Linux: tear down Zygote at browser shutdown.

content/browser/zygote_host/zygote_host_impl_linux.h

 // Copyright (c) 2012 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 CONTENT_BROWSER_ZYGOTE_HOST_ZYGOTE_HOST_IMPL_LINUX_H_
 #define CONTENT_BROWSER_ZYGOTE_HOST_ZYGOTE_HOST_IMPL_LINUX_H_
 
+#include <set>
 #include <string>
 #include <vector>
 
 #include "base/pickle.h"
 #include "base/process/kill.h"
 #include "base/synchronization/lock.h"
 #include "content/public/browser/file_descriptor_info.h"
 #include "content/public/browser/zygote_host_linux.h"
 
 template<typename Type>
 struct DefaultSingletonTraits;
 
 namespace content {
 
 class CONTENT_EXPORT ZygoteHostImpl : public ZygoteHost {
  public:
   // Returns the singleton instance.
   static ZygoteHostImpl* GetInstance();
 
   void Init(const std::string& sandbox_cmd);
 
+  // After the last known Zygote child exits, notify the Zygote to exit.
+  void TearDownAfterLastChild();
+
   // Tries to start a process of type indicated by process_type.
   // Returns its pid on success, otherwise
   // base::kNullProcessHandle;
   pid_t ForkRequest(const std::vector<std::string>& command_line,
                     const std::vector<FileDescriptorInfo>& mapping,
                     const std::string& process_type);
   void EnsureProcessTerminated(pid_t process);
 
   // Get the termination status (and, optionally, the exit code) of
   // the process. |exit_code| is set to the exit code of the child
@@ skipping 16 matching lines @@
   virtual int GetSandboxStatus() const OVERRIDE;
   virtual void AdjustRendererOOMScore(base::ProcessHandle process_handle,
                                       int score) OVERRIDE;
 
  private:
   friend struct DefaultSingletonTraits<ZygoteHostImpl>;
 
   ZygoteHostImpl();
   virtual ~ZygoteHostImpl();
 
+  // Notify the Zygote to exit immediately. This object should not be
+  // used afterwards.
+  void TearDown();
+
+  // Should be called every time a Zygote child is born.
+  void ZygoteChildBorn(pid_t process);
+
+  // Should be called every time a Zygote child died.
+  void ZygoteChildDied(pid_t process);
+
   // Sends |data| to the zygote via |control_fd_|.  If |fds| is non-NULL, the
   // included file descriptors will also be passed.  The caller is responsible
   // for acquiring |control_lock_|.
   bool SendMessage(const Pickle& data, const std::vector<int>* fds);
 
   ssize_t ReadReply(void* buf, size_t buflen);
 
   int control_fd_;  // the socket to the zygote
   // A lock protecting all communication with the zygote. This lock must be
   // acquired before sending a command and released after the result has been
   // received.
   base::Lock control_lock_;
   pid_t pid_;
   bool init_;
   bool using_suid_sandbox_;
   std::string sandbox_binary_;
   bool have_read_sandbox_status_word_;
   int sandbox_status_;
+  // A lock protecting list_of_running_zygote_children_ and
+  // should_teardown_after_last_child_exits_.
+  base::Lock child_tracking_lock_;
+  std::set<pid_t> list_of_running_zygote_children_;
+  bool should_teardown_after_last_child_exits_;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_ZYGOTE_HOST_ZYGOTE_HOST_IMPL_LINUX_H_