Mercurial > hg > icedtea9-forest > hotspot
changeset 615:c6c601a0f2d6
6797870: Add -XX:+{HeapDump,PrintClassHistogram}{Before,After}FullGC
Summary: Call newly created CollectedHeap::dump_{pre,post}_full_gc before and after every stop-world full collection cycle on GenCollectedHeap and ParallelScavengeHeap. (Support for G1CollectedHeap forthcoming under CR 6810861.) Small modifications to existing heap dumping and class histogram implementation, especially to allow multiple on-the-fly histos/dumps by the VM thread during a single safepoint.
Reviewed-by: jmasa, alanb, mchung
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--- a/src/share/vm/gc_implementation/parallelScavenge/psMarkSweep.cpp Fri Feb 27 15:30:47 2009 -0800 +++ b/src/share/vm/gc_implementation/parallelScavenge/psMarkSweep.cpp Mon Mar 02 16:37:04 2009 -0800 @@ -125,6 +125,8 @@ perm_gen->verify_object_start_array(); } + heap->pre_full_gc_dump(); + // Filled in below to track the state of the young gen after the collection. bool eden_empty; bool survivors_empty; @@ -363,6 +365,8 @@ Universe::print_heap_after_gc(); } + heap->post_full_gc_dump(); + #ifdef TRACESPINNING ParallelTaskTerminator::print_termination_counts(); #endif
--- a/src/share/vm/gc_implementation/parallelScavenge/psParallelCompact.cpp Fri Feb 27 15:30:47 2009 -0800 +++ b/src/share/vm/gc_implementation/parallelScavenge/psParallelCompact.cpp Mon Mar 02 16:37:04 2009 -0800 @@ -1982,6 +1982,8 @@ heap->record_gen_tops_before_GC(); } + heap->pre_full_gc_dump(); + _print_phases = PrintGCDetails && PrintParallelOldGCPhaseTimes; // Make sure data structures are sane, make the heap parsable, and do other @@ -2204,6 +2206,8 @@ gc_task_manager()->print_task_time_stamps(); } + heap->post_full_gc_dump(); + #ifdef TRACESPINNING ParallelTaskTerminator::print_termination_counts(); #endif
--- a/src/share/vm/gc_implementation/shared/vmGCOperations.cpp Fri Feb 27 15:30:47 2009 -0800 +++ b/src/share/vm/gc_implementation/shared/vmGCOperations.cpp Mon Mar 02 16:37:04 2009 -0800 @@ -121,7 +121,7 @@ // make the heap parsable (no need to retire TLABs) ch->ensure_parsability(false); } - HeapInspection::heap_inspection(_out); + HeapInspection::heap_inspection(_out, _need_prologue /* need_prologue */); }
--- a/src/share/vm/gc_implementation/shared/vmGCOperations.hpp Fri Feb 27 15:30:47 2009 -0800 +++ b/src/share/vm/gc_implementation/shared/vmGCOperations.hpp Mon Mar 02 16:37:04 2009 -0800 @@ -112,13 +112,16 @@ private: outputStream* _out; bool _full_gc; + bool _need_prologue; public: - VM_GC_HeapInspection(outputStream* out, bool request_full_gc) : + VM_GC_HeapInspection(outputStream* out, bool request_full_gc, + bool need_prologue) : VM_GC_Operation(0 /* total collections, dummy, ignored */, 0 /* total full collections, dummy, ignored */, request_full_gc) { _out = out; _full_gc = request_full_gc; + _need_prologue = need_prologue; } ~VM_GC_HeapInspection() {}
--- a/src/share/vm/gc_interface/collectedHeap.cpp Fri Feb 27 15:30:47 2009 -0800 +++ b/src/share/vm/gc_interface/collectedHeap.cpp Mon Mar 02 16:37:04 2009 -0800 @@ -294,3 +294,29 @@ ThreadLocalAllocBuffer::resize_all_tlabs(); } } + +void CollectedHeap::pre_full_gc_dump() { + if (HeapDumpBeforeFullGC) { + TraceTime tt("Heap Dump: ", PrintGCDetails, false, gclog_or_tty); + // We are doing a "major" collection and a heap dump before + // major collection has been requested. + HeapDumper::dump_heap(); + } + if (PrintClassHistogramBeforeFullGC) { + TraceTime tt("Class Histogram: ", PrintGCDetails, true, gclog_or_tty); + VM_GC_HeapInspection inspector(gclog_or_tty, false /* ! full gc */, false /* ! prologue */); + inspector.doit(); + } +} + +void CollectedHeap::post_full_gc_dump() { + if (HeapDumpAfterFullGC) { + TraceTime tt("Heap Dump", PrintGCDetails, false, gclog_or_tty); + HeapDumper::dump_heap(); + } + if (PrintClassHistogramAfterFullGC) { + TraceTime tt("Class Histogram", PrintGCDetails, true, gclog_or_tty); + VM_GC_HeapInspection inspector(gclog_or_tty, false /* ! full gc */, false /* ! prologue */); + inspector.doit(); + } +}
