Linux: refactor zygote support

http://code.google.com/p/chromium/wiki/LinuxZygote

* Move Chrome specific bits out of base
* Move away from the idea of reserved file descriptors (which don't
  really work with zygotes)
* Load resources before forking renderers (means that we don't need
  communication between the zygote process and the renderers)
* Make sure that gdb works against the browser again
* Make sure that we have different ASLR between the renderers and the
  browser.

http://codereview.chromium.org/119335


git-svn-id: svn://svn.chromium.org/chrome/trunk/src@18109 0039d316-1c4b-4281-b951-d872f2087c98

14 files changed, 246 insertions, 1074 deletions

diff --git a/base/base.gyp b/base/base.gyp
index 5d09098..96deb53 100644
--- a/base/base.gyp
+++ b/base/base.gyp
@@ -133,6 +133,8 @@
         'fix_wp64.h',
         'float_util.h',
         'foundation_utils_mac.h',
+        'global_descriptors_posix.h',
+        'global_descriptors_posix.cc',
         'hash_tables.h',
         'histogram.cc',
         'histogram.h',
@@ -324,6 +326,7 @@
         'tracked_objects.cc',
         'tracked_objects.h',
         'tuple.h',
+        'unix_domain_socket_posix.cc',
         'values.cc',
         'values.h',
         'version.cc',
@@ -418,9 +421,6 @@
               # so use idle_timer_none.cc instead.
               'idle_timer.cc',
             ],
-            'sources': [
-              'zygote_manager.cc',
-            ],
             'dependencies': [
               '../build/util/build_util.gyp:lastchange',
               '../build/linux/system.gyp:gtk',
@@ -685,9 +685,6 @@
       ],
       'conditions': [
         ['OS == "linux"', {
-          'sources': [
-            'zygote_manager_unittest.cc',
-          ],
           'sources!': [
             'file_version_info_unittest.cc',
             # Linux has an implementation of idle_timer, but it's unclear
diff --git a/base/command_line.cc b/base/command_line.cc
index 735620d..582c8b8 100644
--- a/base/command_line.cc
+++ b/base/command_line.cc
@@ -168,6 +168,12 @@ bool CommandLine::IsSwitch(const StringType& parameter_string,
 }
 
 // static
+void CommandLine::Reset() {
+  delete current_process_commandline_;
+  current_process_commandline_ = NULL;
+}
+
+// static
 void CommandLine::Init(int argc, const char* const* argv) {
 #if defined(OS_WIN)
   current_process_commandline_ = new CommandLine;
diff --git a/base/command_line.h b/base/command_line.h
index c895b81..d128d49 100644
--- a/base/command_line.h
+++ b/base/command_line.h
@@ -45,6 +45,9 @@ class CommandLine {
   // TODO(port): should be a FilePath.
   explicit CommandLine(const std::wstring& program);
 
+  // Uninit and free the current process's command line.
+  static void Reset();
+
   // Initialize the current process CommandLine singleton.  On Windows,
   // ignores its arguments (we instead parse GetCommandLineW()
   // directly) because we don't trust the CRT's parsing of the command
diff --git a/base/file_util_posix.cc b/base/file_util_posix.cc
index 92b9d00..aca0ff9 100644
--- a/base/file_util_posix.cc
+++ b/base/file_util_posix.cc
@@ -27,7 +27,6 @@
 #include "base/logging.h"
 #include "base/string_util.h"
 #include "base/time.h"
-#include "base/zygote_manager.h"
 
 namespace file_util {
 
@@ -646,19 +645,8 @@ MemoryMappedFile::MemoryMappedFile()
 }
 
 bool MemoryMappedFile::MapFileToMemory(const FilePath& file_name) {
-  file_ = -1;
-#if defined(OS_LINUX)
-  base::ZygoteManager* zm = base::ZygoteManager::Get();
-  if (zm) {
-    file_ = zm->OpenFile(file_name.value().c_str());
-    if (file_ == -1) {
-      LOG(INFO) << "Zygote manager can't open " << file_name.value()
-                << ", retrying locally.  (OK at start of ui_tests.)";
-    }
-  }
-#endif  // defined(OS_LINUX)
-  if (file_ == -1)
-    file_ = open(file_name.value().c_str(), O_RDONLY);
+  file_ = open(file_name.value().c_str(), O_RDONLY);
+
   if (file_ == -1) {
     LOG(ERROR) << "Couldn't open " << file_name.value();
     return false;
diff --git a/base/global_descriptors_posix.cc b/base/global_descriptors_posix.cc
new file mode 100644
index 0000000..869d196
--- /dev/null
+++ b/base/global_descriptors_posix.cc
@@ -0,0 +1,46 @@
+// 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 "base/global_descriptors_posix.h"
+
+#include <vector>
+#include <utility>
+
+#include "base/logging.h"
+
+namespace base {
+
+int GlobalDescriptors::MaybeGet(Key key) const {
+  for (Mapping::const_iterator
+       i = descriptors_.begin(); i != descriptors_.end(); ++i) {
+    if (i->first == key)
+      return i->second;
+  }
+
+  // In order to make unittests pass, we define a default mapping from keys to
+  // descriptors by adding a fixed offset:
+  return kBaseDescriptor + key;
+}
+
+int GlobalDescriptors::Get(Key key) const {
+  const int ret = MaybeGet(key);
+
+  if (ret == -1)
+    LOG(FATAL) << "Unknown global descriptor: " << key;
+  return ret;
+}
+
+void GlobalDescriptors::Set(Key key, int fd) {
+  for (Mapping::iterator
+       i = descriptors_.begin(); i != descriptors_.end(); ++i) {
+    if (i->first == key) {
+      i->second = fd;
+      return;
+    }
+  }
+
+  descriptors_.push_back(std::make_pair(key, fd));
+}
+
+}  // namespace base
diff --git a/base/global_descriptors_posix.h b/base/global_descriptors_posix.h
new file mode 100644
index 0000000..f606a82
--- /dev/null
+++ b/base/global_descriptors_posix.h
@@ -0,0 +1,66 @@
+// 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.
+
+#ifndef BASE_GLOBAL_DESCRIPTORS_POSIX_H_
+#define BASE_GLOBAL_DESCRIPTORS_POSIX_H_
+
+#include "build/build_config.h"
+
+#include <vector>
+#include <utility>
+
+#include <stdint.h>
+
+#include "base/singleton.h"
+
+namespace base {
+
+// It's common practice to install file descriptors into well known slot
+// numbers before execing a child; stdin, stdout and stderr are ubiqutous
+// examples.
+//
+// However, when using a zygote model, this becomes troublesome. Since the
+// descriptors which need to be in these slots generally aren't known, any code
+// could open a resource and take one of the reserved descriptors. Simply
+// overwriting the slot isn't a viable solution.
+//
+// We could try to fill the reserved slots as soon as possible, but this is a
+// fragile solution since global constructors etc are able to open files.
+//
+// Instead, we retreat from the idea of installing descriptors in specific
+// slots and add a layer of indirection in the form of this singleton object.
+// It maps from an abstract key to a descriptor. If independent modules each
+// need to define keys, then values should be chosen randomly so as not to
+// collide.
+class GlobalDescriptors {
+ public:
+  typedef uint32_t Key;
+  // Often we want a canonical descriptor for a given Key. In this case, we add
+  // the following constant to the key value:
+  static const int kBaseDescriptor = 3;  // 0, 1, 2 are already taken.
+
+  // Get a descriptor given a key. It is a fatal error if the key is not known.
+  int Get(Key key) const;
+  // Get a descriptor give a key. Returns -1 on error.
+  int MaybeGet(Key key) const;
+
+  typedef std::vector<std::pair<Key, int> > Mapping;
+
+  // Set the descriptor for the given key.
+  void Set(Key key, int fd);
+
+  void Reset(const Mapping& mapping) {
+    descriptors_ = mapping;
+  }
+
+ private:
+  GlobalDescriptors() { }
+  friend struct DefaultSingletonTraits<GlobalDescriptors>;
+
+  Mapping descriptors_;
+};
+
+}  // namespace base
+
+#endif  // BASE_GLOBAL_DESCRIPTORS_POSIX_H_
diff --git a/base/logging.cc b/base/logging.cc
index 77e9583..b5af671 100644
--- a/base/logging.cc
+++ b/base/logging.cc
@@ -19,12 +19,9 @@ typedef HANDLE MutexHandle;
 #endif
 
