupts(true, g_fds.p)) return -1;
+  union AcceptExAddr local;
-  for (;;) {
+  union AcceptExAddr remote;
-    if (!WSAPoll(&(struct sys_pollfd_nt){fd->handle, POLLIN}, 1,
+};
-                 __SIG_POLLING_INTERVAL_MS)) {
+
-      if (_check_interrupts(true, g_fds.p)) {
+static void CopyLinuxSockAddr(const union sockaddr_storage_linux *addr,
-        return eintr();
+                              void *out_addr, uint32_t *inout_addrsize) {
-      }
+  uint32_t insize, outsize;
-      continue;
+  if (out_addr && inout_addrsize) {
+    if (addr->sa.sa_family == AF_INET) {
+      outsize = sizeof(struct sockaddr_in);
+    } else if (addr->sa.sa_family == AF_INET6) {
+      outsize = sizeof(struct sockaddr_in6);
+    } else if (addr->sa.sa_family == AF_UNIX) {
+      outsize = sizeof(addr->sun.sun_family) +
+                strnlen(addr->sun.sun_path, sizeof(addr->sun.sun_path)) + 1;
+    } else {
+      outsize = sizeof(union sockaddr_storage_linux);
     }
-    if ((h = WSAAccept(fd->handle, addr, (int32_t *)addrsize, 0, 0)) != -1) {
+    insize = *inout_addrsize;
-      oflags = 0;
+    if (insize) bzero(out_addr, insize);
-      if (flags & SOCK_CLOEXEC) oflags |= O_CLOEXEC;
+    outsize = MIN(insize, outsize);
-      if (flags & SOCK_NONBLOCK) oflags |= O_NONBLOCK;
+    if (outsize) memcpy(out_addr, addr, outsize);
-      if ((!(flags & SOCK_NONBLOCK) ||
+    *inout_addrsize = outsize;
-           __sys_ioctlsocket_nt(h, FIONBIO, (uint32_t[]){1}) != -1) &&
-          (sockfd2 = calloc(1, sizeof(struct SockFd)))) {
-        __fds_lock();
-        if ((client = __reservefd_unlocked(-1)) != -1) {
-          sockfd2->family = sockfd->family;
-          sockfd2->type = sockfd->type;
-          sockfd2->protocol = sockfd->protocol;
-          g_fds.p[client].kind = kFdSocket;
-          g_fds.p[client].flags = oflags;
-          g_fds.p[client].mode = 0140666;
-          g_fds.p[client].handle = h;
-          g_fds.p[client].extra = (uintptr_t)sockfd2;
-          __fds_unlock();
-          return client;
-        }
-        __fds_unlock();
-        free(sockfd2);
-      }
-      __sys_closesocket_nt(h);
-    }
-    return __winsockerr();
   }
 }
+
+textwindows int sys_accept_nt(struct Fd *fd, void *out_addr,
+                              uint32_t *inout_addrsize, int accept4_flags) {
+  int64_t handle;
+  int rc, client, oflags;
+  uint32_t bytes_received;
+  uint32_t completion_flags;
+  struct AcceptExBuffer buffer;
+  struct SockFd *sockfd, *sockfd2;
+
+  // deliver interrupt instead if any are pending
+  if (_check_interrupts(true, g_fds.p)) {
+    return -1;
+  }
+
+  // creates resources for child socket
+  // inherit the listener configuration
+  sockfd = (struct SockFd *)fd->extra;
+  if (!(sockfd2 = malloc(sizeof(struct SockFd)))) {
+    return -1;
+  }
+  memcpy(sockfd2, sockfd, sizeof(*sockfd));
+  if ((handle = WSASocket(sockfd2->family, sockfd2->type, sockfd2->protocol,
+                          NULL, 0, kNtWsaFlagOverlapped)) == -1) {
+    free(sockfd2);
+    return __winsockerr();
+  }
+
+  // accept network connection
+  struct NtOverlapped overlapped = {.hEvent = WSACreateEvent()};
+  if (!AcceptEx(fd->handle, handle, &buffer, 0, sizeof(buffer.local),
+                sizeof(buffer.remote), &bytes_received, &overlapped)) {
+    sockfd = (struct SockFd *)fd->extra;
+    if (__wsablock(fd, &overlapped, &completion_flags, true,
+                   sockfd->rcvtimeo) == -1) {
+      WSACloseEvent(overlapped.hEvent);
+      __sys_closesocket_nt(handle);
+      free(sockfd2);
+      return -1;
+    }
+  }
+  WSACloseEvent(overlapped.hEvent);
+
+  // create file descriptor for new socket
+  // don't inherit the file open mode bits
+  oflags = 0;
+  if (accept4_flags & SOCK_CLOEXEC) oflags |= O_CLOEXEC;
+  if (accept4_flags & SOCK_NONBLOCK) oflags |= O_NONBLOCK;
+  __fds_lock();
+  client = __reservefd_unlocked(-1);
+  g_fds.p[client].kind = kFdSocket;
+  g_fds.p[client].flags = oflags;
+  g_fds.p[client].mode = 0140666;
+  g_fds.p[client].handle = handle;
+  g_fds.p[client].extra = (uintptr_t)sockfd2;
+  __fds_unlock();
+
+  // handoff information to caller;
+  CopyLinuxSockAddr(&buffer.remote.addr, out_addr, inout_addrsize);
+  return client;
+}

libc/sock/accept4-sysv.c

@@ -16,15 +16,20 @@
 │ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
+#include "libc/assert.h"
+#include "libc/calls/syscall-sysv.internal.h"
 #include "libc/dce.h"
 #include "libc/errno.h"
 #include "libc/sock/internal.h"
 #include "libc/sock/sock.h"
 #include "libc/sock/struct/sockaddr.internal.h"
+#include "libc/sysv/consts/f.h"
+#include "libc/sysv/consts/fd.h"
+#include "libc/sysv/consts/o.h"
+#include "libc/sysv/consts/sock.h"
 
 int sys_accept4(int server, void *addr, uint32_t *addrsize, int flags) {
-  if (!flags) return sys_accept(server, addr, addrsize);
+  int olderr, client, file_mode;
-  int olderr, client;
   union sockaddr_storage_bsd bsd;
   uint32_t size = sizeof(bsd);
   void *out_addr = !IsBsd() ? addr : &bsd;
@@ -37,8 +42,17 @@ int sys_accept4(int server, void *addr, uint32_t *addrsize, int flags) {
     errno = olderr;
     demodernize = true;
   TriedAndTrue:
-    client = __fixupnewsockfd(__sys_accept(server, out_addr, out_addrsize, 0),
+    if ((client = __sys_accept(server, out_addr, out_addrsize, 0)) != -1) {
-                              flags);
+      // __sys_accept() has inconsistent flag inheritence across platforms
+      _unassert((file_mode = __sys_fcntl(client, F_GETFD)) != -1);
+      _unassert(!__sys_fcntl(client, F_SETFD,
+                             ((file_mode & ~FD_CLOEXEC) |
+                              (flags & SOCK_CLOEXEC ? FD_CLOEXEC : 0))));
+      _unassert((file_mode = __sys_fcntl(client, F_GETFL)) != -1);
+      _unassert(!__sys_fcntl(client, F_SETFL,
+                             ((file_mode & ~O_NONBLOCK) |
+                              (flags & SOCK_NONBLOCK ? O_NONBLOCK : 0))));
+    }
   }
   if (client != -1 && IsBsd()) {
     sockaddr2linux(&bsd, size, addr, addrsize);

libc/sock/connect-nt.c

@@ -17,6 +17,7 @@
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
 #include "libc/assert.h"
+#include "libc/intrin/bsr.h"
 #include "libc/nt/winsock.h"
 #include "libc/sock/internal.h"
 #include "libc/sock/syscall_fd.internal.h"
@@ -29,7 +30,7 @@ textwindows int sys_connect_nt(struct Fd *fd, const void *addr,
   sockfd = (struct SockFd *)fd->extra;
   _npassert(fd->kind == kFdSocket);
   return __winsockblock(
-      fd->handle, FD_CONNECT_BIT,
+      fd->handle, _bsr(kNtFdConnect),
       WSAConnect(fd->handle, addr, addrsize, NULL, NULL, NULL, NULL),
       sockfd->rcvtimeo);
 }

libc/sock/fixupnewsockfd.c

@@ -21,11 +21,6 @@
 #include "libc/sysv/consts/o.h"
 #include "libc/sysv/consts/sock.h"
 
