Changeset 168 for trunk

Timestamp:

Jan 6, 2007, 7:38:01 PM (19 years ago)

Author:

dmik

Message:

Kernel/QProcess: Use spawnvpe() instead of DosExecPgm() in order to make it possible for a child process to correctly inherit LIBC file descriptors. Note though that inheritance doesn't always work correctly by now (at least for socket descriptors, see ​http://svn.netlabs.org/qtapps/ticket/6). QT_QPROCESS_USE_DOSEXECPGM can be defined to restore the old behavior.

File:

• trunk/src/kernel/qprocess_pm.cpp (modified) (10 diffs)

trunk/src/kernel/qprocess_pm.cpp

@@ -48 +48 @@
 #include "qintdict.h"
 #include "qmutex.h"
+#include "qfile.h"
 #include "private/qinternal_p.h"
 #include "qt_os2.h"
 
+// When QT_QPROCESS_USE_DOSEXECPGM is not defined, we use spawnvpe() instead of
+// DosExecPgm() to let LIBC file (pipe, socket) descriptors be properly
+// inherited if the child uses the same LIBC version.
+//#define QT_QPROCESS_USE_DOSEXECPGM
+
 #include <string.h>
+
+#if !defined(QT_QPROCESS_USE_DOSEXECPGM)
+#include <process.h>
+#include <sys/wait.h>
+#endif
 
 //#define QT_QPROCESS_DEBUG
@@ -754 +765 @@
     if ( _arguments.isEmpty() )
         return FALSE;
+
+#if defined(QT_QPROCESS_USE_DOSEXECPGM)
 
     // construct the arguments for DosExecPgm()
@@ -979 +992 @@
             appNameFull.data(), buf.data(), buf.data() + strlen( buf.data() ) + 1 ); 
 #endif
-    
+
+#else // QT_QPROCESS_USE_DOSEXECPGM
+
+    // construct the arguments for spawnvpe()
+
+    QCString appName;
+    QStrList appArgs;
+
+    for ( QStringList::ConstIterator it = _arguments.begin();
+          it != _arguments.end(); ++ it
+    ) {
+        if ( it == _arguments.begin() ) {
+            appName = QFile::encodeName( *it );
+        } else {
+            appArgs.append( QFile::encodeName( *it ) );
+        }
+    }
+
+#if defined(QT_QPROCESS_DEBUG)
+    qDebug( "QProcess::start(): [%s]",
+            QFile::encodeName( _arguments.join( "] [" ) ).data() );
+#endif
+
+    // prepare the environment
+
+    QStrList envList;
+    if ( env != 0 ) {
+        // add the user environment
+        bool seenPATH = FALSE;
+        bool seenCOMSPEC = FALSE;
+        for ( QStringList::ConstIterator it = env->begin();
+              it != env->end(); ++ it
+        ) {
+            envList.append( QFile::encodeName( *it ) );
+            if ( !seenPATH )
+                seenPATH = !strncmp( envList.current(), "PATH=", 4 );
+            if ( !seenCOMSPEC )
+                seenCOMSPEC = !strncmp( envList.current(), "COMSPEC=", 8 );
+        }
+        if ( !seenPATH ) {
+            // inherit PATH if missing (for convenience)
+            // (note that BEGINLIBPATH and ENDLIBPATH, if any, are automatically
+            // inherited, while LIBPATH is always a global setting)
+            const char *path = getenv( "PATH" );
+            QCString str( 5 /* PATH= */ + strlen( path ) + 1 /* \0 */ );
+            strcpy( str.data(), "PATH=" );
+            strcat( str.data() + 5, path );
+            envList.append( str );
+        }
+        // inherit COMSPEC if missing (to let the child start .cmd and .bat)
+        if ( !seenCOMSPEC ) {
+            const char *comspec = getenv( "COMSPEC" );
+            QCString str( 8 /* COMSPEC= */ + strlen( comspec ) + 1 /* \0 */ );
+            strcpy( str.data(), "COMSPEC=" );
+            strcat( str.data() + 5, comspec );
+            envList.append( str );
+        }
+    }
+
+    APIRET rc = 0;
+    char pathBuf[ CCHMAXPATH ];
+
+#endif // QT_QPROCESS_USE_DOSEXECPGM
+
     // create STDIN/OUT/ERR redirection pipes
     
@@ -1206 +1282 @@
 #endif
     
+#if defined(QT_QPROCESS_USE_DOSEXECPGM)
+
     // DosExecPgm()
     
@@ -1213 +1291 @@
                      buf.data(), envlist.data(), &resc, appNameFull.data() );
 
