/* * Copyright (c) 2005, 2017, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. * */ #include "precompiled.hpp" #include "jvm.h" #include "classfile/symbolTable.hpp" #include "classfile/systemDictionary.hpp" #include "classfile/vmSymbols.hpp" #include "gc/shared/gcLocker.inline.hpp" #include "gc/shared/genCollectedHeap.hpp" #include "gc/shared/vmGCOperations.hpp" #include "memory/resourceArea.hpp" #include "memory/universe.hpp" #include "oops/objArrayKlass.hpp" #include "oops/objArrayOop.inline.hpp" #include "oops/oop.inline.hpp" #include "runtime/javaCalls.hpp" #include "runtime/jniHandles.hpp" #include "runtime/os.hpp" #include "runtime/reflectionUtils.hpp" #include "runtime/thread.inline.hpp" #include "runtime/threadSMR.hpp" #include "runtime/vframe.hpp" #include "runtime/vmThread.hpp" #include "runtime/vm_operations.hpp" #include "services/heapDumper.hpp" #include "services/threadService.hpp" #include "utilities/macros.hpp" #include "utilities/ostream.hpp" #if INCLUDE_ALL_GCS #include "gc/parallel/parallelScavengeHeap.hpp" #endif // INCLUDE_ALL_GCS /* * HPROF binary format - description copied from: * src/share/demo/jvmti/hprof/hprof_io.c * * * header "JAVA PROFILE 1.0.2" (0-terminated) * * u4 size of identifiers. Identifiers are used to represent * UTF8 strings, objects, stack traces, etc. They usually * have the same size as host pointers. For example, on * Solaris and Win32, the size is 4. * u4 high word * u4 low word number of milliseconds since 0:00 GMT, 1/1/70 * [record]* a sequence of records. * * * Record format: * * u1 a TAG denoting the type of the record * u4 number of *microseconds* since the time stamp in the * header. (wraps around in a little more than an hour) * u4 number of bytes *remaining* in the record. Note that * this number excludes the tag and the length field itself. * [u1]* BODY of the record (a sequence of bytes) * * * The following TAGs are supported: * * TAG BODY notes *---------------------------------------------------------- * HPROF_UTF8 a UTF8-encoded name * * id name ID * [u1]* UTF8 characters (no trailing zero) * * HPROF_LOAD_CLASS a newly loaded class * * u4 class serial number (> 0) * id class object ID * u4 stack trace serial number * id class name ID * * HPROF_UNLOAD_CLASS an unloading class * * u4 class serial_number * * HPROF_FRAME a Java stack frame * * id stack frame ID * id method name ID * id method signature ID * id source file name ID * u4 class serial number * i4 line number. >0: normal * -1: unknown * -2: compiled method * -3: native method * * HPROF_TRACE a Java stack trace * * u4 stack trace serial number * u4 thread serial number * u4 number of frames * [id]* stack frame IDs * * * HPROF_ALLOC_SITES a set of heap allocation sites, obtained after GC * * u2 flags 0x0001: incremental vs. complete * 0x0002: sorted by allocation vs. live * 0x0004: whether to force a GC * u4 cutoff ratio * u4 total live bytes * u4 total live instances * u8 total bytes allocated * u8 total instances allocated * u4 number of sites that follow * [u1 is_array: 0: normal object * 2: object array * 4: boolean array * 5: char array * 6: float array * 7: double array * 8: byte array * 9: short array * 10: int array * 11: long array * u4 class serial number (may be zero during startup) * u4 stack trace serial number * u4 number of bytes alive * u4 number of instances alive * u4 number of bytes allocated * u4]* number of instance allocated * * HPROF_START_THREAD a newly started thread. * * u4 thread serial number (> 0) * id thread object ID * u4 stack trace serial number * id thread name ID * id thread group name ID * id thread group parent name ID * * HPROF_END_THREAD a terminating thread. * * u4 thread serial number * * HPROF_HEAP_SUMMARY heap summary * * u4 total live bytes * u4 total live instances * u8 total bytes allocated * u8 total instances allocated * * HPROF_HEAP_DUMP denote a heap dump * * [heap dump sub-records]* * * There are four kinds of heap dump sub-records: * * u1 sub-record type * * HPROF_GC_ROOT_UNKNOWN unknown root * * id object ID * * HPROF_GC_ROOT_THREAD_OBJ thread object * * id thread object ID (may be 0 for a * thread newly attached through JNI) * u4 thread sequence number * u4 stack trace sequence number * * HPROF_GC_ROOT_JNI_GLOBAL JNI global ref root * * id object ID * id JNI global ref ID * * HPROF_GC_ROOT_JNI_LOCAL JNI local ref * * id object ID * u4 thread serial number * u4 frame # in stack trace (-1 for empty) * * HPROF_GC_ROOT_JAVA_FRAME Java stack frame * * id object ID * u4 thread serial number * u4 frame # in stack trace (-1 for