addressing crash when G4VisExecutive is destroyed. fixing show_gemc_installation and dockerfile_creator.py to use new path

Author: maureeungaro

ci/build.sh

@@ -3,7 +3,7 @@
 # Purpose: compiles gemc with optional sanitizers or debugging options.
 
 # Container run:
-# docker run --rm -it  ghcr.io/gemc/g4install:11.4.1-fedora-40  bash -li
+# docker run --rm -it  ghcr.io/gemc/g4install:11.4.1-ubuntu-24.04  bash -li
 # git clone http://github.com/gemc/src /root/src && cd /root/src
 # ./ci/build.sh
 
@@ -108,6 +108,6 @@ else
   echo " > Meson Tests Successful"
   echo
 fi
-echo "   - Successful: $(grep -m1 'Ok:' "$test_log" | awk '{print $2}')" | tee -a "$test_log"
-echo "   - Failures: $(grep -m1 'Fail:' "$test_log" | awk '{print $2}')" | tee -a "$test_log"
+echo "   - Successful: $(grep 'Ok:' "$test_log" | tail -n 1 | awk '{print $2}')" | tee -a "$test_log"
+echo "   - Failures: $(grep 'Fail:' "$test_log" | tail -n 1 | awk '{print $2}')" | tee -a "$test_log"
 echo " > Complete test log: $test_log"

ci/dockerfile_creator.py

@@ -46,7 +46,7 @@ def install_gemc(geant4_version: str, gemc_version: str) -> str:
     commands += f"     && DOCKER_ENTRYPOINT_SOURCE_ONLY=1 . {remote_entrypoint()} \\\n"
     commands += f'     && module load geant4/{geant4_version} \\\n'
     commands += f'     &&  ./ci/build.sh  \\\n'
-    commands += f'     && echo ". \\${{SIM_HOME}}/gemc/gemc.sh" >> {remote_entrypoint_addon()} \n'
+    commands += f'     && echo ". \\${{SIM_HOME}}/gemc/dev/gemc.sh" >> {remote_entrypoint_addon()} \n'
     return commands
 
 

ci/env.sh

@@ -11,26 +11,27 @@ function enable_git_describe {
 }
 
 function show_gemc_installation {
-
   {
-    echo "- Content of \$GEMC=$GEMC" 
-    ls -lrt $GEMC 
+  	local install_dir="${SIM_HOME:?SIM_HOME not set}/gemc/dev"
+
+    echo "- Content of $install_dir=$install_dir"
+    ls -lrt $install_dir
 
-    echo "- Content of \$GEMC/bin=$GEMC/bin" 
-    ls -lrt $GEMC/bin 
+    echo "- Content of \$install_dir/bin=$install_dir/bin"
+    ls -lrt $install_dir/bin
 
-    if [ -d $GEMC/lib ]; then
-      echo "- Content of \$GEMC/lib=$GEMC/lib" 
-      ls -lrt $GEMC/lib 
+    if [ -d $install_dir/lib ]; then
+      echo "- Content of \$install_dir/lib=$install_dir/lib"
+      ls -lrt $install_dir/lib
     fi
 
-    echo " ldd of $GEMC/bin/gemc:" 
+    echo " ldd of $install_dir/bin/gemc:"
 
     # if on unix, use ldd , if on mac, use otool -L
     if [[ "$(uname)" == "Darwin" ]]; then
-      otool -L $GEMC/bin/gemc 
+      otool -L $install_dir/bin/gemc
     else
-      ldd $GEMC/bin/gemc 
+      ldd $install_dir/bin/gemc
     fi
 
     echo " > To check gemc installation:  cat $gemc_install_show"

gemc.cc

@@ -17,6 +17,10 @@
 #include "gaction.h"
 #include "gstreamer.h"
 
+// c++
+#include <cstdio>
+#include <cstdlib>
+
 int main(int argc, char* argv[]) {
 
 	auto gopts = std::make_shared<GOptions>(argc, argv, gemc::defineOptions());
@@ -37,14 +41,13 @@ int main(int argc, char* argv[]) {
 	// random engine set by options
 	gemc::start_random_engine(gopts, log);
 
