From 2db2f40a98565eb82df1a50cd44daa02fb28350a Mon Sep 17 00:00:00 2001
From: Justine Tunney <jtunney@gmail.com>
Date: Sat, 14 Oct 2023 01:06:00 -0700
Subject: [PATCH] Rewrite special file handling on Windows

This change gets GNU grep working. What caused it to not work, is it
wouldn't write to an output file descriptor when its dev/ino equaled
/dev/null's. So now we invent special dev/ino values for these files
---
 libc/calls/abort.c                            |  4 +-
 libc/calls/fcntl-nt.c                         | 55 ++-----------
 libc/calls/fstat-nt.c                         | 43 +++++++++-
 libc/calls/fstat.c                            |  2 +-
 libc/calls/fstatat-nt.c                       | 44 ++++++++--
 libc/calls/getloadavg-nt.c                    |  3 +
 libc/calls/getuid-nt.c                        | 12 +--
 libc/calls/ioctl.c                            |  3 +
 libc/calls/ischardev.c                        |  2 +-
 libc/calls/lseek-nt.c                         |  4 +-
 libc/calls/mkntpath.c                         | 20 -----
 libc/calls/ntmagicpaths.inc                   |  7 --
 libc/calls/ntmagicpaths.internal.h            | 16 ----
 libc/calls/open-nt.c                          | 72 ++++++++++++----
 libc/calls/openat-sysv.c                      |  8 +-
 libc/calls/park.c                             | 10 +--
 libc/calls/pause-nt.c                         |  1 -
 libc/calls/poll-nt.c                          | 27 +++---
 libc/calls/pread.c                            |  2 +-
 libc/calls/printfds.c                         |  2 +
 libc/calls/pwrite.c                           |  2 +-
 libc/calls/read-nt.c                          | 10 ++-
 libc/calls/readv-nt.c                         |  1 +
 libc/calls/readwrite-nt.c                     |  4 +-
 libc/calls/setfl.c                            | 71 ++++++++++++++++
 libc/calls/sig.c                              | 11 ++-
 libc/calls/sigignore.c                        |  5 +-
 libc/calls/sigpending.c                       |  4 +-
 libc/calls/state.internal.h                   |  1 +
 libc/calls/struct/fd.internal.h               |  1 +
 libc/calls/struct/stat.internal.h             |  4 +-
 libc/calls/syscall_support-nt.internal.h      |  1 +
 libc/calls/writev-nt.c                        |  1 +
 libc/intrin/describestat.c                    |  4 +-
 libc/{calls/ntmagicpaths.c => intrin/fnv.c}   | 19 +++--
 .../pthread_unref.c}                          | 43 ++++------
 libc/intrin/reopenfile.c                      |  2 -
 libc/log/libfatal.internal.h                  | 14 ----
 libc/proc/cocmd.c                             | 12 ++-
 libc/proc/fork-nt.c                           |  4 +-
 libc/proc/getrusage-nt.c                      |  3 +-
 libc/runtime/mprotect-nt.greg.c               |  3 +
 libc/runtime/zipos-inode.c                    | 12 +--
 libc/str/str.h                                |  1 +
 libc/thread/posixthread.internal.h            | 21 +++--
 libc/thread/pthread_create.c                  | 23 +++++-
 libc/thread/pthread_timedjoin_np.c            |  3 +-
 test/libc/calls/specialfile_test.c            | 82 +++++++++++++++++++
 test/libc/proc/system_test.c                  |  9 ++
 third_party/nsync/futex.c                     |  7 +-
 tool/build/runitd.c                           |  5 +-
 tool/net/redbean.c                            |  8 +-
 tool/net/winbench.c                           | 54 +++++-------
 53 files changed, 484 insertions(+), 298 deletions(-)
 delete mode 100644 libc/calls/ntmagicpaths.inc
 delete mode 100644 libc/calls/ntmagicpaths.internal.h
 create mode 100644 libc/calls/setfl.c
 rename libc/{calls/ntmagicpaths.c => intrin/fnv.c} (84%)
 rename libc/{thread/pthread_decimate.c => intrin/pthread_unref.c} (66%)
 create mode 100644 test/libc/calls/specialfile_test.c

diff --git a/libc/calls/abort.c b/libc/calls/abort.c
index cbe973e801d..ce8150e9284 100644
--- a/libc/calls/abort.c
+++ b/libc/calls/abort.c
@@ -33,9 +33,7 @@
  * @noreturn
  */
 wontreturn void abort(void) {
-  sigset_t m;
-  sigemptyset(&m);
-  sigaddset(&m, SIGABRT);
+  sigset_t m = 1ull << (SIGABRT - 1);
   sigprocmask(SIG_UNBLOCK, &m, 0);
   raise(SIGABRT);
   signal(SIGABRT, SIG_DFL);
diff --git a/libc/calls/fcntl-nt.c b/libc/calls/fcntl-nt.c
index eb5fe2036b7..51e44d64039 100644
--- a/libc/calls/fcntl-nt.c
+++ b/libc/calls/fcntl-nt.c
@@ -321,63 +321,18 @@ 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 mode, unsigned arg,
-                                          intptr_t *handle) {
-
-  // you may change the following:
-  //
-  // - O_NONBLOCK     make read() raise EAGAIN
-  // - O_APPEND       for toggling append mode
-  // - O_RANDOM       alt. for posix_fadvise()
-  // - O_SEQUENTIAL   alt. for posix_fadvise()
-  // - O_DIRECT       works but haven't tested
-  //
-  // the other bits are ignored.
-  unsigned allowed = O_APPEND | O_SEQUENTIAL | O_RANDOM | O_DIRECT | O_NONBLOCK;
-  unsigned needreo = O_APPEND | O_SEQUENTIAL | O_RANDOM | O_DIRECT;
-  unsigned newflag = (*flags & ~allowed) | (arg & allowed);
-
-  if ((*flags & needreo) ^ (arg & needreo)) {
-    unsigned perm, share, attr;
-    if (GetNtOpenFlags(newflag, mode, &perm, &share, 0, &attr) == -1) {
-      return -1;
-    }
-    // MSDN says only these are allowed, otherwise it returns EINVAL.
-    attr &= kNtFileFlagBackupSemantics | kNtFileFlagDeleteOnClose |
-            kNtFileFlagNoBuffering | kNtFileFlagOpenNoRecall |
-            kNtFileFlagOpenReparsePoint | kNtFileFlagOverlapped |
-            kNtFileFlagPosixSemantics | kNtFileFlagRandomAccess |
-            kNtFileFlagSequentialScan | kNtFileFlagWriteThrough;
-    intptr_t hand;
-    if ((hand = ReOpenFile(*handle, perm, share, attr)) != -1) {
-      if (hand != *handle) {
-        CloseHandle(*handle);
-        *handle = hand;
-      }
-    } else {
-      return __winerr();
-    }
-  }
-
-  // 1. ignore flags that aren't access mode flags
-  // 2. return zero if nothing's changed
-  *flags = newflag;
-  return 0;
-}
-
 textwindows int sys_fcntl_nt(int fd, int cmd, uintptr_t arg) {
   int rc;
   BLOCK_SIGNALS;
-  if (__isfdkind(fd, kFdFile) ||    //
-      __isfdkind(fd, kFdSocket) ||  //
-      __isfdkind(fd, kFdConsole)) {
+  if (__isfdkind(fd, kFdFile) ||     //
+      __isfdkind(fd, kFdSocket) ||   //
+      __isfdkind(fd, kFdConsole) ||  //
+      __isfdkind(fd, kFdDevNull)) {
     if (cmd == F_GETFL) {
       rc = g_fds.p[fd].flags & (O_ACCMODE | O_APPEND | O_DIRECT | O_NONBLOCK |
                                 O_RANDOM | O_SEQUENTIAL);
     } else if (cmd == F_SETFL) {
-      rc = sys_fcntl_nt_setfl(fd, &g_fds.p[fd].flags, g_fds.p[fd].mode, arg,
-                              &g_fds.p[fd].handle);
+      rc = sys_fcntl_nt_setfl(fd, arg);
     } else if (cmd == F_GETFD) {
       if (g_fds.p[fd].flags & O_CLOEXEC) {
         rc = FD_CLOEXEC;
diff --git a/libc/calls/fstat-nt.c b/libc/calls/fstat-nt.c
index bf563c98824..b71f17ac146 100644
--- a/libc/calls/fstat-nt.c
+++ b/libc/calls/fstat-nt.c
@@ -19,7 +19,9 @@
 #include "libc/assert.h"
 #include "libc/calls/calls.h"
 #include "libc/calls/internal.h"
+#include "libc/calls/struct/fd.internal.h"
 #include "libc/calls/struct/stat.h"
+#include "libc/calls/struct/stat.internal.h"
 #include "libc/calls/syscall_support-nt.internal.h"
 #include "libc/fmt/wintime.internal.h"
 #include "libc/intrin/atomic.h"
@@ -76,13 +78,47 @@ static textwindows long GetSizeOfReparsePoint(int64_t fh) {
   return z;
 }
 
-textwindows int sys_fstat_nt(int64_t handle, struct stat *out_st) {
+static textwindows int sys_fstat_nt_socket(int kind, struct stat *st) {
+  bzero(st, sizeof(*st));
+  st->st_blksize = 512;
+  st->st_mode = S_IFSOCK | 0666;
+  st->st_dev = 0x44444444;
+  st->st_ino = kind;
+  return 0;
+}
+
+textwindows int sys_fstat_nt_special(int kind, struct stat *st) {
+  bzero(st, sizeof(*st));
+  st->st_blksize = 512;
+  st->st_mode = S_IFCHR | 0666;
+  st->st_dev = 0x77777777;
+  st->st_ino = kind;
+  return 0;
+}
+
+textwindows int sys_fstat_nt(int fd, struct stat *st) {
+  if (fd + 0u >= g_fds.n) return ebadf();
+  switch (g_fds.p[fd].kind) {
+    case kFdEmpty:
+      return ebadf();
+    case kFdConsole:
+    case kFdDevNull:
+      return sys_fstat_nt_special(g_fds.p[fd].kind, st);
+    case kFdSocket:
+      return sys_fstat_nt_socket(g_fds.p[fd].kind, st);
+    default:
+      return sys_fstat_nt_handle(g_fds.p[fd].handle, st);
+  }
+}
+
+textwindows int sys_fstat_nt_handle(int64_t handle, struct stat *out_st) {
   struct stat st = {0};
 