-/**
- * Applies non-atomic file descriptor fixups on XNU or ancient Linux.
- *
- * @param fd of -1 means no-op
- */
 int __fixupnewsockfd(int fd, int flags) {
   return __fixupnewfd(fd, (((flags & SOCK_CLOEXEC) ? O_CLOEXEC : 0) |
                            ((flags & SOCK_NONBLOCK) ? O_NONBLOCK : 0)));

libc/sock/internal.h

@@ -11,18 +11,16 @@
 #if !(__ASSEMBLER__ + __LINKER__ + 0)
 COSMOPOLITAN_C_START_
 
-#define FD_READ        (1 << FD_READ_BIT)
+#define kNtFdRead                   1
-#define FD_READ_BIT    0
+#define kNtFdWrite                  2
-#define FD_WRITE       (1 << FD_WRITE_BIT)
+#define kNtFdOob                    4
-#define FD_WRITE_BIT   1
+#define kNtFdAccept                 8
-#define FD_OOB         (1 << FD_OOB_BIT)
+#define kNtFdConnect                16
-#define FD_OOB_BIT     2
+#define kNtFdClose                  32
-#define FD_ACCEPT      (1 << FD_ACCEPT_BIT)
+#define kNtFdQos                    64
-#define FD_ACCEPT_BIT  3
+#define kNtFdGroupQos               128
-#define FD_CONNECT     (1 << FD_CONNECT_BIT)
+#define kNtFdRoutingInterfaceChange 256
-#define FD_CONNECT_BIT 4
+#define kNtFdAddressListChange      512
-#define FD_CLOSE       (1 << FD_CLOSE_BIT)
-#define FD_CLOSE_BIT   5
 
 /* ------------------------------------------------------------------------------------*/
 
@@ -34,17 +32,6 @@ struct SockFd {
   int protocol;
   uint32_t rcvtimeo;
   uint32_t sndtimeo;
-  bool32 (*__msabi ConnectEx)(int64_t s, const struct sockaddr *name,
-                              int namelen, const void *opt_lpSendBuffer,
-                              uint32_t dwSendDataLength,
-                              uint32_t *out_lpdwBytesSent,
-                              struct NtOverlapped *inout_lpOverlapped);
-  bool32 (*__msabi AcceptEx)(
-      int64_t sListenSocket, int64_t sAcceptSocket,
-      void *out_lpOutputBuffer /*[recvlen+local+remoteaddrlen]*/,
-      uint32_t dwReceiveDataLength, uint32_t dwLocalAddressLength,
-      uint32_t dwRemoteAddressLength, uint32_t *out_lpdwBytesReceived,
-      struct NtOverlapped *inout_lpOverlapped);
 };
 
 errno_t __dos2errno(uint32_t) _Hide;
@@ -59,7 +46,6 @@ int32_t __sys_socket(int32_t, int32_t, int32_t) _Hide;
 int32_t __sys_socketpair(int32_t, int32_t, int32_t, int32_t[2]) _Hide;
 
 int32_t sys_accept4(int32_t, void *, uint32_t *, int) dontdiscard _Hide;
-int32_t sys_accept(int32_t, void *, uint32_t *) _Hide;
 int32_t sys_bind(int32_t, const void *, uint32_t) _Hide;
 int32_t sys_connect(int32_t, const void *, uint32_t) _Hide;
 int32_t sys_getsockopt(int32_t, int32_t, int32_t, void *, uint32_t *) _Hide;
@@ -99,8 +85,6 @@ size_t __iovec2nt(struct NtIovec[hasatleast 16], const struct iovec *,
 void WinSockInit(void) _Hide;
 int64_t __winsockerr(void) nocallback _Hide;
 int __fixupnewsockfd(int, int) _Hide;
-int __wsablock(int64_t, struct NtOverlapped *, uint32_t *, bool,
-               uint32_t) _Hide;
 int64_t __winsockblock(int64_t, unsigned, int64_t, uint32_t) _Hide;
 struct SockFd *_dupsockfd(struct SockFd *) _Hide;
 int64_t GetNtBaseSocket(int64_t) _Hide;

libc/sock/recv-nt.c

@@ -16,9 +16,11 @@
 │ 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/struct/fd.internal.h"
 #include "libc/errno.h"
+#include "libc/intrin/strace.internal.h"
 #include "libc/nt/struct/iovec.h"
 #include "libc/nt/struct/overlapped.h"
 #include "libc/nt/winsock.h"
@@ -30,20 +32,24 @@ textwindows ssize_t sys_recv_nt(struct Fd *fd, const struct iovec *iov,
                                 size_t iovlen, uint32_t flags) {
   int err;
   ssize_t rc;
-  uint32_t got = 0;
+  uint32_t got = -666;
   struct SockFd *sockfd;
   struct NtIovec iovnt[16];
-  struct NtOverlapped overlapped = {.hEvent = WSACreateEvent()};
   if (_check_interrupts(true, g_fds.p)) return -1;
+  struct NtOverlapped overlapped = {.hEvent = WSACreateEvent()};
   err = errno;
-  if (!WSARecv(fd->handle, iovnt, __iovec2nt(iovnt, iov, iovlen), &got, &flags,
+  if (!WSARecv(fd->handle, iovnt, __iovec2nt(iovnt, iov, iovlen), 0, &flags,
-               &overlapped, NULL)) {
+               &overlapped, 0)) {
-    rc = got;
+    if (WSAGetOverlappedResult(fd->handle, &overlapped, &got, false, &flags)) {
+      rc = got;
+    } else {
+      rc = -1;
+    }
   } else {
     errno = err;
     sockfd = (struct SockFd *)fd->extra;
-    rc = __wsablock(fd->handle, &overlapped, &flags, true, sockfd->rcvtimeo);
+    rc = __wsablock(fd, &overlapped, &flags, true, sockfd->rcvtimeo);
   }
-  WSACloseEvent(overlapped.hEvent);
+  _unassert(WSACloseEvent(overlapped.hEvent));
   return rc;
 }

libc/sock/recvfrom-nt.c

@@ -31,20 +31,23 @@ textwindows ssize_t sys_recvfrom_nt(struct Fd *fd, const struct iovec *iov,
                                     uint32_t *opt_inout_srcaddrsize) {
   int err;
   ssize_t rc;
-  uint32_t got = 0;
+  uint32_t got = -666;
   struct SockFd *sockfd;
   struct NtIovec iovnt[16];
-  struct NtOverlapped overlapped = {.hEvent = WSACreateEvent()};
   if (_check_interrupts(true, g_fds.p)) return -1;
+  struct NtOverlapped overlapped = {.hEvent = WSACreateEvent()};
   err = errno;
-  if (!WSARecvFrom(fd->handle, iovnt, __iovec2nt(iovnt, iov, iovlen), &got,
+  if (!WSARecvFrom(fd->handle, iovnt, __iovec2nt(iovnt, iov, iovlen), 0, &flags,
-                   &flags, opt_out_srcaddr, opt_inout_srcaddrsize, &overlapped,
+                   opt_out_srcaddr, opt_inout_srcaddrsize, &overlapped, NULL)) {
-                   NULL)) {
+    if (WSAGetOverlappedResult(fd->handle, &overlapped, &got, false, &flags)) {
-    rc = got;
+      rc = got;
+    } else {
+      rc = -1;
+    }
   } else {
     errno = err;
     sockfd = (struct SockFd *)fd->extra;
-    rc = __wsablock(fd->handle, &overlapped, &flags, true, sockfd->rcvtimeo);
+    rc = __wsablock(fd, &overlapped, &flags, true, sockfd->rcvtimeo);
   }
   WSACloseEvent(overlapped.hEvent);
   return rc;

libc/sock/send-nt.c

@@ -21,23 +21,28 @@
 #include "libc/nt/struct/overlapped.h"
 #include "libc/nt/winsock.h"
 #include "libc/sock/internal.h"
+#include "libc/sock/syscall_fd.internal.h"
 #include "libc/sysv/errfuns.h"
 
