java -Xmx8000000000 -Xss4m -jar ./plugins/org.eclipse.equinox.launcher_1.3.100.v20150511-1540.jar -data @noDefault -ultimatedata ./data -tc ../../../trunk/examples/toolchains/AbstractInterpretationC.xml -s ../../../trunk/examples/settings/ai/svcomp-Reach-32bit-Automizer_Default+AIv2_INT.epf -i ../../../trunk/examples/svcomp/loop-new/count_by_nondet.i -------------------------------------------------------------------------------- This is Ultimate 0.1.24-112bae1 [2019-09-11 16:13:23,865 INFO L177 SettingsManager]: Resetting all preferences to default values... [2019-09-11 16:13:23,867 INFO L181 SettingsManager]: Resetting UltimateCore preferences to default values [2019-09-11 16:13:23,884 INFO L184 SettingsManager]: Ultimate Commandline Interface provides no preferences, ignoring... [2019-09-11 16:13:23,884 INFO L181 SettingsManager]: Resetting Boogie Preprocessor preferences to default values [2019-09-11 16:13:23,886 INFO L181 SettingsManager]: Resetting Boogie Procedure Inliner preferences to default values [2019-09-11 16:13:23,888 INFO L181 SettingsManager]: Resetting Abstract Interpretation preferences to default values [2019-09-11 16:13:23,897 INFO L181 SettingsManager]: Resetting LassoRanker preferences to default values [2019-09-11 16:13:23,899 INFO L181 SettingsManager]: Resetting Reaching Definitions preferences to default values [2019-09-11 16:13:23,901 INFO L181 SettingsManager]: Resetting SyntaxChecker preferences to default values [2019-09-11 16:13:23,902 INFO L181 SettingsManager]: Resetting Sifa preferences to default values [2019-09-11 16:13:23,904 INFO L184 SettingsManager]: Büchi Program Product provides no preferences, ignoring... [2019-09-11 16:13:23,905 INFO L181 SettingsManager]: Resetting LTL2Aut preferences to default values [2019-09-11 16:13:23,905 INFO L181 SettingsManager]: Resetting PEA to Boogie preferences to default values [2019-09-11 16:13:23,908 INFO L181 SettingsManager]: Resetting BlockEncodingV2 preferences to default values [2019-09-11 16:13:23,910 INFO L181 SettingsManager]: Resetting ChcToBoogie preferences to default values [2019-09-11 16:13:23,911 INFO L181 SettingsManager]: Resetting AutomataScriptInterpreter preferences to default values [2019-09-11 16:13:23,912 INFO L181 SettingsManager]: Resetting BuchiAutomizer preferences to default values [2019-09-11 16:13:23,916 INFO L181 SettingsManager]: Resetting CACSL2BoogieTranslator preferences to default values [2019-09-11 16:13:23,919 INFO L181 SettingsManager]: Resetting CodeCheck preferences to default values [2019-09-11 16:13:23,920 INFO L181 SettingsManager]: Resetting InvariantSynthesis preferences to default values [2019-09-11 16:13:23,924 INFO L181 SettingsManager]: Resetting RCFGBuilder preferences to default values [2019-09-11 16:13:23,927 INFO L181 SettingsManager]: Resetting Referee preferences to default values [2019-09-11 16:13:23,928 INFO L181 SettingsManager]: Resetting TraceAbstraction preferences to default values [2019-09-11 16:13:23,931 INFO L184 SettingsManager]: TraceAbstractionConcurrent provides no preferences, ignoring... [2019-09-11 16:13:23,931 INFO L184 SettingsManager]: TraceAbstractionWithAFAs provides no preferences, ignoring... [2019-09-11 16:13:23,931 INFO L181 SettingsManager]: Resetting TreeAutomizer preferences to default values [2019-09-11 16:13:23,934 INFO L181 SettingsManager]: Resetting IcfgToChc preferences to default values [2019-09-11 16:13:23,935 INFO L181 SettingsManager]: Resetting IcfgTransformer preferences to