empty) * * HPROF_GC_ROOT_NATIVE_STACK Native stack * * id object ID * u4 thread serial number * * HPROF_GC_ROOT_STICKY_CLASS System class * * id object ID * * HPROF_GC_ROOT_THREAD_BLOCK Reference from thread block * * id object ID * u4 thread serial number * * HPROF_GC_ROOT_MONITOR_USED Busy monitor * * id object ID * * HPROF_GC_CLASS_DUMP dump of a class object * * id class object ID * u4 stack trace serial number * id super class object ID * id class loader object ID * id signers object ID * id protection domain object ID * id reserved * id reserved * * u4 instance size (in bytes) * * u2 size of constant pool * [u2, constant pool index, * ty, type * 2: object * 4: boolean * 5: char * 6: float * 7: double * 8: byte * 9: short * 10: int * 11: long * vl]* and value * * u2 number of static fields * [id, static field name, * ty, type, * vl]* and value * * u2 number of inst. fields (not inc. super) * [id, instance field name, * ty]* type * * HPROF_GC_INSTANCE_DUMP dump of a normal object * * id object ID * u4 stack trace serial number * id class object ID * u4 number of bytes that follow * [vl]* instance field values (class, followed * by super, super's super ...) * * HPROF_GC_OBJ_ARRAY_DUMP dump of an object array * * id array object ID * u4 stack trace serial number * u4 number of elements * id array class ID * [id]* elements * * HPROF_GC_PRIM_ARRAY_DUMP dump of a primitive array * * id array object ID * u4 stack trace serial number * u4 number of elements * u1 element type * 4: boolean array * 5: char array * 6: float array * 7: double array * 8: byte array * 9: short array * 10: int array * 11: long array * [u1]* elements * * HPROF_CPU_SAMPLES a set of sample traces of running threads * * u4 total number of samples * u4 # of traces * [u4 # of samples * u4]* stack trace serial number * * HPROF_CONTROL_SETTINGS the settings of on/off switches * * u4 0x00000001: alloc traces on/off * 0x00000002: cpu sampling on/off * u2 stack trace depth * * * When the header is "JAVA PROFILE 1.0.2" a heap dump can optionally * be generated as a sequence of heap dump segments. This sequence is * terminated by an end record. The additional tags allowed by format * "JAVA PROFILE 1.0.2" are: * * HPROF_HEAP_DUMP_SEGMENT denote a heap dump segment * * [heap dump sub-records]* * The same sub-record types allowed by HPROF_HEAP_DUMP * * HPROF_HEAP_DUMP_END denotes the end of a heap dump * */ // HPROF tags typedef enum { // top-level records HPROF_UTF8 = 0x01, HPROF_LOAD_CLASS = 0x02, HPROF_UNLOAD_CLASS = 0x03, HPROF_FRAME = 0x04, HPROF_TRACE = 0x05, HPROF_ALLOC_SITES = 0x06, HPROF_HEAP_SUMMARY = 0x07, HPROF_START_THREAD = 0x0A, HPROF_END_THREAD = 0x0B, HPROF_HEAP_DUMP = 0x0C, HPROF_CPU_SAMPLES = 0x0D, HPROF_CONTROL_SETTINGS = 0x0E, // 1.0.2 record types HPROF_HEAP_DUMP_SEGMENT = 0x1C, HPROF_HEAP_DUMP_END = 0x2C, // field types HPROF_ARRAY_OBJECT = 0x01, HPROF_NORMAL_OBJECT = 0x02, HPROF_BOOLEAN = 0x04, HPROF_CHAR = 0x05, HPROF_FLOAT = 0x06, HPROF_DOUBLE = 0x07, HPROF_BYTE = 0x08, HPROF_SHORT = 0x09, HPROF_INT = 0x0A, HPROF_LONG = 0x0B, // data-dump sub-records HPROF_GC_ROOT_UNKNOWN = 0xFF, HPROF_GC_ROOT_JNI_GLOBAL = 0x01, HPROF_GC_ROOT_JNI_LOCAL = 0x02, HPROF_GC_ROOT_JAVA_FRAME = 0x03, HPROF_GC_ROOT_NATIVE_STACK = 0x04, HPROF_GC_ROOT_STICKY_CLASS = 0x05, HPROF_GC_ROOT_THREAD_BLOCK = 0x06, HPROF_GC_ROOT_MONITOR_USED = 0x07, HPROF_GC_ROOT_THREAD_OBJ = 0x08, HPROF_GC_CLASS_DUMP = 0x20, HPROF_GC_INSTANCE_DUMP = 0x21, HPROF_GC_OBJ_ARRAY_DUMP = 0x22, HPROF_GC_PRIM_ARRAY_DUMP = 0x23 } hprofTag; // Default stack trace ID (used for dummy HPROF_TRACE record) enum { STACK_TRACE_ID = 1, INITIAL_CLASS_COUNT = 200 }; // Supports I/O operations on a dump file class DumpWriter : public StackObj { private: enum { io_buffer_size = 8*M }; int _fd; // file descriptor (-1 if dump file not open) julong _bytes_written; // number of byte written to dump file char* _buffer; // internal buffer size_t _size; size_t _pos; jlong _dump_start; char* _error; // error message when I/O fails void set_file_descriptor(int fd) { _fd = fd; } int file_descriptor() const { return _fd; } char* buffer() const { return _buffer; } size_t buffer_size() const { return _size; } size_t position() const { return _pos; } void set_position(size_t pos) { _pos = pos; } void set_error(const char* error) { _error = (char*)os::strdup(error); } // all I/O go through this function void write_internal(void* s, size_t len); public: DumpWriter(const char* path); ~DumpWriter(); void close(); bool is_open() const { return file_descriptor() >= 0; } void flush(); jlong dump_start() const { return _dump_start; } void