changed sylvan behaviour to take auto-detected number of threads if no thread count was set

src/storm/settings/modules/SylvanSettings.cpp

@@ -17,12 +17,16 @@ namespace storm {
             
             SylvanSettings::SylvanSettings() : ModuleSettings(moduleName) {
                 this->addOption(storm::settings::OptionBuilder(moduleName, maximalMemoryOptionName, true, "Sets the upper bound of memory available to Sylvan in MB.").addArgument(storm::settings::ArgumentBuilder::createUnsignedIntegerArgument("value", "The memory available to Sylvan.").setDefaultValueUnsignedInteger(4096).build()).build());
-                this->addOption(storm::settings::OptionBuilder(moduleName, threadCountOptionName, true, "Sets the number of threads used by Sylvan.").addArgument(storm::settings::ArgumentBuilder::createUnsignedIntegerArgument("value", "The number of threads available to Sylvan (0 means 'auto-detect').").setDefaultValueUnsignedInteger(1).build()).build());
+                this->addOption(storm::settings::OptionBuilder(moduleName, threadCountOptionName, true, "Sets the number of threads used by Sylvan.").addArgument(storm::settings::ArgumentBuilder::createUnsignedIntegerArgument("value", "The number of threads available to Sylvan (0 means 'auto-detect').").build()).build());
             }
             
             uint_fast64_t SylvanSettings::getMaximalMemory() const {
                 return this->getOption(maximalMemoryOptionName).getArgumentByName("value").getValueAsUnsignedInteger();
             }
+
+            bool SylvanSettings::isNumberOfThreadsSet() const {
+                return this->getOption(threadCountOptionName).getArgumentByName("value").getHasBeenSet();
+            }
             
             uint_fast64_t SylvanSettings::getNumberOfThreads() const {
                 return this->getOption(threadCountOptionName).getArgumentByName("value").getValueAsUnsignedInteger();

src/storm/settings/modules/SylvanSettings.h

@@ -32,6 +32,11 @@ namespace storm {
                  */
                 uint_fast64_t getNumberOfThreads() const;
                 
+                /*!
+                 * Retrieves whether the number of threads to use was set.
+                 */
+                bool isNumberOfThreadsSet() const;
+                
                 // The name of the module.
                 static const std::string moduleName;
                 

src/storm/storage/dd/sylvan/InternalSylvanDdManager.cpp

@@ -33,8 +33,12 @@ namespace storm {
         
         InternalDdManager<DdType::Sylvan>::InternalDdManager() {
             if (numberOfInstances == 0) {
-                // Initialize lace: auto-detect number of workers.
-                lace_init(storm::settings::getModule<storm::settings::modules::SylvanSettings>().getNumberOfThreads(), 1000000);
+                storm::settings::modules::SylvanSettings const& settings = storm::settings::getModule<storm::settings::modules::SylvanSettings>();
+                if (settings.isNumberOfThreadsSet()) {
+                    lace_init(settings.getNumberOfThreads(), 1000000);
+                } else {
+                    lace_init(0, 1000000);
+                }
                 lace_startup(0, 0, 0);
                 
                 // Each node takes 24 bytes and the maximal memory is specified in megabytes.