   // Always set st_blksize to avoid divide by zero issues.
   // The Linux kernel sets this for /dev/tty and similar too.
   // TODO(jart): GetVolumeInformationByHandle?
   st.st_blksize = 4096;
+  st.st_gid = st.st_uid = sys_getuid_nt();
 
   // We'll use the "umask" to fake out the mode bits.
   uint32_t umask = atomic_load_explicit(&__umask, memory_order_acquire);
@@ -92,9 +128,13 @@ textwindows int sys_fstat_nt(int64_t handle, struct stat *out_st) {
       break;
     case kNtFileTypeChar:
       st.st_mode = S_IFCHR | (0666 & ~umask);
+      st.st_dev = 0x66666666;
+      st.st_ino = handle;
       break;
     case kNtFileTypePipe:
       st.st_mode = S_IFIFO | (0666 & ~umask);
+      st.st_dev = 0x55555555;
+      st.st_ino = handle;
       break;
     case kNtFileTypeDisk: {
       struct NtByHandleFileInformation wst;
@@ -126,7 +166,6 @@ textwindows int sys_fstat_nt(int64_t handle, struct stat *out_st) {
       } else {
         st.st_ctim = st.st_mtim;
       }
-      st.st_gid = st.st_uid = sys_getuid_nt();
       st.st_size = (wst.nFileSizeHigh + 0ull) << 32 | wst.nFileSizeLow;
       st.st_dev = wst.dwVolumeSerialNumber;
       st.st_ino = (wst.nFileIndexHigh + 0ull) << 32 | wst.nFileIndexLow;
diff --git a/libc/calls/fstat.c b/libc/calls/fstat.c
index 6355de08a72..017d3c2d754 100644
--- a/libc/calls/fstat.c
+++ b/libc/calls/fstat.c
@@ -52,7 +52,7 @@ int fstat(int fd, struct stat *st) {
   } else if (IsMetal()) {
     rc = sys_fstat_metal(fd, st);
   } else if (IsWindows()) {
-    rc = sys_fstat_nt(__getfdhandleactual(fd), st);
+    rc = sys_fstat_nt(fd, st);
   } else {
     rc = enosys();
   }
diff --git a/libc/calls/fstatat-nt.c b/libc/calls/fstatat-nt.c
index 8a3b7f93d7f..720110ae7ff 100644
--- a/libc/calls/fstatat-nt.c
+++ b/libc/calls/fstatat-nt.c
@@ -16,9 +16,8 @@
 │ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
-#include "libc/calls/sig.internal.h"
+#include "libc/calls/struct/fd.internal.h"
 #include "libc/calls/struct/sigset.internal.h"
-#include "libc/calls/struct/stat.h"
 #include "libc/calls/struct/stat.internal.h"
 #include "libc/calls/syscall_support-nt.internal.h"
 #include "libc/errno.h"
@@ -29,18 +28,43 @@
 #include "libc/nt/enum/filesharemode.h"
 #include "libc/nt/errors.h"
 #include "libc/nt/runtime.h"
+#include "libc/str/str.h"
 #include "libc/sysv/consts/at.h"
+#include "libc/sysv/consts/fileno.h"
+#include "libc/sysv/errfuns.h"
 
 textwindows int sys_fstatat_nt(int dirfd, const char *path, struct stat *st,
                                int flags) {
-  int rc, e;
-  int64_t fh;
-  uint32_t dwDesiredAccess;
+
+  // handle special files
+  if (startswith(path, "/dev/")) {
+    if (!strcmp(path + 5, "tty")) {
+      return sys_fstat_nt_special(kFdConsole, st);
+    } else if (!strcmp(path + 5, "null")) {
+      return sys_fstat_nt_special(kFdDevNull, st);
+    } else if (!strcmp(path + 5, "stdin")) {
+      return sys_fstat_nt(STDIN_FILENO, st);
+    } else if (!strcmp(path + 5, "stdout")) {
+      return sys_fstat_nt(STDOUT_FILENO, st);
+    } else if (!strcmp(path + 5, "stderr")) {
+      return sys_fstat_nt(STDERR_FILENO, st);
+    } else {
+      return enoent();
+    }
+  }
+
+  // convert path from utf-8 to utf-16
   uint16_t path16[PATH_MAX];
-  if (__mkntpathat(dirfd, path, 0, path16) == -1) return -1;
+  if (__mkntpathat(dirfd, path, 0, path16) == -1) {
+    return -1;
+  }
+
+  // open an actual file
+  int rc;
+  int64_t fh;
+  int e = errno;
+  uint32_t dwDesiredAccess = kNtFileGenericRead;
   BLOCK_SIGNALS;
-  e = errno;
-  dwDesiredAccess = kNtFileGenericRead;
 TryAgain:
   if ((fh = CreateFile(
            path16, dwDesiredAccess,
@@ -50,7 +74,7 @@ textwindows int sys_fstatat_nt(int dirfd, const char *path, struct stat *st,
                ((flags & AT_SYMLINK_NOFOLLOW) ? kNtFileFlagOpenReparsePoint
                                               : 0),
            0)) != -1) {
-    rc = st ? sys_fstat_nt(fh, st) : 0;
+    rc = st ? sys_fstat_nt_handle(fh, st) : 0;
     CloseHandle(fh);
   } else if (dwDesiredAccess == kNtFileGenericRead &&
              GetLastError() == kNtErrorSharingViolation) {
@@ -61,5 +85,7 @@ textwindows int sys_fstatat_nt(int dirfd, const char *path, struct stat *st,
     rc = __winerr();
   }
   ALLOW_SIGNALS;
+
+  // mop up errors
   return __fix_enotdir(rc, path16);
 }
diff --git a/libc/calls/getloadavg-nt.c b/libc/calls/getloadavg-nt.c
index 6e90db64baf..fd48d1bd91c 100644
--- a/libc/calls/getloadavg-nt.c
+++ b/libc/calls/getloadavg-nt.c
@@ -17,6 +17,7 @@
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
 #include "libc/calls/calls.h"
+#include "libc/calls/struct/sigset.internal.h"
 #include "libc/calls/syscall_support-nt.internal.h"
 #include "libc/dce.h"
 #include "libc/fmt/conv.h"
@@ -36,6 +37,7 @@ textwindows int sys_getloadavg_nt(double *a, int n) {
   int i, rc;
   uint64_t elapsed, used;
   struct NtFileTime idle, kern, user;
+  BLOCK_SIGNALS;
   pthread_spin_lock(&lock);
   if (GetSystemTimes(&idle, &kern, &user)) {
     elapsed = (FT(kern) - FT(kern1)) + (FT(user) - FT(user1));
@@ -53,6 +55,7 @@ textwindows int sys_getloadavg_nt(double *a, int n) {
     rc = __winerr();
   }
   pthread_spin_unlock(&lock);
+  ALLOW_SIGNALS;
   return rc;
 }
 
diff --git a/libc/calls/getuid-nt.c b/libc/calls/getuid-nt.c
index 0de3eba66db..1cb4ad292ca 100644
--- a/libc/calls/getuid-nt.c
+++ b/libc/calls/getuid-nt.c
@@ -20,15 +20,7 @@
 #include "libc/intrin/atomic.h"
 #include "libc/macros.internal.h"
 #include "libc/nt/accounting.h"
-
-static textwindows uint32_t __kmp32(const void *buf, size_t size) {
-  size_t i;
-  uint32_t h;
-  const uint32_t kPhiPrime = 0x9e3779b1;
-  const unsigned char *p = (const unsigned char *)buf;
-  for (h = i = 0; i < size; i++) h = (p[i] + h) * kPhiPrime;
-  return h;
-}
+#include "libc/str/str.h"
 
 textwindows uint32_t sys_getuid_nt(void) {
   char16_t buf[257];
@@ -36,7 +28,7 @@ textwindows uint32_t sys_getuid_nt(void) {
   uint32_t tmp, size = ARRAYLEN(buf);
   if (!(tmp = atomic_load_explicit(&uid, memory_order_acquire))) {
     GetUserName(&buf, &size);
-    tmp = __kmp32(buf, size >> 1) & 32767;
+    tmp = __fnv(buf, size >> 1) & 32767;
     if (!tmp) ++tmp;
     atomic_store_explicit(&uid, tmp, memory_order_release);
   }
diff --git a/libc/calls/ioctl.c b/libc/calls/ioctl.c
index 8bd31b81467..aca879bdbd7 100644
--- a/libc/calls/ioctl.c
+++ b/libc/calls/ioctl.c
@@ -106,6 +106,9 @@ static int ioctl_fionread(int fd, uint32_t *arg) {
       int bytes = CountConsoleInputBytes();
       *arg = MAX(0, bytes);
       return 0;
+    } else if (g_fds.p[fd].kind == kFdDevNull) {
+      *arg = 1;
+      return 0;
     } else if (GetFileType(handle) == kNtFileTypePipe) {
       uint32_t avail;
       if (PeekNamedPipe(handle, 0, 0, 0, &avail, 0)) {
diff --git a/libc/calls/ischardev.c b/libc/calls/ischardev.c
index 6d460d7f4a5..06e02653126 100644
--- a/libc/calls/ischardev.c
+++ b/libc/calls/ischardev.c
@@ -54,7 +54,7 @@ bool32 ischardev(int fd) {
       return false;
     }
   } else {
-    return __isfdkind(fd, kFdConsole) ||
+    return __isfdkind(fd, kFdConsole) || __isfdkind(fd, kFdDevNull) ||
            (__isfdkind(fd, kFdFile) &&
             GetFileType(__getfdhandleactual(fd)) == kNtFileTypeChar);
   }
diff --git a/libc/calls/lseek-nt.c b/libc/calls/lseek-nt.c
index 27b83312760..82e0f2b58d7 100644
--- a/libc/calls/lseek-nt.c
+++ b/libc/calls/lseek-nt.c
@@ -62,7 +62,9 @@ static textwindows int64_t Seek(struct Fd *f, int64_t offset, int whence) {
 }
 
 textwindows int64_t sys_lseek_nt(int fd, int64_t offset, int whence) {
-  if (__isfdkind(fd, kFdFile)) {
+  if (__isfdkind(fd, kFdDevNull)) {
+    return offset;
+  } else if (__isfdkind(fd, kFdFile)) {
     struct Fd *f = g_fds.p + fd;
     int filetype = GetFileType(f->handle);
     if (filetype != kNtFileTypePipe && filetype != kNtFileTypeChar) {
diff --git a/libc/calls/mkntpath.c b/libc/calls/mkntpath.c
index b5dff02894b..add261725e0 100644
--- a/libc/calls/mkntpath.c
+++ b/libc/calls/mkntpath.c
@@ -16,7 +16,6 @@
 │ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
-#include "libc/calls/ntmagicpaths.internal.h"
 #include "libc/calls/syscall_support-nt.internal.h"
 #include "libc/dce.h"
 #include "libc/intrin/asan.internal.h"
@@ -36,24 +35,6 @@ static inline int IsAlpha(int c) {
   return ('A' <= c && c <= 'Z') || ('a' <= c && c <= 'z');
 }
 
