Revert 240670 "Revert 239894 "Linux Sandbox: check no threads be..."

trunk/src/sandbox/linux/services/broker_process.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 "sandbox/linux/services/broker_process.h"
 
 #include <fcntl.h>
 #include <sys/socket.h>
 #include <sys/stat.h>
 #include <sys/syscall.h>
 #include <sys/types.h>
 #include <unistd.h>
 
 #include <algorithm>
 #include <string>
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/logging.h"
 #include "base/pickle.h"
 #include "base/posix/eintr_wrapper.h"
 #include "base/posix/unix_domain_socket_linux.h"
+#include "base/process/process_metrics.h"
 #include "build/build_config.h"
 #include "sandbox/linux/services/linux_syscalls.h"
 
 #if defined(OS_ANDROID) && !defined(MSG_CMSG_CLOEXEC)
 #define MSG_CMSG_CLOEXEC 0x40000000
 #endif
 
 namespace {
 
 static const size_t kMaxMessageLength = 4096;
@@ skipping 105 matching lines @@
   CHECK(!initialized_);
   int socket_pair[2];
   // Use SOCK_SEQPACKET, because we need to preserve message boundaries
   // but we also want to be notified (recvmsg should return and not block)
   // when the connection has been broken (one of the processes died).
   if (socketpair(AF_UNIX, SOCK_SEQPACKET, 0, socket_pair)) {
     LOG(ERROR) << "Failed to create socketpair";
     return false;
   }
 
+  DCHECK_EQ(1, base::GetNumberOfThreads(base::GetCurrentProcessHandle()));
   int child_pid = fork();
   if (child_pid == -1) {
     close(socket_pair[0]);
     close(socket_pair[1]);
     return false;
   }
   if (child_pid) {
     // We are the parent and we have just forked our broker process.
     close(socket_pair[0]);
     // We should only be able to write to the IPC channel. We'll always send
@@ skipping 350 matching lines @@
           GetFileNameInWhitelist(allowed_w_files_, requested_filename,
                                  file_to_open);
       return allowed_for_read_and_write;
     }
     default:
       return false;
   }
 }
 
 }  // namespace sandbox.