Chromium roll (https://codereview.chromium.org/976353002)

base/process/kill_posix.cc

 // Copyright (c) 2013 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/process/kill.h"
 
 #include <signal.h>
 #include <sys/types.h>
 #include <sys/wait.h>
 #include <unistd.h>
 
 #include "base/files/file_util.h"
 #include "base/files/scoped_file.h"
 #include "base/logging.h"
 #include "base/posix/eintr_wrapper.h"
 #include "base/process/process_iterator.h"
 #include "base/synchronization/waitable_event.h"
 #include "base/third_party/dynamic_annotations/dynamic_annotations.h"
 #include "base/threading/platform_thread.h"
 
 namespace base {
 
 namespace {
 
-#if !defined(OS_NACL_NONSFI)
-bool WaitpidWithTimeout(ProcessHandle handle,
-                        int* status,
-                        base::TimeDelta wait) {
-  // This POSIX version of this function only guarantees that we wait no less
-  // than |wait| for the process to exit.  The child process may
-  // exit sometime before the timeout has ended but we may still block for up
-  // to 256 milliseconds after the fact.
-  //
-  // waitpid() has no direct support on POSIX for specifying a timeout, you can
-  // either ask it to block indefinitely or return immediately (WNOHANG).
-  // When a child process terminates a SIGCHLD signal is sent to the parent.
-  // Catching this signal would involve installing a signal handler which may
-  // affect other parts of the application and would be difficult to debug.
-  //
-  // Our strategy is to call waitpid() once up front to check if the process
-  // has already exited, otherwise to loop for |wait|, sleeping for
-  // at most 256 milliseconds each time using usleep() and then calling
-  // waitpid().  The amount of time we sleep starts out at 1 milliseconds, and
-  // we double it every 4 sleep cycles.
-  //
-  // usleep() is speced to exit if a signal is received for which a handler
-  // has been installed.  This means that when a SIGCHLD is sent, it will exit
-  // depending on behavior external to this function.
-  //
-  // This function is used primarily for unit tests, if we want to use it in
-  // the application itself it would probably be best to examine other routes.
-
-  if (wait.InMilliseconds() == base::kNoTimeout) {
-    return HANDLE_EINTR(waitpid(handle, status, 0)) > 0;
-  }
-
-  pid_t ret_pid = HANDLE_EINTR(waitpid(handle, status, WNOHANG));
-  static const int64 kMaxSleepInMicroseconds = 1 << 18;  // ~256 milliseconds.
-  int64 max_sleep_time_usecs = 1 << 10;  // ~1 milliseconds.
-  int64 double_sleep_time = 0;
-
-  // If the process hasn't exited yet, then sleep and try again.
-  TimeTicks wakeup_time = TimeTicks::Now() + wait;
-  while (ret_pid == 0) {
-    TimeTicks now = TimeTicks::Now();
-    if (now > wakeup_time)
-      break;
-    // Guaranteed to be non-negative!
-    int64 sleep_time_usecs = (wakeup_time - now).InMicroseconds();
-    // Sleep for a bit while we wait for the process to finish.
-    if (sleep_time_usecs > max_sleep_time_usecs)
-      sleep_time_usecs = max_sleep_time_usecs;
-
-    // usleep() will return 0 and set errno to EINTR on receipt of a signal
-    // such as SIGCHLD.
-    usleep(sleep_time_usecs);
-    ret_pid = HANDLE_EINTR(waitpid(handle, status, WNOHANG));
-
-    if ((max_sleep_time_usecs < kMaxSleepInMicroseconds) &&
-        (double_sleep_time++ % 4 == 0)) {
-      max_sleep_time_usecs *= 2;
-    }
-  }
-
-  return ret_pid > 0;
-}
-
-#if defined(OS_MACOSX)
-// Using kqueue on Mac so that we can wait on non-child processes.
-// We can't use kqueues on child processes because we need to reap
-// our own children using wait.
-static bool WaitForSingleNonChildProcess(ProcessHandle handle,
-                                         TimeDelta wait) {
-  DCHECK_GT(handle, 0);
-  DCHECK(wait.InMilliseconds() == kNoTimeout || wait > TimeDelta());
-
-  ScopedFD kq(kqueue());
-  if (!kq.is_valid()) {
-    DPLOG(ERROR) << "kqueue";
-    return false;
-  }
-
-  struct kevent change = {0};
-  EV_SET(&change, handle, EVFILT_PROC, EV_ADD, NOTE_EXIT, 0, NULL);
-  int result = HANDLE_EINTR(kevent(kq.get(), &change, 1, NULL, 0, NULL));
-  if (result == -1) {
-    if (errno == ESRCH) {
-      // If the process wasn't found, it must be dead.
-      return true;
-    }
-
-    DPLOG(ERROR) << "kevent (setup " << handle << ")";
-    return false;
-  }
-
-  // Keep track of the elapsed time to be able to restart kevent if it's
-  // interrupted.
-  bool wait_forever = wait.InMilliseconds() == kNoTimeout;
-  TimeDelta remaining_delta;
-  TimeTicks deadline;
-  if (!wait_forever) {
-    remaining_delta = wait;
-    deadline = TimeTicks::Now() + remaining_delta;
-  }
-
-  result = -1;
-  struct kevent event = {0};
-
-  while (wait_forever || remaining_delta > TimeDelta()) {
-    struct timespec remaining_timespec;
-    struct timespec* remaining_timespec_ptr;
-    if (wait_forever) {
-      remaining_timespec_ptr = NULL;
-    } else {
-      remaining_timespec = remaining_delta.ToTimeSpec();
-      remaining_timespec_ptr = &remaining_timespec;
-    }
-
-    result = kevent(kq.get(), NULL, 0, &event, 1, remaining_timespec_ptr);
-
-    if (result == -1 && errno == EINTR) {
-      if (!wait_forever) {
-        remaining_delta = deadline - TimeTicks::Now();
-      }
-      result = 0;
-    } else {
-      break;
-    }
-  }
-
-  if (result < 0) {
-    DPLOG(ERROR) << "kevent (wait " << handle << ")";
-    return false;
-  } else if (result > 1) {
-    DLOG(ERROR) << "kevent (wait " << handle << "): unexpected result "
-                << result;
-    return false;
-  } else if (result == 0) {
-    // Timed out.
-    return false;
-  }
-
-  DCHECK_EQ(result, 1);
-
-  if (event.filter != EVFILT_PROC ||
-      (event.fflags & NOTE_EXIT) == 0 ||
-      event.ident != static_cast<uintptr_t>(handle)) {
-    DLOG(ERROR) << "kevent (wait " << handle
-                << "): unexpected event: filter=" << event.filter
-                << ", fflags=" << event.fflags
-                << ", ident=" << event.ident;
-    return false;
-  }
-
-  return true;
-}
-#endif  // OS_MACOSX
-#endif  // !defined(OS_NACL_NONSFI)
-
 TerminationStatus GetTerminationStatusImpl(ProcessHandle handle,
                                            bool can_block,
                                            int* exit_code) {
   int status = 0;
   const pid_t result = HANDLE_EINTR(waitpid(handle, &status,
                                             can_block ? 0 : WNOHANG));
   if (result == -1) {
     DPLOG(ERROR) << "waitpid(" << handle << ")";
     if (exit_code)
       *exit_code = 0;
@@ skipping 105 matching lines @@
                                                 int* exit_code) {
   bool result = kill(handle, SIGKILL) == 0;
 