-textwindows static const char *FixNtMagicPath(const char *path,
-                                              unsigned flags) {
-  const struct NtMagicPaths *mp = &kNtMagicPaths;
-  asm("" : "+r"(mp));
-  if (!IsSlash(path[0])) return path;
-  if (strcmp(path, mp->devtty) == 0) {
-    if ((flags & O_ACCMODE) == O_RDONLY) {
-      return mp->conin;
-    } else if ((flags & O_ACCMODE) == O_WRONLY) {
-      return mp->conout;
-    }
-  }
-  if (strcmp(path, mp->devnull) == 0) return mp->nul;
-  if (strcmp(path, mp->devstdin) == 0) return mp->conin;
-  if (strcmp(path, mp->devstdout) == 0) return mp->conout;
-  return path;
-}
-
 textwindows size_t __normntpath(char16_t *p, size_t n) {
   size_t i, j;
   for (j = i = 0; i < n; ++i) {
@@ -116,7 +97,6 @@ textwindows int __mkntpath2(const char *path,
   if (!path || (IsAsan() && !__asan_is_valid_str(path))) {
     return efault();
   }
-  path = FixNtMagicPath(path, flags);
 
   size_t x, z;
   char16_t *p = path16;
diff --git a/libc/calls/ntmagicpaths.inc b/libc/calls/ntmagicpaths.inc
deleted file mode 100644
index e052ccf0570..00000000000
--- a/libc/calls/ntmagicpaths.inc
+++ /dev/null
@@ -1,7 +0,0 @@
-TAB(devtty, "/dev/tty")
-TAB(devnull, "/dev/null")
-TAB(devstdin, "/dev/stdin")
-TAB(devstdout, "/dev/stdout")
-TAB(nul, "NUL")
-TAB(conin, "CONIN$")
-TAB(conout, "CONOUT$")
diff --git a/libc/calls/ntmagicpaths.internal.h b/libc/calls/ntmagicpaths.internal.h
deleted file mode 100644
index 20b2be0fd22..00000000000
--- a/libc/calls/ntmagicpaths.internal.h
+++ /dev/null
@@ -1,16 +0,0 @@
-#ifndef COSMOPOLITAN_LIBC_CALLS_NTMAGICPATHS_H_
-#define COSMOPOLITAN_LIBC_CALLS_NTMAGICPATHS_H_
-#if !(__ASSEMBLER__ + __LINKER__ + 0)
-COSMOPOLITAN_C_START_
-
-struct NtMagicPaths {
-#define TAB(NAME, STRING) char NAME[sizeof(STRING)];
-#include "libc/calls/ntmagicpaths.inc"
-#undef TAB
-};
-
-extern const struct NtMagicPaths kNtMagicPaths;
-
-COSMOPOLITAN_C_END_
-#endif /* !(__ASSEMBLER__ + __LINKER__ + 0) */
-#endif /* COSMOPOLITAN_LIBC_CALLS_NTMAGICPATHS_H_ */
diff --git a/libc/calls/open-nt.c b/libc/calls/open-nt.c
index ba3d70b2133..570ff6d59f4 100644
--- a/libc/calls/open-nt.c
+++ b/libc/calls/open-nt.c
@@ -18,8 +18,8 @@
 ╚─────────────────────────────────────────────────────────────────────────────*/
 #include "libc/assert.h"
 #include "libc/calls/internal.h"
-#include "libc/calls/ntmagicpaths.internal.h"
 #include "libc/calls/state.internal.h"
+#include "libc/calls/struct/sigset.internal.h"
 #include "libc/calls/syscall-nt.internal.h"
 #include "libc/calls/syscall_support-nt.internal.h"
 #include "libc/errno.h"
@@ -131,24 +131,13 @@ static textwindows int64_t sys_open_nt_impl(int dirfd, const char *path,
   return __fix_enotdir(hand, path16);
 }
 
-static textwindows int sys_open_nt_console(int dirfd,
-                                           const struct NtMagicPaths *mp,
-                                           uint32_t flags, int32_t mode,
-                                           size_t fd) {
-  g_fds.p[fd].kind = kFdConsole;
-  g_fds.p[fd].flags = flags;
-  g_fds.p[fd].mode = mode;
-  g_fds.p[fd].handle =
-      CreateFile(u"CONIN$", kNtGenericRead | kNtGenericWrite, kNtFileShareRead,
-                 &kNtIsInheritable, kNtOpenExisting, 0, 0);
-  return fd;
-}
-
 static textwindows int sys_open_nt_file(int dirfd, const char *file,
                                         uint32_t flags, int32_t mode,
                                         size_t fd) {
-  if ((g_fds.p[fd].handle = sys_open_nt_impl(dirfd, file, flags, mode,
-                                             kNtFileFlagOverlapped)) != -1) {
+  int64_t handle;
+  if ((handle = sys_open_nt_impl(dirfd, file, flags, mode,
+                                 kNtFileFlagOverlapped)) != -1) {
+    g_fds.p[fd].handle = handle;
     g_fds.p[fd].kind = kFdFile;
     g_fds.p[fd].flags = flags;
     g_fds.p[fd].mode = mode;
@@ -158,15 +147,61 @@ static textwindows int sys_open_nt_file(int dirfd, const char *file,
   }
 }
 
+static textwindows int sys_open_nt_special(int fd, int flags, int mode,
+                                           int kind, const char16_t *name) {
+  g_fds.p[fd].kind = kind;
+  g_fds.p[fd].mode = mode;
+  g_fds.p[fd].flags = flags;
+  g_fds.p[fd].handle = CreateFile(name, kNtGenericRead | kNtGenericWrite,
+                                  kNtFileShareRead | kNtFileShareWrite,
+                                  &kNtIsInheritable, kNtOpenExisting, 0, 0);
+  return fd;
+}
+
+static textwindows int sys_open_nt_dup(int fd, int flags, int mode, int oldfd) {
+  int64_t handle;
+  if (!__isfdopen(oldfd)) {
+    return enoent();
+  }
+  if (DuplicateHandle(GetCurrentProcess(), g_fds.p[oldfd].handle,
+                      GetCurrentProcess(), &handle, 0, true,
+                      kNtDuplicateSameAccess)) {
+    g_fds.p[fd] = g_fds.p[oldfd];
+    g_fds.p[fd].handle = handle;
+    g_fds.p[fd].mode = mode;
+    if (!sys_fcntl_nt_setfl(fd, flags)) {
+      return fd;
+    } else {
+      CloseHandle(handle);
+      return -1;
+    }
+  } else {
+    return __winerr();
+  }
+}
+
 textwindows int sys_open_nt(int dirfd, const char *file, uint32_t flags,
                             int32_t mode) {
   int fd;
   ssize_t rc;
+  BLOCK_SIGNALS;
   __fds_lock();
   if (!(flags & O_CREAT)) mode = 0;
   if ((rc = fd = __reservefd_unlocked(-1)) != -1) {
-    if (!strcmp(file, kNtMagicPaths.devtty)) {
-      rc = sys_open_nt_console(dirfd, &kNtMagicPaths, flags, mode, fd);
+    if (startswith(file, "/dev/")) {
+      if (!strcmp(file + 5, "tty")) {
+        rc = sys_open_nt_special(fd, flags, mode, kFdConsole, u"CONIN$");
+      } else if (!strcmp(file + 5, "null")) {
+        rc = sys_open_nt_special(fd, flags, mode, kFdDevNull, u"NUL");
+      } else if (!strcmp(file + 5, "stdin")) {
+        rc = sys_open_nt_dup(fd, flags, mode, STDIN_FILENO);
+      } else if (!strcmp(file + 5, "stdout")) {
+        rc = sys_open_nt_dup(fd, flags, mode, STDOUT_FILENO);
+      } else if (!strcmp(file + 5, "stderr")) {
+        rc = sys_open_nt_dup(fd, flags, mode, STDERR_FILENO);
+      } else {
+        rc = enoent();
+      }
     } else {
       rc = sys_open_nt_file(dirfd, file, flags, mode, fd);
     }
@@ -175,5 +210,6 @@ textwindows int sys_open_nt(int dirfd, const char *file, uint32_t flags,
     }
     __fds_unlock();
   }
+  ALLOW_SIGNALS;
   return rc;
 }
diff --git a/libc/calls/openat-sysv.c b/libc/calls/openat-sysv.c
index 8088d5e59b7..cf1699aa52e 100644
--- a/libc/calls/openat-sysv.c
+++ b/libc/calls/openat-sysv.c
@@ -27,11 +27,9 @@
 int sys_openat(int dirfd, const char *file, int flags, unsigned mode) {
   static bool once, modernize;
   int d, e, f;
-  /*
-   * RHEL5 doesn't support O_CLOEXEC. It's hard to test for this.
-   * Sometimes the system call succeeds and it just doesn't set the
-   * flag. Other times, it return -530 which makes no sense.
-   */
+  // RHEL5 doesn't support O_CLOEXEC. It's hard to test for this.
+  // Sometimes the system call succeeds and it just doesn't set the
+  // flag. Other times, it return -530 which makes no sense.
   if (!IsLinux() || !(flags & O_CLOEXEC) || modernize) {
     d = __sys_openat(dirfd, file, flags, mode);
   } else if (once) {
diff --git a/libc/calls/park.c b/libc/calls/park.c
index 06f1f4233fe..119e29854aa 100644
--- a/libc/calls/park.c
+++ b/libc/calls/park.c
@@ -47,13 +47,9 @@ static textwindows int _park_thread(uint32_t msdelay, sigset_t waitmask,
   om = __sig_beginwait(waitmask);
   if ((rc = _check_cancel()) != -1 && (rc = _check_signal(restartable)) != -1) {
     unassert((wi = WaitForSingleObject(sem, msdelay)) != -1u);
-    if (wi != kNtWaitTimeout) {
-      _check_signal(false);
-      rc = eintr();
-      _check_cancel();
-    } else if ((rc = _check_signal(restartable))) {
-      _check_cancel();
-    }
+    if (restartable && !(pt->pt_flags & PT_RESTARTABLE)) rc = eintr();
+    rc |= _check_signal(restartable);
+    if (rc == -1 && errno == EINTR) _check_cancel();
   }
   __sig_finishwait(om);
   atomic_store_explicit(&pt->pt_blocker, PT_BLOCKER_CPU, memory_order_release);
diff --git a/libc/calls/pause-nt.c b/libc/calls/pause-nt.c
index f9f2c23acbc..61a809ec44f 100644
--- a/libc/calls/pause-nt.c
+++ b/libc/calls/pause-nt.c
@@ -17,7 +17,6 @@
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
 #include "libc/calls/internal.h"
-#include "libc/calls/sig.internal.h"
 #include "libc/calls/syscall_support-nt.internal.h"
 #ifdef __x86_64__
 