 textwindows ssize_t sys_send_nt(int fd, const struct iovec *iov, size_t iovlen,
                                 uint32_t flags) {
   ssize_t rc;
-  uint32_t sent = 0;
+  uint32_t sent = -666;
   struct SockFd *sockfd;
   struct NtIovec iovnt[16];
-  struct NtOverlapped overlapped = {.hEvent = WSACreateEvent()};
   if (_check_interrupts(true, g_fds.p)) return -1;
-  if (!WSASend(g_fds.p[fd].handle, iovnt, __iovec2nt(iovnt, iov, iovlen), &sent,
+  struct NtOverlapped overlapped = {.hEvent = WSACreateEvent()};
+  if (!WSASend(g_fds.p[fd].handle, iovnt, __iovec2nt(iovnt, iov, iovlen), 0,
                flags, &overlapped, NULL)) {
-    rc = sent;
+    if (WSAGetOverlappedResult(g_fds.p[fd].handle, &overlapped, &sent, false,
+                               &flags)) {
+      rc = sent;
+    } else {
+      rc = -1;
+    }
   } else {
     sockfd = (struct SockFd *)g_fds.p[fd].extra;
-    rc = __wsablock(g_fds.p[fd].handle, &overlapped, &flags, true,
+    rc = __wsablock(g_fds.p + fd, &overlapped, &flags, true, sockfd->sndtimeo);
-                    sockfd->sndtimeo);
   }
   WSACloseEvent(overlapped.hEvent);
   return rc;

libc/sock/sendfile.c

@@ -65,11 +65,11 @@ static textwindows int SendfileBlock(int64_t handle,
       break;
     }
   }
-  if (!WSAGetOverlappedResult(handle, overlapped, &got, false, &flags)) {
+  if (WSAGetOverlappedResult(handle, overlapped, &got, false, &flags)) {
-    NTTRACE("WSAGetOverlappedResult failed %lm");
+    return got;
-    return __winsockerr();
+  } else {
+    return -1;
   }
-  return got;
 }
 
 static dontinline textwindows ssize_t sys_sendfile_nt(

libc/sock/sendto-nt.c

@@ -21,6 +21,7 @@
 #include "libc/nt/struct/overlapped.h"
 #include "libc/nt/winsock.h"
 #include "libc/sock/internal.h"
+#include "libc/sock/syscall_fd.internal.h"
 #include "libc/sysv/errfuns.h"
 
 textwindows ssize_t sys_sendto_nt(int fd, const struct iovec *iov,
@@ -30,15 +31,19 @@ textwindows ssize_t sys_sendto_nt(int fd, const struct iovec *iov,
   uint32_t sent = 0;
   struct SockFd *sockfd;
   struct NtIovec iovnt[16];
-  struct NtOverlapped overlapped = {.hEvent = WSACreateEvent()};
   if (_check_interrupts(true, g_fds.p)) return -1;
-  if (!WSASendTo(g_fds.p[fd].handle, iovnt, __iovec2nt(iovnt, iov, iovlen),
+  struct NtOverlapped overlapped = {.hEvent = WSACreateEvent()};
-                 &sent, flags, opt_in_addr, in_addrsize, &overlapped, NULL)) {
+  if (!WSASendTo(g_fds.p[fd].handle, iovnt, __iovec2nt(iovnt, iov, iovlen), 0,
-    rc = sent;
+                 flags, opt_in_addr, in_addrsize, &overlapped, NULL)) {
+    if (WSAGetOverlappedResult(g_fds.p[fd].handle, &overlapped, &sent, false,
+                               &flags)) {
+      rc = sent;
+    } else {
+      rc = -1;
+    }
   } else {
     sockfd = (struct SockFd *)g_fds.p[fd].extra;
-    rc = __wsablock(g_fds.p[fd].handle, &overlapped, &flags, true,
+    rc = __wsablock(g_fds.p + fd, &overlapped, &flags, true, sockfd->sndtimeo);
-                    sockfd->sndtimeo);
   }
   WSACloseEvent(overlapped.hEvent);
   return rc;

libc/sock/sockatmark.c

@@ -16,36 +16,50 @@
 │ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
+#include "libc/calls/internal.h"
+#include "libc/calls/struct/fd.internal.h"
 #include "libc/calls/syscall-sysv.internal.h"
 #include "libc/dce.h"
 #include "libc/intrin/strace.internal.h"
 #include "libc/nt/winsock.h"
+#include "libc/sock/internal.h"
 #include "libc/sock/sock.h"
-#include "libc/sysv/consts/sio.h"
+#include "libc/sysv/errfuns.h"
 
-static textwindows int sockatmark_nt(int64_t fd) {
+static textwindows int sockatmark_nt(int fd, unsigned long magnum) {
   bool32 res;
+  int64_t hand;
   uint32_t bytes;
-  if (WSAIoctl(fd, SIOCATMARK, 0, 0, &res, sizeof(res), &bytes, 0, 0) != -1) {
+  if (fd >= g_fds.n) return ebadf();
-    return !res;
+  if (g_fds.p[fd].kind != kFdSocket) return einval();
-  } else {
+  hand = g_fds.p[fd].handle;
-    return -1;
+  if (WSAIoctl(hand, magnum, 0, 0, &res, sizeof(res), &bytes, 0, 0) == -1) {
+    return __winsockerr();
   }
+  return !res;
 }
 
 /**
  * Returns true if out of band data is available on socket for reading.
  *
  * @return 1 if OOB'd, 0 if not, or -1 w/ errno
+ * @raise EBADF if `fd` isn't an open file descriptor
+ * @raise EINVAL if `fd` isn't an appropriate file descriptor
  */
 int sockatmark(int fd) {
   int rc;
+  unsigned long magnum;
+  if (IsLinux()) {
+    magnum = 0x8905;      // SIOCATMARK (Linux only)
+  } else {                //
+    magnum = 0x40047307;  // SIOCATMARK (BSD, Windows)
+  }
   if (!IsWindows()) {
-    if (sys_ioctl(fd, SIOCATMARK, &rc) == -1) {
+    if (sys_ioctl(fd, magnum, &rc) == -1) {
       rc = -1;
     }
   } else {
-    rc = sockatmark_nt(fd);
+    rc = sockatmark_nt(fd, magnum);
   }
   STRACE("sockatmark(%d) → %d% m", fd, rc);
   return rc;

libc/sock/socket-nt.c

@@ -24,7 +24,6 @@
 #include "libc/nt/winsock.h"
 #include "libc/sock/internal.h"
 #include "libc/sock/yoink.inc"
-#include "libc/sysv/consts/fio.h"
 #include "libc/sysv/consts/ipproto.h"
 #include "libc/sysv/consts/o.h"
 #include "libc/sysv/consts/so.h"
@@ -52,13 +51,6 @@ textwindows int sys_socket_nt(int family, int type, int protocol) {
     oflags = 0;
     if (type & SOCK_CLOEXEC) oflags |= O_CLOEXEC;
     if (type & SOCK_NONBLOCK) oflags |= O_NONBLOCK;
-    if (type & SOCK_NONBLOCK) {
-      if (__sys_ioctlsocket_nt(h, FIONBIO, (uint32_t[1]){1}) == -1) {
-        __sys_closesocket_nt(h);
-        __releasefd(fd);
-        return __winsockerr();
-      }
-    }
     sockfd = calloc(1, sizeof(struct SockFd));
     sockfd->family = family;
     sockfd->type = truetype;

libc/sock/socket-sysv.c

@@ -22,29 +22,12 @@
 #include "libc/sysv/consts/sock.h"
 
 int sys_socket(int family, int type, int protocol) {
-  static bool once, demodernize;
+  int sock, tf, e = errno;
-  int sock, olderr;
+  tf = SOCK_CLOEXEC | SOCK_NONBLOCK;
-  if (!once && (type & (SOCK_CLOEXEC | SOCK_NONBLOCK))) {
+  sock = __sys_socket(family, type, protocol);
-    if (IsXnu()) {
+  if (sock == -1 && (type & tf) && (errno == EINVAL || errno == EPROTOTYPE)) {
-      demodernize = true;
+    errno = e;  // XNU/RHEL5/etc. don't support flags; see if removing helps
-      once = true;
+    sock = __fixupnewsockfd(__sys_socket(family, type & ~tf, protocol), type);
-    } else {
-      olderr = errno;
-      if ((sock = __sys_socket(family, type, protocol)) != -1) {
-        once = true;
-        return sock;
-      } else {
-        errno = olderr;
-        demodernize = true;
-        once = true;
-      }
-    }
-  }
-  if (!demodernize) {
-    return __sys_socket(family, type, protocol);
-  } else {
-    return __fixupnewsockfd(
-        __sys_socket(family, type & ~(SOCK_CLOEXEC | SOCK_NONBLOCK), protocol),
-        type);
   }
+  return sock;
 }

libc/sock/syscall_fd.internal.h

@@ -2,6 +2,7 @@
 #define COSMOPOLITAN_LIBC_SOCK_SYSCALL_INTERNAL_H_
 #include "libc/calls/struct/fd.internal.h"
 #include "libc/calls/struct/iovec.h"
+#include "libc/nt/struct/overlapped.h"
 #if !(__ASSEMBLER__ + __LINKER__ + 0)
 COSMOPOLITAN_C_START_
 
