summaryrefslogtreecommitdiffstats
path: root/tdecore/kprocctrl.cpp
blob: 6774eee5fe2420bb1a1cf2fd76efab7405ee3d57 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
/* This file is part of the KDE libraries
    Copyright (C) 1997 Christian Czezakte (e9025461@student.tuwien.ac.at)

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Library General Public
    License as published by the Free Software Foundation; either
    version 2 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    Library General Public License for more details.

    You should have received a copy of the GNU Library General Public License
    along with this library; see the file COPYING.LIB.  If not, write to
    the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
    Boston, MA 02110-1301, USA.
*/

#include "kprocess.h"
#include "kprocctrl.h"

#include <config.h>

#include <sys/time.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>

#include <tqsocketnotifier.h>

KProcessController *KProcessController::theKProcessController;
int KProcessController::refCount;

void KProcessController::ref()
{
  if( !refCount ) {
    theKProcessController = new KProcessController;
    setupHandlers();
  }
  refCount++;
}

void KProcessController::deref()
{
  refCount--;
  if( !refCount ) {
    resetHandlers();
    delete theKProcessController;
    theKProcessController = 0;
  }
}

KProcessController::KProcessController()
  : needcheck( false )
{
  if( pipe( fd ) )
  {
    perror( "pipe" );
    abort();
  }

  fcntl( fd[0], F_SETFL, O_NONBLOCK ); // in case slotDoHousekeeping is called without polling first
  fcntl( fd[1], F_SETFL, O_NONBLOCK ); // in case it fills up
  fcntl( fd[0], F_SETFD, FD_CLOEXEC );
  fcntl( fd[1], F_SETFD, FD_CLOEXEC );

  notifier = new TQSocketNotifier( fd[0], TQSocketNotifier::Read );
  notifier->setEnabled( true );
  TQObject::connect( notifier, TQT_SIGNAL(activated(int)),
                    TQT_SLOT(slotDoHousekeeping()));
}

KProcessController::~KProcessController()
{
  delete notifier;

  close( fd[0] );
  close( fd[1] );
}


extern "C" {
static void theReaper( int num )
{
  KProcessController::theSigCHLDHandler( num );
}
}

#ifdef Q_OS_UNIX
struct sigaction KProcessController::oldChildHandlerData;
#endif
bool KProcessController::handlerSet = false;

void KProcessController::setupHandlers()
{
  if( handlerSet )
      return;
  handlerSet = true;

#ifdef Q_OS_UNIX
  struct sigaction act;
  sigemptyset( &act.sa_mask );

  act.sa_handler = SIG_IGN;
  act.sa_flags = 0;
  sigaction( SIGPIPE, &act, 0L );

  act.sa_handler = theReaper;
  act.sa_flags = SA_NOCLDSTOP;
  // CC: take care of SunOS which automatically restarts interrupted system
  // calls (and thus does not have SA_RESTART)
#ifdef SA_RESTART
  act.sa_flags |= SA_RESTART;
#endif
  sigaction( SIGCHLD, &act, &oldChildHandlerData );

  sigaddset( &act.sa_mask, SIGCHLD );
  // Make sure we don't block this signal. gdb tends to do that :-(
  sigprocmask( SIG_UNBLOCK, &act.sa_mask, 0 );
#else
  //TODO: win32
#endif
}

void KProcessController::resetHandlers()
{
  if( !handlerSet )
      return;
  handlerSet = false;

#ifdef Q_OS_UNIX
  sigaction( SIGCHLD, &oldChildHandlerData, 0 );
#else
  //TODO: win32
#endif
  // there should be no problem with SIGPIPE staying SIG_IGN
}

// the pipe is needed to sync the child reaping with our event processing,
// as otherwise there are race conditions, locking requirements, and things
// generally get harder
void KProcessController::theSigCHLDHandler( int arg )
{
  int saved_errno = errno;

  char dummy = 0;
  ::write( theKProcessController->fd[1], &dummy, 1 );

#ifdef Q_OS_UNIX
  if( oldChildHandlerData.sa_handler != SIG_IGN &&
      oldChildHandlerData.sa_handler != SIG_DFL )
     oldChildHandlerData.sa_handler( arg ); // call the old handler
#else
  //TODO: win32
#endif

  errno = saved_errno;
}

int KProcessController::notifierFd() const
{
  return fd[0];
}

void KProcessController::unscheduleCheck()
{
  char dummy[16]; // somewhat bigger - just in case several have queued up
  if( ::read( fd[0], dummy, sizeof(dummy) ) > 0 )
    needcheck = true;
}

void
KProcessController::rescheduleCheck()
{
  if( needcheck )
  {
    needcheck = false;
    char dummy = 0;
    ::write( fd[1], &dummy, 1 );
  }
}

void KProcessController::slotDoHousekeeping()
{
  char dummy[16]; // somewhat bigger - just in case several have queued up
  ::read( fd[0], dummy, sizeof(dummy) );

  int status;
 again:
  TQValueListIterator<KProcess*> it( kProcessList.begin() );
  TQValueListIterator<KProcess*> eit( kProcessList.end() );
  while( it != eit )
  {
    KProcess *prc = *it;
    if( prc->runs && waitpid( prc->pid_, &status, WNOHANG ) > 0 )
    {
      prc->processHasExited( status );
      // the callback can nuke the whole process list and even 'this'
      if (!theKProcessController)
        return;
      goto again;
    }
    ++it;
  }
  TQValueListIterator<int> uit( unixProcessList.begin() );
  TQValueListIterator<int> ueit( unixProcessList.end() );
  while( uit != ueit )
  {
    if( waitpid( *uit, 0, WNOHANG ) > 0 )
    {
      uit = unixProcessList.remove( uit );
      deref(); // counterpart to addProcess, can tqinvalidate 'this'
    } else
      ++uit;
  }
}

bool KProcessController::waitForProcessExit( int timeout )
{
#ifdef Q_OS_UNIX
  for(;;)
  {
    struct timeval tv, *tvp;
    if (timeout < 0)
      tvp = 0;
    else
    {
      tv.tv_sec = timeout;
      tv.tv_usec = 0;
      tvp = &tv;
    }

    fd_set fds;
    FD_ZERO( &fds );
    FD_SET( fd[0], &fds );

    switch( select( fd[0]+1, &fds, 0, 0, tvp ) )
    {
    case -1:
      if( errno == EINTR )
        continue;
      // fall through; should never happen
    case 0:
      return false;
    default:
      slotDoHousekeeping();
      return true;
    }
  }
#else
  //TODO: win32
  return false;
#endif
}

void KProcessController::addKProcess( KProcess* p )
{
  kProcessList.append( p );
}

void KProcessController::removeKProcess( KProcess* p )
{
  kProcessList.remove( p );
}

void KProcessController::addProcess( int pid )
{
  unixProcessList.append( pid );
  ref(); // make sure we stay around when the KProcess goes away
}

#include "kprocctrl.moc"