diff --git a/libc/calls/poll-nt.c b/libc/calls/poll-nt.c
index 40898f116ae..3e37c8da446 100644
--- a/libc/calls/poll-nt.c
+++ b/libc/calls/poll-nt.c
@@ -58,10 +58,10 @@
 // Polls on the New Technology.
 //
 // This function is used to implement poll() and select(). You may poll
-// on both sockets and files at the same time. We also poll for signals
-// while poll is polling.
-textwindows int sys_poll_nt(struct pollfd *fds, uint64_t nfds, uint32_t *ms,
-                            const sigset_t *sigmask) {
+// on sockets, files and the console at the same time. We also poll for
+// both signals and posix thread cancelation, while the poll is polling
+static textwindows int sys_poll_nt_impl(struct pollfd *fds, uint64_t nfds,
+                                        uint32_t *ms, sigset_t sigmask) {
   bool ok;
   uint64_t millis;
   uint32_t cm, avail, waitfor;
@@ -72,7 +72,6 @@ textwindows int sys_poll_nt(struct pollfd *fds, uint64_t nfds, uint32_t *ms,
   struct timespec started, deadline, remain, now;
   int i, rc, sn, pn, gotinvals, gotpipes, gotsocks;
 
-  BLOCK_SIGNALS;
   started = timespec_real();
   deadline = timespec_add(started, timespec_frommillis(ms ? *ms : -1u));
 
@@ -128,7 +127,7 @@ textwindows int sys_poll_nt(struct pollfd *fds, uint64_t nfds, uint32_t *ms,
   __fds_unlock();
   if (rc) {
     // failed to create a polling solution
-    goto Finished;
+    return rc;
   }
 
   // perform the i/o and sleeping and looping
@@ -170,8 +169,7 @@ textwindows int sys_poll_nt(struct pollfd *fds, uint64_t nfds, uint32_t *ms,
     // compute a small time slice we don't mind sleeping for
     if (sn) {
       if ((gotsocks = WSAPoll(sockfds, sn, 0)) == -1) {
-        rc = __winsockerr();
-        goto Finished;
+        return __winsockerr();
       }
     } else {
       gotsocks = 0;
@@ -190,8 +188,8 @@ textwindows int sys_poll_nt(struct pollfd *fds, uint64_t nfds, uint32_t *ms,
         if (waitfor) {
           POLLTRACE("poll() sleeping for %'d out of %'lu ms", waitfor,
                     timespec_tomillis(remain));
-          if ((rc = _park_norestart(waitfor, sigmask ? *sigmask : 0)) == -1) {
-            goto Finished;  // eintr, ecanceled, etc.
+          if ((rc = _park_norestart(waitfor, sigmask)) == -1) {
+            return -1;  // eintr, ecanceled, etc.
           }
         }
       }
@@ -221,9 +219,14 @@ textwindows int sys_poll_nt(struct pollfd *fds, uint64_t nfds, uint32_t *ms,
   }
 
   // and finally return
-  rc = gotinvals + gotpipes + gotsocks;
+  return gotinvals + gotpipes + gotsocks;
+}
 
-Finished:
+textwindows int sys_poll_nt(struct pollfd *fds, uint64_t nfds, uint32_t *ms,
+                            const sigset_t *sigmask) {
+  int rc;
+  BLOCK_SIGNALS;
+  rc = sys_poll_nt_impl(fds, nfds, ms, sigmask ? *sigmask : 0);
   ALLOW_SIGNALS;
   return rc;
 }
diff --git a/libc/calls/pread.c b/libc/calls/pread.c
index d274ac1572a..99054957185 100644
--- a/libc/calls/pread.c
+++ b/libc/calls/pread.c
@@ -72,7 +72,7 @@ ssize_t pread(int fd, void *buf, size_t size, int64_t offset) {
     rc = sys_pread(fd, buf, size, offset, offset);
   } else if (__isfdkind(fd, kFdSocket)) {
     rc = espipe();
-  } else if (__isfdkind(fd, kFdFile)) {
+  } else if (__isfdkind(fd, kFdFile) || __isfdkind(fd, kFdDevNull)) {
     rc = sys_read_nt(fd, (struct iovec[]){{buf, size}}, 1, offset);
   } else {
     rc = ebadf();
diff --git a/libc/calls/printfds.c b/libc/calls/printfds.c
index d37d6078414..a8602a59a43 100644
--- a/libc/calls/printfds.c
+++ b/libc/calls/printfds.c
@@ -32,6 +32,8 @@ static const char *__fdkind2str(int x) {
       return "kFdSocket";
     case kFdConsole:
       return "kFdConsole";
+    case kFdDevNull:
+      return "kFdDevNull";
     case kFdSerial:
       return "kFdSerial";
     case kFdZip:
diff --git a/libc/calls/pwrite.c b/libc/calls/pwrite.c
index 2696dc553a4..2ae7252f6ce 100644
--- a/libc/calls/pwrite.c
+++ b/libc/calls/pwrite.c
@@ -65,7 +65,7 @@ ssize_t pwrite(int fd, const void *buf, size_t size, int64_t offset) {
     rc = sys_pwrite(fd, buf, size, offset, offset);
   } else if (__isfdkind(fd, kFdSocket)) {
     rc = espipe();
-  } else if (__isfdkind(fd, kFdFile)) {
+  } else if (__isfdkind(fd, kFdFile) || __isfdkind(fd, kFdDevNull)) {
     rc = sys_write_nt(fd, (struct iovec[]){{(void *)buf, size}}, 1, offset);
   } else {
     return ebadf();
diff --git a/libc/calls/read-nt.c b/libc/calls/read-nt.c
index 245e2e2b75d..2894af20f9d 100644
--- a/libc/calls/read-nt.c
+++ b/libc/calls/read-nt.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/atomic.h"
 #include "libc/calls/internal.h"
 #include "libc/calls/sig.internal.h"
@@ -733,8 +734,10 @@ static textwindows int WaitForConsole(struct Fd *f, sigset_t waitmask) {
   atomic_store_explicit(&pt->pt_blocker, PT_BLOCKER_SEM, memory_order_release);
   m = __sig_beginwait(waitmask);
   if ((rc = _check_cancel()) != -1 && (rc = _check_signal(true)) != -1) {
-    WaitForMultipleObjects(2, (int64_t[2]){sem, __keystroke.cin}, 0, ms);
+    int64_t hands[2] = {sem, __keystroke.cin};
+    unassert(WaitForMultipleObjects(2, hands, 0, ms) != -1u);
     if (~pt->pt_flags & PT_RESTARTABLE) rc = eintr();
+    rc |= _check_signal(true);
     if (rc == -1 && errno == EINTR) _check_cancel();
   }
   __sig_finishwait(m);
@@ -763,6 +766,11 @@ textwindows ssize_t sys_read_nt_impl(int fd, void *data, size_t size,
 