 #if defined(OS_POSIX)
-#include <fcntl.h>
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
-#include <sys/types.h>
-#include <sys/stat.h>
 #include <unistd.h>
 #define MAX_PATH PATH_MAX
 typedef FILE* FileHandle;
@@ -40,7 +37,6 @@ typedef pthread_mutex_t* MutexHandle;
 #include "base/command_line.h"
 #include "base/debug_util.h"
 #include "base/lock_impl.h"
-#include "base/reserved_file_descriptors.h"
 #include "base/string_piece.h"
 #include "base/string_util.h"
 #include "base/sys_string_conversions.h"
@@ -208,20 +204,6 @@ bool InitializeLogFileHandle() {
       }
     }
     SetFilePointer(log_file, 0, 0, FILE_END);
-#elif defined(OS_LINUX)
-    // Reserve global fd slots.
-    int reserved_fds[kReservedFds];
-    for (int i=0; i < kReservedFds; i++)
-      reserved_fds[i] = open("/dev/null", O_RDONLY, 0);
-
-    log_file = fopen(log_file_name->c_str(), "a");
-
-    // Release the reserved fds.
-    for (int i=0; i < kReservedFds; i++)
-      close(reserved_fds[i]);
-
-    if (log_file == NULL)
-      return false;
 #elif defined(OS_POSIX)
     log_file = fopen(log_file_name->c_str(), "a");
     if (log_file == NULL)
diff --git a/base/process_util.h b/base/process_util.h
index 4fe081f..41d0470 100644
--- a/base/process_util.h
+++ b/base/process_util.h
@@ -141,14 +141,6 @@ typedef std::vector<std::pair<int, int> > file_handle_mapping_vector;
 bool LaunchApp(const std::vector<std::string>& argv,
                const file_handle_mapping_vector& fds_to_remap,
                bool wait, ProcessHandle* process_handle);
-
-#if defined(OS_LINUX)
-// Like LaunchApp, but if zygote manager is enabled,
-// forks the zygote instead of forking and exec'ing.
-bool ForkApp(const std::vector<std::string>& argv,
-             const file_handle_mapping_vector& fds_to_remap,
-             ProcessHandle* process_handle);
-#endif
 #endif
 
 // Executes the application specified by cl. This function delegates to one
diff --git a/base/process_util_linux.cc b/base/process_util_linux.cc
index ba2d8cd..7560257 100644
--- a/base/process_util_linux.cc
+++ b/base/process_util_linux.cc
@@ -17,7 +17,6 @@
 #include "base/logging.h"
 #include "base/string_tokenizer.h"
 #include "base/string_util.h"
-#include "base/zygote_manager.h"
 
 namespace {
 
@@ -86,22 +85,6 @@ FilePath GetProcessExecutablePath(ProcessHandle process) {
   return FilePath(std::string(exename, len));
 }
 
