Linux: refactor zygote support

chrome/browser/zygote_host_linux.h

+// Copyright (c) 2009 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CHROME_BROWSER_ZYGOTE_HOST_LINUX_H_
+#define CHROME_BROWSER_ZYGOTE_HOST_LINUX_H_
+
+#include <string>
+#include <vector>
+
+#include "base/global_descriptors_posix.h"
+#include "base/singleton.h"
+
+// http://code.google.com/p/chromium/wiki/LinuxZygote
+
+// The zygote host is the interface, in the browser process, to the zygote
+// process.
+class ZygoteHost {
+ public:
+  ~ZygoteHost();
+
+  pid_t ForkRenderer(const std::vector<std::string>& command_line,
+                     const base::GlobalDescriptors::Mapping& mapping);
+  void EnsureProcessTerminated(pid_t process);
+
+  // These are the command codes used on the wire between the browser and the
+  // zygote.
+  enum {
+    kCmdFork = 0,  // Fork off a new renderer.
+    kCmdReap = 1,  // Reap a renderer child.
+  };
+
+ private:
+  friend struct DefaultSingletonTraits<ZygoteHost>;
+  ZygoteHost();
+  void LaunchZygoteProcess();
+
+  int control_fd_;  // the socket to the zygote
+};
+
+#endif  // CHROME_BROWSER_ZYGOTE_HOST_LINUX_H_