-	// Pre-load streamer plugins before Geant4 creates worker threads. Sanitized Linux
-	// builds can fail late dlopen() calls from workers with static TLS exhaustion.
-	auto preloaded_gstreamer_map = gstreamer::preloadGStreamerPlugins(gopts);
-	(void) preloaded_gstreamer_map;
-
 	// init geant4 run manager with then number of threads coming from options. always fails if unavailable
 	auto runManager = std::unique_ptr<G4RunManager>(G4RunManagerFactory::CreateRunManager(G4RunManagerType::Default, true, nthreads));
 
+	// Pre-load streamer plugins before Geant4 creates worker threads. Sanitized Linux
+	// builds can fail late dlopen() calls from workers with static TLS exhaustion.
+	// Declaring this after runManager makes it destruct before runManager at shutdown.
+	auto preloaded_gstreamer_map = gstreamer::preloadGStreamerPlugins(gopts);
 
 	// must be a raw pointer because geant4 takes ownership
 	auto gdetector = new GDetectorConstruction(gopts);
@@ -111,6 +114,7 @@ int main(int argc, char* argv[]) {
 		spash_screen->finish(&gemcGui);
 		app_result = QApplication::exec();
 
+		preloaded_gstreamer_map.reset();
 		runManager.reset();
 		delete g4SceneProperties;
 		delete uiQtSession;
@@ -133,10 +137,20 @@ int main(int argc, char* argv[]) {
 		delete session;
 	}
 
-
-	delete visManager;
+	geventDispenser.reset();
+	preloaded_gstreamer_map.reset();
+	runManager.reset();
+	// Avoid explicit G4VisExecutive teardown in batch shutdown. On Linux/Geant4 11.4
+	// this can double-free the process-wide G4Colour table during static exit.
 
 	log->info(0, "Simulation completed, arrivederci! ");
 
+#if defined(__linux__)
+	if (!gui) {
+		std::fflush(nullptr);
+		std::_Exit(app_result);
+	}
+#endif
+
 	return app_result;
 }

gfactory/gdl.h

@@ -152,16 +152,22 @@ dlhandle load_lib(const std::string& lib) // never throws
 {
 	dlhandle h = nullptr;
 
+#if defined(__linux__) && defined(RTLD_NODELETE)
+	constexpr int dlopen_flags = RTLD_NOW | RTLD_NODELETE;
+#else
+	constexpr int dlopen_flags = RTLD_NOW;
+#endif
+
 	// If the caller already supplied a path (has a slash) just try it.
-	if (lib.find('/') != std::string::npos) { h = dlopen(lib.c_str(), RTLD_NOW); }
+	if (lib.find('/') != std::string::npos) { h = dlopen(lib.c_str(), dlopen_flags); }
 	else {
 		// 1. Try the file in the current working directory.
 		std::string cwdPath = "./" + lib;
-		h                   = dlopen(cwdPath.c_str(), RTLD_NOW);
+		h                   = dlopen(cwdPath.c_str(), dlopen_flags);
 
 		// 2. Fallback to the normal search path so LD_LIBRARY_PATH,
 		//    RPATH/RUNPATH, system dirs, etc. are still honoured.
-		if (!h) { h = dlopen(lib.c_str(), RTLD_NOW); }
+		if (!h) { h = dlopen(lib.c_str(), dlopen_flags); }
 	}
 	return h; // may be nullptr – caller should check and use dlerror()
 }

gstreamer/gstreamer.h

@@ -614,6 +614,7 @@ namespace gstreamer {
 	 * \return Shared pointer that should be retained until threaded streaming is complete.
 	 */
 	inline std::shared_ptr<const gstreamersMap> preloadGStreamerPlugins(const std::shared_ptr<GOptions>& gopts) {
+		if (gstreamer::getGStreamerDefinition(gopts).empty()) { return std::make_shared<gstreamersMap>(); }
 		return gstreamersMapPtr(gopts);
 	}
 

releases/0.2.md

@@ -82,4 +82,6 @@ Both x86_64 and ARM64 platforms are supported.
 - Using $SIM_HOME instead of $GEMC for installation paths
 - Pre-load streamer plugins before Geant4 creates worker threads
 - gemc.cc preloads only whatever streamers are actually configured.
+- Temporarely protecting, on linux, explicit G4VisExecutive teardown. This is a possible
+  Geant4 bug: a double-free in a process-wide G4Colour map during static destruction
 - Various code cleanups