-bool ForkApp(const std::vector<std::string>& argv,
-             const file_handle_mapping_vector& fds_to_remap,
-             ProcessHandle* process_handle) {
-  ZygoteManager* zm = ZygoteManager::Get();
-  if (!zm)
-    return LaunchApp(argv, fds_to_remap, false, process_handle);
-
-  pid_t pid = zm->LongFork(argv, fds_to_remap);
-  if (pid < 0)
-    return false;
-
-  if (process_handle)
-    *process_handle = pid;
-  return true;
-}
-
 bool LaunchApp(const std::vector<std::string>& argv,
                const file_handle_mapping_vector& fds_to_remap,
                bool wait, ProcessHandle* process_handle) {
diff --git a/base/reserved_file_descriptors.h b/base/reserved_file_descriptors.h
deleted file mode 100644
index 5236a08..0000000
--- a/base/reserved_file_descriptors.h
+++ /dev/null
@@ -1,36 +0,0 @@
-// Copyright (c) 2006-2009 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.
-
-#ifndef BASE_RESERVED_FILE_DESCRIPTORS_H_
-#define BASE_RESERVED_FILE_DESCRIPTORS_H_
-
-#if defined(OS_POSIX)
-
-// Chrome uses predefined file descriptors to communicate with child processes.
-// Normally this is a private contract between code that does fork/exec and the
-// code it invokes, but in zygote mode, things get a little more interesting.
-// It's a huge layering violation for this to be in base, but
-// logging and ZygoteManager need kReservedFileDescriptors, so there.
-
-enum GlobalReservedFds {
-  // Classic unix file descriptors.
-  // Let's leave them alone even if we don't use them.
-  kStdinFd = 0,
-  kStdoutFd = 1,
-  kStderrFd = 2,
-
-  // See chrome/common/ipc_channel_posix.cc
-  kClientChannelFd = 3,
-
-  // See chrome/app/breakpad_linux.cc and
-  // chrome/browser/renderer_host/browser_render_process_host.cc
-  kMagicCrashSignalFd = 4,
-
-  // One plus highest fd mentioned in this enum.
-  kReservedFds = 5
-};
-
-#endif
-
-#endif
diff --git a/base/unix_domain_socket_posix.cc b/base/unix_domain_socket_posix.cc
new file mode 100644
index 0000000..af7c0c3
--- /dev/null
+++ b/base/unix_domain_socket_posix.cc
@@ -0,0 +1,98 @@
+// 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 "base/unix_domain_socket_posix.h"
+
+#include <unistd.h>
+#include <sys/uio.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+
+#include "base/eintr_wrapper.h"
+#include "base/logging.h"
+
+namespace base {
+
+bool SendMsg(int fd, const void* buf, size_t length, std::vector<int>& fds) {
+  struct msghdr msg;
+  memset(&msg, 0, sizeof(msg));
+  struct iovec iov = {const_cast<void*>(buf), length};
+  msg.msg_iov = &iov;
+  msg.msg_iovlen = 1;
+
+  char* control_buffer = NULL;
+  if (fds.size()) {
+    const unsigned control_len = CMSG_SPACE(sizeof(int) * fds.size());
+    control_buffer = new char[control_len];
+    if (!control_buffer)
+      return false;
+
+    struct cmsghdr *cmsg;
+
+    msg.msg_control = control_buffer;
+    msg.msg_controllen = control_len;
+    cmsg = CMSG_FIRSTHDR(&msg);
+    cmsg->cmsg_level = SOL_SOCKET;
+    cmsg->cmsg_type = SCM_RIGHTS;
+    cmsg->cmsg_len = CMSG_LEN(sizeof(int) * fds.size());
+    memcpy(CMSG_DATA(cmsg), &fds[0], sizeof(int) * fds.size());
+    msg.msg_controllen = cmsg->cmsg_len;
+  }
+
+  const ssize_t r = HANDLE_EINTR(sendmsg(fd, &msg, 0));
+  const bool ret = static_cast<ssize_t>(length) == r;
+  delete[] control_buffer;
+  return ret;
+}
+
+ssize_t RecvMsg(int fd, void* buf, size_t length, std::vector<int>* fds) {
+  static const unsigned kMaxDescriptors = 16;
+
+  fds->clear();
+
+  struct msghdr msg;
+  memset(&msg, 0, sizeof(msg));
+  struct iovec iov = {buf, length};
+  msg.msg_iov = &iov;
+  msg.msg_iovlen = 1;
+
+  char control_buffer[CMSG_SPACE(sizeof(int) * kMaxDescriptors)];
+  msg.msg_control = control_buffer;
+  msg.msg_controllen = sizeof(control_buffer);
+
+  const ssize_t r = HANDLE_EINTR(recvmsg(fd, &msg, 0));
+  if (r == -1)
+    return -1;
+
+  int* wire_fds;
+  unsigned wire_fds_len = 0;
+
+  if (msg.msg_controllen > 0) {
+    struct cmsghdr* cmsg;
+    for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
+      if (cmsg->cmsg_level == SOL_SOCKET &&
+          cmsg->cmsg_type == SCM_RIGHTS) {
+        const unsigned payload_len = cmsg->cmsg_len - CMSG_LEN(0);
+        DCHECK(payload_len % sizeof(int) == 0);
+        wire_fds = reinterpret_cast<int*>(CMSG_DATA(cmsg));
+        wire_fds_len = payload_len / sizeof(int);
+        break;
+      }
+    }
+  }
+
+  if (msg.msg_flags & MSG_TRUNC || msg.msg_flags & MSG_CTRUNC) {
+    for (unsigned i = 0; i < wire_fds_len; ++i)
+      close(wire_fds[i]);
+    errno = EMSGSIZE;
+    return -1;
+  }
+
+  fds->resize(wire_fds_len);
+  memcpy(&(*fds)[0], wire_fds, sizeof(int) * wire_fds_len);
+
+  return r;
+}
+
+}  // namespace base
diff --git a/base/unix_domain_socket_posix.h b/base/unix_domain_socket_posix.h
new file mode 100644
index 0000000..46c473a
--- /dev/null
+++ b/base/unix_domain_socket_posix.h
@@ -0,0 +1,22 @@
+// 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.
+
+#ifndef BASE_UNIX_DOMAIN_SOCKET_POSIX_H_
+#define BASE_UNIX_DOMAIN_SOCKET_POSIX_H_
+
+#include <vector>
+
+namespace base {
+
+// Use sendmsg to write the given msg and include a vector
+// of file descriptors. Returns true iff successful.
+bool SendMsg(int fd, const void* msg, size_t length,
+             std::vector<int>& fds);
+// Use recvmsg to read a message and an array of file descriptors. Returns
+// -1 on failure. Note: will read, at most, 16 descriptors.
+ssize_t RecvMsg(int fd, void* msg, size_t length, std::vector<int>* fds);
+
+}  // namespace base
+
+#endif  // BASE_UNIX_DOMAIN_SOCKET_POSIX_H_
diff --git a/base/zygote_manager.cc b/base/zygote_manager.cc
deleted file mode 100644
index 7b2c026..0000000
--- a/base/zygote_manager.cc
+++ /dev/null
@@ -1,832 +0,0 @@
-// Copyright (c) 2006-2009 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 "base/zygote_manager.h"
-
-#if defined(OS_LINUX)
-
-#include <errno.h>
-#include <fcntl.h>
-#include <poll.h>
-#include <stdlib.h>
