LCOV - code coverage report
Current view: directory - ipc/chromium/src/chrome/common - process_watcher_posix_sigchld.cc (source / functions) Found Hit Coverage
Test: app.info Lines: 74 0 0.0 %
Date: 2012-06-02 Functions: 17 0 0.0 %

       1                 : /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
       2                 :  * vim: set ts=8 et sw=2 tw=80: 
       3                 :  */
       4                 : /* ***** BEGIN LICENSE BLOCK *****
       5                 :  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
       6                 :  *
       7                 :  * The contents of this file are subject to the Mozilla Public License Version
       8                 :  * 1.1 (the "License"); you may not use this file except in compliance with
       9                 :  * the License. You may obtain a copy of the License at
      10                 :  * http://www.mozilla.org/MPL/
      11                 :  *
      12                 :  * Software distributed under the License is distributed on an "AS IS" basis,
      13                 :  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
      14                 :  * for the specific language governing rights and limitations under the
      15                 :  * License.
      16                 :  *
      17                 :  * The Original Code is Mozilla IPC.
      18                 :  *
      19                 :  * The Initial Developer of the Original Code is
      20                 :  *   Mozilla Foundation
      21                 :  * Portions created by the Initial Developer are Copyright (C) 2009
      22                 :  * the Initial Developer. All Rights Reserved.
      23                 :  *
      24                 :  * Contributor(s):
      25                 :  *   Chris Jones <jones.chris.g@gmail.com>
      26                 :  *
      27                 :  * Alternatively, the contents of this file may be used under the terms of
      28                 :  * either the GNU General Public License Version 2 or later (the "GPL"), or
      29                 :  * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
      30                 :  * in which case the provisions of the GPL or the LGPL are applicable instead
      31                 :  * of those above. If you wish to allow use of your version of this file only
      32                 :  * under the terms of either the GPL or the LGPL, and not to allow others to
      33                 :  * use your version of this file under the terms of the MPL, indicate your
      34                 :  * decision by deleting the provisions above and replace them with the notice
      35                 :  * and other provisions required by the GPL or the LGPL. If you do not delete
      36                 :  * the provisions above, a recipient may use your version of this file under
      37                 :  * the terms of any one of the MPL, the GPL or the LGPL.
      38                 :  *
      39                 :  * ***** END LICENSE BLOCK ***** */
      40                 : 
      41                 : //-----------------------------------------------------------------------------
      42                 : //   XXXXXXXXXXXXXXXX
      43                 : //
      44                 : // How is this code supposed to be licensed?  I don't /think/ that
      45                 : // this code is doing anything different than, say,
      46                 : // GeckoChildProcess.h/cpp, so I /think/ this gets a MoFo copyright
      47                 : // and license.  Yes?
      48                 : //
      49                 : //   XXXXXXXXXXXXXXXX
      50                 : //-----------------------------------------------------------------------------
      51                 : 
      52                 : #include <errno.h>
      53                 : #include <signal.h>
      54                 : #include <sys/types.h>
      55                 : #include <sys/wait.h>
      56                 : 
      57                 : #include "base/eintr_wrapper.h"
      58                 : #include "base/message_loop.h"
      59                 : #include "base/process_util.h"
      60                 : 
      61                 : #include "chrome/common/process_watcher.h"
      62                 : 
      63                 : // Maximum amount of time (in milliseconds) to wait for the process to exit.
      64                 : // XXX/cjones: fairly arbitrary, chosen to match process_watcher_win.cc
      65                 : static const int kMaxWaitMs = 2000;
      66                 : 
      67                 : namespace {
      68                 : 
      69                 : bool
      70               0 : IsProcessDead(pid_t process)
      71                 : {
      72               0 :   bool exited = false;
      73                 :   // don't care if the process crashed, just if it exited
      74               0 :   base::DidProcessCrash(&exited, process);
      75               0 :   return exited;
      76                 : }
      77                 : 
      78                 : 
      79                 : class ChildReaper : public base::MessagePumpLibevent::SignalEvent,
      80                 :                     public base::MessagePumpLibevent::SignalWatcher
      81                 : {
      82                 : public:
      83               0 :   explicit ChildReaper(pid_t process) : process_(process)
      84                 :   {
      85               0 :   } 
      86                 : 
      87               0 :   virtual ~ChildReaper()
      88               0 :   {
      89                 :     // subclasses should have cleaned up |process_| already
      90               0 :     DCHECK(!process_);
      91                 : 
      92                 :     // StopCatching() is implicit
      93               0 :   }
      94                 : 
      95                 :   // @override
      96               0 :   virtual void OnSignal(int sig)
      97                 :   {
      98               0 :     DCHECK(SIGCHLD == sig);
      99               0 :     DCHECK(process_);
     100                 : 
     101                 :     // this may be the SIGCHLD for a process other than |process_|
     102               0 :     if (IsProcessDead(process_)) {
     103               0 :       process_ = 0;
     104               0 :       StopCatching();
     105                 :     }
     106               0 :   }
     107                 : 
     108                 : protected:
     109               0 :   void WaitForChildExit()
     110                 :   {
     111               0 :     DCHECK(process_);
     112               0 :     HANDLE_EINTR(waitpid(process_, NULL, 0));
     113               0 :   }
     114                 : 
     115                 :   pid_t process_;
     116                 : 
     117                 : private:
     118                 :   DISALLOW_EVIL_CONSTRUCTORS(ChildReaper);
     119                 : };
     120                 : 
     121                 : 
     122                 : // Fear the reaper
     123                 : class ChildGrimReaper : public ChildReaper,
     124                 :                         public Task
     125                 : {
     126                 : public:
     127               0 :   explicit ChildGrimReaper(pid_t process) : ChildReaper(process)
     128                 :   {
     129               0 :   } 
     130                 : 
     131               0 :   virtual ~ChildGrimReaper()
     132               0 :   {
     133               0 :     if (process_)
     134               0 :       KillProcess();
     135               0 :   }
     136                 : 
     137                 :   // @override
     138               0 :   virtual void Run()
     139                 :   {
     140                 :     // we may have already been signaled by the time this runs
     141               0 :     if (process_)
     142               0 :       KillProcess();
     143               0 :   }
     144                 : 
     145                 : private:
     146               0 :   void KillProcess()
     147                 :   {
     148               0 :     DCHECK(process_);
     149                 : 
     150               0 :     if (IsProcessDead(process_)) {
     151               0 :       process_ = 0;
     152               0 :       return;
     153                 :     }
     154                 : 
     155               0 :     if (0 == kill(process_, SIGKILL)) {
     156                 :       // XXX this will block for whatever amount of time it takes the
     157                 :       // XXX OS to tear down the process's resources.  might need to
     158                 :       // XXX rethink this if it proves expensive
     159               0 :       WaitForChildExit();
     160                 :     }
     161                 :     else {
     162               0 :       LOG(ERROR) << "Failed to deliver SIGKILL to " << process_ << "!"