default values [2019-09-11 16:13:23,937 INFO L184 SettingsManager]: ReqToTest provides no preferences, ignoring... [2019-09-11 16:13:23,937 INFO L181 SettingsManager]: Resetting Boogie Printer preferences to default values [2019-09-11 16:13:23,939 INFO L181 SettingsManager]: Resetting ChcSmtPrinter preferences to default values [2019-09-11 16:13:23,940 INFO L181 SettingsManager]: Resetting ReqPrinter preferences to default values [2019-09-11 16:13:23,940 INFO L181 SettingsManager]: Resetting Witness Printer preferences to default values [2019-09-11 16:13:23,944 INFO L184 SettingsManager]: Boogie PL CUP Parser provides no preferences, ignoring... [2019-09-11 16:13:23,945 INFO L181 SettingsManager]: Resetting CDTParser preferences to default values [2019-09-11 16:13:23,945 INFO L184 SettingsManager]: AutomataScriptParser provides no preferences, ignoring... [2019-09-11 16:13:23,946 INFO L184 SettingsManager]: ReqParser provides no preferences, ignoring... [2019-09-11 16:13:23,946 INFO L181 SettingsManager]: Resetting SmtParser preferences to default values [2019-09-11 16:13:23,947 INFO L181 SettingsManager]: Resetting Witness Parser preferences to default values [2019-09-11 16:13:23,947 INFO L188 SettingsManager]: Finished resetting all preferences to default values... [2019-09-11 16:13:23,949 INFO L101 SettingsManager]: Beginning loading settings from /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/../../../trunk/examples/settings/ai/svcomp-Reach-32bit-Automizer_Default+AIv2_INT.epf [2019-09-11 16:13:23,965 INFO L113 SettingsManager]: Loading preferences was successful [2019-09-11 16:13:23,966 INFO L115 SettingsManager]: Preferences different from defaults after loading the file: [2019-09-11 16:13:23,966 INFO L136 SettingsManager]: Preferences of UltimateCore differ from their defaults: [2019-09-11 16:13:23,966 INFO L138 SettingsManager]: * Log level for plugins=info [2019-09-11 16:13:23,967 INFO L136 SettingsManager]: Preferences of Boogie Procedure Inliner differ from their defaults: [2019-09-11 16:13:23,967 INFO L138 SettingsManager]: * User list type=DISABLED [2019-09-11 16:13:23,967 INFO L138 SettingsManager]: * Ignore calls to and inside polymorphic procedures=false [2019-09-11 16:13:23,967 INFO L138 SettingsManager]: * Ignore calls to recursive procedures=false [2019-09-11 16:13:23,968 INFO L136 SettingsManager]: Preferences of Abstract Interpretation differ from their defaults: [2019-09-11 16:13:23,968 INFO L138 SettingsManager]: * Abstract domain=IntervalDomain [2019-09-11 16:13:23,968 INFO L136 SettingsManager]: Preferences of CACSL2BoogieTranslator differ from their defaults: [2019-09-11 16:13:23,969 INFO L138 SettingsManager]: * sizeof long=4 [2019-09-11 16:13:23,969 INFO L138 SettingsManager]: * sizeof POINTER=4 [2019-09-11 16:13:23,969 INFO L138 SettingsManager]: * Check division by zero=IGNORE [2019-09-11 16:13:23,969 INFO L138 SettingsManager]: * Pointer to allocated memory at dereference=IGNORE [2019-09-11 16:13:23,970 INFO L138 SettingsManager]: * If two pointers are subtracted or compared they have the same base address=IGNORE [2019-09-11 16:13:23,970 INFO L138 SettingsManager]: * Check array bounds for arrays that are off heap=IGNORE [2019-09-11 16:13:23,970 INFO L138 SettingsManager]: * sizeof long double=12 [2019-09-11 16:13:23,970 INFO L138 SettingsManager]: * Check if freed pointer was valid=false [2019-09-11 16:13:23,970 INFO L138 SettingsManager]: * Pointer base address is valid at dereference=IGNORE [2019-09-11 