set_dump_start(jlong pos); julong current_record_length(); // total number of bytes written to the disk julong bytes_written() const { return _bytes_written; } // adjust the number of bytes written to disk (used to keep the count // of the number of bytes written in case of rewrites) void adjust_bytes_written(jlong n) { _bytes_written += n; } // number of (buffered) bytes as yet unwritten to the dump file size_t bytes_unwritten() const { return position(); } char* error() const { return _error; } jlong current_offset(); void seek_to_offset(jlong pos); // writer functions void write_raw(void* s, size_t len); void write_u1(u1 x) { write_raw((void*)&x, 1); } void write_u2(u2 x); void write_u4(u4 x); void write_u8(u8 x); void write_objectID(oop o); void write_symbolID(Symbol* o); void write_classID(Klass* k); void write_id(u4 x); }; DumpWriter::DumpWriter(const char* path) { // try to allocate an I/O buffer of io_buffer_size. If there isn't // sufficient memory then reduce size until we can allocate something. _size = io_buffer_size; do { _buffer = (char*)os::malloc(_size, mtInternal); if (_buffer == NULL) { _size = _size >> 1; } } while (_buffer == NULL && _size > 0); assert((_size > 0 && _buffer != NULL) || (_size == 0 && _buffer == NULL), "sanity check"); _pos = 0; _error = NULL; _bytes_written = 0L; _dump_start = (jlong)-1; _fd = os::create_binary_file(path, false); // don't replace existing file // if the open failed we record the error if (_fd < 0) { _error = (char*)os::strdup(os::strerror(errno)); } } DumpWriter::~DumpWriter() { // flush and close dump file if (is_open()) { close(); } if (_buffer != NULL) os::free(_buffer); if (_error != NULL) os::free(_error); } // closes dump file (if open) void DumpWriter::close() { // flush and close dump file if (is_open()) { flush(); os::close(file_descriptor()); set_file_descriptor(-1); } } // sets the dump starting position void DumpWriter::set_dump_start(jlong pos) { _dump_start = pos; } julong DumpWriter::current_record_length() { if (is_open()) { // calculate the size of the dump record julong dump_end = bytes_written() + bytes_unwritten(); assert(dump_end == (size_t)current_offset(), "checking"); julong dump_len = dump_end - dump_start() - 4; return dump_len; } return 0; } // write directly to the file void DumpWriter::write_internal(void* s, size_t len) { if (is_open()) { const char* pos = (char*)s; ssize_t n = 0; while (len > 0) { uint tmp = (uint)MIN2(len, (size_t)UINT_MAX); n = os::write(file_descriptor(), pos, tmp); if (n < 0) { // EINTR cannot happen here, os::write will take care of that set_error(os::strerror(errno)); os::close(file_descriptor()); set_file_descriptor(-1); return; } _bytes_written += n; pos += n; len -= n; } } } // write raw bytes void DumpWriter::write_raw(void* s, size_t len) { if (is_open()) { // flush buffer to make room if ((position() + len) >= buffer_size()) { flush(); } // buffer not available or too big to buffer it if ((buffer() == NULL) || (len >= buffer_size())) { write_internal(s, len); } else { // Should optimize this for u1/u2/u4/u8 sizes. memcpy(buffer() + position(), s, len); set_position(position() + len); } } } // flush any buffered bytes to the file void DumpWriter::flush() { if (is_open() && position() > 0) { write_internal(buffer(), position()); set_position(0); } } jlong DumpWriter::current_offset() { if (is_open()) { // the offset is the file offset plus whatever we have buffered jlong offset = os::current_file_offset(file_descriptor()); assert(offset >= 0, "lseek failed"); return offset + position(); } else { return (jlong)-1; } } void DumpWriter::seek_to_offset(jlong off) { assert(off >= 0, "bad offset"); // need to flush before seeking flush(); // may be closed due to I/O error if (is_open()) { jlong n = os::seek_to_file_offset(file_descriptor(), off); assert(n >= 0, "lseek failed"); } } void DumpWriter::write_u2(u2 x) { u2 v; Bytes::put_Java_u2((address)&v, x); write_raw((void*)&v, 2); } void DumpWriter::write_u4(u4 x) { u4 v; Bytes::put_Java_u4((address)&v, x); write_raw((void*)&v, 4); } void DumpWriter::write_u8(u8 x) { u8 v; Bytes::put_Java_u8((address)&v, x); write_raw((void*)&v, 8); } void DumpWriter::write_objectID(oop o) { address a = (address)o; #ifdef _LP64 write_u8((u8)a); #else write_u4((u4)a); #endif } void DumpWriter::write_symbolID(Symbol* s) { address a = (address)((uintptr_t)s); #ifdef _LP64 write_u8((u8)a); #else write_u4((u4)a); #endif } void DumpWriter::write_id(u4 x) { #ifdef _LP64 write_u8((u8) x); #else write_u4(x); #endif } // We use java mirror as the class ID void