     163               0 :                  << "("<< errno << ").";
     164                 :     }
     165               0 :     process_ = 0;
     166                 :   }
     167                 : 
     168                 :   DISALLOW_EVIL_CONSTRUCTORS(ChildGrimReaper);
     169                 : };
     170                 : 
     171                 : 
     172                 : class ChildLaxReaper : public ChildReaper,
     173                 :                        public MessageLoop::DestructionObserver
     174                 : {
     175                 : public:
     176               0 :   explicit ChildLaxReaper(pid_t process) : ChildReaper(process)
     177                 :   {
     178               0 :   } 
     179                 : 
     180               0 :   virtual ~ChildLaxReaper()
     181               0 :   {
     182                 :     // WillDestroyCurrentMessageLoop() should have reaped process_ already
     183               0 :     DCHECK(!process_);
     184               0 :   }
     185                 : 
     186                 :   // @override
     187               0 :   virtual void OnSignal(int sig)
     188                 :   {
     189               0 :     ChildReaper::OnSignal(sig);
     190                 : 
     191               0 :     if (!process_) {
     192               0 :       MessageLoop::current()->RemoveDestructionObserver(this);
     193               0 :       delete this;
     194                 :     }
     195               0 :   }
     196                 : 
     197                 :   // @override
     198               0 :   virtual void WillDestroyCurrentMessageLoop()
     199                 :   {
     200               0 :     DCHECK(process_);
     201                 : 
     202               0 :     WaitForChildExit();
     203               0 :     process_ = 0;
     204                 : 
     205                 :     // XXX don't think this is necessary, since destruction can only
     206                 :     // be observed once, but can't hurt
     207               0 :     MessageLoop::current()->RemoveDestructionObserver(this);
     208               0 :     delete this;
     209               0 :   }
     210                 : 
     211                 : private:
     212                 :   DISALLOW_EVIL_CONSTRUCTORS(ChildLaxReaper);
     213                 : };
     214                 : 
     215                 : }  // namespace <anon>
     216                 : 
     217                 : 
     218                 : /**
     219                 :  * Do everything possible to ensure that |process| has been reaped
     220                 :  * before this process exits.
     221                 :  *
     222                 :  * |grim| decides how strict to be with the child's shutdown.
     223                 :  *
     224                 :  *                | child exit timeout | upon parent shutdown:
     225                 :  *                +--------------------+----------------------------------
     226                 :  *   force=true   | 2 seconds          | kill(child, SIGKILL)
     227                 :  *   force=false  | infinite           | waitpid(child)
     228                 :  *
     229                 :  * If a child process doesn't shut down properly, and |grim=false|
     230                 :  * used, then the parent will wait on the child forever.  So,
     231                 :  * |force=false| is expected to be used when an external entity can be
     232                 :  * responsible for terminating hung processes, e.g. automated test
     233                 :  * harnesses.
     234                 :  */
     235                 : void
     236               0 : ProcessWatcher::EnsureProcessTerminated(base::ProcessHandle process,
     237                 :                                         bool force)
     238                 : {
     239               0 :   DCHECK(process != base::GetCurrentProcId());
     240               0 :   DCHECK(process > 0);
     241                 : 
     242               0 :   if (IsProcessDead(process))
     243               0 :     return;
     244                 : 
     245               0 :   MessageLoopForIO* loop = MessageLoopForIO::current();
     246               0 :   if (force) {
     247               0 :     ChildGrimReaper* reaper = new ChildGrimReaper(process);
     248                 : 
     249               0 :     loop->CatchSignal(SIGCHLD, reaper, reaper);
     250                 :     // |loop| takes ownership of |reaper|
     251               0 :     loop->PostDelayedTask(FROM_HERE, reaper, kMaxWaitMs);
     252                 :   } else {
     253               0 :     ChildLaxReaper* reaper = new ChildLaxReaper(process);
     254                 : 
     255               0 :     loop->CatchSignal(SIGCHLD, reaper, reaper);
     256                 :     // |reaper| destroys itself after destruction notification
     257               0 :     loop->AddDestructionObserver(reaper);
     258                 :   }
     259                 : }

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