Create the fcntl.h portability header

Summary: Windows has it, but all it does is define a few constants.

Reviewed By: yfeldblum

Differential Revision: D3002161

fb-gh-sync-id: a719faf391125522b2cb21471a56e8a9fe894225
fbshipit-source-id: a719faf391125522b2cb21471a56e8a9fe894225

folly/Makefile.am

@@ -278,6 +278,7 @@ nobase_follyinclude_HEADERS = \
 	portability/Constexpr.h \
 	portability/Dirent.h \
 	portability/Environment.h \
+	portability/Fcntl.h \
 	portability/GFlags.h \
 	portability/IOVec.h \
 	portability/Libgen.h \
@@ -426,6 +427,7 @@ libfolly_la_SOURCES = \
 	MemoryMapping.cpp \
 	portability/Dirent.cpp \
 	portability/Environment.cpp \
+	portability/Fcntl.cpp \
 	portability/Libgen.cpp \
 	portability/Malloc.cpp \
 	portability/Memory.cpp \

folly/portability/Fcntl.cpp

+/*
+ * Copyright 2016 Facebook, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <folly/portability/Fcntl.h>
+
+#ifdef _WIN32
+#include <folly/portability/Sockets.h>
+#include <folly/portability/Windows.h>
+
+namespace folly {
+namespace portability {
+namespace fcntl {
+int creat(char const* fn, int pm) { return _creat(fn, pm); }
+
+int fcntl(int fd, int cmd, ...) {
+  va_list args;
+  int res = -1;
+  va_start(args, cmd);
+  switch (cmd) {
+    case F_GETFD: {
+      HANDLE h = (HANDLE)_get_osfhandle(fd);
+      if (h != INVALID_HANDLE_VALUE) {
+        DWORD flags;
+        if (GetHandleInformation(h, &flags)) {
+          res = flags & HANDLE_FLAG_INHERIT;
+        }
+      }
+      break;
+    }
+    case F_SETFD: {
+      int flags = va_arg(args, int);
+      HANDLE h = (HANDLE)_get_osfhandle(fd);
+      if (h != INVALID_HANDLE_VALUE) {
+        if (SetHandleInformation(
+                h, HANDLE_FLAG_INHERIT, (DWORD)(flags & FD_CLOEXEC))) {
+          res = 0;
+        }
+      }
+      break;
+    }
+    case F_GETFL: {
+      // No idea how to get the IO blocking mode, so return 0.
+      res = 0;
+      break;
+    }
+    case F_SETFL: {
+      int flags = va_arg(args, int);
+      if (flags & O_NONBLOCK) {
+        // If it's not a socket, it's probably a pipe, and
+        // those are non-blocking by default with Windows.
+        if (folly::portability::sockets::is_fh_socket(fd)) {
+          SOCKET s = (SOCKET)_get_osfhandle(fd);
+          if (s != INVALID_SOCKET) {
+            u_long nonBlockingEnabled = 1;
+            res = ioctlsocket(s, FIONBIO, &nonBlockingEnabled);
+          }
+        } else {
+          res = 0;
+        }
+      }
+      break;
+    }
+  }
+  va_end(args);
+  return res;
+}
+
+int open(char const* fn, int of, int pm) {
+  int fh;
+  errno_t res = _sopen_s(&fh, fn, of, _SH_DENYNO, pm);
+  return res ? -1 : fh;
+}
+
+int posix_fallocate(int fd, off_t offset, off_t len) {
+  // We'll pretend we always have enough space. We
+  // can't exactly pre-allocate on windows anyways.
+  return 0;
+}
+}
+}
+}
+#endif

folly/portability/Fcntl.h

+/*
+ * Copyright 2016 Facebook, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include <fcntl.h>
+
+#ifdef _WIN32
+#include <sys/types.h>
+
+// I have no idea what the normal values for these are,
+// and really don't care what they are. They're only used
+// within fcntl, so it's not an issue.
+#define FD_CLOEXEC HANDLE_FLAG_INHERIT
+#define O_NONBLOCK 1
+#define F_GETFD 1
+#define F_SETFD 2
+#define F_GETFL 3
+#define F_SETFL 4
+
+#ifdef HAVE_POSIX_FALLOCATE
+#undef HAVE_POSIX_FALLOCATE
+#endif
+#define HAVE_POSIX_FALLOCATE 1
+
+// See portability/Unistd.h for why these need to be in a namespace
+// rather then extern "C".
+namespace folly {
+namespace portability {
+namespace fcntl {
+int creat(char const* fn, int pm);
+int fcntl(int fd, int cmd, ...);
+int posix_fallocate(int fd, off_t offset, off_t len);
+int open(char const* fn, int of, int pm = 0);
+}
+}
+}
+
+/* using override */ using namespace folly::portability::fcntl;
+#endif