-#include <sys/file.h>     // for flock()
-#include <sys/stat.h>
-#include <sys/uio.h>      // for struct iovec
-#include <sys/wait.h>
-#include <unistd.h>       // for ssize_t
-
-#include <string>
-
-#include "base/eintr_wrapper.h"
-#include "base/file_descriptor_shuffle.h"
-#include "base/file_util.h"
-#include "base/logging.h"
-#include "base/process_util.h"
-#include "base/reserved_file_descriptors.h"
-#include "base/singleton.h"
-
-using file_util::Delete;
-
-// See comment below, where sigaction is called.
-static void SIGCHLDHandler(int signal) {
-}
-
-namespace base {
-
-const char ZygoteManager::kZMagic[] = "zygo";
-
-ZygoteManager::~ZygoteManager() {
-  if (server_fd_ != -1) {
-    close(server_fd_);
-    server_fd_ = -1;
-  }
-  if (client_fd_ != -1) {
-    close(client_fd_);
-    client_fd_ = -1;
-  }
-  if (lockfd_ != -1) {
-    close(lockfd_);
-    lockfd_ = -1;
-  }
-  if (canary_fd_ != -1) {
-    // Wake up the poll() in ReadAndHandleMessage()
-    close(canary_fd_);
-    canary_fd_ = -1;
-  }
-#ifndef OFFICIAL_BUILD
-  // Closing the canary kills the server,
-  // so after this it's ok for e.g. unit tests
-  // to start a new zygote server.
-  (void) unsetenv("ZYGOTE_MANAGER_STARTED");
-#endif
-}
-
-// Runs in client process
-ZygoteManager* ZygoteManager::Get() {
-  static bool checked = false;
-  static bool enabled = false;
-  if (!checked) {
-    enabled = (getenv("ENABLE_ZYGOTE_MANAGER") != NULL);
-    checked = true;
-  }
-  if (!enabled)
-    return NULL;
-  return Singleton<ZygoteManager>::get();
-}
-
-// Runs in zygote manager process
-int ZygoteManager::UnpickleHeader(const Pickle& reply, void** iter) {
-  std::string magic;
-  if (!reply.ReadString(iter, &magic) || magic != std::string(kZMagic)) {
-    LOG(ERROR) << "reply didn't start with " << kZMagic;
-    return ZMBAD;
-  }
-  pid_t clientpid = (pid_t) -1;
-  if (!reply.ReadInt(iter, &clientpid)) {
-    LOG(ERROR) << "Can't read client pid";
-    return ZMBAD;
-  }
-  if (clientpid != getpid()) {
-    LOG(ERROR) << "got client pid " << clientpid << ", expected " << getpid();
-    DCHECK(clientpid == getpid());
-    return ZMBAD;
-  }
-  int kind;
-  if (!reply.ReadInt(iter, &kind)) {
-    LOG(ERROR) << "can't read kind";
-    return ZMBAD;
-  }
-  return kind;
-}
-
-// Runs in client process (only used in unit test)
-bool ZygoteManager::Ping(base::TimeDelta* delta) {
-  if (client_fd_ == -1)
-    return false;
-
-  Pickle pickle;
-  pickle.WriteString(kZMagic);
-  pickle.WriteInt(getpid());
-  pickle.WriteInt(ZMPING);
-
-  int bytes_sent;
-  int bytes_read = -1;
-
-  TimeTicks time_sent = TimeTicks::HighResNow();
-
-  // Lock fork server, send the pickle, wait for the reply, unlock
-  if (flock(lockfd_, LOCK_EX))
-    LOG(ERROR) << "flock failed, errno " << errno;
-  bytes_sent = HANDLE_EINTR(write(client_fd_,
-      const_cast<void *>(pickle.data()), pickle.size()));
-  if (bytes_sent > 0) {
-    bytes_read = HANDLE_EINTR(read(client_fd_, msg_buf_, kMAX_MSG_LEN));
-  }
-  if (flock(lockfd_, LOCK_UN))
-    LOG(ERROR) << "flock failed, errno " << errno;
-
-  TimeTicks time_received = TimeTicks::HighResNow();
-
-  if (bytes_sent < 1) {
-    LOG(ERROR) << "Can't send to zm, errno " << errno;
-    return false;
-  }
-  if (bytes_read < 1) {
-    LOG(ERROR) << "Can't get from zm, errno " << errno;
-    return false;
-  }
-
-  // Unpickle the reply
-  Pickle reply(msg_buf_, bytes_read);
-  void* iter = NULL;
-  int kind = UnpickleHeader(reply, &iter);
-  if (kind != ZMPINGED) {
-    LOG(ERROR) << "reply wrong kind " << kind;
-    return false;
-  }
-  *delta = TimeTicks::HighResNow() - time_sent;
-  LOG(INFO) << "Round trip time in microseconds: " << delta->InMicroseconds();
-  return true;
-}
-
-// Runs in zygote manager process
-void ZygoteManager::PingHandler(const Pickle& request, void* iter,
-    Pickle* reply, std::vector<std::string>** newargv) {
-    reply->WriteInt(ZMPINGED);
-}
-
-// Runs in browser process, called only by base::ForkApp()
-pid_t ZygoteManager::LongFork(const std::vector<std::string>& argv,
-           const file_handle_mapping_vector& fds_to_remap) {
-  if (client_fd_ == -1)
-    return -1;
-
-  Pickle pickle;
-
-  // Encode the arguments and the desired remote fd numbers in the pickle,
-  // and the fds in a separate buffer
-  pickle.WriteString(kZMagic);
-  pickle.WriteInt(getpid());
-  pickle.WriteInt(ZMFORK);
-  pickle.WriteInt(argv.size());
-  std::vector<std::string>::const_iterator argi;
-  for (argi = argv.begin(); argi != argv.end(); ++argi)
-    pickle.WriteString(*argi);
-  pickle.WriteInt(fds_to_remap.size());
-
-  // Wrap the pickle and the fds together in a msghdr
-  ::msghdr msg;
-  memset(&msg, 0, sizeof(msg));
-  struct iovec iov;
-  msg.msg_iov = &iov;
-  msg.msg_iovlen = 1;
-  msg.msg_control = cmsg_buf_;
-  msg.msg_controllen = CMSG_LEN(sizeof(int) * fds_to_remap.size());
-  struct cmsghdr* cmsg;
-  cmsg = CMSG_FIRSTHDR(&msg);
-  cmsg->cmsg_level = SOL_SOCKET;
-  cmsg->cmsg_type = SCM_RIGHTS;
-  cmsg->cmsg_len = msg.msg_controllen;
-  int* wire_fds = reinterpret_cast<int*>(CMSG_DATA(cmsg));
-  for (size_t i = 0; i < fds_to_remap.size(); i++) {
-    pickle.WriteInt(fds_to_remap[i].second);
-    wire_fds[i] = fds_to_remap[i].first;
-  }
-  iov.iov_base = const_cast<void *>(pickle.data());
-  iov.iov_len = pickle.size();
-
-  int bytes_sent;
-  int bytes_read = -1;
-
-  // Lock fork server, send the pickle, wait for the reply, unlock
-  if (flock(lockfd_, LOCK_EX))
-    LOG(ERROR) << "flock failed, errno " << errno;
-  bytes_sent = HANDLE_EINTR(sendmsg(client_fd_, &msg, MSG_WAITALL));
-  if (bytes_sent > 0) {
-    bytes_read = HANDLE_EINTR(read(client_fd_, msg_buf_, kMAX_MSG_LEN));
-  }
-  if (flock(lockfd_, LOCK_UN))
-    LOG(ERROR) << "flock failed, errno " << errno;
-
-  if (bytes_sent < 1) {
-    LOG(ERROR) << "Can't send to zm, errno " << errno << ", fd " << client_fd_;
-    return (pid_t) -1;
-  }
-  if (bytes_read < 1) {
-    LOG(ERROR) << "Can't get from zm, errno " << errno;
