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// 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_CHILD_PROCESS_LAUNCHER_H_
#define CONTENT_BROWSER_CHILD_PROCESS_LAUNCHER_H_
#include "base/basictypes.h"
#include "base/files/scoped_file.h"
#include "base/memory/weak_ptr.h"
#include "base/process/kill.h"
#include "base/process/launch.h"
#include "base/process/process.h"
#include "base/threading/non_thread_safe.h"
#include "content/common/content_export.h"
#include "content/public/browser/browser_thread.h"
namespace base {
class CommandLine;
}
namespace content {
class SandboxedProcessLauncherDelegate;
// Launches a process asynchronously and notifies the client of the process
// handle when it's available. It's used to avoid blocking the calling thread
// on the OS since often it can take > 100 ms to create the process.
class CONTENT_EXPORT ChildProcessLauncher : public base::NonThreadSafe {
public:
class CONTENT_EXPORT Client {
public:
// Will be called on the thread that the ChildProcessLauncher was
// constructed on.
virtual void OnProcessLaunched() = 0;
virtual void OnProcessLaunchFailed() {};
protected:
virtual ~Client() {}
};
// Launches the process asynchronously, calling the client when the result is
// ready. Deleting this object before the process is created is safe, since
// the callback won't be called. If the process is still running by the time
// this object destructs, it will be terminated.
// Takes ownership of cmd_line.
ChildProcessLauncher(
SandboxedProcessLauncherDelegate* delegate,
base::CommandLine* cmd_line,
int child_process_id,
Client* client,
bool terminate_on_shutdown = true);
~ChildProcessLauncher();
// True if the process is being launched and so the handle isn't available.
bool IsStarting();
// Getter for the process. Only call after the process has started.
const base::Process& GetProcess() const;
// Call this when the child process exits to know what happened to it.
// |known_dead| can be true if we already know the process is dead as it can
// help the implemention figure the proper TerminationStatus.
// On Linux, the use of |known_dead| is subtle and can be crucial if an
// accurate status is important. With |known_dead| set to false, a dead
// process could be seen as running. With |known_dead| set to true, the
// process will be killed if it was still running. See ZygoteHostImpl for
// more discussion of Linux implementation details.
// |exit_code| is the exit code of the process if it exited (e.g. status from
// waitpid if on posix, from GetExitCodeProcess on Windows). |exit_code| may
// be NULL.
base::TerminationStatus GetChildTerminationStatus(bool known_dead,
int* exit_code);
// Changes whether the process runs in the background or not. Only call
// this after the process has started.
void SetProcessBackgrounded(bool background);
// Replaces the ChildProcessLauncher::Client for testing purposes. Returns the
// previous client.
Client* ReplaceClientForTest(Client* client);
private:
// Posts a task to the launcher thread to do the actual work.
void Launch(SandboxedProcessLauncherDelegate* delegate,
base::CommandLine* cmd_line,
int child_process_id);
void UpdateTerminationStatus(bool known_dead);
// This is always called on the client thread after an attempt
// to launch the child process on the launcher thread.
// It makes sure we always perform the necessary cleanup if the
// client went away.
static void DidLaunch(base::WeakPtr<ChildProcessLauncher> instance,
bool terminate_on_shutdown,
bool zygote,
#if defined(OS_ANDROID)
base::ScopedFD ipcfd,
#endif
base::Process process);
// Notifies the client about the result of the operation.
void Notify(bool zygote,
#if defined(OS_ANDROID)
base::ScopedFD ipcfd,
#endif
base::Process process);
#if defined(MOJO_SHELL_CLIENT)
// When this process is run from an external Mojo shell, this function will
// create a channel and pass one end to the spawned process and register the
// other end with the external shell, allowing the spawned process to bind an
// Application request from the shell.
void CreateMojoShellChannel(base::CommandLine* command_line,
int child_process_id);
#endif
Client* client_;
BrowserThread::ID client_thread_id_;
base::Process process_;
base::TerminationStatus termination_status_;
int exit_code_;
bool zygote_;
bool starting_;
// Controls whether the child process should be terminated on browser
// shutdown. Default behavior is to terminate the child.
const bool terminate_child_on_shutdown_;
base::WeakPtrFactory<ChildProcessLauncher> weak_factory_;
DISALLOW_COPY_AND_ASSIGN(ChildProcessLauncher);
};
} // namespace content
#endif // CONTENT_BROWSER_CHILD_PROCESS_LAUNCHER_H_