--- a/src/share/vm/gc_interface/collectedHeap.hpp Fri Feb 27 15:30:47 2009 -0800 +++ b/src/share/vm/gc_interface/collectedHeap.hpp Mon Mar 02 16:37:04 2009 -0800 @@ -514,6 +514,10 @@ // Perform any cleanup actions necessary before allowing a verification. virtual void prepare_for_verify() = 0; + // Generate any dumps preceding or following a full gc + void pre_full_gc_dump(); + void post_full_gc_dump(); + virtual void print() const = 0; virtual void print_on(outputStream* st) const = 0;
--- a/src/share/vm/includeDB_gc Fri Feb 27 15:30:47 2009 -0800 +++ b/src/share/vm/includeDB_gc Mon Mar 02 16:37:04 2009 -0800 @@ -26,10 +26,12 @@ collectedHeap.cpp collectedHeap.hpp collectedHeap.cpp collectedHeap.inline.hpp +collectedHeap.cpp heapDumper.hpp collectedHeap.cpp init.hpp collectedHeap.cpp oop.inline.hpp collectedHeap.cpp systemDictionary.hpp collectedHeap.cpp thread_<os_family>.inline.hpp +collectedHeap.cpp vmGCOperations.hpp collectedHeap.hpp allocation.hpp collectedHeap.hpp barrierSet.hpp
--- a/src/share/vm/memory/genCollectedHeap.cpp Fri Feb 27 15:30:47 2009 -0800 +++ b/src/share/vm/memory/genCollectedHeap.cpp Mon Mar 02 16:37:04 2009 -0800 @@ -456,6 +456,9 @@ int max_level_collected = starting_level; for (int i = starting_level; i <= max_level; i++) { if (_gens[i]->should_collect(full, size, is_tlab)) { + if (i == n_gens() - 1) { // a major collection is to happen + pre_full_gc_dump(); // do any pre full gc dumps + } // Timer for individual generations. Last argument is false: no CR TraceTime t1(_gens[i]->short_name(), PrintGCDetails, false, gclog_or_tty); TraceCollectorStats tcs(_gens[i]->counters()); @@ -573,6 +576,10 @@ // a whole heap collection. complete = complete || (max_level_collected == n_gens() - 1); + if (complete) { // We did a "major" collection + post_full_gc_dump(); // do any post full gc dumps + } + if (PrintGCDetails) { print_heap_change(gch_prev_used);
--- a/src/share/vm/memory/heapInspection.cpp Fri Feb 27 15:30:47 2009 -0800 +++ b/src/share/vm/memory/heapInspection.cpp Mon Mar 02 16:37:04 2009 -0800 @@ -233,7 +233,7 @@ size_t missed_count() { return _missed_count; } }; -void HeapInspection::heap_inspection(outputStream* st) { +void HeapInspection::heap_inspection(outputStream* st, bool need_prologue) { ResourceMark rm; HeapWord* ref; @@ -244,7 +244,9 @@ case CollectedHeap::GenCollectedHeap: { is_shared_heap = true; SharedHeap* sh = (SharedHeap*)heap; - sh->gc_prologue(false /* !full */); // get any necessary locks, etc. + if (need_prologue) { + sh->gc_prologue(false /* !full */); // get any necessary locks, etc. + } ref = sh->perm_gen()->used_region().start(); break; } @@ -290,7 +292,7 @@ } st->flush(); - if (is_shared_heap) { + if (need_prologue && is_shared_heap) { SharedHeap* sh = (SharedHeap*)heap; sh->gc_epilogue(false /* !full */); // release all acquired locks, etc. }
--- a/src/share/vm/memory/heapInspection.hpp Fri Feb 27 15:30:47 2009 -0800 +++ b/src/share/vm/memory/heapInspection.hpp Mon Mar 02 16:37:04 2009 -0800 @@ -127,6 +127,6 @@ class HeapInspection : public AllStatic { public: - static void heap_inspection(outputStream* st) KERNEL_RETURN; + static void heap_inspection(outputStream* st, bool need_prologue) KERNEL_RETURN; static void find_instances_at_safepoint(klassOop k, GrowableArray<oop>* result) KERNEL_RETURN; };