-    return (pid_t) -1;
-  }
-
-  // Unpickle the reply
-  Pickle reply(msg_buf_, bytes_read);
-  void* iter = NULL;
-  int kind = UnpickleHeader(reply, &iter);
-  if (kind != ZMFORKED) {
-    LOG(ERROR) << "reply wrong kind " << kind;
-    return (pid_t) -1;
-  }
-  pid_t newpid = (pid_t) -1;
-  int pid_errno;
-  if (!reply.ReadInt(&iter, &newpid) || !reply.ReadInt(&iter, &pid_errno)) {
-    LOG(ERROR) << "fork failed, can't read pid/errno";
-    return (pid_t) -1;
-  }
-  if ((newpid == (pid_t) -1) || pid_errno != 0) {
-    LOG(ERROR) << "fork failed, pid " << newpid << ", errno " << pid_errno;
-    return (pid_t) -1;
-  }
-  return newpid;
-}
-
-// Runs in zygote manager process
-bool ZygoteManager::LongForkHandler(const Pickle& request, void* iter,
-    Pickle* reply, std::vector<std::string>** newargv,
-    const int wire_fds[], int num_wire_fds) {
-  file_handle_mapping_vector fds_to_remap;
-  pid_t childpid;
-
-  reply->WriteInt(ZMFORKED);
-
-  // Unpickle commandline for new child
-  std::vector<std::string>* argv = new std::vector<std::string>;
-  int argc;
-  request.ReadInt(&iter, &argc);
-  for (int i = 0; i < argc; i++) {
-    std::string arg;
-    if (!request.ReadString(&iter, &arg)) {
-      LOG(ERROR) << "can't read arg?";
-      goto error_reply;
-    }
-    argv->push_back(arg);
-  }
-  // Unpickle file descriptor map for new child
-  int numfds;
-  request.ReadInt(&iter, &numfds);
-  DCHECK(numfds == num_wire_fds);
-  if (numfds != num_wire_fds) {
-    LOG(ERROR) << "numfds " << numfds << " != num_wire_fds " << num_wire_fds;
-    goto error_reply;
-  }
-  for (int i = 0; i < numfds; i++) {
-    int fd;
-    if (!request.ReadInt(&iter, &fd)) {
-      LOG(ERROR) << "can't read fd?";
-      goto error_reply;
-    }
-    fds_to_remap.push_back(std::pair<int, int>(wire_fds[i], fd));
-  }
-
-  // Mitosis!
-  childpid = fork();
-
-  if (childpid != 0) {
-    // parent
-    // first off, close our copy of the child's file descriptors
-    for (file_handle_mapping_vector::const_iterator
-        it = fds_to_remap.begin(); it != fds_to_remap.end(); ++it) {
-      close(it->first);
-    }
-
-    // Finish formatting the reply
-    reply->WriteInt(childpid);
-    if (childpid == (pid_t) -1) {
-      reply->WriteInt(errno);
-      return false;
-    } else {
-      reply->WriteInt(0);
-    }
-  } else {
-    // child
-    // Apply file descriptor map
-    InjectiveMultimap fd_shuffle;
-    for (file_handle_mapping_vector::const_iterator
-        it = fds_to_remap.begin(); it != fds_to_remap.end(); ++it) {
-      fd_shuffle.push_back(InjectionArc(it->first, it->second, false));
-    }
-
-    // Avoid closing descriptor children will need to contact fork server.
-    fd_shuffle.push_back(InjectionArc(client_fd_, client_fd_, false));
-    // Avoid closing log descriptor we're using
-    int logfd = logging::GetLoggingFileDescriptor();
-    if (logfd != -1)
-      fd_shuffle.push_back(InjectionArc(logfd, logfd, false));
-    // And of course avoid closing the cached fds.
-    std::map<std::string, int>::iterator i;
-    for (i = cached_fds_.begin(); i != cached_fds_.end(); ++i) {
-      fd_shuffle.push_back(InjectionArc(i->second, i->second, false));
-    }
-
-    // If there is any clash in the mapping, this function will DCHECK.
-    if (!ShuffleFileDescriptors(fd_shuffle))
-      exit(127);
-
-    // Open this after shuffle to avoid using reserved slots.
-    lockfd_ = open(lockfile_.c_str(), O_RDWR, 0);
-    if (lockfd_ == -1) {
-      // TODO(dkegel): real error handling
-      exit(126);
-    }
-    // Mark it as not to be closed.
-    fd_shuffle.push_back(InjectionArc(lockfd_, lockfd_, false));
-
-    // Also closes reserved fds.
-    CloseSuperfluousFds(fd_shuffle);
-
-    *newargv = argv;
-    // Because *newargv is set, we will return to main instead of looping
-  }
-  return true;
-
- error_reply:
-  reply->WriteInt(-1);
-  reply->WriteInt(-1);
-  for (int i=0; i<num_wire_fds; i++)
-    close(wire_fds[i]);
-  return false;
-}
-
-// Runs in browser process, called by ProcessWatcher::EnsureProcessTerminated().
-void ZygoteManager::EnsureProcessTerminated(pid_t childpid) {
-  if (client_fd_ == -1)
-    return;
-
-  Pickle pickle;
-
-  pickle.WriteString(kZMagic);
-  pickle.WriteInt(getpid());
-  pickle.WriteInt(ZMREAP);
-  pickle.WriteInt(childpid);
-
-  int bytes_sent = HANDLE_EINTR(
-      write(client_fd_, const_cast<void*>(pickle.data()), pickle.size()));
-
-  if (bytes_sent < 1) {
-    LOG(ERROR) << "Can't send to zm, errno " << errno << ", fd " << client_fd_;
-  }
-}
-
-// Runs in zygote manager process
-void ZygoteManager::EnsureProcessTerminatedHandler(const Pickle& request,
-    void* iter) {
-  pid_t childpid;
-  request.ReadInt(&iter, &childpid);
-  NOTIMPLEMENTED();
-  // TODO(dkegel): put childpid on a watch list, and terminate it
-  // after a while as chrome/common/process_watcher does.
-}
-
-static bool ValidateFilename(const std::string& filename) {
-  // We only have to open one kind of file, but we don't know
-  // the directory it's in, so be as restrictive as we can within
-  // those bounds.
-
-  static const char* allowed_prefix = "/";
-  if (filename.compare(0, strlen(allowed_prefix), allowed_prefix) != 0) {
-    LOG(ERROR) << "filename did not start with " << allowed_prefix;
-    return false;
-  }
-  static const char* allowed_suffix = ".pak";
-  if ((filename.length() <= strlen(allowed_suffix)) ||
-      (filename.compare(filename.length() - strlen(allowed_suffix),
-                       strlen(allowed_suffix), allowed_suffix) != 0)) {
-    LOG(ERROR) << "filename did not end in " << allowed_suffix;
-    return false;
-  }
-  if (filename.find("../") != std::string::npos) {
-    LOG(ERROR) << "filename contained relative component";
-    return false;
-  }
-  static const char* forbidden_prefixes[] = {
-    "/var/", "/tmp/", "/etc/", "/dev/", "/proc/", 0 };
-  for (const char** p = forbidden_prefixes;
-       *p; p++) {
