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// 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.
#include "chrome/browser/child_process_launcher.h"
#include "base/command_line.h"
#include "base/lazy_instance.h"
#include "base/logging.h"
#include "base/scoped_ptr.h"
#include "base/thread.h"
#include "chrome/browser/chrome_thread.h"
#include "chrome/common/chrome_descriptors.h"
#include "chrome/common/chrome_switches.h"
#include "chrome/common/process_watcher.h"
#include "chrome/common/result_codes.h"
#include "ipc/ipc_sync_channel.h"
#if defined(OS_WIN)
#include "chrome/browser/sandbox_policy.h"
#elif defined(OS_LINUX)
#include "base/singleton.h"
#include "chrome/browser/crash_handler_host_linux.h"
#include "chrome/browser/zygote_host_linux.h"
#include "chrome/browser/renderer_host/render_sandbox_host_linux.h"
#endif
namespace {
class LauncherThread : public base::Thread {
public:
LauncherThread() : base::Thread("LauncherThread") { }
};
static base::LazyInstance<LauncherThread> launcher(base::LINKER_INITIALIZED);
}
// Having the functionality of ChildProcessLauncher be in an internal
// ref counted object allows us to automatically terminate the process when the
// parent class destructs, while still holding on to state that we need.
class ChildProcessLauncher::Context
: public base::RefCountedThreadSafe<ChildProcessLauncher::Context> {
public:
Context() : starting_(true), zygote_(false) {}
void Launch(CommandLine* cmd_line, int ipcfd, Client* client) {
client_ = client;
CHECK(ChromeThread::GetCurrentThreadIdentifier(&client_thread_id_));
if (!launcher.Get().message_loop())
launcher.Get().Start();
launcher.Get().message_loop()->PostTask(
FROM_HERE,
NewRunnableMethod(
this, &Context::LaunchInternal, ipcfd, cmd_line));
}
void ResetClient() {
// No need for locking as this function gets called on the same thread that
// client_ would be used.
CHECK(ChromeThread::CurrentlyOn(client_thread_id_));
client_ = NULL;
}
private:
friend class base::RefCountedThreadSafe<ChildProcessLauncher::Context>;
friend class ChildProcessLauncher;
~Context() {
Terminate();
}
void LaunchInternal(int ipcfd, CommandLine* cmd_line) {
scoped_ptr<CommandLine> cmd_line_deleter(cmd_line);
base::ProcessHandle handle = base::kNullProcessHandle;
bool zygote = false;
#if defined(OS_WIN)
handle = sandbox::StartProcess(cmd_line);
#elif defined(OS_POSIX)
#if defined(OS_LINUX)
// On Linux, normally spawn processes with zygotes. We can't do this when
// we're spawning child processes through an external program (i.e. there is
// a command prefix) like GDB so fall through to the POSIX case then.
if (!CommandLine::ForCurrentProcess()->HasSwitch(
switches::kRendererCmdPrefix)) {
zygote = true;
base::GlobalDescriptors::Mapping mapping;
mapping.push_back(std::pair<uint32_t, int>(kPrimaryIPCChannel, ipcfd));
const int crash_signal_fd =
Singleton<RendererCrashHandlerHostLinux>()->GetDeathSignalSocket();
if (crash_signal_fd >= 0) {
mapping.push_back(std::pair<uint32_t, int>(kCrashDumpSignal,
crash_signal_fd));
}
handle = Singleton<ZygoteHost>()->ForkRenderer(cmd_line->argv(), mapping);
}
#endif
if (!zygote) {
base::file_handle_mapping_vector fds_to_map;
fds_to_map.push_back(std::make_pair(ipcfd, kPrimaryIPCChannel + 3));
#if defined(OS_LINUX)
// On Linux, we need to add some extra file descriptors for crash handling
// and the sandbox.