16:13:23,971 INFO L136 SettingsManager]: Preferences of RCFGBuilder differ from their defaults: [2019-09-11 16:13:23,971 INFO L138 SettingsManager]: * Remove goto edges from RCFG=true [2019-09-11 16:13:23,971 INFO L138 SettingsManager]: * Size of a code block=SequenceOfStatements [2019-09-11 16:13:23,971 INFO L138 SettingsManager]: * Command for external solver=z3 SMTLIB2_COMPLIANT=true -memory:2024 -smt2 -in -t:2000 [2019-09-11 16:13:23,971 INFO L136 SettingsManager]: Preferences of TraceAbstraction differ from their defaults: [2019-09-11 16:13:23,972 INFO L138 SettingsManager]: * Compute Interpolants along a Counterexample=FPandBP [2019-09-11 16:13:23,972 INFO L138 SettingsManager]: * Trace refinement strategy=TAIPAN [2019-09-11 16:13:23,972 INFO L138 SettingsManager]: * SMT solver=External_ModelsAndUnsatCoreMode [2019-09-11 16:13:23,972 INFO L138 SettingsManager]: * Command for external solver=z3 SMTLIB2_COMPLIANT=true -memory:2024 -smt2 -in [2019-09-11 16:13:23,972 INFO L138 SettingsManager]: * Abstract interpretation Mode=USE_PREDICATES [2019-09-11 16:13:24,000 INFO L81 nceAwareModelManager]: Repository-Root is: /tmp [2019-09-11 16:13:24,013 INFO L258 ainManager$Toolchain]: [Toolchain 1]: Applicable parser(s) successfully (re)initialized [2019-09-11 16:13:24,017 INFO L214 ainManager$Toolchain]: [Toolchain 1]: Toolchain selected. [2019-09-11 16:13:24,018 INFO L271 PluginConnector]: Initializing CDTParser... [2019-09-11 16:13:24,019 INFO L275 PluginConnector]: CDTParser initialized [2019-09-11 16:13:24,019 INFO L428 ainManager$Toolchain]: [Toolchain 1]: Parsing single file: /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/../../../trunk/examples/svcomp/loop-new/count_by_nondet.i [2019-09-11 16:13:24,075 INFO L220 CDTParser]: Created temporary CDT project at /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/data/73fb5011d/3f33f0e2647e42bd870c3e01385d3e7f/FLAG9d31ed267 [2019-09-11 16:13:24,506 INFO L306 CDTParser]: Found 1 translation units. [2019-09-11 16:13:24,507 INFO L160 CDTParser]: Scanning /storage/repos/ultimate/trunk/examples/svcomp/loop-new/count_by_nondet.i [2019-09-11 16:13:24,516 INFO L349 CDTParser]: About to delete temporary CDT project at /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/data/73fb5011d/3f33f0e2647e42bd870c3e01385d3e7f/FLAG9d31ed267 [2019-09-11 16:13:24,912 INFO L357 CDTParser]: Successfully deleted /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/data/73fb5011d/3f33f0e2647e42bd870c3e01385d3e7f [2019-09-11 16:13:24,926 INFO L296 ainManager$Toolchain]: ####################### [Toolchain 1] ####################### [2019-09-11 16:13:24,927 INFO L131 ToolchainWalker]: Walking toolchain with 4 elements. [2019-09-11 16:13:24,928 INFO L113 PluginConnector]: ------------------------CACSL2BoogieTranslator---------------------------- [2019-09-11 16:13:24,928 INFO L271 PluginConnector]: Initializing CACSL2BoogieTranslator... [2019-09-11 16:13:24,932 INFO L275 PluginConnector]: CACSL2BoogieTranslator initialized [2019-09-11 16:13:24,933 INFO L185 PluginConnector]: Executing the observer ACSLObjectContainerObserver from plugin CACSL2BoogieTranslator for "CDTParser AST 11.09 04:13:24" (1/1) ... [2019-09-11 16:13:24,937 INFO L205 PluginConnector]: Invalid model from CACSL2BoogieTranslator for observer de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator.ACSLObjectContainerObserver@22a917 and model type de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 11.09 04:13:24, skipping insertion in model