@@ -18,6 +19,8 @@ int sys_shutdown_nt(struct Fd *, int) _Hide;
 ssize_t sys_recv_nt(struct Fd *, const struct iovec *, size_t, uint32_t) _Hide;
 ssize_t sys_recvfrom_nt(struct Fd *, const struct iovec *, size_t, uint32_t,
                         void *, uint32_t *) _Hide;
+int __wsablock(struct Fd *, struct NtOverlapped *, uint32_t *, bool,
+               uint32_t) _Hide;
 
 COSMOPOLITAN_C_END_
 #endif /* !(__ASSEMBLER__ + __LINKER__ + 0) */

libc/sock/wsablock.c

@@ -16,24 +16,41 @@
 │ 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/sig.internal.h"
+#include "libc/errno.h"
+#include "libc/intrin/kprintf.h"
 #include "libc/intrin/strace.internal.h"
 #include "libc/nt/enum/wait.h"
+#include "libc/nt/enum/wsa.h"
 #include "libc/nt/errors.h"
+#include "libc/nt/runtime.h"
+#include "libc/nt/thread.h"
+#include "libc/nt/winsock.h"
+#include "libc/runtime/runtime.h"
 #include "libc/sock/internal.h"
 #include "libc/sock/sock.h"
+#include "libc/sock/syscall_fd.internal.h"
+#include "libc/str/str.h"
+#include "libc/sysv/consts/o.h"
 #include "libc/sysv/errfuns.h"
 
-textwindows int __wsablock(int64_t handle, struct NtOverlapped *overlapped,
+textwindows int __wsablock(struct Fd *fd, struct NtOverlapped *overlapped,
                            uint32_t *flags, bool restartable,
                            uint32_t timeout) {
-  int rc;
+  int e, rc;
-  uint32_t i, got;
+  uint32_t i, got = -666;
   if (WSAGetLastError() != kNtErrorIoPending) {
-    NTTRACE("sock i/o failed %lm");
+    NTTRACE("sock i/o failed %s", strerror(errno));
     return __winsockerr();
   }
+  if (fd->flags & O_NONBLOCK) {
+    e = errno;
+    _unassert(CancelIoEx(fd->handle, overlapped) ||
+              WSAGetLastError() == kNtErrorNotFound);
+    errno = e;
+  }
   for (;;) {
     i = WSAWaitForMultipleEvents(1, &overlapped->hEvent, true,
                                  __SIG_POLLING_INTERVAL_MS, true);
@@ -46,6 +63,7 @@ textwindows int __wsablock(int64_t handle, struct NtOverlapped *overlapped,
       }
       if (timeout) {
         if (timeout <= __SIG_POLLING_INTERVAL_MS) {
+          NTTRACE("__wsablock timeout elapsed");
           return eagain();
         }
         timeout -= __SIG_POLLING_INTERVAL_MS;
@@ -54,9 +72,12 @@ textwindows int __wsablock(int64_t handle, struct NtOverlapped *overlapped,
       break;
     }
   }
-  if (!WSAGetOverlappedResult(handle, overlapped, &got, false, flags)) {
+  if (WSAGetOverlappedResult(fd->handle, overlapped, &got, false, flags)) {
-    NTTRACE("WSAGetOverlappedResult failed %lm");
+    return got;
-    return __winsockerr();
+  } else if ((fd->flags & O_NONBLOCK) &&
+             WSAGetLastError() == kNtErrorOperationAborted) {
+    return eagain();
+  } else {
+    return -1;
   }
-  return got;
 }

libc/sysv/consts.sh

@@ -947,7 +947,6 @@ syscon	ioctl	FIONCLEX				0x5450			0x5450			0x20006602		0x20006602		0x20006602		0
 #syscon	ioctl	FIONWRITE				0x0			0x0			0x0			0x0			0x40046677		0x0			0x0			-1			# [FreeBSD Generalization] bytes queued in FD's output buffer (same as TIOCOUTQ for TTY FDs; see also SO_SNDBUF)
 #syscon	ioctl	FIONSPACE				0x0			0x0			0x0			0x0			0x40046676		0x0			0x0			-1			# [FreeBSD Generalization] capacity of FD's output buffer, e.g. equivalent to TIOCGSERIAL w/ UART
 syscon	ioctl	SIOCGIFCONF				0x8912			0x8912			0xc00c6924		0xc00c6924		0xc0106924		0xc0106924		0xc0106924		0
-syscon	ioctl	SIOCATMARK				0x8905			0x8905			0x40047307		0x40047307		0x40047307		0x40047307		0x40047307		0x40047307		# use sockatmark(); determines if oob is available; bsd consensus
 syscon	ioctl	SIOCADDMULTI				0x8931			0x8931			0x80206931		0x80206931		0x80206931		0x80206931		0x80206931		0			# bsd consensus
 syscon	ioctl	SIOCDELMULTI				0x8932			0x8932			0x80206932		0x80206932		0x80206932		0x80206932		0x80206932		0			# bsd consensus
 syscon	ioctl	SIOCDIFADDR				0x8936			0x8936			0x80206919		0x80206919		0x80206919		0x80206919		0x80206919		0			# bsd consensus

libc/sysv/consts/SIOCADDDLCI.S

@@ -1,2 +1,2 @@
 #include "libc/sysv/consts/syscon.internal.h"
-.syscon sio,SIOCADDDLCI,0x8980,0x8980,0,0,0,0,0,0
+.syscon ioctl,SIOCADDDLCI,0x8980,0x8980,0,0,0,0,0,0

libc/sysv/consts/SIOCADDMULTI.S

@@ -1,2 +1,2 @@
 #include "libc/sysv/consts/syscon.internal.h"
-.syscon sio,SIOCADDMULTI,0x8931,0x8931,0x80206931,0x80206931,0x80206931,0x80206931,0x80206931,0
+.syscon ioctl,SIOCADDMULTI,0x8931,0x8931,0x80206931,0x80206931,0x80206931,0x80206931,0x80206931,0

libc/sysv/consts/SIOCADDRT.S

@@ -1,2 +1,2 @@
 #include "libc/sysv/consts/syscon.internal.h"
-.syscon sio,SIOCADDRT,0x890b,0x890b,0,0,0,0,0,0
+.syscon ioctl,SIOCADDRT,0x890b,0x890b,0,0,0,0,0,0

libc/sysv/consts/SIOCATMARK.S

@@ -1,2 +0,0 @@
-#include "libc/sysv/consts/syscon.internal.h"
-.syscon sio,SIOCATMARK,0x8905,0x8905,0x40047307,0x40047307,0x40047307,0x40047307,0x40047307,0x40047307

libc/sysv/consts/SIOCDARP.S

@@ -1,2 +1,2 @@
 #include "libc/sysv/consts/syscon.internal.h"
-.syscon sio,SIOCDARP,0x8953,0x8953,0,0,0,0,0,0
+.syscon ioctl,SIOCDARP,0x8953,0x8953,0,0,0,0,0,0

libc/sysv/consts/SIOCDELDLCI.S

@@ -1,2 +1,2 @@
 #include "libc/sysv/consts/syscon.internal.h"
-.syscon sio,SIOCDELDLCI,0x8981,0x8981,0,0,0,0,0,0
+.syscon ioctl,SIOCDELDLCI,0x8981,0x8981,0,0,0,0,0,0

