disable the profiler if -XX:+UseAdaptiveGCBoundary is set

[richardstartin]

This flag was made obsolete in JDK15 (so that is has no effect) and was removed entirely in JDK16 (so that it causes an error when set), but has made its way into JVM tuning folklore so shows up from time to time. We have seen it crash the profiler with the following backtrace, which reproduces reliably with -XX:+UseAdaptiveGCBoundary on older JDK versions:

Current thread (0x00007f22c9cce800):  JavaThread "dd-profiler-recording-scheduler" daemon [_thread_in_vm, id=1356, stack(0x00007f226232c000,0x00007f226242d000)]

Stack: [0x00007f226232c000,0x00007f226242d000],  sp=0x00007f226242af30,  free space=1019k
Native frames: (J=compiled Java code, A=aot compiled Java code, j=interpreted, Vv=VM code, C=native code)
V  [libjvm.so+0x999dc6]  oopDesc::is_a(Klass*) const+0x26
V  [libjvm.so+0xa0b933]  jvmti_GetClassSignature+0x1e3
C  [libjavaProfiler3325426718231816309.so+0x41444]  Recording::writeCpool(Buffer*)+0x2314
C  [libjavaProfiler3325426718231816309.so+0x428a5]  Recording::finishChunk(bool)+0x845
C  [libjavaProfiler3325426718231816309.so+0x35dc8]  FlightRecorder::dump(char const*, int)+0x88
C  [libjavaProfiler3325426718231816309.so+0x28f2f]  Profiler::dump(char const*, int)+0xef
C  [libjavaProfiler3325426718231816309.so+0x12157]  Java_com_datadoghq_profiler_JavaProfiler_dump0+0x47
j  com.datadoghq.profiler.JavaProfiler.dump0(Ljava/lang/String;)V+0
j  com.datadoghq.profiler.JavaProfiler.dump(Ljava/nio/file/Path;)V+11
j  com.datadog.profiling.ddprof.DatadogProfiler.dump(Ljava/nio/file/Path;)V+5
j  com.datadog.profiling.ddprof.DatadogProfilerRecording.snapshot(Ljava/time/Instant;Ldatadog/trace/api/profiling/ProfilingSnapshot$Kind;)Lcom/datadog/profiling/controller/RecordingData;+17
j  com.datadog.profiling.controller.openjdk.OpenJdkOngoingRecording.snapshot(Ljava/time/Instant;Ldatadog/trace/api/profiling/ProfilingSnapshot$Kind;)Lcom/datadog/profiling/controller/RecordingData;+94
j  com.datadog.profiling.controller.ProfilingSystem$SnapshotRecording.snapshot(Z)V+38
j  com.datadog.profiling.controller.ProfilingSystem$SnapshotRecording.snapshot()V+2
j  com.datadog.profiling.controller.ProfilingSystem$$Lambda$555.run(Ljava/lang/Object;)V+4
J 22328 c2 datadog.trace.util.AgentTaskScheduler$PeriodicTask.run()V (25 bytes) @ 0x00007f22bfdf74b8 [0x00007f22bfdf7440+0x0000000000000078]
j  datadog.trace.util.AgentTaskScheduler$Worker.run()V+27
j  java.lang.Thread.run()V+11 java.base@11.0.17
v  ~StubRoutines::call_stub
V  [libjvm.so+0x8dc0ab]  JavaCalls::call_helper(JavaValue*, methodHandle const&, JavaCallArguments*, Thread*)+0x39b
V  [libjvm.so+0x8da06d]  JavaCalls::call_virtual(JavaValue*, Handle, Klass*, Symbol*, Symbol*, Thread*)+0x1ed
V  [libjvm.so+0x98912c]  thread_entry(JavaThread*, Thread*)+0x6c
V  [libjvm.so+0xedb02a]  JavaThread::thread_main_inner()+0x1ba
V  [libjvm.so+0xed7c2f]  Thread::call_run()+0x14f
V  [libjvm.so+0xc776a6]  thread_native_entry(Thread*)+0xe6

[github-actions]

🔧 Report generated by pr-comment-cppcheck

CppCheck Report

Style Violations (151)