-    if (filename.compare(0, strlen(*p), *p) == 0) {
-      LOG(ERROR) << "filename began with " << *p;
-      return false;
-    }
-  }
-  return true;
-}
-
-// Runs in browser process
-int ZygoteManager::OpenFile(const std::string& filename) {
-  // For security reasons, we only support .pak files,
-  // and only in certain locations.
-  if (!ValidateFilename(filename)) {
-    LOG(INFO) << "ZygoteManager: filename " << filename << " disallowed.";
-    return -1;
-  }
-
-  std::map<std::string, int>::iterator mapiter = cached_fds_.find(filename);
-  if (mapiter != cached_fds_.end())
-    return mapiter->second;
-
-  if (client_fd_ == -1)
-    return -1;
-
-  Pickle pickle;
-
-  pickle.WriteString(kZMagic);
-  pickle.WriteInt(getpid());
-  pickle.WriteInt(ZMOPEN);
-  pickle.WriteString(filename);
-
-  // Get ready to receive fds
-  ::msghdr msg = {0};
-  struct iovec iov = {msg_buf_, kMAX_MSG_LEN};
-  msg.msg_iov = &iov;
-  msg.msg_iovlen = 1;
-  msg.msg_control = cmsg_buf_;
-  msg.msg_controllen = kMAX_CMSG_LEN;
-
-  ssize_t bytes_sent;
-  ssize_t bytes_read = 0;
-
-  if (flock(lockfd_, LOCK_EX))
-    LOG(ERROR) << "flock failed, errno " << errno;
-  bytes_sent = HANDLE_EINTR(
-      write(client_fd_, const_cast<void *>(pickle.data()), pickle.size()));
-  if (bytes_sent > 0) {
-    bytes_read = HANDLE_EINTR(recvmsg(client_fd_, &msg, MSG_WAITALL));
-  }
-  if (flock(lockfd_, LOCK_UN))
-    LOG(ERROR) << "flock failed, errno " << errno;
-
-  if (bytes_sent < 1) {
-    LOG(ERROR) << "Can't send to zm, errno " << errno << ", fd " << client_fd_;
-    return -1;
-  }
-  if (bytes_read < 1) {
-    LOG(ERROR) << "Can't get from zm, errno " << errno;
-    return -1;
-  }
-
-  // Locate the sole block of sent file descriptors within the list of
-  // control messages
-  const int* wire_fds = NULL;
-  unsigned num_wire_fds = 0;
-  if (msg.msg_controllen > 0) {
-    struct cmsghdr* cmsg;
-    for (cmsg = CMSG_FIRSTHDR(&msg); cmsg;
-         cmsg = CMSG_NXTHDR(&msg, cmsg)) {
-      if (cmsg->cmsg_level == SOL_SOCKET &&
-          cmsg->cmsg_type == SCM_RIGHTS) {
-        const unsigned payload_len = cmsg->cmsg_len - CMSG_LEN(0);
-        assert(payload_len % sizeof(int) == 0);
-        wire_fds = reinterpret_cast<int*>(CMSG_DATA(cmsg));
-        num_wire_fds = payload_len / sizeof(int);
-        break;
-      }
-    }
-  }
-  DCHECK(!(msg.msg_flags & MSG_CTRUNC));
-
-  // Unpickle the reply
-  Pickle reply(msg_buf_, bytes_read);
-  void* iter = NULL;
-  int kind = UnpickleHeader(reply, &iter);
-  if (kind != ZMOPENED) {
-    LOG(ERROR) << "reply wrong kind " << kind;
-    goto error_close;
-  }
-  int newfd_errno;
-  if (!reply.ReadInt(&iter, &newfd_errno)) {
-    LOG(ERROR) << "open failed, can't read errno";
-    goto error_close;
-  }
-  if (newfd_errno != 0) {
-    LOG(ERROR) << "open failed, errno " << newfd_errno;
-    goto error_close;
-  }
-  if (num_wire_fds != 1) {
-    LOG(ERROR) << "open failed, reply wrong number fds " << num_wire_fds;
-    goto error_close;
-  }
-  if (wire_fds[0] == -1) {
-    LOG(ERROR) << "open failed, fd -1";
-    NOTREACHED();
-    return -1;
-  }
-  return wire_fds[0];
-
- error_close:
-  for (unsigned i=0; i<num_wire_fds; i++)
-    close(wire_fds[i]);
-  return -1;
-}
-
-// Runs in zygote manager process
-bool ZygoteManager::OpenFileHandler(const Pickle& request, void* iter,
-    Pickle* reply, ::msghdr* msg) {
-  reply->WriteInt(ZMOPENED);
-
-  std::string filename;
-  if (!request.ReadString(&iter, &filename)) {
-    LOG(ERROR) << "no filename?";
-    return false;
-  }
-  if (!ValidateFilename(filename)) {
-    // Fake a unix error code
-    reply->WriteInt(EPERM);
-    return false;
-  }
-
-  std::map<std::string, int>::iterator i;
-  int newfd;
-  std::map<std::string, int>::iterator mapiter = cached_fds_.find(filename);
-  if (mapiter == cached_fds_.end()) {
-    // Verify that file is a plain file
-    struct stat statbuf;
-    if (lstat(filename.c_str(), &statbuf) != 0) {
-      LOG(ERROR) << "can't stat " << filename << ", errno " << errno;
-      return false;
-    }
-    if (!S_ISREG(statbuf.st_mode)) {
-      LOG(ERROR) << "not regular file " << filename;
-      // Fake a unix error code
-      reply->WriteInt(EISDIR);
-      return false;
-    }
-    newfd = open(filename.c_str(), O_RDONLY, 0);
-    if (newfd != -1) {
-      cached_fds_[filename] = newfd;
-    } else {
-      LOG(ERROR) << "can't open " << filename << ", errno " << errno;
-    }
-  } else {
-    newfd = mapiter->second;
-  }
-  if (newfd == -1) {
-    reply->WriteInt(errno);
-  } else {
-    reply->WriteInt(0);
-    msg->msg_control = cmsg_buf_;
-    msg->msg_controllen = CMSG_LEN(sizeof(int));
-    struct cmsghdr* cmsg;
-    cmsg = CMSG_FIRSTHDR(msg);
-    cmsg->cmsg_level = SOL_SOCKET;
-    cmsg->cmsg_type = SCM_RIGHTS;
-    cmsg->cmsg_len = msg->msg_controllen;
-    int* wire_fds = reinterpret_cast<int*>(CMSG_DATA(cmsg));
-    wire_fds[0] = newfd;
-  }
-
-  return true;
-}
-
-// Runs in zygote manager process
-bool ZygoteManager::ReadAndHandleMessage(std::vector<std::string>** newargv) {
-  // Wait for activity either on canary fd or main fd.
-  struct pollfd watcher[2];
-  memset(watcher, 0, sizeof(watcher));
-  watcher[0].fd = canary_fd_;
-  watcher[0].events = POLLIN|POLLHUP;
-  watcher[1].fd = server_fd_;
-  watcher[1].events = POLLIN;
-  // Wait at most one minute.  This lets us detect case where
-  // canary socket is closed abruptly because the main client aborted.
-  // Also lets us reap dead children once a minute even if we don't get SIGCHLD.
-  // We'd like to wait less time, but that's hard on battery life.
-  // Note: handle EINTR manually here, not with wrapper, as we need
-  // to return when we're interrupted so caller can reap promptly.
-  int nactive = poll(watcher, 2, 60*1000);
-
-  if (nactive == -1) {
-    if (errno == EINTR) {
-      // Probably SIGCHLD.  Return to main loop so it can reap.
-      return true;
-    }
-    LOG(ERROR) << "poll failed, errno " << errno << ", aborting";