libc/sysv/consts/SIOCDELMULTI.S

@@ -1,2 +1,2 @@
 #include "libc/sysv/consts/syscon.internal.h"
-.syscon sio,SIOCDELMULTI,0x8932,0x8932,0x80206932,0x80206932,0x80206932,0x80206932,0x80206932,0
+.syscon ioctl,SIOCDELMULTI,0x8932,0x8932,0x80206932,0x80206932,0x80206932,0x80206932,0x80206932,0

libc/sysv/consts/SIOCDELRT.S

@@ -1,2 +1,2 @@
 #include "libc/sysv/consts/syscon.internal.h"
-.syscon sio,SIOCDELRT,0x890c,0x890c,0,0,0,0,0,0
+.syscon ioctl,SIOCDELRT,0x890c,0x890c,0,0,0,0,0,0

libc/sysv/consts/SIOCDEVPRIVATE.S

@@ -1,2 +1,2 @@
 #include "libc/sysv/consts/syscon.internal.h"
-.syscon sio,SIOCDEVPRIVATE,0x89f0,0x89f0,0,0,0,0,0,0
+.syscon ioctl,SIOCDEVPRIVATE,0x89f0,0x89f0,0,0,0,0,0,0

libc/sysv/consts/SIOCDIFADDR.S

@@ -1,2 +1,2 @@
 #include "libc/sysv/consts/syscon.internal.h"
-.syscon sio,SIOCDIFADDR,0x8936,0x8936,0x80206919,0x80206919,0x80206919,0x80206919,0x80206919,0
+.syscon ioctl,SIOCDIFADDR,0x8936,0x8936,0x80206919,0x80206919,0x80206919,0x80206919,0x80206919,0

libc/sysv/consts/SIOCDRARP.S

@@ -1,2 +1,2 @@
 #include "libc/sysv/consts/syscon.internal.h"
-.syscon sio,SIOCDRARP,0x8960,0x8960,0,0,0,0,0,0
+.syscon ioctl,SIOCDRARP,0x8960,0x8960,0,0,0,0,0,0

libc/sysv/consts/SIOCGARP.S

@@ -1,2 +1,2 @@
 #include "libc/sysv/consts/syscon.internal.h"
-.syscon sio,SIOCGARP,0x8954,0x8954,0,0,0,0,0,0
+.syscon ioctl,SIOCGARP,0x8954,0x8954,0,0,0,0,0,0

libc/sysv/consts/SIOCGIFADDR.S

@@ -1,2 +1,2 @@
 #include "libc/sysv/consts/syscon.internal.h"
-.syscon sio,SIOCGIFADDR,0x8915,0x8915,0xc0206921,0xc0206921,0xc0206921,0xc0206921,0xc0206921,0
+.syscon ioctl,SIOCGIFADDR,0x8915,0x8915,0xc0206921,0xc0206921,0xc0206921,0xc0206921,0xc0206921,0

libc/sysv/consts/SIOCGIFBR.S

@@ -1,2 +1,2 @@
 #include "libc/sysv/consts/syscon.internal.h"
-.syscon sio,SIOCGIFBR,0x8940,0x8940,0,0,0,0,0,0
+.syscon ioctl,SIOCGIFBR,0x8940,0x8940,0,0,0,0,0,0

libc/sysv/consts/SIOCGIFBRDADDR.S

@@ -1,2 +1,2 @@
 #include "libc/sysv/consts/syscon.internal.h"
-.syscon sio,SIOCGIFBRDADDR,0x8919,0x8919,0xc0206923,0xc0206923,0xc0206923,0xc0206923,0xc0206923,0
+.syscon ioctl,SIOCGIFBRDADDR,0x8919,0x8919,0xc0206923,0xc0206923,0xc0206923,0xc0206923,0xc0206923,0

libc/sysv/consts/SIOCGIFCONF.S

@@ -1,2 +1,2 @@
 #include "libc/sysv/consts/syscon.internal.h"
-.syscon sio,SIOCGIFCONF,0x8912,0x8912,0xc00c6924,0xc00c6924,0xc0106924,0xc0106924,0xc0106924,0
+.syscon ioctl,SIOCGIFCONF,0x8912,0x8912,0xc00c6924,0xc00c6924,0xc0106924,0xc0106924,0xc0106924,0

libc/sysv/consts/SIOCGIFCOUNT.S

@@ -1,2 +1,2 @@
 #include "libc/sysv/consts/syscon.internal.h"
-.syscon sio,SIOCGIFCOUNT,0x8938,0x8938,0,0,0,0,0,0
+.syscon ioctl,SIOCGIFCOUNT,0x8938,0x8938,0,0,0,0,0,0

libc/sysv/consts/SIOCGIFDSTADDR.S

@@ -1,2 +1,2 @@
 #include "libc/sysv/consts/syscon.internal.h"
-.syscon sio,SIOCGIFDSTADDR,0x8917,0x8917,0xc0206922,0xc0206922,0xc0206922,0xc0206922,0xc0206922,0
+.syscon ioctl,SIOCGIFDSTADDR,0x8917,0x8917,0xc0206922,0xc0206922,0xc0206922,0xc0206922,0xc0206922,0

libc/sysv/consts/SIOCGIFENCAP.S

@@ -1,2 +1,2 @@
 #include "libc/sysv/consts/syscon.internal.h"
-.syscon sio,SIOCGIFENCAP,0x8925,0x8925,0,0,0,0,0,0
+.syscon ioctl,SIOCGIFENCAP,0x8925,0x8925,0,0,0,0,0,0

libc/sysv/consts/SIOCGIFFLAGS.S

@@ -1,2 +1,2 @@
 #include "libc/sysv/consts/syscon.internal.h"
-.syscon sio,SIOCGIFFLAGS,0x8913,0x8913,0xc0206911,0xc0206911,0xc0206911,0xc0206911,0xc0206911,0
+.syscon ioctl,SIOCGIFFLAGS,0x8913,0x8913,0xc0206911,0xc0206911,0xc0206911,0xc0206911,0xc0206911,0

libc/sysv/consts/SIOCGIFHWADDR.S

@@ -1,2 +1,2 @@
 #include "libc/sysv/consts/syscon.internal.h"
-.syscon sio,SIOCGIFHWADDR,0x8927,0x8927,0,0,0,0,0,0
+.syscon ioctl,SIOCGIFHWADDR,0x8927,0x8927,0,0,0,0,0,0

libc/sysv/consts/SIOCGIFINDEX.S

@@ -1,2 +1,2 @@
 #include "libc/sysv/consts/syscon.internal.h"
-.syscon sio,SIOCGIFINDEX,0x8933,0x8933,0,0,0xc0206920,0,0,0
+.syscon ioctl,SIOCGIFINDEX,0x8933,0x8933,0,0,0xc0206920,0,0,0

libc/sysv/consts/SIOCGIFMAP.S

@@ -1,2 +1,2 @@
 #include "libc/sysv/consts/syscon.internal.h"
-.syscon sio,SIOCGIFMAP,0x8970,0x8970,0,0,0,0,0,0
+.syscon ioctl,SIOCGIFMAP,0x8970,0x8970,0,0,0,0,0,0

libc/sysv/consts/SIOCGIFMEM.S

@@ -1,2 +1,2 @@
 #include "libc/sysv/consts/syscon.internal.h"
-.syscon sio,SIOCGIFMEM,0x891f,0x891f,0,0,0,0,0,0
+.syscon ioctl,SIOCGIFMEM,0x891f,0x891f,0,0,0,0,0,0

libc/sysv/consts/SIOCGIFMETRIC.S

@@ -1,2 +1,2 @@
 #include "libc/sysv/consts/syscon.internal.h"
-.syscon sio,SIOCGIFMETRIC,0x891d,0x891d,0xc0206917,0xc0206917,0xc0206917,0xc0206917,0xc0206917,0
+.syscon ioctl,SIOCGIFMETRIC,0x891d,0x891d,0xc0206917,0xc0206917,0xc0206917,0xc0206917,0xc0206917,0

libc/sysv/consts/SIOCGIFMTU.S

@@ -1,2 +1,2 @@
 #include "libc/sysv/consts/syscon.internal.h"
-.syscon sio,SIOCGIFMTU,0x8921,0x8921,0xc0206933,0xc0206933,0xc0206933,0xc020697e,0xc020697e,0
+.syscon ioctl,SIOCGIFMTU,0x8921,0x8921,0xc0206933,0xc0206933,0xc0206933,0xc020697e,0xc020697e,0