--- a/src/share/vm/runtime/globals.hpp Fri Feb 27 15:30:47 2009 -0800 +++ b/src/share/vm/runtime/globals.hpp Mon Mar 02 16:37:04 2009 -0800 @@ -662,6 +662,12 @@ product(ccstrlist, OnOutOfMemoryError, "", \ "Run user-defined commands on first java.lang.OutOfMemoryError") \ \ + manageable(bool, HeapDumpBeforeFullGC, false, \ + "Dump heap to file before any major stop-world GC") \ + \ + manageable(bool, HeapDumpAfterFullGC, false, \ + "Dump heap to file after any major stop-world GC") \ + \ manageable(bool, HeapDumpOnOutOfMemoryError, false, \ "Dump heap to file when java.lang.OutOfMemoryError is thrown") \ \ @@ -1971,6 +1977,12 @@ product(bool, PrintHeapAtSIGBREAK, true, \ "Print heap layout in response to SIGBREAK") \ \ + manageable(bool, PrintClassHistogramBeforeFullGC, false, \ + "Print a class histogram before any major stop-world GC") \ + \ + manageable(bool, PrintClassHistogramAfterFullGC, false, \ + "Print a class histogram after any major stop-world GC") \ + \ manageable(bool, PrintClassHistogram, false, \ "Print a histogram of class instances") \ \
--- a/src/share/vm/runtime/os.cpp Fri Feb 27 15:30:47 2009 -0800 +++ b/src/share/vm/runtime/os.cpp Mon Mar 02 16:37:04 2009 -0800 @@ -207,7 +207,8 @@ VMThread::execute(&op1); Universe::print_heap_at_SIGBREAK(); if (PrintClassHistogram) { - VM_GC_HeapInspection op1(gclog_or_tty, true /* force full GC before heap inspection */); + VM_GC_HeapInspection op1(gclog_or_tty, true /* force full GC before heap inspection */, + true /* need_prologue */); VMThread::execute(&op1); } if (JvmtiExport::should_post_data_dump()) {
--- a/src/share/vm/services/attachListener.cpp Fri Feb 27 15:30:47 2009 -0800 +++ b/src/share/vm/services/attachListener.cpp Mon Mar 02 16:37:04 2009 -0800 @@ -194,7 +194,7 @@ } live_objects_only = strcmp(arg0, "-live") == 0; } - VM_GC_HeapInspection heapop(out, live_objects_only /* request gc */); + VM_GC_HeapInspection heapop(out, live_objects_only /* request full gc */, true /* need_prologue */); VMThread::execute(&heapop); return JNI_OK; }
--- a/src/share/vm/services/heapDumper.cpp Fri Feb 27 15:30:47 2009 -0800 +++ b/src/share/vm/services/heapDumper.cpp Mon Mar 02 16:37:04 2009 -0800 @@ -347,7 +347,6 @@ INITIAL_CLASS_COUNT = 200 }; - // Supports I/O operations on a dump file class DumpWriter : public StackObj { @@ -1303,7 +1302,9 @@ // The VM operation that performs the heap dump class VM_HeapDumper : public VM_GC_Operation { private: - DumpWriter* _writer; + static VM_HeapDumper* _global_dumper; + static DumpWriter* _global_writer; + DumpWriter* _local_writer; bool _gc_before_heap_dump; bool _is_segmented_dump; jlong _dump_start; @@ -1311,8 +1312,20 @@ ThreadStackTrace** _stack_traces; int _num_threads; - // accessors - DumpWriter* writer() const { return _writer; } + // accessors and setters + static VM_HeapDumper* dumper() { assert(_global_dumper != NULL, "Error"); return _global_dumper; } + static DumpWriter* writer() { assert(_global_writer != NULL, "Error"); return _global_writer; } + void set_global_dumper() { + assert(_global_dumper == NULL, "Error"); + _global_dumper = this; + } + void set_global_writer() { + assert(_global_writer == NULL, "Error"); + _global_writer = _local_writer; + } + void clear_global_dumper() { _global_dumper = NULL; } + void clear_global_writer() { _global_writer = NULL; } + bool is_segmented_dump() const { return _is_segmented_dump; } void set_segmented_dump() { _is_segmented_dump = true; } jlong dump_start() const { return _dump_start; } @@ -1357,7 +1370,7 @@ VM_GC_Operation(0 /* total collections, dummy, ignored */, 0 /* total full collections, dummy, ignored */, gc_before_heap_dump) { - _writer = writer; + _local_writer = writer; _gc_before_heap_dump = gc_before_heap_dump; _is_segmented_dump = false; _dump_start = (jlong)-1; @@ -1381,6 +1394,9 @@ void doit(); }; +VM_HeapDumper* VM_HeapDumper::_global_dumper = NULL; +DumpWriter* VM_HeapDumper::_global_writer = NULL; + bool VM_HeapDumper::skip_operation() const { return false; } @@ -1479,31 +1495,28 @@ void VM_HeapDumper::do_load_class(klassOop