   // switch to terminal polyfill if reading from win32 console
   struct Fd *f = g_fds.p + fd;
+
+  if (f->kind == kFdDevNull) {
+    return 0;
+  }
+
   if (f->kind == kFdConsole) {
     return ReadFromConsole(f, data, size, waitmask);
   }
diff --git a/libc/calls/readv-nt.c b/libc/calls/readv-nt.c
index 261ceeb5b7a..11cd46cad8f 100644
--- a/libc/calls/readv-nt.c
+++ b/libc/calls/readv-nt.c
@@ -28,6 +28,7 @@ textwindows ssize_t sys_readv_nt(int fd, const struct iovec *iov, int iovlen) {
   switch (g_fds.p[fd].kind) {
     case kFdFile:
     case kFdConsole:
+    case kFdDevNull:
       return sys_read_nt(fd, iov, iovlen, -1);
     case kFdSocket:
       return _weaken(sys_recv_nt)(fd, iov, iovlen, 0);
diff --git a/libc/calls/readwrite-nt.c b/libc/calls/readwrite-nt.c
index 9f6e4884f26..06ba2b37bcb 100644
--- a/libc/calls/readwrite-nt.c
+++ b/libc/calls/readwrite-nt.c
@@ -83,7 +83,9 @@ sys_readwrite_nt(int fd, void *data, size_t size, ssize_t offset,
   // similar to the lseek() system call, they too raise ESPIPE when
   // operating on a non-seekable file.
   bool pwriting = offset != -1;
-  bool seekable = f->kind == kFdFile && GetFileType(handle) == kNtFileTypeDisk;
+  bool seekable =
+      (f->kind == kFdFile && GetFileType(handle) == kNtFileTypeDisk) ||
+      f->kind == kFdDevNull;
   if (pwriting && !seekable) {
     return espipe();
   }
diff --git a/libc/calls/setfl.c b/libc/calls/setfl.c
new file mode 100644
index 00000000000..e1fb8841ad3
--- /dev/null
+++ b/libc/calls/setfl.c
@@ -0,0 +1,71 @@
+/*-*- 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/internal.h"
+#include "libc/calls/struct/fd.internal.h"
+#include "libc/calls/syscall_support-nt.internal.h"
+#include "libc/nt/createfile.h"
+#include "libc/nt/enum/fileflagandattributes.h"
+#include "libc/nt/files.h"
+#include "libc/nt/runtime.h"
+#include "libc/sysv/consts/o.h"
+
+textwindows int sys_fcntl_nt_setfl(int fd, unsigned flags) {
+
+  // you may change the following:
+  //
+  // - O_NONBLOCK     make read() raise EAGAIN
+  // - O_APPEND       for toggling append mode
+  // - O_RANDOM       alt. for posix_fadvise()
+  // - O_SEQUENTIAL   alt. for posix_fadvise()
+  // - O_DIRECT       works but haven't tested
+  //
+  // the other bits are ignored.
+  unsigned allowed = O_APPEND | O_SEQUENTIAL | O_RANDOM | O_DIRECT | O_NONBLOCK;
+  unsigned needreo = O_APPEND | O_SEQUENTIAL | O_RANDOM | O_DIRECT;
+  unsigned newflag = (g_fds.p[fd].flags & ~allowed) | (flags & allowed);
+
+  if (g_fds.p[fd].kind == kFdFile &&
+      ((g_fds.p[fd].flags & needreo) ^ (flags & needreo))) {
+    unsigned perm, share, attr;
+    if (GetNtOpenFlags(newflag, g_fds.p[fd].mode, &perm, &share, 0, &attr) ==
+        -1) {
+      return -1;
+    }
+    // MSDN says only these are allowed, otherwise it returns EINVAL.
+    attr &= kNtFileFlagBackupSemantics | kNtFileFlagDeleteOnClose |
+            kNtFileFlagNoBuffering | kNtFileFlagOpenNoRecall |
+            kNtFileFlagOpenReparsePoint | kNtFileFlagOverlapped |
+            kNtFileFlagPosixSemantics | kNtFileFlagRandomAccess |
+            kNtFileFlagSequentialScan | kNtFileFlagWriteThrough;
+    intptr_t hand;
+    if ((hand = ReOpenFile(g_fds.p[fd].handle, perm, share, attr)) != -1) {
+      if (hand != g_fds.p[fd].handle) {
+        CloseHandle(g_fds.p[fd].handle);
+        g_fds.p[fd].handle = hand;
+      }
+    } else {
+      return __winerr();
+    }
+  }
+
+  // 1. ignore flags that aren't access mode flags
+  // 2. return zero if nothing's changed
+  g_fds.p[fd].flags = newflag;
+  return 0;
+}
diff --git a/libc/calls/sig.c b/libc/calls/sig.c
index c59d7dbd07a..9c0c6a8daef 100644
--- a/libc/calls/sig.c
+++ b/libc/calls/sig.c
@@ -88,11 +88,13 @@ textwindows bool __sig_ignored(int sig) {
 textwindows void __sig_delete(int sig) {
   struct Dll *e;
   __sig.pending &= ~(1ull << (sig - 1));
+  BLOCK_SIGNALS;
   _pthread_lock();
   for (e = dll_last(_pthread_list); e; e = dll_prev(_pthread_list, e)) {
     POSIXTHREAD_CONTAINER(e)->tib->tib_sigpending &= ~(1ull << (sig - 1));
   }
   _pthread_unlock();
+  ALLOW_SIGNALS;
 }
 
 static textwindows bool __sig_should_use_altstack(unsigned flags,
@@ -219,7 +221,7 @@ textwindows void __sig_cancel(struct PosixThread *pt, int sig, unsigned flags) {
 }
 
 static textwindows wontreturn void __sig_tramp(struct SignalFrame *sf) {
-  ++__sig.count;
+  atomic_fetch_add_explicit(&__sig.count, 1, memory_order_relaxed);
   int sig = sf->si.si_signo;
   sigset_t blocksigs = __sighandmask[sig];
   if (!(sf->flags & SA_NODEFER)) blocksigs |= 1ull << (sig - 1);
@@ -309,7 +311,9 @@ static int __sig_killer(struct PosixThread *pt, int sig, int sic) {
 textwindows int __sig_kill(struct PosixThread *pt, int sig, int sic) {
   int rc;
   BLOCK_SIGNALS;
+  _pthread_ref(pt);
   rc = __sig_killer(pt, sig, sic);
+  _pthread_unref(pt);
   ALLOW_SIGNALS;
   return rc;
 }
@@ -333,7 +337,7 @@ textwindows void __sig_generate(int sig, int sic) {
         atomic_load_explicit(&pt->pt_status, memory_order_acquire) <
             kPosixThreadTerminated &&
         !(pt->tib->tib_sigmask & (1ull << (sig - 1)))) {
-      mark = pt;
+      _pthread_ref((mark = pt));
       break;
     }
   }
@@ -345,6 +349,7 @@ textwindows void __sig_generate(int sig, int sic) {
     STRACE("all threads block %G so adding to pending signals of process", sig);
     __sig.pending |= 1ull << (sig - 1);
   }
+  _pthread_unref(mark);
   ALLOW_SIGNALS;
 }
 
@@ -411,7 +416,7 @@ static void __sig_unmaskable(struct NtExceptionPointers *ep, int code, int sig,
                              struct CosmoTib *tib) {
 
   // increment the signal count for getrusage()
-  ++__sig.count;
+  atomic_fetch_add_explicit(&__sig.count, 1, memory_order_relaxed);
 
   // log vital crash information reliably for --strace before doing much
   // we don't print this without the flag since raw numbers scare people
diff --git a/libc/calls/sigignore.c b/libc/calls/sigignore.c
index c8a7b3ee4bf..16498d20ea3 100644
--- a/libc/calls/sigignore.c
+++ b/libc/calls/sigignore.c
@@ -18,14 +18,11 @@
 ╚─────────────────────────────────────────────────────────────────────────────*/
 #include "libc/calls/calls.h"
 #include "libc/calls/struct/sigaction.h"
-#include "libc/str/str.h"
 
 /**
  * Configures process to ignore signal.
  */
 int sigignore(int sig) {
-  struct sigaction sa;
-  bzero(&sa, sizeof(sa));
-  sa.sa_handler = SIG_IGN;
+  struct sigaction sa = {.sa_handler = SIG_IGN};
   return sigaction(sig, &sa, 0);
 }
diff --git a/libc/calls/sigpending.c b/libc/calls/sigpending.c
index 7dd73d38b2f..d9400b92d17 100644
--- a/libc/calls/sigpending.c
+++ b/libc/calls/sigpending.c
@@ -21,6 +21,7 @@
 #include "libc/calls/struct/sigset.internal.h"
 #include "libc/dce.h"
 #include "libc/intrin/asan.internal.h"
+#include "libc/intrin/atomic.h"
 #include "libc/intrin/describeflags.internal.h"
 #include "libc/intrin/strace.internal.h"
 #include "libc/sysv/errfuns.h"
@@ -53,7 +54,8 @@ int sigpending(sigset_t *pending) {
     }
     rc = 0;
   } else if (IsWindows()) {
-    *pending = __sig.pending | __get_tls()->tib_sigpending;
+    *pending = atomic_load_explicit(&__sig.pending, memory_order_acquire) |
+               __get_tls()->tib_sigpending;
     rc = 0;
   } else {
     rc = enosys();
diff --git a/libc/calls/state.internal.h b/libc/calls/state.internal.h
index 81fc2dc094c..a37a780bc16 100644
--- a/libc/calls/state.internal.h
+++ b/libc/calls/state.internal.h
@@ -1,6 +1,7 @@
 #ifndef COSMOPOLITAN_LIBC_CALLS_STATE_INTERNAL_H_
 #define COSMOPOLITAN_LIBC_CALLS_STATE_INTERNAL_H_
 #include "libc/calls/calls.h"
+#include "libc/nt/struct/securityattributes.h"
 #include "libc/thread/thread.h"
 #include "libc/thread/tls.h"
 #if !(__ASSEMBLER__ + __LINKER__ + 0)
diff --git a/libc/calls/struct/fd.internal.h b/libc/calls/struct/fd.internal.h
index 2e7405c55ab..5c54a97d457 100644
--- a/libc/calls/struct/fd.internal.h
+++ b/libc/calls/struct/fd.internal.h
@@ -11,6 +11,7 @@ COSMOPOLITAN_C_START_
 #define kFdZip      6
 #define kFdEpoll    7
 #define kFdReserved 8
+#define kFdDevNull  9
 
 struct Fd {
   char kind;
diff --git a/libc/calls/struct/stat.internal.h b/libc/calls/struct/stat.internal.h
index 29861e85b1a..4e4fdcbfadf 100644
--- a/libc/calls/struct/stat.internal.h
+++ b/libc/calls/struct/stat.internal.h
@@ -7,7 +7,9 @@ COSMOPOLITAN_C_START_
 
 int sys_fstat(int, struct stat *);
 int sys_fstatat(int, const char *, struct stat *, int);
-int sys_fstat_nt(int64_t, struct stat *);
+int sys_fstat_nt(int, struct stat *);
+int sys_fstat_nt_special(int, struct stat *);
+int sys_fstat_nt_handle(int64_t, struct stat *);
 int sys_fstatat_nt(int, const char *, struct stat *, int);
 int sys_lstat_nt(const char *, struct stat *);
 int sys_fstat_metal(int, struct stat *);
diff --git a/libc/calls/syscall_support-nt.internal.h b/libc/calls/syscall_support-nt.internal.h
index 9fdaa7d8021..2e79b21f8e5 100644
--- a/libc/calls/syscall_support-nt.internal.h
+++ b/libc/calls/syscall_support-nt.internal.h
@@ -16,6 +16,7 @@ int __mkntpath2(const char *, char16_t[hasatleast PATH_MAX], int);
 int __mkntpathat(int, const char *, int, char16_t[hasatleast PATH_MAX]);
 int __mkntpathath(int64_t, const char *, int, char16_t[hasatleast PATH_MAX]);
 int ntaccesscheck(const char16_t *, uint32_t) paramsnonnull();
+int sys_fcntl_nt_setfl(int, unsigned);
 int sys_pause_nt(void);
 int64_t __fix_enotdir(int64_t, char16_t *);
 int64_t __fix_enotdir3(int64_t, char16_t *, char16_t *);
diff --git a/libc/calls/writev-nt.c b/libc/calls/writev-nt.c
index 0e78534302b..c630e031e9b 100644
--- a/libc/calls/writev-nt.c
+++ b/libc/calls/writev-nt.c
@@ -27,6 +27,7 @@ textwindows ssize_t sys_writev_nt(int fd, const struct iovec *iov, int iovlen) {
   switch (g_fds.p[fd].kind) {
     case kFdFile:
     case kFdConsole:
+    case kFdDevNull:
       return sys_write_nt(fd, iov, iovlen, -1);
     case kFdSocket:
       return _weaken(sys_send_nt)(fd, iov, iovlen, 0);
diff --git a/libc/intrin/describestat.c b/libc/intrin/describestat.c
index 80ad0db058c..97e2b247c91 100644
--- a/libc/intrin/describestat.c
+++ b/libc/intrin/describestat.c
@@ -60,11 +60,11 @@ const char *(DescribeStat)(char buf[N], int rc, const struct stat *st) {
   }
 
   if (st->st_dev) {
-    append(", .st_%s=%lu", "dev", st->st_dev);
+    append(", .st_%s=%#lx", "dev", st->st_dev);
   }
 
   if (st->st_ino) {
-    append(", .st_%s=%lu", "ino", st->st_ino);
+    append(", .st_%s=%#lx", "ino", st->st_ino);
   }
 
   if (st->st_gen) {
diff --git a/libc/calls/ntmagicpaths.c b/libc/intrin/fnv.c
similarity index 84%
rename from libc/calls/ntmagicpaths.c
rename to libc/intrin/fnv.c
index 30269b7c9a9..3f605ffbe46 100644
--- a/libc/calls/ntmagicpaths.c
+++ b/libc/intrin/fnv.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         │
@@ -16,10 +16,15 @@
 │ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
-#include "libc/calls/ntmagicpaths.internal.h"
+#include "libc/str/str.h"
 
