QGIS » QGIS Application

Still happening as of today. Any idea ?

Valgrind view on the matter:

src/providers/postgres/qgspostgresconnpool.cpp: 33: (~QgsPostgresConnPool) [36ms] Entering.
src/providers/postgres/qgspostgresconnpool.cpp: 33: (~QgsPostgresConnPool) [1ms] Leaving.
src/providers/ogr/qgsogrconnpool.cpp: 33: (~QgsOgrConnPool) [14ms] Entering.
src/providers/ogr/qgsogrconnpool.cpp: 33: (~QgsOgrConnPool) [1ms] Leaving.
==17630== Invalid read of size 8
==17630==    at 0x95CF5A5: OGR_DS_Destroy (ogrdatasource.cpp:69)
==17630==    by 0x2E1EB54C: qgsConnectionPool_ConnectionDestroy(QgsOgrConn*) (qgsogrconnpool.h:45)
==17630==    by 0x2E1EC369: QgsConnectionPoolGroup<QgsOgrConn*>::~QgsConnectionPoolGroup() (qgsconnectionpool.h:77)
==17630==    by 0x2E1FDB89: QgsOgrConnPoolGroup::~QgsOgrConnPoolGroup() (in /usr/src/qgis/build/0-master/output/lib/qgis/plugins/libogrprovider.so)
==17630==    by 0x2E1FDBC5: QgsOgrConnPoolGroup::~QgsOgrConnPoolGroup() (qgsogrconnpool.h:59)
==17630==    by 0x2E1FBA21: QgsConnectionPool<QgsOgrConn*, QgsOgrConnPoolGroup>::~QgsConnectionPool() (qgsconnectionpool.h:238)
==17630==    by 0x2E1FB6BA: QgsOgrConnPool::~QgsOgrConnPool() (qgsogrconnpool.cpp:31)
==17630==    by 0x75A0258: __run_exit_handlers (exit.c:82)
==17630==    by 0x75A02A4: exit (exit.c:104)
==17630==    by 0x7585ECB: (below main) (libc-start.c:321)
==17630==  Address 0x320543c0 is 0 bytes inside a block of size 280 free'd
==17630==    at 0x4C2C131: operator delete(void*) (vg_replace_malloc.c:510)
==17630==    by 0x9379FF5: GDALDriverManager::~GDALDriverManager() (gdaldrivermanager.cpp:183)
==17630==    by 0x937A158: GDALDriverManager::~GDALDriverManager() (gdaldrivermanager.cpp:289)
==17630==    by 0x2BC2EB4D: cleanupProvider (qgsgdalprovider.cpp:3024)
==17630==    by 0x5D0F0F1: QgsProviderRegistry::clean() (qgsproviderregistry.cpp:244)
==17630==    by 0x5D0F205: QgsProviderRegistry::~QgsProviderRegistry() (qgsproviderregistry.cpp:253)
==17630==    by 0x5D0F2A5: QgsProviderRegistry::~QgsProviderRegistry() (qgsproviderregistry.cpp:254)
==17630==    by 0x5AF7EA2: QgsApplication::exitQgis() (qgsapplication.cpp:868)
==17630==    by 0x406064: TestQgsVectorAnalyzer::cleanupTestCase() (testqgsvectoranalyzer.cpp:89)
==17630==    by 0x406566: TestQgsVectorAnalyzer::qt_static_metacall(QObject*, QMetaObject::Call, int, void**) (testqgsvectoranalyzer.moc:64)
==17630==    by 0x4FBB907: QMetaMethod::invoke(QObject*, Qt::ConnectionType, QGenericReturnArgument, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument) const (in /usr/lib/x86_64-linux-gnu/libQtCore.so.4.8.6)
==17630==    by 0x532408E: ??? (in /usr/lib/x86_64-linux-gnu/libQtTest.so.4.8.6)
==17630== 

My build configuration (while I clearn-rebuild):

cmake \\
  -D CMAKE_BUILD_TYPE=Debug \\
  -D WITH_SERVER=ON \\
  -D WITH_STAGED_PLUGINS=ON \\
  -D WITH_PYSPATIALITE=ON \\
  -D ENABLE_TESTS=1 \\
  -D CMAKE_CXX_COMPILER:FILEPATH=/usr/lib/ccache/g++ \\
  -D WITH_ASTYLE=1 \\
  -D WITH_INTERNAL_QWTPOLAR=1 

Still happens on a clean rebuild. GDAL version is 2.1.0. Segfault is on exit, so might be related to how the compiler chooses to order deinizialization:

(gdb) bt
#0  0x0000000000000161 in ?? ()
#1  0x00007fadcac66577 in qgsConnectionPool_ConnectionDestroy (c=0x16fad60) at /usr/src/qgis/qgis-master/src/providers/ogr/qgsogrconnpool.h:45
#2  0x00007fadcac67394 in QgsConnectionPoolGroup<QgsOgrConn*>::~QgsConnectionPoolGroup (this=0x15fde30, __in_chrg=<optimized out>)
    at /usr/src/qgis/qgis-master/src/providers/ogr/../../core/qgsconnectionpool.h:77
#3  0x00007fadcac78bb4 in QgsOgrConnPoolGroup::~QgsOgrConnPoolGroup (this=0x15fde20, __in_chrg=<optimized out>)
    at /usr/src/qgis/build/master/src/providers/ogr/../../../../../qgis-master/src/providers/ogr/qgsogrconnpool.h:59
#4  0x00007fadcac78bf0 in QgsOgrConnPoolGroup::~QgsOgrConnPoolGroup (this=0x15fde20, __in_chrg=<optimized out>)
    at /usr/src/qgis/build/master/src/providers/ogr/../../../../../qgis-master/src/providers/ogr/qgsogrconnpool.h:59
#5  0x00007fadcac76a4c in QgsConnectionPool<QgsOgrConn*, QgsOgrConnPoolGroup>::~QgsConnectionPool (
    this=0x7fadcae8b310 <QgsOgrConnPool::sInstance>, __in_chrg=<optimized out>)
    at /usr/src/qgis/qgis-master/src/providers/ogr/../../core/qgsconnectionpool.h:238
#6  0x00007fadcac766e5 in QgsOgrConnPool::~QgsOgrConnPool (this=0x7fadcae8b310 <QgsOgrConnPool::sInstance>, __in_chrg=<optimized out>)
    at /usr/src/qgis/qgis-master/src/providers/ogr/qgsogrconnpool.cpp:31
#7  0x00007fae0044c259 in __run_exit_handlers (status=0, listp=0x7fae007ce6c8 <__exit_funcs>, run_list_atexit=run_list_atexit@entry=true)
    at exit.c:82
#8  0x00007fae0044c2a5 in __GI_exit (status=<optimized out>) at exit.c:104
#9  0x00007fae00431ecc in __libc_start_main (main=0x406440 <main(int, char**)>, argc=1, argv=0x7fff95784758, init=<optimized out>, 
    fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7fff95784748) at libc-start.c:321
#10 0x0000000000404619 in _start ()

Compiler is g++ (Ubuntu 4.8.4-2ubuntu1~14.04) 4.8.4

I see code in QgsOgrConnPool class that seem to protect against a call to ::instance() happening after a call to the destructor, and it surprises me such an occurrence may actually happen (why should it?).

Allocating the singleton on the heap and letting it leak fixes the segfault for me, see https://github.com/qgis/QGIS/pull/2754

Nice catch.

For completeness - there is one other test with issues. QgsLegendRenderer fails occasionally under windows.

There is also output/bin/qgis_diagramtest (#14212) which seems to be another symptom of the same bug