initializeGCParameters For CRIU Restore

Relates to
eclipse-openj9/openj9#17459 (comment)

Signed-off-by: Salman Rana <salman.rana@ibm.com>

gc/base/Configuration.cpp

@@ -525,3 +525,27 @@ MM_Configuration::createParallelDispatcher(MM_EnvironmentBase *env, omrsig_handl
 {
 	return MM_ParallelDispatcher::newInstance(env, handler, handler_arg, defaultOSStackSize);
 }
+
+#if defined(J9VM_OPT_CRIU_SUPPORT)
+bool
+MM_Configuration::reinitializeForRestore(MM_EnvironmentBase* env)
+{
+	MM_GCExtensionsBase *extensions = env->getExtensions();
+
+	/* The initialization of the GC thread count can only happen if it is not enforced by the user. */
+	initializeGCThreadCount(env);
+
+	/* Currently, threads don't shutdown during reinitialization, so it is important to
+	 * prevent the thread count from dropping below the number of checkpoint threads.
+	 * This adjustment may no longer be necessary in the future once the shutdown behavior
+	 * of dispatcher threads during restore is thoroughly tested.
+	 */
+	extensions->gcThreadCount = OMR_MAX(
+			extensions->dispatcher->threadCountMaximum(),
+			extensions->gcThreadCount);
+
+	initializeGCParameters(env);
+
+	return true;
+}
+#endif /* defined(J9VM_OPT_CRIU_SUPPORT) */

gc/base/Configuration.hpp

@@ -178,11 +178,7 @@ class MM_Configuration : public MM_BaseVirtual
 	 * @param[in] env the current environment.
 	 * @return boolean indicating whether the configuration was successfully updated.
 	 */
-	virtual bool reinitializeForRestore(MM_EnvironmentBase* env)
-	{
-		Assert_MM_unreachable();
-		return false;
-	}
+	virtual bool reinitializeForRestore(MM_EnvironmentBase* env);
 #endif /* defined(J9VM_OPT_CRIU_SUPPORT) */
 
 	MM_Configuration(MM_EnvironmentBase* env, MM_GCPolicy gcPolicy, MM_AlignmentType alignmentType, uintptr_t defaultRegionSize, uintptr_t defaultArrayletLeafSize, MM_GCWriteBarrierType writeBarrierType, MM_GCAllocationType allocationType)

gc/base/standard/ConfigurationStandard.cpp

@@ -338,7 +338,9 @@ MM_ConfigurationStandard::createHeapRegionManager(MM_EnvironmentBase* env)
 bool
 MM_ConfigurationStandard::reinitializeForRestore(MM_EnvironmentBase* env)
 {
-	MM_GCExtensionsBase* extensions = env->getExtensions();
+	MM_GCExtensionsBase *extensions = env->getExtensions();
+
+	MM_Configuration::reinitializeForRestore(env);
 
 	MM_MemoryPool *memoryPool;
 	MM_HeapMemoryPoolIterator poolIterator(env, extensions->heap);