-const struct NtMagicPaths kNtMagicPaths = {
-#define TAB(NAME, STRING) STRING,
-#include "libc/calls/ntmagicpaths.inc"
-#undef TAB
-};
+uint64_t __fnv(const void *data, size_t size) {
+  const unsigned char *p = data;
+  const unsigned char *pe = p + size;
+  uint64_t hash = 0xcbf29ce484222325;
+  while (p < pe) {
+    hash *= 0x100000001b3;
+    hash ^= *p++;
+  }
+  return hash;
+}
diff --git a/libc/thread/pthread_decimate.c b/libc/intrin/pthread_unref.c
similarity index 66%
rename from libc/thread/pthread_decimate.c
rename to libc/intrin/pthread_unref.c
index df13fd35cf9..20c40740d61 100644
--- a/libc/thread/pthread_decimate.c
+++ b/libc/intrin/pthread_unref.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 2022 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         │
@@ -16,35 +16,22 @@
 │ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
-#include "libc/atomic.h"
+#include "libc/assert.h"
 #include "libc/intrin/atomic.h"
-#include "libc/intrin/dll.h"
-#include "libc/intrin/strace.internal.h"
-#include "libc/runtime/runtime.h"
+#include "libc/intrin/weaken.h"
 #include "libc/thread/posixthread.internal.h"
-#include "libc/thread/thread.h"
-#include "libc/thread/tls.h"
 
-/**
- * Releases memory of detached threads that have terminated.
- */
-void _pthread_decimate(void) {
-  struct Dll *e;
-  struct PosixThread *pt;
-  enum PosixThreadStatus status;
-StartOver:
-  _pthread_lock();
-  for (e = dll_last(_pthread_list); e; e = dll_prev(_pthread_list, e)) {
-    pt = POSIXTHREAD_CONTAINER(e);
-    if (pt->tib == __get_tls()) continue;
-    status = atomic_load_explicit(&pt->pt_status, memory_order_acquire);
-    if (status != kPosixThreadZombie) break;
-    if (!atomic_load_explicit(&pt->tib->tib_tid, memory_order_acquire)) {
-      dll_remove(&_pthread_list, e);
-      _pthread_unlock();
-      _pthread_free(pt, false);
-      goto StartOver;
-    }
+static bool _pthread_deref(struct PosixThread *pt) {
+  int refs = atomic_load_explicit(&pt->pt_refs, memory_order_acquire);
+  if (!refs) return true;
+  unassert(refs > 0);
+  return !atomic_fetch_sub(&pt->pt_refs, 1);
+}
+
+void _pthread_unref(struct PosixThread *pt) {
+  if (_pthread_deref(pt)) {
+    unassert(_weaken(_pthread_free));
+    _weaken(_pthread_free)(pt, false);
+    _weaken(_pthread_decimate)();
   }
-  _pthread_unlock();
 }
diff --git a/libc/intrin/reopenfile.c b/libc/intrin/reopenfile.c
index bb81cc056ef..759e06274c4 100644
--- a/libc/intrin/reopenfile.c
+++ b/libc/intrin/reopenfile.c
@@ -28,14 +28,12 @@ __msabi extern typeof(ReOpenFile) *const __imp_ReOpenFile;
  * Reopens file on the New Technology.
  *
  * @return handle, or -1 on failure
- * @note this wrapper takes care of ABI, STRACE(), and __winerr()
  */
 int64_t ReOpenFile(int64_t hOriginalFile, uint32_t dwDesiredAccess,
                    uint32_t dwShareMode, uint32_t dwFlagsAndAttributes) {
   int64_t hHandle;
   hHandle = __imp_ReOpenFile(hOriginalFile, dwDesiredAccess, dwShareMode,
                              dwFlagsAndAttributes);
-  if (hHandle == -1) __winerr();
   NTTRACE("ReOpenFile(%ld, %s, %s, %s) → %ld% m", hOriginalFile,
           DescribeNtFileAccessFlags(dwDesiredAccess),
           DescribeNtFileShareFlags(dwShareMode),
diff --git a/libc/log/libfatal.internal.h b/libc/log/libfatal.internal.h
index a837e7ea602..c214e979e97 100644
--- a/libc/log/libfatal.internal.h
+++ b/libc/log/libfatal.internal.h
@@ -1,11 +1,6 @@
 #ifndef COSMOPOLITAN_LIBC_LOG_LIBFATAL_INTERNAL_H_
 #define COSMOPOLITAN_LIBC_LOG_LIBFATAL_INTERNAL_H_
-#include "libc/calls/calls.h"
-#include "libc/calls/syscall-sysv.internal.h"
-#include "libc/dce.h"
 #include "libc/macros.internal.h"
-#include "libc/nt/runtime.h"
-#include "libc/sysv/consts/nr.h"
 #if !(__ASSEMBLER__ + __LINKER__ + 0)
 COSMOPOLITAN_C_START_
 
@@ -30,15 +25,6 @@ __funline char *__stpcpy(char *d, const char *s) {
   }
 }
 
-__funline long __write_linux(int fd, const void *p, long n) {
-  long ax = 1;
-  asm volatile("syscall"
-               : "+a"(ax)
-               : "D"(fd), "S"(p), "d"(n)
-               : "rcx", "r11", "memory");
-  return ax;
-}
-
 __funline void *__repstosb(void *di, char al, size_t cx) {
 #if defined(__x86__) && defined(__GNUC__) && !defined(__STRICT_ANSI__)
   asm("rep stosb"
diff --git a/libc/proc/cocmd.c b/libc/proc/cocmd.c
index 583d27d22df..4fafca4b06e 100644
--- a/libc/proc/cocmd.c
+++ b/libc/proc/cocmd.c
@@ -96,11 +96,19 @@ static wontreturn void UnsupportedSyntax(unsigned char c) {
 }
 
 static void Open(const char *path, int fd, int flags) {
-  close(fd);
-  if (open(path, flags, 0644) == -1) {
+  int tmpfd;
+  // use open+dup2 to support things like >/dev/stdout
+  if ((tmpfd = open(path, flags, 0644)) == -1) {
     perror(path);
     _Exit(1);
   }
+  if (tmpfd != fd) {
+    if (dup2(tmpfd, fd) == -1) {
+      perror("dup2");
+      _Exit(1);
+    }
+    close(tmpfd);
+  }
 }
 
 static int SystemExec(void) {
diff --git a/libc/proc/fork-nt.c b/libc/proc/fork-nt.c
index 6174035b4e9..d0e7a7fa6a0 100644
--- a/libc/proc/fork-nt.c
+++ b/libc/proc/fork-nt.c
@@ -67,10 +67,8 @@
 #include "libc/thread/itimer.internal.h"
 #include "libc/thread/posixthread.internal.h"
 #include "libc/thread/tls.h"
-
 #ifdef __x86_64__
 
-extern int64_t __wincrashearly;
 void __keystroke_wipe(void);
 
 static textwindows wontreturn void AbortFork(const char *func) {
@@ -399,7 +397,7 @@ textwindows int sys_fork_nt(uint32_t dwCreationFlags) {
     __tls_enabled_set(true);
     // clear pending signals
     tib->tib_sigpending = 0;
-    __sig.pending = 0;
+    atomic_store_explicit(&__sig.pending, 0, memory_order_relaxed);
     // re-enable threads
     __enable_threads();
     // re-apply code morphing for function tracing
diff --git a/libc/proc/getrusage-nt.c b/libc/proc/getrusage-nt.c
index b7e56a5fed2..a5b4a8645c4 100644
--- a/libc/proc/getrusage-nt.c
+++ b/libc/proc/getrusage-nt.c
@@ -21,6 +21,7 @@
 #include "libc/calls/struct/rusage.internal.h"
 #include "libc/calls/syscall_support-nt.internal.h"
 #include "libc/fmt/wintime.internal.h"
+#include "libc/intrin/atomic.h"
 #include "libc/nt/accounting.h"
 #include "libc/nt/process.h"
 #include "libc/nt/runtime.h"
@@ -75,7 +76,7 @@ textwindows int sys_getrusage_nt(int who, struct rusage *usage) {
       .ru_majflt = memcount.PageFaultCount,
       .ru_inblock = iocount.ReadOperationCount,
       .ru_oublock = iocount.WriteOperationCount,
-      .ru_nsignals = __sig.count,
+      .ru_nsignals = atomic_load_explicit(&__sig.count, memory_order_acquire),
   };
 
   if (who == RUSAGE_BOTH) {
diff --git a/libc/runtime/mprotect-nt.greg.c b/libc/runtime/mprotect-nt.greg.c
index 24f5073814b..8289fe3d9a5 100644
--- a/libc/runtime/mprotect-nt.greg.c
+++ b/libc/runtime/mprotect-nt.greg.c
@@ -16,6 +16,7 @@
 │ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
+#include "libc/calls/struct/sigset.internal.h"
 #include "libc/intrin/directmap.internal.h"
 #include "libc/nt/memory.h"
 #include "libc/runtime/internal.h"
@@ -26,6 +27,7 @@ textwindows int sys_mprotect_nt(void *addr, size_t size, int prot) {
   unsigned i;
   uint32_t op;
   char *a, *b, *x, *y, *p;
+  BLOCK_SIGNALS;
   __mmi_lock();
   size = (size + 4095) & -4096;
   p = addr;
@@ -62,5 +64,6 @@ textwindows int sys_mprotect_nt(void *addr, size_t size, int prot) {
     }
   }
   __mmi_unlock();
+  ALLOW_SIGNALS;
   return rc;
 }
diff --git a/libc/runtime/zipos-inode.c b/libc/runtime/zipos-inode.c
index 0dbb7fcfdf5..1b5f1fea4d8 100644
--- a/libc/runtime/zipos-inode.c
+++ b/libc/runtime/zipos-inode.c
@@ -20,23 +20,15 @@
 #include "libc/limits.h"
 #include "libc/runtime/zipos.internal.h"
 #include "libc/stdio/stdio.h"
+#include "libc/str/str.h"
 #include "libc/zip.internal.h"
 