• Local variable 'jni' shadows outer function
• Local variable 'size' shadows outer function
• Local variable 'prev' shadows outer function
• Class 'Cleaner' has a constructor with 1 argument that is not explicit.
• Variable 'numRefs' is assigned a value that is never used.
• The class 'NativeFunc' does not declare a constructor although it has private member variables which likely require initialization.
• Local variable 'i' shadows outer variable
• Consider using std::transform algorithm instead of a raw loop.
• struct member 'Tag::value' is never used.
• struct member 'ContextPage::capacity' is never used.
• struct member 'ContextPage::storage' is never used.
• Class 'Dictionary' has a constructor with 1 argument that is not explicit.
• struct member 'DictRow::keys' is never used.
• struct member 'DictRow::next' is never used.
• Local variable 'pc_off' shadows outer variable
• Class 'WallClockEpochEvent' has a constructor with 1 argument that is not explicit.
• struct member 'QueueTimeEvent::_start' is never used.
• struct member 'QueueTimeEvent::_end' is never used.
• struct member 'QueueTimeEvent::_task' is never used.
• struct member 'QueueTimeEvent::_scheduler' is never used.
• struct member 'QueueTimeEvent::_origin' is never used.
• The class 'ObjectSampler' does not declare a constructor although it has private member variables which likely require initialization.
• The class 'VirtualSpaceSummary' does not declare a constructor although it has private member variables which likely require initialization.
• The class 'GCHeapSummary' does not declare a constructor although it has private member variables which likely require initialization.
• The class 'CollectedHeap' does not declare a constructor although it has private member variables which likely require initialization.
• Class 'Element' has a constructor with 1 argument that is not explicit.
• Class 'NoField' has a constructor with 1 argument that is not explicit.
• Class 'MutexLocker' has a constructor with 1 argument that is not explicit.
• Class 'MethodList' has a constructor with 1 argument that is not explicit.
• The function 'is_nofield' overrides a function in a base class but is not marked with a 'override' specifier.
• The function 'check' overrides a function in a base class but is not marked with a 'override' specifier.
• The function 'start' overrides a function in a base class but is not marked with a 'override' specifier.
• The function 'stop' overrides a function in a base class but is not marked with a 'override' specifier.
• The function 'interval' overrides a function in a base class but is not marked with a 'override' specifier.
• Condition 'enabled()' is always false
• Condition 'usage._maxSize==-1' is always false
• Variable 'thread_ids' can be declared with const
• struct member 'CpuTime::real' is never used.
• struct member 'CpuTime::user' is never used.
• struct member 'CpuTime::system' is never used.
• The function 'name' overrides a function in a base class but is not marked with a 'override' specifier.
• The function 'interval' overrides a function in a base class but is not marked with a 'override' specifier.
• The function 'check' overrides a function in a base class but is not marked with a 'override' specifier.
• The function 'start' overrides a function in a base class but is not marked with a 'override' specifier.
• The function 'stop' overrides a function in a base class but is not marked with a 'override' specifier.
• The function 'enableEvents' overrides a function in a base class but is not marked with a 'override' specifier.
• The function 'check' overrides a function in a base class but is not marked with a 'override' specifier.
• The function 'start' overrides a function in a base class but is not marked with a 'override' specifier.
• The function 'stop' overrides a function in a base class but is not marked with a 'override' specifier.
• struct member 'jvmtiStackInfoExtended::frame_buffer' is never used.
• The class 'J9WallClock' does not declare a constructor although it has private member variables which likely require initialization.
• The function 'name' overrides a function in a base class but is not marked with a 'override' specifier.
• The function 'interval' overrides a function in a base class but is not marked with a 'override' specifier.
• The function 'start' overrides a function in a base class but is not marked with a 'override' specifier.
• The function 'stop' overrides a function in a base class but is not marked with a 'override' specifier.
• The function 'enableEvents' overrides a function in a base class but is not marked with a 'override' specifier.
• The function 'name' overrides a function in a base class but is not marked with a 'override' specifier.
• The function 'interval' overrides a function in a base class but is not marked with a 'override' specifier.
• The function 'start' overrides a function in a base class but is not marked with a 'override' specifier.
• The function 'stop' overrides a function in a base class but is not marked with a 'override' specifier.
• The function 'enableEvents' overrides a function in a base class but is not marked with a 'override' specifier.
• Condition 'max_heap==-1' is always false
• Condition 'max_heap==-1' is always false
• Condition 'level>=_level' is always true
• The function 'rewind' overrides a function in a base class but is not marked with a 'override' specifier.
• The function 'next' overrides a function in a base class but is not marked with a 'override' specifier.
• The function 'size' overrides a function in a base class but is not marked with a 'override' specifier.
• The function 'check' overrides a function in a base class but is not marked with a 'override' specifier.
• The function 'start' overrides a function in a base class but is not marked with a 'override' specifier.
