Make SandboxIPCProcess a thread.

content/browser/renderer_host/render_sandbox_host_linux.cc

 // 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.
 
 #include "content/browser/renderer_host/render_sandbox_host_linux.h"
 
 #include <sys/socket.h>
 
 #include "base/memory/singleton.h"
 #include "base/posix/eintr_wrapper.h"
-#include "content/browser/renderer_host/sandbox_ipc_linux.h"
 
 namespace content {
 
 // Runs on the main thread at startup.
 RenderSandboxHostLinux::RenderSandboxHostLinux()
-    : initialized_(false),
-      renderer_socket_(0),
-      childs_lifeline_fd_(0),
-      pid_(0) {
+    : initialized_(false), renderer_socket_(0) {
 }
 
 // static
 RenderSandboxHostLinux* RenderSandboxHostLinux::GetInstance() {
   return Singleton<RenderSandboxHostLinux>::get();
 }
 
 void RenderSandboxHostLinux::Init(const std::string& sandbox_path) {
   DCHECK(!initialized_);
   initialized_ = true;
 
   int fds[2];
   // We use SOCK_SEQPACKET rather than SOCK_DGRAM to prevent the renderer from
   // sending datagrams to other sockets on the system. The sandbox may prevent
   // the renderer from calling socket() to create new sockets, but it'll still
   // inherit some sockets. With AF_UNIX+SOCK_DGRAM, it can call sendmsg to send
   // a datagram to any (abstract) socket on the same system. With
   // SOCK_SEQPACKET, this is prevented.
   CHECK(socketpair(AF_UNIX, SOCK_SEQPACKET, 0, fds) == 0);
 
   renderer_socket_ = fds[0];
   const int browser_socket = fds[1];
 
-  int pipefds[2];
-  CHECK(0 == pipe(pipefds));
-  const int child_lifeline_fd = pipefds[0];
-  childs_lifeline_fd_ = pipefds[1];
-
-  // We need to be monothreaded before we fork().
-#if !defined(THREAD_SANITIZER)
-  DCHECK_EQ(1, base::GetNumberOfThreads(base::GetCurrentProcessHandle()));
-#endif  // !defined(THREAD_SANITIZER)
-  pid_ = fork();
-  if (pid_ == 0) {
-    if (IGNORE_EINTR(close(fds[0])) < 0)
-      DPLOG(ERROR) << "close";
-    if (IGNORE_EINTR(close(pipefds[1])) < 0)
-      DPLOG(ERROR) << "close";
-
-    SandboxIPCProcess handler(child_lifeline_fd, browser_socket, sandbox_path);
-    handler.Run();
-    _exit(0);
-  }
+  ipc_handler_.reset(new SandboxIPCHandler(browser_socket, sandbox_path));
+  ipc_thread_.reset(
+      new base::DelegateSimpleThread(ipc_handler_.get(), "sandbox_ipc_thread"));
+  ipc_thread_->Start();
 }
 
 RenderSandboxHostLinux::~RenderSandboxHostLinux() {
   if (initialized_) {
     if (IGNORE_EINTR(close(renderer_socket_)) < 0)
       PLOG(ERROR) << "close";
-    if (IGNORE_EINTR(close(childs_lifeline_fd_)) < 0)
-      PLOG(ERROR) << "close";
+
+    ipc_thread_->Join();
   }
 }
 
 }  // namespace content