container [2019-09-11 16:13:24,937 INFO L185 PluginConnector]: Executing the observer CACSL2BoogieTranslatorObserver from plugin CACSL2BoogieTranslator for "CDTParser AST 11.09 04:13:24" (1/1) ... [2019-09-11 16:13:24,945 INFO L142 MainTranslator]: Starting translation in SV-COMP mode [2019-09-11 16:13:24,966 INFO L173 MainTranslator]: Built tables and reachable declarations [2019-09-11 16:13:25,186 INFO L206 PostProcessor]: Analyzing one entry point: main [2019-09-11 16:13:25,193 INFO L188 MainTranslator]: Completed pre-run [2019-09-11 16:13:25,212 INFO L206 PostProcessor]: Analyzing one entry point: main [2019-09-11 16:13:25,224 INFO L192 MainTranslator]: Completed translation [2019-09-11 16:13:25,224 INFO L202 PluginConnector]: Adding new model de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 11.09 04:13:25 WrapperNode [2019-09-11 16:13:25,225 INFO L132 PluginConnector]: ------------------------ END CACSL2BoogieTranslator---------------------------- [2019-09-11 16:13:25,225 INFO L113 PluginConnector]: ------------------------Boogie Preprocessor---------------------------- [2019-09-11 16:13:25,225 INFO L271 PluginConnector]: Initializing Boogie Preprocessor... [2019-09-11 16:13:25,226 INFO L275 PluginConnector]: Boogie Preprocessor initialized [2019-09-11 16:13:25,333 INFO L185 PluginConnector]: Executing the observer EnsureBoogieModelObserver from plugin Boogie Preprocessor for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 11.09 04:13:25" (1/1) ... [2019-09-11 16:13:25,333 INFO L185 PluginConnector]: Executing the observer TypeChecker from plugin Boogie Preprocessor for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 11.09 04:13:25" (1/1) ... [2019-09-11 16:13:25,338 INFO L185 PluginConnector]: Executing the observer ConstExpander from plugin Boogie Preprocessor for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 11.09 04:13:25" (1/1) ... [2019-09-11 16:13:25,339 INFO L185 PluginConnector]: Executing the observer StructExpander from plugin Boogie Preprocessor for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 11.09 04:13:25" (1/1) ... [2019-09-11 16:13:25,343 INFO L185 PluginConnector]: Executing the observer UnstructureCode from plugin Boogie Preprocessor for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 11.09 04:13:25" (1/1) ... [2019-09-11 16:13:25,348 INFO L185 PluginConnector]: Executing the observer FunctionInliner from plugin Boogie Preprocessor for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 11.09 04:13:25" (1/1) ... [2019-09-11 16:13:25,349 INFO L185 PluginConnector]: Executing the observer BoogieSymbolTableConstructor from plugin Boogie Preprocessor for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 11.09 04:13:25" (1/1) ... [2019-09-11 16:13:25,350 INFO L132 PluginConnector]: ------------------------ END Boogie Preprocessor---------------------------- [2019-09-11 16:13:25,350 INFO L113 PluginConnector]: ------------------------RCFGBuilder---------------------------- [2019-09-11 16:13:25,351 INFO L271 PluginConnector]: Initializing RCFGBuilder... [2019-09-11 16:13:25,351 INFO L275 PluginConnector]: RCFGBuilder initialized [2019-09-11 16:13:25,352 INFO L185 PluginConnector]: Executing the observer RCFGBuilderObserver from plugin RCFGBuilder for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 11.09 04:13:25" (1/1) ... No working directory specified, using /storage/repos/ultimate/releaseScripts/default/UAutomizer-linux/z3 Starting monitored process 1 with z3 SMTLIB2_COMPLIANT=true -memory:2024 -smt2 -in -t:2000 (exit command is (exit), workingDir is null) Waiting until toolchain timeout for monitored process 1 with z3 SMTLIB2_COMPLIANT=true -memory:2024 -smt2 -in -t:2000 [2019-09-11 16:13:25,412 INFO L138 BoogieDeclarations]: Found implementation of procedure ULTIMATE.init [2019-09-11 16:13:25,413 INFO L138 BoogieDeclarations]: Found implementation of procedure ULTIMATE.start [2019-09-11 16:13:25,413 INFO L138 BoogieDeclarations]: Found implementation of procedure __VERIFIER_assert [2019-09-11 16:13:25,413 INFO L138 BoogieDeclarations]: Found implementation of procedure main [2019-09-11 16:13:25,413 INFO L130 BoogieDeclarations]: Found specification of procedure __VERIFIER_error [2019-09-11 16:13:25,413 INFO L130 BoogieDeclarations]: Found specification of procedure __VERIFIER_assume [2019-09-11 16:13:25,413 INFO L130 BoogieDeclarations]: Found specification of procedure __VERIFIER_assert [2019-09-11 16:13:25,413 INFO L130 BoogieDeclarations]: Found specification of procedure __VERIFIER_nondet_int [2019-09-11 16:13:25,413 INFO L130 BoogieDeclarations]: Found specification of procedure main [2019-09-11 16:13:25,414 INFO L130 BoogieDeclarations]: Found specification of procedure ULTIMATE.init [2019-09-11 16:13:25,414 INFO L130 BoogieDeclarations]: Found specification of procedure ULTIMATE.start [2019-09-11 16:13:25,586 INFO L278 CfgBuilder]: Using the 1 location(s) as analysis (start of procedure ULTIMATE.start) [2019-09-11 16:13:25,587 INFO L283 CfgBuilder]: Removed 1 assume(true) statements. [2019-09-11 16:13:25,588 INFO L202 PluginConnector]: Adding new model de.uni_freiburg.informatik.ultimate.plugins.generator.rcfgbuilder CFG 11.09 04:13:25 BoogieIcfgContainer [2019-09-11 16:13:25,588 INFO L132 PluginConnector]: ------------------------ END RCFGBuilder---------------------------- [2019-09-11 16:13:25,589 INFO L113 PluginConnector]: ------------------------Abstract Interpretation---------------------------- [2019-09-11 16:13:25,589 INFO L271 PluginConnector]: Initializing Abstract Interpretation... [2019-09-11 16:13:25,589 INFO L275 PluginConnector]: Abstract Interpretation initialized [2019-09-11 16:13:25,590 INFO L185 PluginConnector]: Executing the observer AbstractInterpretationRcfgObserver from plugin Abstract Interpretation for "de.uni_freiburg.informatik.ultimate.plugins.generator.rcfgbuilder CFG 11.09 04:13:25" (1/1) ... [2019-09-11 16:13:25,620 INFO L101 FixpointEngine]: Starting fixpoint engine with domain IntervalDomain (maxUnwinding=3, maxParallelStates=2) [2019-09-11 16:13:25,930 INFO L263 AbstractInterpreter]: Some error location(s) were reachable [2019-09-11 16:13:25,947 INFO L272 AbstractInterpreter]: Visited 22 different actions 104 times. Merged at 7 different actions 36 times. Widened at 1 different actions 3 times. Performed 174 root evaluator evaluations with a maximum evaluation depth of 5. Performed 174 inverse root evaluator evaluations with a maximum inverse evaluation depth of 5. Found 12 fixpoints after 3 different actions. Largest state had 6 variables. [2019-09-11 16:13:25,948 INFO L132 PluginConnector]: ------------------------ END Abstract Interpretation---------------------------- [2019-09-11 16:13:25,951 INFO L168 Benchmark]: Toolchain (without parser) took 1022.15 ms. Allocated memory was 134.7 MB in the beginning and 201.3 MB in the end (delta: 66.6 MB). Free memory was 90.9 MB in the beginning and 155.6 MB in the end (delta: -64.7 MB). Peak memory consumption was 1.9 MB. Max. memory