-    return false;
-  }
-
-  // If it was the canary, exit
-  if (watcher[0].revents != 0) {
-    LOG(INFO) << "notified of peer destruction, exiting";
-    return false;
-  }
-  if ((watcher[1].revents & POLLIN) != POLLIN) {
-    // spurious wakeup?
-    return true;
-  }
-
-  ssize_t bytes_read = 0;
-  struct msghdr msg = {0};
-  struct iovec iov = {msg_buf_, kMAX_MSG_LEN};
-  msg.msg_iov = &iov;
-  msg.msg_iovlen = 1;
-  msg.msg_control = cmsg_buf_;
-  msg.msg_controllen = kMAX_CMSG_LEN;
-  bytes_read = HANDLE_EINTR(recvmsg(server_fd_, &msg, MSG_WAITALL));
-  if (bytes_read == 0) {
-    LOG(ERROR) << "got EOF, aborting";
-    return false;
-  }
-  if (bytes_read == -1) {
-    LOG(ERROR) << "got errno " << errno << ", aborting";
-    return false;
-  }
-
-  // Locate the sole block of sent file descriptors within the list of
-  // control messages
-  const int* wire_fds = NULL;
-  unsigned num_wire_fds = 0;
-  if (msg.msg_controllen > 0) {
-    struct cmsghdr* cmsg;
-    for (cmsg = CMSG_FIRSTHDR(&msg); cmsg;
-         cmsg = CMSG_NXTHDR(&msg, cmsg)) {
-      if (cmsg->cmsg_level == SOL_SOCKET &&
-          cmsg->cmsg_type == SCM_RIGHTS) {
-        const unsigned payload_len = cmsg->cmsg_len - CMSG_LEN(0);
-        assert(payload_len % sizeof(int) == 0);
-        wire_fds = reinterpret_cast<int*>(CMSG_DATA(cmsg));
-        num_wire_fds = payload_len / sizeof(int);
-        break;
-      }
-    }
-  }
-  DCHECK(!(msg.msg_flags & MSG_CTRUNC));
-
-  // Unpickle/parse message
-  Pickle pickle(msg_buf_, bytes_read);
-  void* iter = NULL;
-  std::string magic;
-  if (!pickle.ReadString(&iter, &magic) || magic != std::string(kZMagic)) {
-    LOG(ERROR) << "msg didn't start with " << kZMagic << ", got " << magic;
-    for (unsigned i=0; i<num_wire_fds; i++)
-      close(wire_fds[i]);
-    return true;
-  }
-  pid_t clientpid = (pid_t) -1;
-  pickle.ReadInt(&iter, &clientpid);
-  int kind;
-  pickle.ReadInt(&iter, &kind);
-
-  Pickle reply;
-  reply.WriteString(kZMagic);
-  reply.WriteInt(clientpid);
-
-  struct msghdr replymsg = {0};
-  memset(&replymsg, 0, sizeof(replymsg));
-
-  switch (kind) {
-  case ZMPING:
-    DCHECK_EQ(0U, num_wire_fds);
-    PingHandler(pickle, iter, &reply, newargv);
-    break;
-  case ZMFORK:
-    // TODO(dkegel): real error handling
-    (void) LongForkHandler(pickle, iter, &reply, newargv, wire_fds,
-                           num_wire_fds);
-    if (*newargv != NULL) {
-      // Child.  Just return to caller, who will return from SetLongFork.
-      return true;
-    }
-    break;
-  case ZMREAP:
-    DCHECK_EQ(0U, num_wire_fds);
-    EnsureProcessTerminatedHandler(pickle, iter);
-    // no reply to this message
-    return true;
-  case ZMOPEN:
-    DCHECK_EQ(0U, num_wire_fds);
-    // TODO(dkegel): real error handling
-    (void) OpenFileHandler(pickle, iter, &reply, &replymsg);
-    break;
-  default:
-    // TODO(dkegel): real error handling
-    LOG(ERROR) << "Unknown message kind " << kind;
-    DCHECK_EQ(0U, num_wire_fds);
-    break;
-  }
-
-  struct iovec riov = {const_cast<void *>(reply.data()), reply.size()};
-  replymsg.msg_iov = &riov;
-  replymsg.msg_iovlen = 1;
-
-  int bytes_sent;
-  bytes_sent = HANDLE_EINTR(sendmsg(server_fd_, &replymsg, MSG_WAITALL));
-  if (bytes_sent != static_cast<int>(riov.iov_len)) {
-    // TODO(dkegel): real error handling
-    LOG(ERROR) << "Can't send reply.";
-    return false;
-  }
-  return true;
-}
-
-// Called only by ChromeMain(), forks the zygote manager process.
-std::vector<std::string>* ZygoteManager::Start() {
-  DCHECK(lockfd_ == -1);
-  DCHECK(canary_fd_ == -1);
-  DCHECK(server_fd_ == -1);
-  DCHECK(client_fd_ == -1);
-
-#ifndef OFFICIAL_BUILD
-  // Disallow nested ZygoteManager servers
-  CHECK(getenv("ZYGOTE_MANAGER_STARTED") == NULL) << "already started?!";
-  (void) setenv("ZYGOTE_MANAGER_STARTED", "1", 1);
-#endif
-
-  int pipe_fds[2];
-
-  // Avoid using the reserved fd slots.
-  int reserved_fds[kReservedFds];
-  for (int i=0; i < kReservedFds; i++)
-    reserved_fds[i] = open("/dev/null", O_RDONLY, 0);
-
-  // Create the main communications pipe.
-  int err = HANDLE_EINTR(socketpair(AF_UNIX, SOCK_DGRAM, 0, pipe_fds));
-  if (err != 0) {
-    // TODO(dkegel): real error handling
-    exit(99);
-  }
-  server_fd_ = pipe_fds[1];
-  client_fd_ = pipe_fds[0];
-
-  // Create the pipe used only to relay destruction event server.
-  // Must be SOCK_STREAM so close() is sensed by poll().
-  err = HANDLE_EINTR(socketpair(AF_UNIX, SOCK_STREAM, 0, pipe_fds));
-  if (err != 0) {
-    // TODO(dkegel): real error handling
-    exit(99);
-  }
-
-  // Create lock file.
-  // TODO(dkegel): get rid of this
-  char lockfile[256];
-  strcpy(lockfile, "/tmp/zygote_manager_lock.XXXXXX");
-  lockfd_ = mkstemp(lockfile);
-  if (lockfd_ == -1) {
-    // TODO(dkegel): real error handling
-    exit(99);
-  }
-  lockfile_.assign(lockfile);
-
-  // Fork a fork server.
-  pid_t childpid = fork();
-
-  if (!childpid) {
-    for (int i=0; i < kReservedFds; i++)
-      close(reserved_fds[i]);
-
-    // Original child.  Continues on with the main program
-    // and becomes the first client.
-    close(server_fd_);
-    server_fd_ = -1;
-
-    close(pipe_fds[1]);
-    canary_fd_ = pipe_fds[0];
-
-    // Return now to indicate this is the original process.
-    return NULL;
-  } else {
-    close(lockfd_);
-
-    close(pipe_fds[0]);
-    canary_fd_ = pipe_fds[1];
-
-    // We need to accept SIGCHLD, even though our handler is a no-op because
-    // otherwise we cannot wait on children. (According to POSIX 2001.)
-    // (And otherwise poll() might not wake up on SIGCHLD.)
-    struct sigaction action;
-    memset(&action, 0, sizeof(action));
-    action.sa_handler = SIGCHLDHandler;
-    CHECK(sigaction(SIGCHLD, &action, NULL) == 0);
-
-    // Original process.  Acts as the server.
-    while (true) {
-      std::vector<std::string>* newargv = NULL;
-      if (!ReadAndHandleMessage(&newargv))