DumpWriter::write_classID(Klass* k) { write_objectID(k->java_mirror()); } // Support class with a collection of functions used when dumping the heap class DumperSupport : AllStatic { public: // write a header of the given type static void write_header(DumpWriter* writer, hprofTag tag, u4 len); // returns hprof tag for the given type signature static hprofTag sig2tag(Symbol* sig); // returns hprof tag for the given basic type static hprofTag type2tag(BasicType type); // returns the size of the instance of the given class static u4 instance_size(Klass* k); // dump a jfloat static void dump_float(DumpWriter* writer, jfloat f); // dump a jdouble static void dump_double(DumpWriter* writer, jdouble d); // dumps the raw value of the given field static void dump_field_value(DumpWriter* writer, char type, address addr); // dumps static fields of the given class static void dump_static_fields(DumpWriter* writer, Klass* k); // dump the raw values of the instance fields of the given object static void dump_instance_fields(DumpWriter* writer, oop o); // dumps the definition of the instance fields for a given class static void dump_instance_field_descriptors(DumpWriter* writer, Klass* k); // creates HPROF_GC_INSTANCE_DUMP record for the given object static void dump_instance(DumpWriter* writer, oop o); // creates HPROF_GC_CLASS_DUMP record for the given class and each of its // array classes static void dump_class_and_array_classes(DumpWriter* writer, Klass* k); // creates HPROF_GC_CLASS_DUMP record for a given primitive array // class (and each multi-dimensional array class too) static void dump_basic_type_array_class(DumpWriter* writer, Klass* k); // creates HPROF_GC_OBJ_ARRAY_DUMP record for the given object array static void dump_object_array(DumpWriter* writer, objArrayOop array); // creates HPROF_GC_PRIM_ARRAY_DUMP record for the given type array static void dump_prim_array(DumpWriter* writer, typeArrayOop array); // create HPROF_FRAME record for the given method and bci static void dump_stack_frame(DumpWriter* writer, int frame_serial_num, int class_serial_num, Method* m, int bci); // check if we need to truncate an array static int calculate_array_max_length(DumpWriter* writer, arrayOop array, short header_size); // writes a HPROF_HEAP_DUMP_SEGMENT record static void write_dump_header(DumpWriter* writer); // fixes up the length of the current dump record static void write_current_dump_record_length(DumpWriter* writer); // fixes up the current dump record and writes HPROF_HEAP_DUMP_END record static void end_of_dump(DumpWriter* writer); }; // write a header of the given type void DumperSupport:: write_header(DumpWriter* writer, hprofTag tag, u4 len) { writer->write_u1((u1)tag); writer->write_u4(0); // current ticks writer->write_u4(len); } // returns hprof tag for the given type signature hprofTag DumperSupport::sig2tag(Symbol* sig) { switch (sig->byte_at(0)) { case JVM_SIGNATURE_CLASS : return HPROF_NORMAL_OBJECT; case JVM_SIGNATURE_ARRAY : return HPROF_NORMAL_OBJECT; case JVM_SIGNATURE_BYTE : return HPROF_BYTE; case JVM_SIGNATURE_CHAR : return HPROF_CHAR; case JVM_SIGNATURE_FLOAT : return HPROF_FLOAT; case JVM_SIGNATURE_DOUBLE : return HPROF_DOUBLE; case JVM_SIGNATURE_INT : return HPROF_INT; case JVM_SIGNATURE_LONG : return HPROF_LONG; case JVM_SIGNATURE_SHORT : return HPROF_SHORT; case JVM_SIGNATURE_BOOLEAN : return HPROF_BOOLEAN; default : ShouldNotReachHere(); /* to shut up compiler */ return HPROF_BYTE; } } hprofTag DumperSupport::type2tag(BasicType type) { switch (type) { case T_BYTE : return HPROF_BYTE; case T_CHAR : return HPROF_CHAR; case T_FLOAT : return HPROF_FLOAT; case T_DOUBLE : return HPROF_DOUBLE; case T_INT : return HPROF_INT; case T_LONG : return HPROF_LONG; case T_SHORT : return HPROF_SHORT; case T_BOOLEAN : return HPROF_BOOLEAN; default : ShouldNotReachHere(); /* to shut up compiler */ return HPROF_BYTE; } } // dump a jfloat void DumperSupport::dump_float(DumpWriter* writer, jfloat f) { if (g_isnan(f)) { writer->write_u4(0x7fc00000); // collapsing NaNs } else { union { int i; float f; } u; u.f = (float)f; writer->write_u4((u4)u.i); } } // dump a jdouble void DumperSupport::dump_double(DumpWriter* writer, jdouble d) { union { jlong l; double d; } u; if (g_isnan(d)) { // collapsing NaNs u.l = (jlong)(0x7ff80000); u.l = (u.l << 32); } else { u.d = (double)d; } writer->write_u8((u8)u.l); } // dumps the raw value of the given field void DumperSupport::dump_field_value(DumpWriter* writer, char type, address addr) { switch (type) { case JVM_SIGNATURE_CLASS : case JVM_SIGNATURE_ARRAY : { oop o; if (UseCompressedOops) { o = oopDesc::load_decode_heap_oop((narrowOop*)addr); } else { o = oopDesc::load_decode_heap_oop((oop*)addr); } // reflection and Unsafe classes may have a reference to a // Klass* so filter it out. assert(oopDesc::is_oop_or_null(o), "Expected an oop or NULL at " PTR_FORMAT, p2i(o)); writer->write_objectID(o); break; } case JVM_SIGNATURE_BYTE : { jbyte* b = (jbyte*)addr; writer->write_u1((u1)*b); break; } case JVM_SIGNATURE_CHAR : { jchar* c = (jchar*)addr; writer->write_u2((u2)*c); break; } case JVM_SIGNATURE_SHORT : { jshort* s = (jshort*)addr; writer->write_u2((u2)*s); break; } case JVM_SIGNATURE_FLOAT : { jfloat* f = (jfloat*)addr; dump_float(writer, *f); break; } case JVM_SIGNATURE_DOUBLE : { jdouble* f = (jdouble*)addr; dump_double(writer, *f); break; } case JVM_SIGNATURE_INT : { jint* i = (jint*)addr; writer->write_u4((u4)*i); break; } case JVM_SIGNATURE_LONG : { jlong* l = (jlong*)addr; writer->write_u8((u8)*l); break; } case JVM_SIGNATURE_BOOLEAN : { jboolean* b = (jboolean*)addr; writer->write_u1((u1)*b); break; } default : ShouldNotReachHere(); } } // returns the size of the instance of the given class u4 DumperSupport::instance_size(Klass* k) { HandleMark hm; InstanceKlass* ik = InstanceKlass::cast(k); u4 size = 0; for (FieldStream fld(ik, false, false); !fld.eos(); fld.next()) { if (!fld.access_flags().is_static()) { Symbol* sig = fld.signature(); switch (sig->byte_at(0)) { case JVM_SIGNATURE_CLASS : case JVM_SIGNATURE_ARRAY : size += oopSize; break; case JVM_SIGNATURE_BYTE : case JVM_SIGNATURE_BOOLEAN : size += 1; break; case JVM_SIGNATURE_CHAR : case JVM_SIGNATURE_SHORT : size += 2; break; case JVM_SIGNATURE_INT : case JVM_SIGNATURE_FLOAT : size += 4; break; case JVM_SIGNATURE_LONG : case JVM_SIGNATURE_DOUBLE : size += 8; break; default : ShouldNotReachHere(); } } } return size; } // dumps static fields of the given class void DumperSupport::dump_static_fields(DumpWriter* writer, Klass* k) { HandleMark hm; InstanceKlass* ik = InstanceKlass::cast(k); // pass 1 - count the static fields u2 field_count = 0; for (FieldStream fldc(ik, true, true); !fldc.eos(); fldc.next()) { if (fldc.access_flags().is_static()) field_count++; } // Add in resolved_references which is referenced by the cpCache // The resolved_references is an array per InstanceKlass holding the // strings and other oops resolved from the constant pool. oop resolved_references = ik->constants()->resolved_references_or_null(); if (resolved_references != NULL) { field_count++; // Add in the resolved_references of the used previous versions of the class // in the case of RedefineClasses InstanceKlass* prev = ik->previous_versions(); while (prev != NULL && prev->constants()->resolved_references_or_null() != NULL) { field_count++; prev = prev->previous_versions(); } } // Also provide a pointer to the init_lock if present, so there aren't unreferenced int[0] // arrays. oop init_lock = ik->init_lock(); if (init_lock != NULL) { field_count++; } writer->write_u2(field_count); // pass 2 - dump the field descriptors and raw values for (FieldStream fld(ik, true, true); !fld.eos(); fld.next()) { if (fld.access_flags().is_static()) { Symbol* sig = fld.signature(); writer->write_symbolID(fld.name()); // name writer->write_u1(sig2tag(sig)); // type // value int offset = fld.offset(); address addr = (address)ik->java_mirror() + offset; dump_field_value(writer, sig->byte_at(0), addr); } } // Add resolved_references for each class that has them if (resolved_references != NULL) { writer->write_symbolID(vmSymbols::resolved_references_name()); // name writer->write_u1(sig2tag(vmSymbols::object_array_signature())); // type writer->write_objectID(resolved_references); // Also write any previous versions InstanceKlass* prev = ik->previous_versions(); while (prev != NULL && prev->constants()->resolved_references_or_null() != NULL) { writer->write_symbolID(vmSymbols::resolved_references_name()); // name writer->write_u1(sig2tag(vmSymbols::object_array_signature())); // type writer->write_objectID(prev->constants()->resolved_references()); prev = prev->previous_versions(); } } // Add init lock to the end if the class is not yet initialized if (init_lock != NULL) { writer->write_symbolID(vmSymbols::init_lock_name()); // name writer->write_u1(sig2tag(vmSymbols::int_array_signature())); // type writer->write_objectID(init_lock); } } // dump the raw values of the instance fields of the given object void DumperSupport::dump_instance_fields(DumpWriter* writer, oop o) { HandleMark hm; InstanceKlass* ik = InstanceKlass::cast(o->klass()); for (FieldStream