k) { static u4 class_serial_num = 0; - VM_HeapDumper* dumper = ((VM_HeapDumper*)VMThread::vm_operation()); - DumpWriter* writer = dumper->writer(); - // len of HPROF_LOAD_CLASS record u4 remaining = 2*oopSize + 2*sizeof(u4); // write a HPROF_LOAD_CLASS for the class and each array class do { - DumperSupport::write_header(writer, HPROF_LOAD_CLASS, remaining); + DumperSupport::write_header(writer(), HPROF_LOAD_CLASS, remaining); // class serial number is just a number - writer->write_u4(++class_serial_num); + writer()->write_u4(++class_serial_num); // class ID Klass* klass = Klass::cast(k); - writer->write_classID(klass); + writer()->write_classID(klass); // add the klassOop and class serial number pair - dumper->add_class_serial_number(klass, class_serial_num); + dumper()->add_class_serial_number(klass, class_serial_num); - writer->write_u4(STACK_TRACE_ID); + writer()->write_u4(STACK_TRACE_ID); // class name ID symbolOop name = klass->name(); - writer->write_objectID(name); + writer()->write_objectID(name); // write a LOAD_CLASS record for the array type (if it exists) k = klass->array_klass_or_null(); @@ -1512,17 +1525,13 @@ // writes a HPROF_GC_CLASS_DUMP record for the given class void VM_HeapDumper::do_class_dump(klassOop k) { - VM_HeapDumper* dumper = ((VM_HeapDumper*)VMThread::vm_operation()); - DumpWriter* writer = dumper->writer(); - DumperSupport::dump_class_and_array_classes(writer, k); + DumperSupport::dump_class_and_array_classes(writer(), k); } // writes a HPROF_GC_CLASS_DUMP records for a given basic type // array (and each multi-dimensional array too) void VM_HeapDumper::do_basic_type_array_class_dump(klassOop k) { - VM_HeapDumper* dumper = ((VM_HeapDumper*)VMThread::vm_operation()); - DumpWriter* writer = dumper->writer(); - DumperSupport::dump_basic_type_array_class(writer, k); + DumperSupport::dump_basic_type_array_class(writer(), k); } // Walk the stack of the given thread. @@ -1658,6 +1667,11 @@ ch->ensure_parsability(false); } + // At this point we should be the only dumper active, so + // the following should be safe. + set_global_dumper(); + set_global_writer(); + // Write the file header - use 1.0.2 for large heaps, otherwise 1.0.1 size_t used = ch->used(); const char* header; @@ -1667,6 +1681,7 @@ } else { header = "JAVA PROFILE 1.0.1"; } + // header is few bytes long - no chance to overflow int writer()->write_raw((void*)header, (int)strlen(header)); writer()->write_u1(0); // terminator @@ -1723,6 +1738,10 @@ // fixes up the length of the dump record. In the case of a segmented // heap then the HPROF_HEAP_DUMP_END record is also written. end_of_dump(); + + // Now we clear the global variables, so that a future dumper might run. + clear_global_dumper(); + clear_global_writer(); } void VM_HeapDumper::dump_stack_traces() { @@ -1790,7 +1809,12 @@ // generate the dump VM_HeapDumper dumper(&writer, _gc_before_heap_dump); - VMThread::execute(&dumper); + if (Thread::current()->is_VM_thread()) { + assert(SafepointSynchronize::is_at_safepoint(), "Expected to be called at a safepoint"); + dumper.doit(); + } else { + VMThread::execute(&dumper); + } // close dump file and record any error that the writer may have encountered writer.close(); @@ -1845,49 +1869,68 @@ } } - -// Called by error reporting +// Called by error reporting by a single Java thread outside of a JVM safepoint, +// or by heap dumping by the VM thread during a (GC) safepoint. Thus, these various +// callers are strictly serialized and guaranteed not to interfere below. For more +// general use, however, this method will need modification to prevent +// inteference when updating the static variables base_path and dump_file_seq below. void HeapDumper::dump_heap() { - static char path[JVM_MAXPATHLEN]; + static char base_path[JVM_MAXPATHLEN] = {'\0'}; + static