const int crash_signal_fd =
Singleton<RendererCrashHandlerHostLinux>()->GetDeathSignalSocket();
if (crash_signal_fd >= 0) {
fds_to_map.push_back(std::make_pair(crash_signal_fd,
kCrashDumpSignal + 3));
}
const int sandbox_fd =
Singleton<RenderSandboxHostLinux>()->GetRendererSocket();
fds_to_map.push_back(std::make_pair(sandbox_fd, kSandboxIPCChannel + 3));
#endif // defined(OS_LINUX)
// Actually launch the app.
if (!base::LaunchApp(cmd_line->argv(), fds_to_map, false, &handle))
handle = base::kNullProcessHandle;
}
#endif
ChromeThread::PostTask(
client_thread_id_, FROM_HERE,
NewRunnableMethod(
this, &ChildProcessLauncher::Context::Notify, handle, zygote));
}
void Notify(base::ProcessHandle handle, bool zygote) {
starting_ = false;
process_.set_handle(handle);
zygote_ = zygote;
if (client_) {
client_->OnProcessLaunched();
} else {
Terminate();
}
}
void Terminate() {
if (!process_.handle())
return;
// On Posix, EnsureProcessTerminated can lead to 2 seconds of sleep! So
// don't this on the UI/IO threads.
launcher.Get().message_loop()->PostTask(
FROM_HERE,
NewRunnableFunction(
&ChildProcessLauncher::Context::TerminateInternal,
process_.handle(), zygote_));
process_.set_handle(base::kNullProcessHandle);
}
static void TerminateInternal(base::ProcessHandle handle, bool zygote) {
base::Process process(handle);
// Client has gone away, so just kill the process. Using exit code 0
// means that UMA won't treat this as a crash.
process.Terminate(ResultCodes::NORMAL_EXIT);
// On POSIX, we must additionally reap the child.
#if defined(OS_POSIX)
if (zygote) {
#if defined(OS_LINUX)
// If the renderer was created via a zygote, we have to proxy the reaping
// through the zygote process.
Singleton<ZygoteHost>()->EnsureProcessTerminated(handle);
#endif // defined(OS_LINUX)
} else {
ProcessWatcher::EnsureProcessTerminated(handle);
}
#endif
process.Close();
}
Client* client_;
ChromeThread::ID client_thread_id_;
base::Process process_;
bool starting_;
bool zygote_;
};
ChildProcessLauncher::ChildProcessLauncher(CommandLine* cmd_line,
IPC::SyncChannel* channel,
Client* client) {
context_ = new Context();
int ipcfd = 0;
#if defined(OS_POSIX)
ipcfd = channel->GetClientFileDescriptor();
#endif
context_->Launch(cmd_line, ipcfd, client);
}
ChildProcessLauncher::~ChildProcessLauncher() {
context_->ResetClient();
}
bool ChildProcessLauncher::IsStarting() {
return context_->starting_;
}
base::ProcessHandle ChildProcessLauncher::GetHandle() {
DCHECK(!context_->starting_);
return context_->process_.handle();
}
bool ChildProcessLauncher::DidProcessCrash() {
bool did_crash, child_exited;
base::ProcessHandle handle = context_->process_.handle();
#if defined(OS_LINUX)
if (context_->zygote_) {
did_crash = Singleton<ZygoteHost>()->DidProcessCrash(handle, &child_exited);
} else
#endif
{
did_crash = base::DidProcessCrash(&child_exited, handle);
}
// POSIX: If the process crashed, then the kernel closed the socket for it
// and so the child has already died by the time we get here. Since
// DidProcessCrash called waitpid with WNOHANG, it'll reap the process.
// However, if DidProcessCrash didn't reap the child, we'll need to in
// Terminate via ProcessWatcher. So we can't close the handle here.
//
// This is moot on Windows where |child_exited| will always be true.
if (child_exited)
context_->process_.Close();
return did_crash;
}
void ChildProcessLauncher::SetProcessBackgrounded(bool background) {
DCHECK(!context_->starting_);
context_->process_.SetProcessBackgrounded(background);
}
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