fld(ik, false, false); !fld.eos(); fld.next()) { if (!fld.access_flags().is_static()) { Symbol* sig = fld.signature(); address addr = (address)o + fld.offset(); dump_field_value(writer, sig->byte_at(0), addr); } } } // dumps the definition of the instance fields for a given class void DumperSupport::dump_instance_field_descriptors(DumpWriter* writer, Klass* k) { HandleMark hm; InstanceKlass* ik = InstanceKlass::cast(k); // pass 1 - count the instance fields u2 field_count = 0; for (FieldStream fldc(ik, true, true); !fldc.eos(); fldc.next()) { if (!fldc.access_flags().is_static()) field_count++; } writer->write_u2(field_count); // pass 2 - dump the field descriptors for (FieldStream fld(ik, true, true); !fld.eos(); fld.next()) { if (!fld.access_flags().is_static()) { Symbol* sig = fld.signature(); writer->write_symbolID(fld.name()); // name writer->write_u1(sig2tag(sig)); // type } } } // creates HPROF_GC_INSTANCE_DUMP record for the given object void DumperSupport::dump_instance(DumpWriter* writer, oop o) { Klass* k = o->klass(); writer->write_u1(HPROF_GC_INSTANCE_DUMP); writer->write_objectID(o); writer->write_u4(STACK_TRACE_ID); // class ID writer->write_classID(k); // number of bytes that follow writer->write_u4(instance_size(k) ); // field values dump_instance_fields(writer, o); } // creates HPROF_GC_CLASS_DUMP record for the given class and each of // its array classes void DumperSupport::dump_class_and_array_classes(DumpWriter* writer, Klass* k) { InstanceKlass* ik = InstanceKlass::cast(k); // We can safepoint and do a heap dump at a point where we have a Klass, // but no java mirror class has been setup for it. So we need to check // that the class is at least loaded, to avoid crash from a null mirror. if (!ik->is_loaded()) { return; } writer->write_u1(HPROF_GC_CLASS_DUMP); // class ID writer->write_classID(ik); writer->write_u4(STACK_TRACE_ID); // super class ID Klass* java_super = ik->java_super(); if (java_super == NULL) { writer->write_objectID(oop(NULL)); } else { writer->write_classID(java_super); } writer->write_objectID(ik->class_loader()); writer->write_objectID(ik->signers()); writer->write_objectID(ik->protection_domain()); // reserved writer->write_objectID(oop(NULL)); writer->write_objectID(oop(NULL)); // instance size writer->write_u4(DumperSupport::instance_size(k)); // size of constant pool - ignored by HAT 1.1 writer->write_u2(0); // number of static fields dump_static_fields(writer, k); // description of instance fields dump_instance_field_descriptors(writer, k); // array classes k = k->array_klass_or_null(); while (k != NULL) { Klass* klass = k; assert(klass->is_objArray_klass(), "not an ObjArrayKlass"); writer->write_u1(HPROF_GC_CLASS_DUMP); writer->write_classID(klass); writer->write_u4(STACK_TRACE_ID); // super class of array classes is java.lang.Object java_super = klass->java_super(); assert(java_super != NULL, "checking"); writer->write_classID(java_super); writer->write_objectID(ik->class_loader()); writer->write_objectID(ik->signers()); writer->write_objectID(ik->protection_domain()); writer->write_objectID(oop(NULL)); // reserved writer->write_objectID(oop(NULL)); writer->write_u4(0); // instance size writer->write_u2(0); // constant pool writer->write_u2(0); // static fields writer->write_u2(0); // instance fields // get the array class for the next rank k = klass->array_klass_or_null(); } } // creates HPROF_GC_CLASS_DUMP record for a given primitive array // class (and each multi-dimensional array class too) void DumperSupport::dump_basic_type_array_class(DumpWriter* writer, Klass* k) { // array classes while (k != NULL) { Klass* klass = k; writer->write_u1(HPROF_GC_CLASS_DUMP); writer->write_classID(klass); writer->write_u4(STACK_TRACE_ID); // super class of array classes is java.lang.Object Klass* java_super = klass->java_super(); assert(java_super != NULL, "checking"); writer->write_classID(java_super); writer->write_objectID(oop(NULL)); // loader writer->write_objectID(oop(NULL)); // signers writer->write_objectID(oop(NULL)); // protection domain writer->write_objectID(oop(NULL)); // reserved writer->write_objectID(oop(NULL)); writer->write_u4(0); // instance size writer->write_u2(0); // constant pool writer->write_u2(0); // static fields writer->write_u2(0); // instance fields // get the array class for the next rank k = klass->array_klass_or_null(); } } // Hprof uses an u4 as record length field, // which means we need to truncate arrays that are too long. int DumperSupport::calculate_array_max_length(DumpWriter* writer, arrayOop array, short header_size) { BasicType type = ArrayKlass::cast(array->klass())->element_type(); assert(type >= T_BOOLEAN && type <= T_OBJECT, "invalid array element type"); int length = array->length(); int type_size; if (type == T_OBJECT) { type_size = sizeof(address); } else { type_size = type2aelembytes(type); } size_t length_in_bytes = (size_t)length * type_size; // Create a new record if the current record is non-empty and the array can't fit. julong current_record_length = writer->current_record_length(); if (current_record_length > 0 && (current_record_length + header_size + length_in_bytes) > max_juint) { write_current_dump_record_length(writer); write_dump_header(writer); // We now have an empty record. current_record_length = 0; } // Calculate max bytes we can use. uint max_bytes = max_juint - (header_size + current_record_length); // Array too long for the record? // Calculate max length and return it. if (length_in_bytes > max_bytes) { length = max_bytes / type_size; length_in_bytes = (size_t)length * type_size; warning("cannot dump array of type %s[] with length %d; truncating to length %d", type2name_tab[type], array->length(), length); } return length; } // creates HPROF_GC_OBJ_ARRAY_DUMP record for the given object array void DumperSupport::dump_object_array(DumpWriter* writer, objArrayOop array) { // sizeof(u1) + 2 * sizeof(u4) + sizeof(objectID) + sizeof(classID) short header_size = 1 + 2 * 4 + 2 * sizeof(address); int length = calculate_array_max_length(writer, array, header_size); writer->write_u1(HPROF_GC_OBJ_ARRAY_DUMP); writer->write_objectID(array); writer->write_u4(STACK_TRACE_ID); writer->write_u4(length); // array class ID writer->write_classID(array->klass()); // [id]* elements for (int index = 0; index < length; index++) { oop o = array->obj_at(index); writer->write_objectID(o); } } #define WRITE_ARRAY(Array, Type, Size, Length) \ for (int i = 0; i < Length; i++) { writer->write_##Size((Size)Array->Type##_at(i)); } // creates HPROF_GC_PRIM_ARRAY_DUMP record for the given type array void DumperSupport::dump_prim_array(DumpWriter* writer, typeArrayOop array) { BasicType type = TypeArrayKlass::cast(array->klass())->element_type(); // 2 * sizeof(u1) + 2 * sizeof(u4) + sizeof(objectID) short header_size = 2 * 1 + 2 * 4 + sizeof(address); int length = calculate_array_max_length(writer, array, header_size); int type_size = type2aelembytes(type); u4 length_in_bytes = (u4)length * type_size; writer->write_u1(HPROF_GC_PRIM_ARRAY_DUMP); writer->write_objectID(array); writer->write_u4(STACK_TRACE_ID); writer->write_u4(length); writer->write_u1(type2tag(type)); // nothing to copy if (length == 0) { return; } // If the byte ordering is big endian then we can copy most types directly switch (type) { case T_INT : { if (Endian::is_Java_byte_ordering_different()) { WRITE_ARRAY(array, int, u4, length); } else { writer->write_raw((void*)(array->int_at_addr(0)), length_in_bytes); } break; } case T_BYTE : { writer->write_raw((void*)(array->byte_at_addr(0)), length_in_bytes); break; } case T_CHAR : { if (Endian::is_Java_byte_ordering_different()) { WRITE_ARRAY(array, char, u2, length); } else { writer->write_raw((void*)(array->char_at_addr(0)), length_in_bytes); } break; } case T_SHORT : { if (Endian::is_Java_byte_ordering_different()) { WRITE_ARRAY(array, short, u2, length); } else { writer->write_raw((void*)(array->short_at_addr(0)), length_in_bytes); } break; } case T_BOOLEAN : { if (Endian::is_Java_byte_ordering_different()) { WRITE_ARRAY(array, bool, u1, length); } else { writer->write_raw((void*)(array->bool_at_addr(0)), length_in_bytes); } break; } case T_LONG : { if (Endian::is_Java_byte_ordering_different()) { WRITE_ARRAY(array, long, u8, length); } else { writer->write_raw((void*)(array->long_at_addr(0)), length_in_bytes); } break; } // handle float/doubles in a special value to ensure than NaNs are // written correctly. TO DO: Check if we can avoid this on processors that // use IEEE 754. case T_FLOAT : { for (int i = 0; i < length; i++) { dump_float(writer, array->float_at(i)); } break; } case T_DOUBLE : { for (int i = 0; i < length; i++) { dump_double(writer, array->double_at(i)); } break; } default : ShouldNotReachHere(); } } // create a HPROF_FRAME record of the given Method* and bci void DumperSupport::dump_stack_frame(DumpWriter* writer, int frame_serial_num, int class_serial_num, Method* m, int bci) { int line_number; if (m->is_native()) { line_number = -3; // native frame } else { line_number = m->line_number_from_bci(bci); } write_header(writer, HPROF_FRAME, 4*oopSize + 2*sizeof(u4)); writer->write_id(frame_serial_num); // frame serial number