libc/sysv/consts/SIOCGIFNAME.S

@@ -1,2 +1,2 @@
 #include "libc/sysv/consts/syscon.internal.h"
-.syscon sio,SIOCGIFNAME,0x8910,0x8910,0,0,0,0,0,0
+.syscon ioctl,SIOCGIFNAME,0x8910,0x8910,0,0,0,0,0,0

libc/sysv/consts/SIOCGIFNETMASK.S

@@ -1,2 +1,2 @@
 #include "libc/sysv/consts/syscon.internal.h"
-.syscon sio,SIOCGIFNETMASK,0x891b,0x891b,0xc0206925,0xc0206925,0xc0206925,0xc0206925,0xc0206925,0
+.syscon ioctl,SIOCGIFNETMASK,0x891b,0x891b,0xc0206925,0xc0206925,0xc0206925,0xc0206925,0xc0206925,0

libc/sysv/consts/SIOCGIFPFLAGS.S

@@ -1,2 +1,2 @@
 #include "libc/sysv/consts/syscon.internal.h"
-.syscon sio,SIOCGIFPFLAGS,0x8935,0x8935,0,0,0,0,0,0
+.syscon ioctl,SIOCGIFPFLAGS,0x8935,0x8935,0,0,0,0,0,0

libc/sysv/consts/SIOCGIFSLAVE.S

@@ -1,2 +1,2 @@
 #include "libc/sysv/consts/syscon.internal.h"
-.syscon sio,SIOCGIFSLAVE,0x8929,0x8929,0,0,0,0,0,0
+.syscon ioctl,SIOCGIFSLAVE,0x8929,0x8929,0,0,0,0,0,0

libc/sysv/consts/SIOCGIFTXQLEN.S

@@ -1,2 +1,2 @@
 #include "libc/sysv/consts/syscon.internal.h"
-.syscon sio,SIOCGIFTXQLEN,0x8942,0x8942,0,0,0,0,0,0
+.syscon ioctl,SIOCGIFTXQLEN,0x8942,0x8942,0,0,0,0,0,0

libc/sysv/consts/SIOCGPGRP.S

@@ -1,2 +1,2 @@
 #include "libc/sysv/consts/syscon.internal.h"
-.syscon sio,SIOCGPGRP,0x8904,0x8904,0x40047309,0x40047309,0x40047309,0x40047309,0x40047309,0
+.syscon ioctl,SIOCGPGRP,0x8904,0x8904,0x40047309,0x40047309,0x40047309,0x40047309,0x40047309,0

libc/sysv/consts/SIOCGRARP.S

@@ -1,2 +1,2 @@
 #include "libc/sysv/consts/syscon.internal.h"
-.syscon sio,SIOCGRARP,0x8961,0x8961,0,0,0,0,0,0
+.syscon ioctl,SIOCGRARP,0x8961,0x8961,0,0,0,0,0,0

libc/sysv/consts/SIOCGSTAMP.S

@@ -1,2 +1,2 @@
 #include "libc/sysv/consts/syscon.internal.h"
-.syscon sio,SIOCGSTAMP,0x8906,0x8906,0,0,0,0,0,0
+.syscon ioctl,SIOCGSTAMP,0x8906,0x8906,0,0,0,0,0,0

libc/sysv/consts/SIOCGSTAMPNS.S

@@ -1,2 +1,2 @@
 #include "libc/sysv/consts/syscon.internal.h"
-.syscon sio,SIOCGSTAMPNS,0x8907,0x8907,0,0,0,0,0,0
+.syscon ioctl,SIOCGSTAMPNS,0x8907,0x8907,0,0,0,0,0,0

libc/sysv/consts/SIOCPROTOPRIVATE.S

@@ -1,2 +1,2 @@
 #include "libc/sysv/consts/syscon.internal.h"
-.syscon sio,SIOCPROTOPRIVATE,0x89e0,0x89e0,0,0,0,0,0,0
+.syscon ioctl,SIOCPROTOPRIVATE,0x89e0,0x89e0,0,0,0,0,0,0

libc/sysv/consts/SIOCRTMSG.S

@@ -1,2 +1,2 @@
 #include "libc/sysv/consts/syscon.internal.h"
-.syscon sio,SIOCRTMSG,0x890d,0x890d,0,0,0,0,0,0
+.syscon ioctl,SIOCRTMSG,0x890d,0x890d,0,0,0,0,0,0

libc/sysv/consts/SIOCSARP.S

@@ -1,2 +1,2 @@
 #include "libc/sysv/consts/syscon.internal.h"
-.syscon sio,SIOCSARP,0x8955,0x8955,0,0,0,0,0,0
+.syscon ioctl,SIOCSARP,0x8955,0x8955,0,0,0,0,0,0

libc/sysv/consts/SIOCSIFADDR.S

@@ -1,2 +1,2 @@
 #include "libc/sysv/consts/syscon.internal.h"
-.syscon sio,SIOCSIFADDR,0x8916,0x8916,0x8020690c,0x8020690c,0x8020690c,0x8020690c,0x8020690c,0
+.syscon ioctl,SIOCSIFADDR,0x8916,0x8916,0x8020690c,0x8020690c,0x8020690c,0x8020690c,0x8020690c,0

libc/sysv/consts/SIOCSIFBR.S

@@ -1,2 +1,2 @@
 #include "libc/sysv/consts/syscon.internal.h"
-.syscon sio,SIOCSIFBR,0x8941,0x8941,0,0,0,0,0,0
+.syscon ioctl,SIOCSIFBR,0x8941,0x8941,0,0,0,0,0,0

libc/sysv/consts/SIOCSIFBRDADDR.S

@@ -1,2 +1,2 @@
 #include "libc/sysv/consts/syscon.internal.h"
-.syscon sio,SIOCSIFBRDADDR,0x891a,0x891a,0x80206913,0x80206913,0x80206913,0x80206913,0x80206913,0
+.syscon ioctl,SIOCSIFBRDADDR,0x891a,0x891a,0x80206913,0x80206913,0x80206913,0x80206913,0x80206913,0

libc/sysv/consts/SIOCSIFDSTADDR.S

@@ -1,2 +1,2 @@
 #include "libc/sysv/consts/syscon.internal.h"
-.syscon sio,SIOCSIFDSTADDR,0x8918,0x8918,0x8020690e,0x8020690e,0x8020690e,0x8020690e,0x8020690e,0
+.syscon ioctl,SIOCSIFDSTADDR,0x8918,0x8918,0x8020690e,0x8020690e,0x8020690e,0x8020690e,0x8020690e,0

libc/sysv/consts/SIOCSIFENCAP.S

@@ -1,2 +1,2 @@
 #include "libc/sysv/consts/syscon.internal.h"
-.syscon sio,SIOCSIFENCAP,0x8926,0x8926,0,0,0,0,0,0
+.syscon ioctl,SIOCSIFENCAP,0x8926,0x8926,0,0,0,0,0,0

libc/sysv/consts/SIOCSIFFLAGS.S

@@ -1,2 +1,2 @@
 #include "libc/sysv/consts/syscon.internal.h"
-.syscon sio,SIOCSIFFLAGS,0x8914,0x8914,0x80206910,0x80206910,0x80206910,0x80206910,0x80206910,0
+.syscon ioctl,SIOCSIFFLAGS,0x8914,0x8914,0x80206910,0x80206910,0x80206910,0x80206910,0x80206910,0

libc/sysv/consts/SIOCSIFHWADDR.S

@@ -1,2 +1,2 @@
 #include "libc/sysv/consts/syscon.internal.h"
-.syscon sio,SIOCSIFHWADDR,0x8924,0x8924,0,0,0,0,0,0
+.syscon ioctl,SIOCSIFHWADDR,0x8924,0x8924,0,0,0,0,0,0

libc/sysv/consts/SIOCSIFHWBROADCAST.S

@@ -1,2 +1,2 @@
 #include "libc/sysv/consts/syscon.internal.h"
-.syscon sio,SIOCSIFHWBROADCAST,0x8937,0x8937,0,0,0,0,0,0
+.syscon ioctl,SIOCSIFHWBROADCAST,0x8937,0x8937,0,0,0,0,0,0

