system/FileDescriptor: implement CreatePipe() on Windows

src/system/FileDescriptor.cxx

@@ -99,6 +99,8 @@ FileDescriptor::OpenNonBlocking(const char *pathname) noexcept
 	return Open(pathname, O_RDWR | O_NONBLOCK);
 }
 
+#endif
+
 bool
 FileDescriptor::CreatePipe(FileDescriptor &r, FileDescriptor &w) noexcept
 {
@@ -107,6 +109,8 @@ FileDescriptor::CreatePipe(FileDescriptor &r, FileDescriptor &w) noexcept
 #ifdef HAVE_PIPE2
 	const int flags = O_CLOEXEC;
 	const int result = pipe2(fds, flags);
+#elif defined(_WIN32)
+	const int result = _pipe(fds, 512, _O_BINARY);
 #else
 	const int result = pipe(fds);
 #endif
@@ -119,6 +123,8 @@ FileDescriptor::CreatePipe(FileDescriptor &r, FileDescriptor &w) noexcept
 	return true;
 }
 
+#ifndef _WIN32
+
 void
 FileDescriptor::SetNonBlocking() noexcept
 {

src/system/FileDescriptor.hxx

@@ -110,9 +110,11 @@ public:
 
 #ifndef WIN32
 	bool OpenNonBlocking(const char *pathname) noexcept;
+#endif
 
 	static bool CreatePipe(FileDescriptor &r, FileDescriptor &w) noexcept;
 
+#ifndef _WIN32
 	/**
 	 * Enable non-blocking mode on this file descriptor.
 	 */