is 7.1 GB. [2019-09-11 16:13:25,952 INFO L168 Benchmark]: CDTParser took 0.18 ms. Allocated memory is still 134.7 MB. Free memory is still 109.0 MB. There was no memory consumed. Max. memory is 7.1 GB. [2019-09-11 16:13:25,953 INFO L168 Benchmark]: CACSL2BoogieTranslator took 296.76 ms. Allocated memory is still 134.7 MB. Free memory was 90.9 MB in the beginning and 81.7 MB in the end (delta: 9.1 MB). Peak memory consumption was 9.1 MB. Max. memory is 7.1 GB. [2019-09-11 16:13:25,955 INFO L168 Benchmark]: Boogie Preprocessor took 124.76 ms. Allocated memory was 134.7 MB in the beginning and 201.3 MB in the end (delta: 66.6 MB). Free memory was 81.7 MB in the beginning and 177.8 MB in the end (delta: -96.1 MB). Peak memory consumption was 16.0 MB. Max. memory is 7.1 GB. [2019-09-11 16:13:25,956 INFO L168 Benchmark]: RCFGBuilder took 237.89 ms. Allocated memory is still 201.3 MB. Free memory was 177.8 MB in the beginning and 166.9 MB in the end (delta: 10.9 MB). Peak memory consumption was 10.9 MB. Max. memory is 7.1 GB. [2019-09-11 16:13:25,957 INFO L168 Benchmark]: Abstract Interpretation took 358.80 ms. Allocated memory is still 201.3 MB. Free memory was 166.0 MB in the beginning and 155.6 MB in the end (delta: 10.4 MB). Peak memory consumption was 10.4 MB. Max. memory is 7.1 GB. [2019-09-11 16:13:25,962 INFO L335 ainManager$Toolchain]: ####################### End [Toolchain 1] ####################### --- Results --- * Results from de.uni_freiburg.informatik.ultimate.core: - StatisticsResult: Toolchain Benchmarks Benchmark results are: * CDTParser took 0.18 ms. Allocated memory is still 134.7 MB. Free memory is still 109.0 MB. There was no memory consumed. Max. memory is 7.1 GB. * CACSL2BoogieTranslator took 296.76 ms. Allocated memory is still 134.7 MB. Free memory was 90.9 MB in the beginning and 81.7 MB in the end (delta: 9.1 MB). Peak memory consumption was 9.1 MB. Max. memory is 7.1 GB. * Boogie Preprocessor took 124.76 ms. Allocated memory was 134.7 MB in the beginning and 201.3 MB in the end (delta: 66.6 MB). Free memory was 81.7 MB in the beginning and 177.8 MB in the end (delta: -96.1 MB). Peak memory consumption was 16.0 MB. Max. memory is 7.1 GB. * RCFGBuilder took 237.89 ms. Allocated memory is still 201.3 MB. Free memory was 177.8 MB in the beginning and 166.9 MB in the end (delta: 10.9 MB). Peak memory consumption was 10.9 MB. Max. memory is 7.1 GB. * Abstract Interpretation took 358.80 ms. Allocated memory is still 201.3 MB. Free memory was 166.0 MB in the beginning and 155.6 MB in the end (delta: 10.4 MB). Peak memory consumption was 10.4 MB. Max. memory is 7.1 GB. * Results from de.uni_freiburg.informatik.ultimate.plugins.analysis.abstractinterpretationv2: - UnprovableResult [Line: 5]: Unable to prove that call of __VERIFIER_error() unreachable Unable to prove that call of __VERIFIER_error() unreachable Reason: abstract domain could reach this error location. Possible FailurePath: [L11] int i = 0; [L12] int k = 0; [L13] COND TRUE i < 1000000 [L14] int j = __VERIFIER_nondet_int(); [L15] COND FALSE !(!(1 <= j && j < 1000000)) [L16] i = i + j [L17] k ++ [L13] COND TRUE i < 1000000 [L14] int j = __VERIFIER_nondet_int(); [L15] COND FALSE !(!(1 <= j && j < 1000000)) [L16] i = i + j [L17] k ++ [L13] COND FALSE !(i < 1000000) [L19] CALL __VERIFIER_assert(k <= 1000000) [L4] COND TRUE !(cond) [L5] __VERIFIER_error() RESULT: Ultimate could not prove your program: unable to determine feasibility of some traces Received shutdown request...