libc/sysv/consts/SIOCSIFLINK.S

@@ -1,2 +1,2 @@
 #include "libc/sysv/consts/syscon.internal.h"
-.syscon sio,SIOCSIFLINK,0x8911,0x8911,0,0,0,0,0,0
+.syscon ioctl,SIOCSIFLINK,0x8911,0x8911,0,0,0,0,0,0

libc/sysv/consts/SIOCSIFMAP.S

@@ -1,2 +1,2 @@
 #include "libc/sysv/consts/syscon.internal.h"
-.syscon sio,SIOCSIFMAP,0x8971,0x8971,0,0,0,0,0,0
+.syscon ioctl,SIOCSIFMAP,0x8971,0x8971,0,0,0,0,0,0

libc/sysv/consts/SIOCSIFMEM.S

@@ -1,2 +1,2 @@
 #include "libc/sysv/consts/syscon.internal.h"
-.syscon sio,SIOCSIFMEM,0x8920,0x8920,0,0,0,0,0,0
+.syscon ioctl,SIOCSIFMEM,0x8920,0x8920,0,0,0,0,0,0

libc/sysv/consts/SIOCSIFMETRIC.S

@@ -1,2 +1,2 @@
 #include "libc/sysv/consts/syscon.internal.h"
-.syscon sio,SIOCSIFMETRIC,0x891e,0x891e,0x80206918,0x80206918,0x80206918,0x80206918,0x80206918,0
+.syscon ioctl,SIOCSIFMETRIC,0x891e,0x891e,0x80206918,0x80206918,0x80206918,0x80206918,0x80206918,0

libc/sysv/consts/SIOCSIFMTU.S

@@ -1,2 +1,2 @@
 #include "libc/sysv/consts/syscon.internal.h"
-.syscon sio,SIOCSIFMTU,0x8922,0x8922,0x80206934,0x80206934,0x80206934,0x8020697f,0x8020697f,0
+.syscon ioctl,SIOCSIFMTU,0x8922,0x8922,0x80206934,0x80206934,0x80206934,0x8020697f,0x8020697f,0

libc/sysv/consts/SIOCSIFNAME.S

@@ -1,2 +1,2 @@
 #include "libc/sysv/consts/syscon.internal.h"
-.syscon sio,SIOCSIFNAME,0x8923,0x8923,0,0,0x80206928,0,0,0
+.syscon ioctl,SIOCSIFNAME,0x8923,0x8923,0,0,0x80206928,0,0,0

libc/sysv/consts/SIOCSIFNETMASK.S

@@ -1,2 +1,2 @@
 #include "libc/sysv/consts/syscon.internal.h"
-.syscon sio,SIOCSIFNETMASK,0x891c,0x891c,0x80206916,0x80206916,0x80206916,0x80206916,0x80206916,0
+.syscon ioctl,SIOCSIFNETMASK,0x891c,0x891c,0x80206916,0x80206916,0x80206916,0x80206916,0x80206916,0

libc/sysv/consts/SIOCSIFPFLAGS.S

@@ -1,2 +1,2 @@
 #include "libc/sysv/consts/syscon.internal.h"
-.syscon sio,SIOCSIFPFLAGS,0x8934,0x8934,0,0,0,0,0,0
+.syscon ioctl,SIOCSIFPFLAGS,0x8934,0x8934,0,0,0,0,0,0

libc/sysv/consts/SIOCSIFSLAVE.S

@@ -1,2 +1,2 @@
 #include "libc/sysv/consts/syscon.internal.h"
-.syscon sio,SIOCSIFSLAVE,0x8930,0x8930,0,0,0,0,0,0
+.syscon ioctl,SIOCSIFSLAVE,0x8930,0x8930,0,0,0,0,0,0

libc/sysv/consts/SIOCSIFTXQLEN.S

@@ -1,2 +1,2 @@
 #include "libc/sysv/consts/syscon.internal.h"
-.syscon sio,SIOCSIFTXQLEN,0x8943,0x8943,0,0,0,0,0,0
+.syscon ioctl,SIOCSIFTXQLEN,0x8943,0x8943,0,0,0,0,0,0

libc/sysv/consts/SIOCSPGRP.S

@@ -1,2 +1,2 @@
 #include "libc/sysv/consts/syscon.internal.h"
-.syscon sio,SIOCSPGRP,0x8902,0x8902,0x80047308,0x80047308,0x80047308,0x80047308,0x80047308,0
+.syscon ioctl,SIOCSPGRP,0x8902,0x8902,0x80047308,0x80047308,0x80047308,0x80047308,0x80047308,0

libc/sysv/consts/SIOCSRARP.S

@@ -1,2 +1,2 @@
 #include "libc/sysv/consts/syscon.internal.h"
-.syscon sio,SIOCSRARP,0x8962,0x8962,0,0,0,0,0,0
+.syscon ioctl,SIOCSRARP,0x8962,0x8962,0,0,0,0,0,0

libc/sysv/consts/SIOGIFINDEX.S

@@ -1,2 +1,2 @@
 #include "libc/sysv/consts/syscon.internal.h"
-.syscon sio,SIOGIFINDEX,0x8933,0x8933,0,0,0,0,0,0
+.syscon ioctl,SIOGIFINDEX,0x8933,0x8933,0,0,0,0,0,0

libc/sysv/consts/fio.h

@@ -3,16 +3,12 @@
 #if !(__ASSEMBLER__ + __LINKER__ + 0)
 COSMOPOLITAN_C_START_
 
-extern const uint32_t FIOASYNC;
+extern const uint32_t FIONREAD; /* one of the few encouraged ioctls */
-extern const uint32_t FIOCLEX;
+extern const uint32_t FIONBIO;  /* use fcntl(fd, F_SETFL, O_NONBLOCK) */
-extern const uint32_t FIONBIO;
+extern const uint32_t FIOCLEX;  /* use fcntl(fd, F_SETFD, FD_CLOEXEC) */
-extern const uint32_t FIONCLEX;
+extern const uint32_t FIONCLEX; /* use fcntl(fd, F_SETFD, 0) */
-extern const uint32_t FIONREAD;
+extern const uint32_t FIOASYNC; /* todo: fcntl(fd, F_SETOWN, pid) */
 
-#define FIOASYNC FIOASYNC
-#define FIOCLEX  FIOCLEX
-#define FIONBIO  FIONBIO
-#define FIONCLEX FIONCLEX
 #define FIONREAD FIONREAD
 
 COSMOPOLITAN_C_END_

libc/sysv/consts/sio.h

@@ -6,7 +6,6 @@ COSMOPOLITAN_C_START_
 extern const unsigned long SIOCADDDLCI;
 extern const unsigned long SIOCADDMULTI;
 extern const unsigned long SIOCADDRT;
-extern const unsigned long SIOCATMARK; /* use sockatmark() */
 extern const unsigned long SIOCDARP;
 extern const unsigned long SIOCDELDLCI;
 extern const unsigned long SIOCDELMULTI;

libc/sysv/dos2errno.sh

@@ -55,7 +55,7 @@ dos	kNtErrorInvalidFunction         EINVAL
 dos	kNtErrorNegativeSeek		EINVAL
 dos	kNtErrorInvalidNetname          EADDRNOTAVAIL
 dos	kNtErrorInvalidUserBuffer	EMSGSIZE
-dos	kNtErrorIoPending               EINPROGRESS
+dos	kNtErrorIoPending		EINPROGRESS
 dos	kNtErrorLockViolation           EAGAIN
 dos	kNtErrorMoreData                EMSGSIZE
 dos	kNtErrorNetnameDeleted          ECONNABORTED

libc/thread/pthread_attr_init.c

@@ -23,6 +23,15 @@
  * Initializes pthread attributes.
  *
  * @return 0 on success, or errno on error
+ * @see pthread_attr_setdetachstate()
+ * @see pthread_attr_setsigmask_np()
+ * @see pthread_attr_setstack()
+ * @see pthread_attr_setstacksize()
+ * @see pthread_attr_setguardsize()
+ * @see pthread_attr_setschedparam()
+ * @see pthread_attr_setschedpolicy()
+ * @see pthread_attr_setinheritsched()
+ * @see pthread_attr_setscope()
  */
 errno_t pthread_attr_init(pthread_attr_t *attr) {
   *attr = (pthread_attr_t){

