| -rw-r--r-- | libopie/oprocctrl.cpp | 268 |
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" |