uint dump_file_seq = 0; + char my_path[JVM_MAXPATHLEN] = {'\0'}; // The dump file defaults to java_pid<pid>.hprof in the current working // directory. HeapDumpPath=<file> can be used to specify an alternative // dump file name or a directory where dump file is created. - bool use_default_filename = true; - if (HeapDumpPath == NULL || HeapDumpPath[0] == '\0') { - path[0] = '\0'; // HeapDumpPath=<file> not specified - } else { - assert(strlen(HeapDumpPath) < sizeof(path), "HeapDumpPath too long"); - strcpy(path, HeapDumpPath); - // check if the path is a directory (must exist) - DIR* dir = os::opendir(path); - if (dir == NULL) { - use_default_filename = false; + if (dump_file_seq == 0) { // first time in, we initialize base_path + bool use_default_filename = true; + if (HeapDumpPath == NULL || HeapDumpPath[0] == '\0') { + // HeapDumpPath=<file> not specified } else { - // HeapDumpPath specified a directory. We append a file separator - // (if needed). - os::closedir(dir); - size_t fs_len = strlen(os::file_separator()); - if (strlen(path) >= fs_len) { - char* end = path; - end += (strlen(path) - fs_len); - if (strcmp(end, os::file_separator()) != 0) { - assert(strlen(path) + strlen(os::file_separator()) < sizeof(path), - "HeapDumpPath too long"); - strcat(path, os::file_separator()); + assert(strlen(HeapDumpPath) < sizeof(base_path), "HeapDumpPath too long"); + strcpy(base_path, HeapDumpPath); + // check if the path is a directory (must exist) + DIR* dir = os::opendir(base_path); + if (dir == NULL) { + use_default_filename = false; + } else { + // HeapDumpPath specified a directory. We append a file separator + // (if needed). + os::closedir(dir); + size_t fs_len = strlen(os::file_separator()); + if (strlen(base_path) >= fs_len) { + char* end = base_path; + end += (strlen(base_path) - fs_len); + if (strcmp(end, os::file_separator()) != 0) { + assert(strlen(base_path) + strlen(os::file_separator()) < sizeof(base_path), + "HeapDumpPath too long"); + strcat(base_path, os::file_separator()); + } } } } + // If HeapDumpPath wasn't a file name then we append the default name + if (use_default_filename) { + char fn[32]; + sprintf(fn, "java_pid%d", os::current_process_id()); + assert(strlen(base_path) + strlen(fn) < sizeof(base_path), "HeapDumpPath too long"); + strcat(base_path, fn); + } + assert(strlen(base_path) < sizeof(my_path), "Buffer too small"); + strcpy(my_path, base_path); + } else { + // Append a sequence number id for dumps following the first + char fn[33]; + sprintf(fn, ".%d", dump_file_seq); + assert(strlen(base_path) + strlen(fn) < sizeof(my_path), "HeapDumpPath too long"); + strcpy(my_path, base_path); + strcat(my_path, fn); } - // If HeapDumpPath wasn't a file name then we append the default name - if (use_default_filename) { - char fn[32]; - sprintf(fn, "java_pid%d.hprof", os::current_process_id()); - assert(strlen(path) + strlen(fn) < sizeof(path), "HeapDumpPath too long"); - strcat(path, fn); - } + dump_file_seq++; // increment seq number for next time we dump + assert(strlen(".hprof") + strlen(my_path) < sizeof(my_path), "HeapDumpPath too long"); + strcat(my_path, ".hprof"); HeapDumper dumper(false /* no GC before heap dump */, true /* send to tty */); - dumper.dump(path); + dumper.dump(my_path); }
--- a/src/share/vm/services/heapDumper.hpp Fri Feb 27 15:30:47 2009 -0800 +++ b/src/share/vm/services/heapDumper.hpp Mon Mar 02 16:37:04 2009 -0800 @@ -53,7 +53,7 @@ public: HeapDumper(bool gc_before_heap_dump) : - _gc_before_heap_dump(gc_before_heap_dump), _error(NULL), _print_to_tty(false) { } + _gc_before_heap_dump(gc_before_heap_dump), _error(NULL), _print_to_tty(false) { } HeapDumper(bool gc_before_heap_dump, bool print_to_tty) : _gc_before_heap_dump(gc_before_heap_dump), _error(NULL), _print_to_tty(print_to_tty) { }