+#else // defined(QT_QPROCESS_USE_DOSEXECPGM)
+    
+    // start the application
+    
+    int i = 0;
+
+    char **argv = new char *[ appArgs.count() + 2 ];
+    argv[ i++ ] = appName.data();
+    for ( appArgs.first(); appArgs.current(); appArgs.next() )
+        argv[ i++ ] = appArgs.current();
+    argv[ i ] = NULL;
+
+    char **envv = NULL;
+    if ( envList.count() ) {
+        i = 0;
+        envv = new char *[ envList.count() + 1 ];
+        for ( envList.first(); envList.current(); envList.next() )
+            envv[ i++ ] = envList.current();
+        envv[ i ] = NULL;
+    } else {
+        envv = environ;
+    }
+
+    int pid = spawnvpe( P_NOWAIT | P_DEFAULT, appName.data(), argv, envv );
+    
+    // if spawnvpe() couldn't find the executable, try .CMD and .BAT
+    // extensions (in order of CMD.EXE precedence); spawnvpe() knows how to
+    // locate and run them (i.e. using CMD.EXE /c)
+    if ( pid == -1 && errno == ENOENT ) {
+        appName += ".cmd";
+        pid = spawnvpe( P_NOWAIT | P_DEFAULT, appName.data(), argv, envv );
+        if ( pid == -1 && errno == ENOENT ) {
+            strcpy( appName.data() + appName.length() - 4, ".bat" );
+            pid = spawnvpe( P_NOWAIT | P_DEFAULT, appName.data(), argv, envv );
+        }
+    }
+    
+    if ( envv != environ )
+        delete[] envv;
+    delete[] argv;
+    
+#endif // defined(QT_QPROCESS_USE_DOSEXECPGM)
+    
     // restore the current directory
     QDir::setCurrent( curDir );
@@ -1232 +1353 @@
     UninstallQtMsgHandler();
     
+#if defined(QT_QPROCESS_USE_DOSEXECPGM)
+
     if ( rc != NO_ERROR ) {
 #if defined(QT_CHECK_STATE) || defined(QT_QPROCESS_DEBUG)
@@ -1248 +1371 @@
     // memporize PID of the started process
     d->pid = resc.codeTerminate;
+    
+#else // defined(QT_QPROCESS_USE_DOSEXECPGM)
+
+    if ( pid == -1 ) {
+#if defined(QT_CHECK_STATE) || defined(QT_QPROCESS_DEBUG)
+        qWarning( "Failed to start a new process [%s]\n"
+                  "errno=%d (%s)",
+                  QFile::encodeName( _arguments.join( "] [" ) ).data(),
+                  errno, strerror( errno ) );
+#endif
+        processMonitor->removeProcess( d );
+        d->closeHandles();
+        return FALSE;
+    }
+
+    // memporize PID of the started process
+    d->pid = pid;
+
+#endif // defined(QT_QPROCESS_USE_DOSEXECPGM)
+
+#if defined(QT_QPROCESS_DEBUG)
+    qDebug( "QProcess::start(): started PID %lu (0x%08lX)", d->pid, d->pid ); 
+#endif
     
     // timer is not necessary for ioRedirection (we use the monitor thread)
@@ -1297 +1443 @@
         return FALSE;
 
+#if defined(QT_QPROCESS_USE_DOSEXECPGM)
+    
     PID pidEnded = PID_NULL;
     RESULTCODES resc = { 0 };
@@ -1305 +1453 @@
         return TRUE;
 
+#else // defined(QT_QPROCESS_USE_DOSEXECPGM)
+
+    int stat = 0;
+    int pid = waitpid( d->pid, &stat, WNOHANG );
+    if ( (pid == 0) ||
+         ((PID) pid == d->pid &&
+          !WIFEXITED( stat ) && !WIFSIGNALED( stat ) && !WIFSTOPPED( stat ) ) )
+        return TRUE;
+
+    if ( pid == -1 ) {
+#if defined(QT_CHECK_STATE) || defined(QT_QPROCESS_DEBUG)
+        qWarning( "Failed to wait for a child process\n"
+                  "errno=%d (%s)", errno, strerror( errno ) );
+#endif
+    }
+
+#endif // defined(QT_QPROCESS_USE_DOSEXECPGM)
+    
     QProcess *that = (QProcess *) this;
 
@@ -1318 +1484 @@
     // compute the exit values
     if ( !d->exitValuesCalculated ) {
+#if defined(QT_QPROCESS_USE_DOSEXECPGM)
         that->exitNormal = resc.codeTerminate == TC_EXIT;
         that->exitStat = resc.codeResult;
+#else // defined(QT_QPROCESS_USE_DOSEXECPGM)
+        that->exitNormal = pid != -1 && WIFEXITED( stat );
+        that->exitStat = WEXITSTATUS( stat );
+#endif // defined(QT_QPROCESS_USE_DOSEXECPGM)
         d->exitValuesCalculated = TRUE;
     }