-static uint64_t __zipos_fnv(const char *s, int len) {
-  uint64_t hash = 0xcbf29ce484222325;
-  for (int i = 0; i < len; i++) {
-    hash *= 0x100000001b3;
-    hash ^= (unsigned char)s[i];
-  }
-  return hash;
-}
-
 uint64_t __zipos_inode(struct Zipos *zipos, int64_t cfile,  //
                        const void *name, size_t namelen) {
   unassert(cfile >= 0);
   if (cfile == ZIPOS_SYNTHETIC_DIRECTORY) {
     if (namelen && ((char *)name)[namelen - 1] == '/') --namelen;
-    cfile = INT64_MIN | __zipos_fnv(name, namelen);
+    cfile = INT64_MIN | __fnv(name, namelen);
   }
   return cfile;
 }
diff --git a/libc/str/str.h b/libc/str/str.h
index ec2d8f1097c..732e938f92b 100644
--- a/libc/str/str.h
+++ b/libc/str/str.h
@@ -186,6 +186,7 @@ dontthrow nocallback;
 uint64_t tpenc(uint32_t) pureconst;
 char *chomp(char *) libcesque;
 wchar_t *wchomp(wchar_t *) libcesque;
+uint64_t __fnv(const void *, size_t) strlenesque;
 bool startswith(const char *, const char *) strlenesque;
 bool startswithi(const char *, const char *) strlenesque;
 bool endswith(const char *, const char *) strlenesque;
diff --git a/libc/thread/posixthread.internal.h b/libc/thread/posixthread.internal.h
index 7a252ac97c0..8107b081aa0 100644
--- a/libc/thread/posixthread.internal.h
+++ b/libc/thread/posixthread.internal.h
@@ -2,6 +2,7 @@
 #define COSMOPOLITAN_LIBC_THREAD_POSIXTHREAD_INTERNAL_H_
 #include "libc/calls/struct/sched_param.h"
 #include "libc/calls/struct/sigaltstack.h"
+#include "libc/intrin/atomic.h"
 #include "libc/intrin/dll.h"
 #include "libc/runtime/runtime.h"
 #include "libc/thread/thread.h"
@@ -16,9 +17,9 @@
 #define PT_RESTARTABLE    64
 #define PT_OPENBSD_KLUDGE 128
 
-#define PT_BLOCKER_CPU ((_Atomic(int) *)-0)
-#define PT_BLOCKER_SEM ((_Atomic(int) *)-1)
-#define PT_BLOCKER_IO  ((_Atomic(int) *)-2)
+#define PT_BLOCKER_CPU ((atomic_int *)-0)
+#define PT_BLOCKER_SEM ((atomic_int *)-1)
+#define PT_BLOCKER_IO  ((atomic_int *)-2)
 
 #if !(__ASSEMBLER__ + __LINKER__ + 0)
 COSMOPOLITAN_C_START_
@@ -79,10 +80,11 @@ enum PosixThreadStatus {
 #define POSIXTHREAD_CONTAINER(e) DLL_CONTAINER(struct PosixThread, list, e)
 
 struct PosixThread {
-  int pt_flags;              // 0x00: see PT_* constants
-  _Atomic(int) pt_canceled;  // 0x04: thread has bad beliefs
+  int pt_flags;            // 0x00: see PT_* constants
+  atomic_int pt_canceled;  // 0x04: thread has bad beliefs
   _Atomic(enum PosixThreadStatus) pt_status;
-  _Atomic(int) ptid;          // transitions 0 → tid
+  atomic_int ptid;            // transitions 0 → tid
+  atomic_int pt_refs;         // negative means free
   void *(*pt_start)(void *);  // creation callback
   void *pt_arg;               // start's parameter
   void *pt_rc;                // start's return value
@@ -90,7 +92,7 @@ struct PosixThread {
   struct CosmoTib *tib;       // middle of tls allocation
   struct Dll list;            // list of threads
   struct _pthread_cleanup_buffer *pt_cleanup;
-  _Atomic(_Atomic(int) *) pt_blocker;
+  _Atomic(atomic_int *) pt_blocker;
   int64_t pt_semaphore;
   intptr_t pt_iohandle;
   void *pt_ioverlap;
@@ -119,6 +121,7 @@ void _pthread_onfork_prepare(void);
 void _pthread_ungarbage(void);
 void _pthread_unkey(struct CosmoTib *);
 void _pthread_unlock(void);
+void _pthread_unref(struct PosixThread *);
 void _pthread_unwind(struct PosixThread *);
 void _pthread_zombify(struct PosixThread *);
 
@@ -126,6 +129,10 @@ __funline pureconst struct PosixThread *_pthread_self(void) {
   return (struct PosixThread *)__get_tls()->tib_pthread;
 }
 
+__funline void _pthread_ref(struct PosixThread *pt) {
+  atomic_fetch_add_explicit(&pt->pt_refs, 1, memory_order_relaxed);
+}
+
 COSMOPOLITAN_C_END_
 #endif /* !(__ASSEMBLER__ + __LINKER__ + 0) */
 #endif /* COSMOPOLITAN_LIBC_THREAD_POSIXTHREAD_INTERNAL_H_ */
diff --git a/libc/thread/pthread_create.c b/libc/thread/pthread_create.c
index 794cb02e5ba..8ac15524178 100644
--- a/libc/thread/pthread_create.c
+++ b/libc/thread/pthread_create.c
@@ -17,7 +17,6 @@
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
 #include "libc/assert.h"
-#include "libc/atomic.h"
 #include "libc/calls/calls.h"
 #include "libc/calls/struct/sigset.h"
 #include "libc/calls/struct/sigset.internal.h"
@@ -26,7 +25,6 @@
 #include "libc/errno.h"
 #include "libc/fmt/itoa.h"
 #include "libc/intrin/asan.internal.h"
-#include "libc/intrin/atomic.h"
 #include "libc/intrin/bits.h"
 #include "libc/intrin/bsr.h"
 #include "libc/intrin/describeflags.internal.h"
@@ -67,6 +65,7 @@ __static_yoink("_pthread_atfork");
 #define MAP_STACK_OPENBSD 0x4000
 
 void _pthread_free(struct PosixThread *pt, bool isfork) {
+  unassert(dll_is_alone(&pt->list) && &pt->list != _pthread_list);
   if (pt->pt_flags & PT_STATIC) return;
   if (pt->pt_flags & PT_OWNSTACK) {
     unassert(!munmap(pt->pt_attr.__stackaddr, pt->pt_attr.__stacksize));
@@ -86,6 +85,26 @@ void _pthread_free(struct PosixThread *pt, bool isfork) {
   free(pt);
 }
 
