1 files changed, 109 insertions, 0 deletions
diff --git a/ipc/glue/FileDescriptorUtils.cpp b/ipc/glue/FileDescriptorUtils.cpp
new file mode 100644
index 0000000000..e4af78e79e
--- /dev/null
+++ b/ipc/glue/FileDescriptorUtils.cpp
@@ -0,0 +1,109 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "FileDescriptorUtils.h"
+
+#include "nsIEventTarget.h"
+
+#include "nsCOMPtr.h"
+#include "nsDebug.h"
+#include "nsNetCID.h"
+#include "nsServiceManagerUtils.h"
+#include "prio.h"
+#include "private/pprio.h"
+
+#include <errno.h>
+#ifdef XP_WIN
+#  include <io.h>
+#else
+#  include <unistd.h>
+#endif
+
+using mozilla::ipc::CloseFileRunnable;
+
+CloseFileRunnable::CloseFileRunnable(const FileDescriptor& aFileDescriptor)
+    : Runnable("CloseFileRunnable"), mFileDescriptor(aFileDescriptor) {
+  MOZ_ASSERT(aFileDescriptor.IsValid());
+}
+
+CloseFileRunnable::~CloseFileRunnable() {
+  if (mFileDescriptor.IsValid()) {
+    // It's probably safer to take the main thread IO hit here rather than leak
+    // the file descriptor.
+    CloseFile();
+  }
+}
+
+NS_IMPL_ISUPPORTS_INHERITED0(CloseFileRunnable, Runnable)
+
+void CloseFileRunnable::Dispatch() {
+  nsCOMPtr<nsIEventTarget> eventTarget =
+      do_GetService(NS_STREAMTRANSPORTSERVICE_CONTRACTID);
+  NS_ENSURE_TRUE_VOID(eventTarget);
+
+  nsresult rv = eventTarget->Dispatch(this, NS_DISPATCH_NORMAL);
+  NS_ENSURE_SUCCESS_VOID(rv);
+}
+
+void CloseFileRunnable::CloseFile() {
+  // It's possible for this to happen on the main thread if the dispatch to the
+  // stream service fails so we can't assert the thread on which we're running.
+  mFileDescriptor = FileDescriptor();
+}
+
+NS_IMETHODIMP
+CloseFileRunnable::Run() {
+  MOZ_ASSERT(!NS_IsMainThread());
+
+  CloseFile();
+  return NS_OK;
+}
+
+namespace mozilla {
+namespace ipc {
+
+FILE* FileDescriptorToFILE(const FileDescriptor& aDesc, const char* aOpenMode) {
+  if (!aDesc.IsValid()) {
+    errno = EBADF;
+    return nullptr;
+  }
+  auto handle = aDesc.ClonePlatformHandle();
+#ifdef XP_WIN
+  int fd = _open_osfhandle(static_cast<intptr_t>(handle.get()), 0);
+  if (fd == -1) {
+    return nullptr;
+  }
+  Unused << handle.release();
+#else
+  int fd = handle.release();
+#endif
+  FILE* file = fdopen(fd, aOpenMode);
+  if (!file) {
+    int saved_errno = errno;
+    close(fd);
+    errno = saved_errno;
+  }
+  return file;
+}
+
+FileDescriptor FILEToFileDescriptor(FILE* aStream) {
+  if (!aStream) {
+    errno = EBADF;
+    return FileDescriptor();
+  }
+#ifdef XP_WIN
+  int fd = _fileno(aStream);
+  if (fd == -1) {
+    return FileDescriptor();
+  }
+  return FileDescriptor(reinterpret_cast<HANDLE>(_get_osfhandle(fd)));
+#else
+  return FileDescriptor(fileno(aStream));
+#endif
+}
+
+}  // namespace ipc
+}  // namespace mozilla