1 files changed, 268 insertions, 0 deletions

diff --git a/libopie/oprocctrl.cpp b/libopie/oprocctrl.cpp
new file mode 100644
index 0000000..e7db622
--- a/dev/null
+++ b/libopie/oprocctrl.cpp
@@ -0,0 +1,268 @@
+/* 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., 59 Temple Place - Suite 330,
+    Boston, MA 02111-1307, USA.
+*/
+//
+//  KPROCESSCONTROLLER -- A helper class for KProcess
+//
+//  version 0.3.1, Jan, 8th 1997
+//
+//  (C) Christian Czezatke
+//  e9025461@student.tuwien.ac.at
+//  Ported by Holger Freyther
+//
+
+//#include <config.h>
+
+#include <sys/types.h>
+#include <sys/socket.h>
+
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+#include <assert.h>
+
+#include <qsocketnotifier.h>
+#include "oprocess.h"
+#include "oprocctrl.h"
+
+OProcessController *OProcessController::theOProcessController = 0;
+
+struct sigaction OProcessController::oldChildHandlerData;
+bool OProcessController::handlerSet = false;
+
+OProcessController::OProcessController()
+{
+  assert( theOProcessController == 0 );
+
+  if (0 > pipe(fd))
+        printf(strerror(errno));
+
+  notifier = new QSocketNotifier(fd[0], QSocketNotifier::Read);
+  notifier->setEnabled(true);
+  QObject::connect(notifier, SIGNAL(activated(int)),
+                                   this, SLOT(slotDoHousekeeping(int)));
+  connect( &delayedChildrenCleanupTimer, SIGNAL( timeout()),
+      SLOT( delayedChildrenCleanup()));
+
+  theOProcessController = this;
+
+  setupHandlers();
+}
+
+
+void OProcessController::setupHandlers()
+{
+  if( handlerSet )
+      return;
+  struct sigaction act;
+  act.sa_handler=theSigCHLDHandler;
+  sigemptyset(&(act.sa_mask));
+  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);
+
+  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 );
+
+  act.sa_handler=SIG_IGN;
+  sigemptyset(&(act.sa_mask));
+  sigaddset(&(act.sa_mask), SIGPIPE);
+  act.sa_flags = 0;
+  sigaction( SIGPIPE, &act, 0L);
+  handlerSet = true;
+}
+
+void OProcessController::resetHandlers()
+{
+  if( !handlerSet )
+      return;
+  sigaction( SIGCHLD, &oldChildHandlerData, 0 );
+  // there should be no problem with SIGPIPE staying SIG_IGN
+  handlerSet = false;
+}
+
+// block SIGCHLD handler, because it accesses processList
+void OProcessController::addOProcess( OProcess* p )
+{
+  sigset_t newset, oldset;
+  sigemptyset( &newset );
+  sigaddset( &newset, SIGCHLD );
+  sigprocmask( SIG_BLOCK, &newset, &oldset );
+  processList.append( p );
+  sigprocmask( SIG_SETMASK, &oldset, 0 );
+}
+
+void OProcessController::removeOProcess( OProcess* p )
+{
+  sigset_t newset, oldset;
+  sigemptyset( &newset );
+  sigaddset( &newset, SIGCHLD );
+  sigprocmask( SIG_BLOCK, &newset, &oldset );
+  processList.remove( p );
+  sigprocmask( SIG_SETMASK, &oldset, 0 );
+}
+
+//using a struct which contains both the pid and the status makes it easier to write
+//and read the data into the pipe
+//especially this solves a problem which appeared on my box where slotDoHouseKeeping() received
+//only 4 bytes (with some debug output around the write()'s it received all 8 bytes)
+//don't know why this happened, but when writing all 8 bytes at once it works here, aleXXX
+struct waitdata
+{
+  pid_t pid;
+  int status;
+};
+
+void OProcessController::theSigCHLDHandler(int arg)
+{
+  struct waitdata wd;
+//  int status;
+//  pid_t this_pid;
+  int saved_errno;
+
+  saved_errno = errno;
+  // since waitpid and write change errno, we have to save it and restore it
+  // (Richard Stevens, Advanced programming in the Unix Environment)
+
+  bool found = false;
+  if( theOProcessController != 0 ) {
+      // iterating the list doesn't perform any system call