+void _pthread_decimate(void) {
+  struct Dll *e;
+  struct PosixThread *pt;
+  enum PosixThreadStatus status;
+StartOver:
+  _pthread_lock();
+  for (e = dll_last(_pthread_list); e; e = dll_prev(_pthread_list, e)) {
+    pt = POSIXTHREAD_CONTAINER(e);
+    status = atomic_load_explicit(&pt->pt_status, memory_order_acquire);
+    if (status != kPosixThreadZombie) break;
+    if (!atomic_load_explicit(&pt->tib->tib_tid, memory_order_acquire)) {
+      dll_remove(&_pthread_list, e);
+      _pthread_unlock();
+      _pthread_unref(pt);
+      goto StartOver;
+    }
+  }
+  _pthread_unlock();
+}
+
 static int PosixThread(void *arg, int tid) {
   void *rc;
   struct PosixThread *pt = arg;
diff --git a/libc/thread/pthread_timedjoin_np.c b/libc/thread/pthread_timedjoin_np.c
index 5fea5416ab9..719ea9e3f3f 100644
--- a/libc/thread/pthread_timedjoin_np.c
+++ b/libc/thread/pthread_timedjoin_np.c
@@ -116,8 +116,7 @@ errno_t pthread_timedjoin_np(pthread_t thread, void **value_ptr,
     if (value_ptr) {
       *value_ptr = pt->pt_rc;
     }
-    _pthread_free(pt, false);
-    _pthread_decimate();
+    _pthread_unref(pt);
   }
   STRACE("pthread_timedjoin_np(%d, %s, %s) → %s", _pthread_tid(pt),
          DescribeReturnValue(alloca(30), err, value_ptr),
diff --git a/test/libc/calls/specialfile_test.c b/test/libc/calls/specialfile_test.c
new file mode 100644
index 00000000000..ebc750789fd
--- /dev/null
+++ b/test/libc/calls/specialfile_test.c
@@ -0,0 +1,82 @@
+/*-*- 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/dce.h"
+#include "libc/errno.h"
+#include "libc/nt/files.h"
+#include "libc/sysv/consts/f.h"
+#include "libc/sysv/consts/o.h"
+#include "libc/testlib/testlib.h"
+
+int pipefd[2];
+int stdoutBack;
+
+void SetUpOnce(void) {
+  testlib_enable_tmp_setup_teardown();
+}
+
+void CaptureStdout(void) {
+  ASSERT_NE(-1, (stdoutBack = dup(1)));
+  ASSERT_SYS(0, 0, pipe(pipefd));
+  ASSERT_NE(-1, dup2(pipefd[1], 1));
+}
+
+void RestoreStdout(void) {
+  ASSERT_SYS(0, 1, dup2(stdoutBack, 1));
+  ASSERT_SYS(0, 0, close(stdoutBack));
+  ASSERT_SYS(0, 0, close(pipefd[1]));
+  ASSERT_SYS(0, 0, close(pipefd[0]));
+}
+
+TEST(specialfile, devNull) {
+  ASSERT_SYS(0, 3, creat("/dev/null", 0644));
+  ASSERT_EQ(O_WRONLY, fcntl(3, F_GETFL) & ~O_LARGEFILE);
+  ASSERT_SYS(0, 2, write(3, "hi", 2));
+  ASSERT_SYS(0, 2, pwrite(3, "hi", 2, 0));
+  ASSERT_SYS(0, 2, pwrite(3, "hi", 2, 2));
+  ASSERT_SYS(0, 0, lseek(3, 0, SEEK_END));
+  ASSERT_SYS(0, 0, lseek(3, 0, SEEK_CUR));
+  if (!IsLinux()) {
+    // rhel7 doesn't have this behavior
+    ASSERT_SYS(0, 2, lseek(3, 2, SEEK_CUR));
+    ASSERT_SYS(0, 2, lseek(3, 2, SEEK_END));
+  }
+  ASSERT_SYS(0, 0, close(3));
+}
+
+TEST(specialfile, devNullRead) {
+  char buf[8] = {0};
+  ASSERT_SYS(0, 3, open("/dev/null", O_RDONLY));
+  ASSERT_EQ(O_RDONLY, fcntl(3, F_GETFL) & ~O_LARGEFILE);
+  ASSERT_SYS(0, 0, read(3, buf, 8));
+  ASSERT_SYS(0, 0, close(3));
+}
+
+TEST(specialfile, devStdout) {
+  char buf[8] = {8};
+  CaptureStdout();
+  ASSERT_SYS(0, 6, creat("/dev/stdout", 0644));
+  ASSERT_SYS(0, 2, write(6, "hi", 2));
+  ASSERT_EQ(2, read(pipefd[0], buf, 8));
+  ASSERT_STREQ("hi", buf);
+  ASSERT_SYS(ESPIPE, -1, pwrite(6, "hi", 2, 0));
+  ASSERT_SYS(ESPIPE, -1, lseek(6, 0, SEEK_END));
+  ASSERT_SYS(0, 0, close(6));
+  RestoreStdout();
+}
diff --git a/test/libc/proc/system_test.c b/test/libc/proc/system_test.c
index a7cdf6cc26b..f40e075c891 100644
--- a/test/libc/proc/system_test.c
+++ b/test/libc/proc/system_test.c
@@ -195,6 +195,15 @@ TEST(system, exitStatusPreservedAfterSemiColon) {
   RestoreStdout();
 }
 
+TEST(system, devStdout) {
+  CaptureStdout();
+  ASSERT_EQ(0, GETEXITSTATUS(system("echo sup >/dev/stdout")));
+  char buf[16] = {0};
+  ASSERT_EQ(4, read(pipefd[0], buf, 16));
+  ASSERT_STREQ("sup\n", buf);
+  RestoreStdout();
+}
+
 TEST(system, globio) {
   char buf[9] = {0};
   CaptureStdout();
diff --git a/third_party/nsync/futex.c b/third_party/nsync/futex.c
index 0bef7bcc883..7d651341859 100644
--- a/third_party/nsync/futex.c
+++ b/third_party/nsync/futex.c
@@ -169,10 +169,11 @@ static int nsync_futex_wait_win32_ (atomic_int *w, int expect, char pshare,
 			return 0;
 		}
 		if (pt) atomic_store_explicit (&pt->pt_blocker, w, memory_order_release);
-		if (_check_cancel() == -1) return -1;
-		if (_check_signal(false) == -1) return -1;
+		if (_check_cancel () == -1) return -1;
+		if (_check_signal (false) == -1) return -1;
 		ok = WaitOnAddress (w, &expect, sizeof(int), timespec_tomillis (wait));
-		if (_check_cancel() == -1) return -1;
+		if (_check_signal (false) == -1) { _check_cancel (); return -1; }
+		if (_check_cancel () == -1) return -1;
 		if (ok) {
 			return 0;
 		} else {
diff --git a/tool/build/runitd.c b/tool/build/runitd.c
index 87269f8f34d..e0e14f12218 100644
--- a/tool/build/runitd.c
+++ b/tool/build/runitd.c
@@ -620,9 +620,8 @@ void *ClientWorker(void *arg) {
           goto TerminateJob;
         }
         if (received > 0) {
-          WARNF("%s client sent %d unexpected bytes so killing job", origname,
-                received);
-          goto HangupClientAndTerminateJob;
+          WARNF("%s client sent %d unexpected bytes", origname, received);
+          continue;
         }
         if (received == MBEDTLS_ERR_SSL_WANT_READ) {  // EAGAIN SO_RCVTIMEO
           WARNF("%s (pid %d) is taking a really long time", origname,
diff --git a/tool/net/redbean.c b/tool/net/redbean.c
index 37bd88be521..d6e330a10a8 100644
--- a/tool/net/redbean.c
+++ b/tool/net/redbean.c
@@ -178,14 +178,18 @@ __static_yoink("blink_xnu_aarch64");    // is apple silicon
 #define MONITOR_MICROS   150000
 #define READ(F, P, N)    readv(F, &(struct iovec){P, N}, 1)
 #define WRITE(F, P, N)   writev(F, &(struct iovec){P, N}, 1)
-#define LockInc(P)       (*(_Atomic(typeof(*(P))) *)(P))++
-#define LockDec(P)       (*(_Atomic(typeof(*(P))) *)(P))--
 #define AppendCrlf(P)    mempcpy(P, "\r\n", 2)
 #define HasHeader(H)     (!!cpm.msg.headers[H].a)
 #define HeaderData(H)    (inbuf.p + cpm.msg.headers[H].a)
 #define HeaderLength(H)  (cpm.msg.headers[H].b - cpm.msg.headers[H].a)
 #define HeaderEqualCase(H, S) \
   SlicesEqualCase(S, strlen(S), HeaderData(H), HeaderLength(H))
+#define LockInc(P)                                            \
+  atomic_fetch_add_explicit((_Atomic(typeof(*(P))) *)(P), +1, \
+                            memory_order_relaxed)
+#define LockDec(P)                                            \
+  atomic_fetch_add_explicit((_Atomic(typeof(*(P))) *)(P), -1, \
+                            memory_order_relaxed)
 
 #define TRACE_BEGIN         \
   do {                      \
diff --git a/tool/net/winbench.c b/tool/net/winbench.c
index a7bed81d58b..fb3979a1e0d 100644
--- a/tool/net/winbench.c
+++ b/tool/net/winbench.c
@@ -60,7 +60,6 @@ static char msg[128];
 static uint32_t msglen;
 static const char *prog;
 static atomic_int a_termsig;
-static atomic_long a_errors;
 static atomic_long a_requests;
 static atomic_bool a_finished;
 
@@ -125,23 +124,21 @@ static void NewClient(struct Client *client, const struct sockaddr_in *addr) {
 
 static void *Worker(void *arg) {
   while (!a_finished) {
-    bool32 ok;
+    uint32_t i;
     uint32_t dwFlags;
-    uint32_t dwBytes;
-    struct Client *client;
-    uint64_t CompletionKey;
-    struct NtOverlapped *lpOverlapped;
-    if (!(ok = GetQueuedCompletionStatus(iocp, &dwBytes, &CompletionKey,
-                                         &lpOverlapped, -1u)) &&
-        !lpOverlapped) {
+    uint32_t dwRecordCount;
+    struct NtOverlappedEntry records[8];
+    if (!GetQueuedCompletionStatusEx(iocp, records, ARRAYLEN(records),
+                                     &dwRecordCount, -1u, false)) {
       fprintf(stderr, "GetQueuedCompletionStatus() failed w/ %d\n",
               GetLastError());
       exit(1);
     }
-    client = (struct Client *)CompletionKey;
-    switch (client->state) {
-      case SENDING:
-        if (ok) {
+    for (i = 0; i < dwRecordCount; ++i) {
+      uint32_t dwBytes = records[i].dwNumberOfBytesTransferred;
+      struct Client *client = (struct Client *)records[i].lpCompletionKey;
+      switch (client->state) {
+        case SENDING:
           dwFlags = 0;
           client->state = RECEIVING;
           client->iov.buf = client->buf;
@@ -153,15 +150,8 @@ static void *Worker(void *arg) {
             fprintf(stderr, "WSARecv() failed w/ %d\n", WSAGetLastError());
             exit(1);
           }
-        } else {
-          fprintf(stderr, "WSAConnect() or WSASend() failed w/ %d\n",
-                  WSAGetLastError());
-          __imp_closesocket(client->handle);
-          ++a_errors;
-        }
-        break;
-      case RECEIVING:
-        if (ok) {
+          break;
+        case RECEIVING:
           if (!dwBytes) {
             fprintf(stderr, "got disconnect\n");
             break;
@@ -183,14 +173,10 @@ static void *Worker(void *arg) {
             fprintf(stderr, "WSASend() failed w/ %d\n", WSAGetLastError());
             exit(1);
           }
-        } else {
-          fprintf(stderr, "WSARecv() failed w/ %d\n", WSAGetLastError());
-          __imp_closesocket(client->handle);
-          ++a_errors;
-        }
-        break;
-      default:
-        __builtin_unreachable();
+          break;
+        default:
+          __builtin_unreachable();
+      }
     }
   }
   return 0;
@@ -209,12 +195,12 @@ int main(int argc, char *argv[]) {
 
   prog = argv[0];
   if (!prog) {
-    prog = "ab";
+    prog = "winbench";
   }
 
   int opt;
-  int nclients = 20;
-  int nthreads = GetMaximumProcessorCount(0xffff) * 2;
+  int nclients = 1000;
+  int nthreads = GetMaximumProcessorCount(0xffff);
   struct sockaddr_in destaddr = {AF_INET, htons(8080), {htonl(0x7f000001)}};
   while ((opt = getopt(argc, argv, "hH:P:")) != -1) {
     switch (opt) {
@@ -280,7 +266,7 @@ int main(int argc, char *argv[]) {
     NewClient(clients + i, &destaddr);
   }
 
-  sleep(5);
+  sleep(10);
 
   a_finished = true;
   long request_count = a_requests;