test/libc/sock/nonblock_test.c

@@ -0,0 +1,127 @@
+/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
+│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8                                :vi│
+╞══════════════════════════════════════════════════════════════════════════════╡
+│ Copyright 2023 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/calls.h"
+#include "libc/errno.h"
+#include "libc/intrin/strace.internal.h"
+#include "libc/runtime/runtime.h"
+#include "libc/runtime/syslib.internal.h"
+#include "libc/sock/sock.h"
+#include "libc/sock/struct/sockaddr.h"
+#include "libc/sysv/consts/af.h"
+#include "libc/sysv/consts/f.h"
+#include "libc/sysv/consts/ipproto.h"
+#include "libc/sysv/consts/limits.h"
+#include "libc/sysv/consts/o.h"
+#include "libc/sysv/consts/sock.h"
+#include "libc/testlib/subprocess.h"
+#include "libc/testlib/testlib.h"
+#include "libc/thread/thread.h"
+
+TEST(O_NONBLOCK, canBeSetBySocket_toMakeListenNonBlocking) {
+  int ws, pid;
+  char buf[16] = {0};
+  int64_t inoffset;
+  uint32_t addrsize = sizeof(struct sockaddr_in);
+  struct sockaddr_in addr = {
+      .sin_family = AF_INET,
+      .sin_addr.s_addr = htonl(0x7f000001),
+  };
+  pthread_spinlock_t *phaser = _mapshared(4096);
+  EXPECT_EQ(0, pthread_spin_lock(phaser + 0));
+  EXPECT_EQ(0, pthread_spin_lock(phaser + 1));
+  ASSERT_SYS(0, 3, socket(AF_INET, SOCK_STREAM | SOCK_NONBLOCK, IPPROTO_TCP));
+  ASSERT_SYS(0, 0, bind(3, (struct sockaddr *)&addr, sizeof(addr)));
+  ASSERT_SYS(0, 0, getsockname(3, (struct sockaddr *)&addr, &addrsize));
+  ASSERT_SYS(0, 0, listen(3, SOMAXCONN));
+  SPAWN(fork);
+  ASSERT_SYS(EAGAIN, -1, accept(3, (struct sockaddr *)&addr, &addrsize));
+  EXPECT_EQ(0, pthread_spin_unlock(phaser + 0));
+  for (;;) {
+    int e = errno;
+    int fd = accept(3, (struct sockaddr *)&addr, &addrsize);
+    if (fd == -1 && errno == EAGAIN) {
+      errno = e;
+      usleep(1000);
+      continue;
+    }
+    ASSERT_SYS(0, 4, fd);
+    break;
+  }
+  ASSERT_SYS(0, 5, send(4, "hello", 5, 0));
+  EXPECT_EQ(0, pthread_spin_unlock(phaser + 1));
+  EXPECT_SYS(0, 0, close(4));
+  EXPECT_SYS(0, 0, close(3));
+  PARENT();
+  EXPECT_SYS(0, 0, close(3));
+  ASSERT_SYS(0, 3, socket(AF_INET, SOCK_STREAM, IPPROTO_TCP));
+  EXPECT_EQ(0, pthread_spin_lock(phaser + 0));
+  ASSERT_SYS(0, 0, connect(3, (struct sockaddr *)&addr, sizeof(addr)));
+  EXPECT_EQ(0, pthread_spin_lock(phaser + 1));
+  EXPECT_SYS(0, 5, read(3, buf, 16));
+  EXPECT_STREQ("hello", buf);
+  EXPECT_SYS(0, 0, close(3));
+  WAIT(exit, 0);
+  munmap(phaser, 4096);
+}
+
+TEST(O_NONBLOCK, canBeTunedWithFcntl_toMakeReadNonBlocking) {
+  int ws, pid;
+  char buf[16] = {0};
+  int64_t inoffset;
+  uint32_t addrsize = sizeof(struct sockaddr_in);
+  struct sockaddr_in addr = {
+      .sin_family = AF_INET,
+      .sin_addr.s_addr = htonl(0x7f000001),
+  };
+  pthread_spinlock_t *phaser = _mapshared(4096);
+  EXPECT_EQ(0, pthread_spin_lock(phaser + 0));
+  EXPECT_EQ(0, pthread_spin_lock(phaser + 1));
+  ASSERT_SYS(0, 3, socket(AF_INET, SOCK_STREAM, IPPROTO_TCP));
+  ASSERT_SYS(0, 0, bind(3, (struct sockaddr *)&addr, sizeof(addr)));
+  ASSERT_SYS(0, 0, getsockname(3, (struct sockaddr *)&addr, &addrsize));
+  ASSERT_SYS(0, 0, listen(3, SOMAXCONN));
+  SPAWN(fork);
+  ASSERT_SYS(0, 4, accept(3, (struct sockaddr *)&addr, &addrsize));
+  EXPECT_EQ(0, pthread_spin_lock(phaser + 0));
+  ASSERT_SYS(0, 5, send(4, "hello", 5, 0));
+  EXPECT_EQ(0, pthread_spin_lock(phaser + 1));
+  EXPECT_SYS(0, 0, close(4));
+  EXPECT_SYS(0, 0, close(3));
+  PARENT();
+  EXPECT_SYS(0, 0, close(3));
+  ASSERT_SYS(0, 3, socket(AF_INET, SOCK_STREAM, IPPROTO_TCP));
+  ASSERT_SYS(0, 0, connect(3, (struct sockaddr *)&addr, sizeof(addr)));
+  ASSERT_SYS(0, 0, fcntl(3, F_SETFL, O_NONBLOCK));
+  ASSERT_SYS(EAGAIN, -1, read(3, buf, 16));
+  EXPECT_EQ(0, pthread_spin_unlock(phaser + 0));
+TryAgain:
+  int e = errno;
+  ssize_t rc = read(3, buf, 16);
+  if (rc == -1 && errno == EAGAIN) {
+    errno = e;
+    usleep(1000);
+    goto TryAgain;
+  }
+  EXPECT_SYS(0, 5, rc);
+  EXPECT_STREQ("hello", buf);
+  EXPECT_EQ(0, pthread_spin_unlock(phaser + 1));
+  EXPECT_SYS(0, 0, close(3));
+  WAIT(exit, 0);
+  munmap(phaser, 4096);
+}

test/libc/sock/test.mk

@@ -33,6 +33,7 @@ TEST_LIBC_SOCK_DIRECTDEPS =					\
 	LIBC_STDIO						\
 	LIBC_STR						\
 	LIBC_SYSV						\
+	LIBC_THREAD						\
 	LIBC_LOG						\
 	LIBC_SYSV_CALLS						\
 	LIBC_TESTLIB						\
@@ -58,6 +59,9 @@ o/$(MODE)/test/libc/sock/%.com.dbg:				\
 o/$(MODE)/test/libc/sock/unix_test.com.runs:			\
 		private .PLEDGE = stdio rpath wpath cpath fattr proc unix
 
+o/$(MODE)/test/libc/sock/nonblock_test.com.runs			\
+o/$(MODE)/test/libc/sock/socket_test.com.runs			\
+o/$(MODE)/test/libc/sock/shutdown_test.com.runs			\
 o/$(MODE)/test/libc/sock/setsockopt_test.com.runs		\
 o/$(MODE)/test/libc/sock/sendfile_test.com.runs			\
 o/$(MODE)/test/libc/sock/poll_test.com.runs			\
@@ -70,17 +74,12 @@ o/$(MODE)/test/libc/sock/nointernet_test.com.runs:		\
 
 o/$(MODE)/test/libc/sock/socket_test.com.runs:			\
 		private .INTERNET = 1  # todo: ipv6 filtering
-o/$(MODE)/test/libc/sock/socket_test.com.runs:			\
-		private .PLEDGE = stdio rpath wpath cpath fattr proc inet
 
 o/$(MODE)/test/libc/sock/recvmsg_test.com.runs:			\
 		private .INTERNET = 1  # need to bind to 0.0.0.0
 o/$(MODE)/test/libc/sock/recvmsg_test.com.runs:			\
 		private .PLEDGE = stdio rpath wpath cpath fattr proc inet recvfd sendfd
 
-o/$(MODE)/test/libc/sock/shutdown_test.com.runs:		\
-		private .PLEDGE = stdio rpath wpath cpath fattr proc inet
-
 $(TEST_LIBC_SOCK_OBJS): test/libc/sock/test.mk
 
 .PHONY: o/$(MODE)/test/libc/sock