chrome/common/service_process_util.h

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef CHROME_COMMON_SERVICE_PROCESS_UTIL_H_
   6 #define CHROME_COMMON_SERVICE_PROCESS_UTIL_H_
   7
   8 #include <string>
   9
  10 #include "base/basictypes.h"
  11 #include "base/callback_forward.h"
  12 #include "base/memory/scoped_ptr.h"
  13 #include "base/memory/shared_memory.h"
  14 #include "base/process/process.h"
  15 #include "ipc/ipc_channel_handle.h"
  16
  17 class MultiProcessLock;
  18
  19 #if defined(OS_MACOSX)
  20 #ifdef __OBJC__
  21 @class NSString;
  22 #else
  23 class NSString;
  24 #endif
  25 #endif
  26
  27 namespace base {
  28 class CommandLine;
  29 class MessageLoopProxy;
  30 }
  31
  32 // Return the IPC channel to connect to the service process.
  33 IPC::ChannelHandle GetServiceProcessChannel();
  34
  35 // Return a name that is scoped to this instance of the service process. We
  36 // use the user-data-dir as a scoping prefix.
  37 std::string GetServiceProcessScopedName(const std::string& append_str);
  38
  39 #if !defined(OS_MACOSX)
  40 // Return a name that is scoped to this instance of the service process. We
  41 // use the user-data-dir and the version as a scoping prefix.
  42 std::string GetServiceProcessScopedVersionedName(const std::string& append_str);
  43 #endif  // !OS_MACOSX
  44
  45 #if defined(OS_POSIX)
  46 // Attempts to take a lock named |name|. If |waiting| is true then this will
  47 // make multiple attempts to acquire the lock.
  48 // Caller is responsible for ownership of the MultiProcessLock.
  49 MultiProcessLock* TakeNamedLock(const std::string& name, bool waiting);
  50 #endif
  51
  52 // The following methods are used in a process that acts as a client to the
  53 // service process (typically the browser process).
  54 // --------------------------------------------------------------------------
  55 // This method checks that if the service process is ready to receive
  56 // IPC commands.
  57 bool CheckServiceProcessReady();
  58
  59 // Returns the process id and version of the currently running service process.
  60 // Note: DO NOT use this check whether the service process is ready because
  61 // a true return value only means that some process shared data was available,
  62 // and not that the process is ready to receive IPC commands, or even running.
  63 // This method is only exposed for testing.
  64 bool GetServiceProcessData(std::string* version, base::ProcessId* pid);
  65 // --------------------------------------------------------------------------
  66
  67 // Forces a service process matching the specified version to shut down.
  68 bool ForceServiceProcessShutdown(const std::string& version,
  69                                  base::ProcessId process_id);
  70
  71 // Creates command-line to run the service process.
  72 scoped_ptr<base::CommandLine> CreateServiceProcessCommandLine();
  73
  74 // This is a class that is used by the service process to signal events and
  75 // share data with external clients. This class lives in this file because the
  76 // internal data structures and mechanisms used by the utility methods above
  77 // and this class are shared.
  78 class ServiceProcessState {
  79  public:
  80   ServiceProcessState();
  81   ~ServiceProcessState();
  82
  83   // Tries to become the sole service process for the current user data dir.
  84   // Returns false if another service process is already running.
  85   bool Initialize();
  86
  87   // Signal that the service process is ready.
  88   // This method is called when the service process is running and initialized.
  89   // |terminate_task| is invoked when we get a terminate request from another
  90   // process (in the same thread that called SignalReady). It can be NULL.
  91   // |message_loop_proxy| must be of type IO and is the loop that POSIX uses
  92   // to monitor the service process.
  93   bool SignalReady(
  94       base::MessageLoopProxy* message_loop_proxy,
  95       const base::Closure& terminate_task);
  96
  97   // Signal that the service process is stopped.
  98   void SignalStopped();
  99
 100   // Register the service process to run on startup.
 101   bool AddToAutoRun();
 102
 103   // Unregister the service process to run on startup.
 104   bool RemoveFromAutoRun();
 105
 106   // Return the channel handle used for communicating with the service.
 107   IPC::ChannelHandle GetServiceProcessChannel();
 108
 109  private:
 110 #if !defined(OS_MACOSX)
 111   // Create the shared memory data for the service process.
 112   bool CreateSharedData();
 113
 114   // If an older version of the service process running, it should be shutdown.
 115   // Returns false if this process needs to exit.
 116   bool HandleOtherVersion();
 117
 118   // Acquires a singleton lock for the service process. A return value of false
 119   // means that a service process instance is already running.
 120   bool TakeSingletonLock();
 121 #endif  // !OS_MACOSX
 122
 123   // Creates the platform specific state.
 124   void CreateState();
 125
 126   // Tear down the platform specific state.
 127   void TearDownState();
 128
 129   // An opaque object that maintains state. The actual definition of this is
 130   // platform dependent.
 131   struct StateData;
 132   StateData* state_;
 133   scoped_ptr<base::SharedMemory> shared_mem_service_data_;
 134   scoped_ptr<base::CommandLine> autorun_command_line_;
 135 };
 136
 137 #endif  // CHROME_COMMON_SERVICE_PROCESS_UTIL_H_