• The function 'stop' overrides a function in a base class but is not marked with a 'override' specifier.
• The function 'registerThread' overrides a function in a base class but is not marked with a 'override' specifier.
• The function 'unregisterThread' overrides a function in a base class but is not marked with a 'override' specifier.
• The function 'interval' overrides a function in a base class but is not marked with a 'override' specifier.
• The function 'name' overrides a function in a base class but is not marked with a 'override' specifier.
• The function 'enableEvents' overrides a function in a base class but is not marked with a 'override' specifier.
• Local variable 'ml' shadows outer variable
• Local variable 'ml' shadows outer variable
• Variable 'error' is assigned a value that is never used.
• Variable 'error' is assigned a value that is never used.
• Variable 'error' is assigned a value that is never used.
• Variable 'error' is assigned a value that is never used.
• Unused private function: 'StackFrame::withinCurrentStack'
• Condition 'pc>(const void*)-MIN_VALID_PC' is always true
• Condition 'pc>(const void*)-MIN_VALID_PC' is always true
• The scope of the variable 'prev_sp' can be reduced.
• Class 'SymbolDesc' has a constructor with 1 argument that is not explicit.
• Class 'MemoryMapDesc' has a constructor with 1 argument that is not explicit.
• struct member 'ASGCT_CallTrace::env' is never used.
• struct member 'ASGCT_CallTrace::frames' is never used.
• struct member 'JVMTIFunctions::unused1' is never used.
• struct member 'JVMTIFunctions::unused2' is never used.
• The scope of the variable 'delayedCounter' can be reduced.
• Variable 'error' is assigned a value that is never used.
• Variable 'ctx' can be declared with const
• The function 'Agent_OnAttach' is never used.
• The function 'Agent_OnLoad' is never used.
• The function 'GetJ9vmThread' is never used.
• The function 'JNI_OnLoad' is never used.
• The function 'JNI_OnUnload' is never used.
• The function 'Java_com_datadoghq_profiler_JavaProfiler_currentTicks0' is never used.
• The function 'Java_com_datadoghq_profiler_JavaProfiler_describeDebugCounters0' is never used.
• The function 'Java_com_datadoghq_profiler_JavaProfiler_dump0' is never used.
• The function 'Java_com_datadoghq_profiler_JavaProfiler_execute0' is never used.
• The function 'Java_com_datadoghq_profiler_JavaProfiler_filterThread0' is never used.
• The function 'Java_com_datadoghq_profiler_JavaProfiler_getContextPage0' is never used.
• The function 'Java_com_datadoghq_profiler_JavaProfiler_getContextPageOffset0' is never used.
• The function 'Java_com_datadoghq_profiler_JavaProfiler_getDebugCounters0' is never used.
• The function 'Java_com_datadoghq_profiler_JavaProfiler_getMaxContextPages0' is never used.
• The function 'Java_com_datadoghq_profiler_JavaProfiler_getSamples' is never used.
• The function 'Java_com_datadoghq_profiler_JavaProfiler_getTid0' is never used.
• The function 'Java_com_datadoghq_profiler_JavaProfiler_recordQueueEnd0' is never used.
• The function 'Java_com_datadoghq_profiler_JavaProfiler_recordSettingEvent0' is never used.
• The function 'Java_com_datadoghq_profiler_JavaProfiler_recordTrace0' is never used.
• The function 'Java_com_datadoghq_profiler_JavaProfiler_registerConstant0' is never used.
• The function 'Java_com_datadoghq_profiler_JavaProfiler_stop0' is never used.
• The function 'Java_com_datadoghq_profiler_JavaProfiler_tscFrequency0' is never used.
• The function 'VMObjectAlloc' is never used.
• The function '_min' is never used.
• The function 'appendRecording' is never used.
• The function 'arg0' is never used.
• The function 'arg1' is never used.
• The function 'arg3' is never used.
• The function 'assign' is never used.
• The function 'body' is never used.
• The function 'copyTo' is never used.
• The function 'covers' is never used.
• The function 'cpuMonitorCycle' is never used.
• The function 'cputime' is never used.
• The function 'deallocateLineNumberTable' is never used.
• The function 'describeCounters' is never used.
• The function 'fileSize' is never used.
• The function 'flushJfr' is never used.
• The function 'fromHandle' is never used.
• The function 'fromMethodID' is never used.
• The function 'getCounter' is never used.
• The function 'getCounters' is never used.
• The function 'hasClassNames' is never used.
• The function 'install' is never used.
• The function 'isSystemClassLoader' is never used.
• The function 'is_readable_pointer' is never used.
• The function 'notify' is never used.
• The function 'ntoh64' is never used.
• The function 'pair' is never used.
• The function 'readCounter' is never used.
• The function 'restartProfiler' is never used.
• The function 'schedPolicy' is never used.
• The function 'uninstall' is never used.
• The function 'units' is never used.
• The function 'updateCounter' is never used.
• The function 'waitUntil' is never used.
• The function 'writeListSetting' is never used.

[github-actions]

🔧 Report generated by pr-comment-scanbuild

Scan-Build Report

User:	runner@fv-az887-500
Working Directory:	/home/runner/work/java-profiler/java-profiler/ddprof-lib/src/test/make
Command Line:	make -j4 clean all
Clang Version:	Ubuntu clang version 14.0.0-1ubuntu1.1
Date:	Wed Aug 23 12:55:43 2023

Bug Summary

Bug Type	Quantity	Display?
All Bugs	4
Logic error
Assigned value is garbage or undefined	1
Dereference of null pointer	1
Result of operation is garbage or undefined	1
Unused code
Dead nested assignment	1

Reports

Bug Group	Bug Type ▾	File	Function/Method	Line	Path Length
Logic error	Assigned value is garbage or undefined	dwarf.cpp	parseInstructions	231	20
Unused code	Dead nested assignment	vmStructs.cpp	checkNativeBinding	635	1
Logic error	Dereference of null pointer	symbols_linux.cpp	ElfParser	154	35
Logic error	Result of operation is garbage or undefined	dwarf.h	getSLeb	123	25