+      for( QValueList<OProcess*>::ConstIterator it = theOProcessController->processList.begin();
+           it != theOProcessController->processList.end();
+           ++it )
+      {
+        if( !(*it)->isRunning())
+            continue;
+        wd.pid = waitpid( (*it)->pid(), &wd.status, WNOHANG );
+        if ( wd.pid > 0 ) {
+          ::write(theOProcessController->fd[1], &wd, sizeof(wd));
+          found = true;
+        }
+      }
+  }
+  if( !found && oldChildHandlerData.sa_handler != SIG_IGN
+          && oldChildHandlerData.sa_handler != SIG_DFL )
+        oldChildHandlerData.sa_handler( arg ); // call the old handler
+  // handle the rest
+  if( theOProcessController != 0 ) {
+     static const struct waitdata dwd = { 0, 0 }; // delayed waitpid()
+     ::write(theOProcessController->fd[1], &dwd, sizeof(dwd));
+  } else {
+      int dummy;
+      while( waitpid( -1, &dummy, WNOHANG ) > 0 )
+          ;
+  }
+
+  errno = saved_errno;
+}
+
+
+
+void OProcessController::slotDoHousekeeping(int )
+{
+  unsigned int bytes_read = 0;
+  unsigned int errcnt=0;
+  // read pid and status from the pipe.
+  struct waitdata wd;
+  while ((bytes_read < sizeof(wd)) && (errcnt < 50)) {
+    int r = ::read(fd[0], ((char *)&wd) + bytes_read, sizeof(wd) - bytes_read);
+    if (r > 0) bytes_read += r;
+    else if (r < 0) errcnt++;
+  }
+  if (errcnt >= 50) {
+        fprintf(stderr,
+               "Error: Max. error count for pipe read "
+               "exceeded in OProcessController::slotDoHousekeeping\n");
+        return;           // it makes no sense to continue here!
+  }
+  if (bytes_read != sizeof(wd)) {
+        fprintf(stderr,
+               "Error: Could not read info from signal handler %d <> %d!\n",
+               bytes_read, sizeof(wd));
+        return;           // it makes no sense to continue here!
+  }
+  if (wd.pid==0) { // special case, see delayedChildrenCleanup()
+      delayedChildrenCleanupTimer.start( 1000, true );
+      return;
+  }
+
+  for( QValueList<OProcess*>::ConstIterator it = processList.begin();
+       it != processList.end();
+       ++it ) {
+        OProcess* proc = *it;
+        if (proc->pid() == wd.pid) {
+          // process has exited, so do emit the respective events
+          if (proc->run_mode == OProcess::Block) {
+            // If the reads are done blocking then set the status in proc
+            // but do nothing else because OProcess will perform the other
+            // actions of processHasExited.
+            proc->status = wd.status;
+            proc->runs = false;
+          } else {
+            proc->processHasExited(wd.status);
+          }
+        return;
+        }
+  }
+}
+
+// this is needed e.g. for popen(), which calls waitpid() checking
+// for its forked child, if we did waitpid() directly in the SIGCHLD
+// handler, popen()'s waitpid() call would fail
+void OProcessController::delayedChildrenCleanup()
+{
+  struct waitdata wd;
+  while(( wd.pid = waitpid( -1, &wd.status, WNOHANG ) ) > 0 ) {
+      for( QValueList<OProcess*>::ConstIterator it = processList.begin();
+           it != processList.end();
+           ++it )
+      {
+        if( !(*it)->isRunning() || (*it)->pid() != wd.pid )
+            continue;
+        // it's OProcess, handle it
+        ::write(fd[1], &wd, sizeof(wd));
+        break;
+      }
+  }
+}
+
+OProcessController::~OProcessController()
+{
+  assert( theOProcessController == this );
+  resetHandlers();
+
+  notifier->setEnabled(false);
+
+  close(fd[0]);
+  close(fd[1]);
+
+  delete notifier;
+  theOProcessController = 0;
+}
+
+//#include "kprocctrl.moc"