-        break;
-      if (newargv) {
-        // Return new commandline to show caller this is a new child process.
-        return newargv;
-      }
-      // Server process continues around loop.
-
-      // Reap children.
-      while (true) {
-        int status = -1;
-        pid_t reaped = waitpid(-1, &status, WNOHANG);
-        if (reaped != -1 && reaped != 0) {
-          LOG(INFO) << "Reaped pid " << reaped;
-          continue;
-        }
-        break;
-      }
-    }
-    // Server cleanup after EOF or error reading from the socket.
-    Delete(FilePath(lockfile_), false);
-    // TODO(dkegel): real error handling
-    LOG(INFO) << "exiting.  " << cached_fds_.size() << " cached fds.";
-    std::map<std::string, int>::iterator i;
-    for (i = cached_fds_.begin(); i != cached_fds_.end(); ++i) {
-      LOG(INFO) << "Closing fd " << i->second << " filename " << i->first;
-      close(i->second);
-    }
-    exit(0);
-  }
-}
-}
-#endif  // defined(OS_LINUX)
diff --git a/base/zygote_manager.h b/base/zygote_manager.h
deleted file mode 100644
index 5b94533..0000000
--- a/base/zygote_manager.h
+++ /dev/null
@@ -1,143 +0,0 @@
-// 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.
-
-#ifndef BASE_ZYGOTE_MANAGER_H_
-#define BASE_ZYGOTE_MANAGER_H_
-
-#include "build/build_config.h"
-
-#if defined(OS_LINUX)
-
-#include <sys/socket.h>
-#include <sys/types.h>
-#include <unistd.h>
-
-#include <map>
-#include <string>
-#include <utility>
-#include <vector>
-
-#include "base/pickle.h"
-#include "base/time.h"
-#include "base/process_util.h"  // for file_handle_mapping_vector
-
-namespace base {
-
-class ZygoteManager {
- public:
-  // The normal way to get a ZygoteManager is via this singleton factory.
-  static ZygoteManager* Get();
-
-  ZygoteManager() :
-      server_fd_(-1), client_fd_(-1), canary_fd_(-1), lockfd_(-1) {
-  }
-
-  ~ZygoteManager();
-
-  // Measure round trip time.  Return true on success.
-  // Only used during testing.
-  bool Ping(base::TimeDelta* delta);
-
-  // Start the zygote manager.
-  // Called only once, but returns many times.
-  // Returns once in original process and once in each spawned child.
-  // In original process, returns NULL.
-  // In child processes, returns the argv to use for the child.
-  // In Chromium, called from ChromeMain().
-  std::vector<std::string>* Start();
-
-  // Like longjmp() and base::LaunchApp().
-  // Ask the fork server to spawn a new process with
-  // the given commandline and the given file descriptors.
-  // Returns process id of copy, or -1 on failure.
-  // In Chromium, called from base::ForkApp(), which is
-  // called from BrowserRenderProcessHost::Init().
-  pid_t LongFork(const std::vector<std::string>& argv,
-    const file_handle_mapping_vector& fds_to_remap);
-
-  // Tell ZygoteManager that we expect the given process to
-  // exit on its own soon.  If it doesn't die within a few
-  // seconds, kill it.  Does not block (unless pipe to server full).
-  // In Chromium, called from ProcessWatcher::EnsureProcessTerminated().
-  void EnsureProcessTerminated(pid_t childpid);
-
-  // Open a file, or retrieve a previously cached file descriptor
-  // for this file.  The files are opened for readonly access.
-  // Caution: do not seek file descriptors returned
-  // by this API, as all children share the same file objects, so
-  // a seek on one is a seek on all.
-  // Works even if the file is unlinked after the first call
-  // (e.g. when an app is updated by the linux system autoupdater).
-  // Returns file descriptor, or -1 for error.
-  // In Chromium, called from MemoryMappedFile::MapFileToMemory().
-  // Only allows openeing files named .pak in reasonable looking locations.
-  int OpenFile(const std::string& filename);
-
- private:
-  int UnpickleHeader(const Pickle& reply, void** iter);
-
-  // Returns false on EOF
-  // Sets *newargv to a new commandline if the remote side requested a fork.
-  bool ReadAndHandleMessage(std::vector<std::string>** newargv);
-
-  void PingHandler(const Pickle& request, void* iter, Pickle* reply,
-                   std::vector<std::string>** newargv);
-
-  bool LongForkHandler(const Pickle& request, void* iter, Pickle* reply,
-                   std::vector<std::string>** newargv,
-                   const int wire_fds[], int num_wire_fds);
-
-  void EnsureProcessTerminatedHandler(const Pickle& request, void* iter);
-
-  bool OpenFileHandler(const Pickle& request, void* iter, Pickle* reply,
-      ::msghdr* msg);
-
-  // The fd used by the server to receive requests
-  int server_fd_;
-
-  // The fd used by the clients to send requests
-  int client_fd_;
-
-  // fd used only to notify server of destruction.
-  int canary_fd_;
-
-  // Temporary file used only for locking.
-  // Each client must do its own open for locking to work;
-  // inherited file descriptors can't lock each other out.
-  // FIXME: locking is lame.
-  std::string lockfile_;
-  int lockfd_;
-
-  enum message_kind_t { ZMPING, ZMPINGED,
-                ZMFORK, ZMFORKED,
-                ZMREAP,
-                ZMOPEN, ZMOPENED,
-                ZMBAD };
-
-  // See common/reserved_file_descriptors.h for who uses the reserved
-  // file descriptors.  kReservedFds is one plus the highest fd mentioned there.
-  // TODO(dkegel): move kReservedFds to reserved_file_descriptors.h
-  static const int kReservedFds = 5;
-
-  static const int kMAX_MSG_LEN = 2000;
-  static const int kMAX_CMSG_LEN = 100;
-
-  static const char kZMagic[];
-
-  char msg_buf_[kMAX_MSG_LEN];
-  char cmsg_buf_[kMAX_CMSG_LEN];
-
-  // Where we remember file descriptors for already-opened files.
-  // Both client and server maintain this table.
-  // Client should check the table before requesting the
-  // server to open a file, as it might have been already
-  // opened before this client was forked.
-  std::map<std::string, int> cached_fds_;
-};
-
-}  // namespace base
-
-#endif  // defined(OS_LINUX)
-
-#endif  // BASE_ZYGOTE_MANAGER_H_