   if (!result)
     DPLOG(ERROR) << "Unable to terminate process " << handle;
 
   return GetTerminationStatusImpl(handle, true /* can_block */, exit_code);
 }
 
 #if !defined(OS_NACL_NONSFI)
-bool WaitForExitCode(ProcessHandle handle, int* exit_code) {
-  int status;
-  if (HANDLE_EINTR(waitpid(handle, &status, 0)) == -1) {
-    NOTREACHED();
-    return false;
-  }
-
-  if (WIFEXITED(status)) {
-    *exit_code = WEXITSTATUS(status);
-    return true;
-  }
-
-  // If it didn't exit cleanly, it must have been signaled.
-  DCHECK(WIFSIGNALED(status));
-  return false;
-}
-
-bool WaitForExitCodeWithTimeout(ProcessHandle handle,
-                                int* exit_code,
-                                TimeDelta timeout) {
-  ProcessHandle parent_pid = GetParentProcessId(handle);
-  ProcessHandle our_pid = GetCurrentProcessHandle();
-  if (parent_pid != our_pid) {
-#if defined(OS_MACOSX)
-    // On Mac we can wait on non child processes.
-    return WaitForSingleNonChildProcess(handle, timeout);
-#else
-    // Currently on Linux we can't handle non child processes.
-    NOTIMPLEMENTED();
-#endif  // OS_MACOSX
-  }
-
-  int status;
-  if (!WaitpidWithTimeout(handle, &status, timeout))
-    return false;
-  if (WIFSIGNALED(status)) {
-    *exit_code = -1;
-    return true;
-  }
-  if (WIFEXITED(status)) {
-    *exit_code = WEXITSTATUS(status);
-    return true;
-  }
-  return false;
-}
-
 bool WaitForProcessesToExit(const FilePath::StringType& executable_name,
                             TimeDelta wait,
                             const ProcessFilter* filter) {
   bool result = false;
 
   // TODO(port): This is inefficient, but works if there are multiple procs.
   // TODO(port): use waitpid to avoid leaving zombies around
 
   TimeTicks end_time = TimeTicks::Now() + wait;
   do {
@@ skipping 111 matching lines @@
     return;
 
   BackgroundReaper* reaper = new BackgroundReaper(pid, 0);
   PlatformThread::CreateNonJoinable(0, reaper);
 }
 
 #endif  // !defined(OS_MACOSX)
 #endif  // !defined(OS_NACL_NONSFI)
 
 }  // namespace base