writer->write_symbolID(m->name()); // method's name writer->write_symbolID(m->signature()); // method's signature assert(m->method_holder()->is_instance_klass(), "not InstanceKlass"); writer->write_symbolID(m->method_holder()->source_file_name()); // source file name writer->write_u4(class_serial_num); // class serial number writer->write_u4((u4) line_number); // line number } // Support class used to generate HPROF_UTF8 records from the entries in the // SymbolTable. class SymbolTableDumper : public SymbolClosure { private: DumpWriter* _writer; DumpWriter* writer() const { return _writer; } public: SymbolTableDumper(DumpWriter* writer) { _writer = writer; } void do_symbol(Symbol** p); }; void SymbolTableDumper::do_symbol(Symbol** p) { ResourceMark rm; Symbol* sym = load_symbol(p); int len = sym->utf8_length(); if (len > 0) { char* s = sym->as_utf8(); DumperSupport::write_header(writer(), HPROF_UTF8, oopSize + len); writer()->write_symbolID(sym); writer()->write_raw(s, len); } } // Support class used to generate HPROF_GC_ROOT_JNI_LOCAL records class JNILocalsDumper : public OopClosure { private: DumpWriter* _writer; u4 _thread_serial_num; int _frame_num; DumpWriter* writer() const { return _writer; } public: JNILocalsDumper(DumpWriter* writer, u4 thread_serial_num) { _writer = writer; _thread_serial_num = thread_serial_num; _frame_num = -1; // default - empty stack } void set_frame_number(int n) { _frame_num = n; } void do_oop(oop* obj_p); void do_oop(narrowOop* obj_p) { ShouldNotReachHere(); } }; void JNILocalsDumper::do_oop(oop* obj_p) { // ignore null or deleted handles oop o = *obj_p; if (o != NULL && o != JNIHandles::deleted_handle()) { writer()->write_u1(HPROF_GC_ROOT_JNI_LOCAL); writer()->write_objectID(o); writer()->write_u4(_thread_serial_num); writer()->write_u4((u4)_frame_num); } } // Support class used to generate HPROF_GC_ROOT_JNI_GLOBAL records class JNIGlobalsDumper : public OopClosure { private: DumpWriter* _writer; DumpWriter* writer() const { return _writer; } public: JNIGlobalsDumper(DumpWriter* writer) { _writer = writer; } void do_oop(oop* obj_p); void do_oop(narrowOop* obj_p) { ShouldNotReachHere(); } }; void JNIGlobalsDumper::do_oop(oop* obj_p) { oop o = *obj_p; // ignore these if (o == NULL || o == JNIHandles::deleted_handle()) return; // we ignore global ref to symbols and other internal objects if (o->is_instance() || o->is_objArray() || o->is_typeArray()) { writer()->write_u1(HPROF_GC_ROOT_JNI_GLOBAL); writer()->write_objectID(o); writer()->write_objectID((oopDesc*)obj_p); // global ref ID } }; // Support class used to generate HPROF_GC_ROOT_MONITOR_USED records class MonitorUsedDumper : public OopClosure { private: DumpWriter* _writer; DumpWriter* writer() const { return _writer; } public: MonitorUsedDumper(DumpWriter* writer) { _writer = writer; } void do_oop(oop* obj_p) { writer()->write_u1(HPROF_GC_ROOT_MONITOR_USED); writer()->write_objectID(*obj_p); } void do_oop(narrowOop* obj_p) { ShouldNotReachHere(); } }; // Support class used to generate HPROF_GC_ROOT_STICKY_CLASS records class StickyClassDumper : public KlassClosure { private: DumpWriter* _writer; DumpWriter* writer() const { return _writer; } public: StickyClassDumper(DumpWriter* writer) { _writer = writer; } void do_klass(Klass* k) { if (k->is_instance_klass()) { InstanceKlass* ik = InstanceKlass::cast(k); writer()->write_u1(HPROF_GC_ROOT_STICKY_CLASS); writer()->write_classID(ik); } } }; class VM_HeapDumper; // Support class using when iterating over the heap. class HeapObjectDumper : public ObjectClosure { private: VM_HeapDumper* _dumper; DumpWriter* _writer; VM_HeapDumper* dumper() { return _dumper; } DumpWriter* writer() { return _writer; } // used to indicate that a record has been writen void mark_end_of_record(); public: HeapObjectDumper(VM_HeapDumper* dumper, DumpWriter* writer) { _dumper = dumper; _writer = writer; } // called for each object in the heap void do_object(oop o); }; void HeapObjectDumper::do_object(oop o) { // hide the sentinel for deleted handles if (o == JNIHandles::deleted_handle()) return; // skip classes as these emitted as HPROF_GC_CLASS_DUMP records if (o->klass() == SystemDictionary::Class_klass()) { if (!java_lang_Class::is_primitive(o)) { return; } } if (o->is_instance()) { // create a HPROF_GC_INSTANCE record for each object DumperSupport::dump_instance(writer(), o); mark_end_of_record(); } else if (o->is_objArray()) { // create a HPROF_GC_OBJ_ARRAY_DUMP record for each object array DumperSupport::dump_object_array(writer(), objArrayOop(o)); mark_end_of_record(); } else if (o->is_typeArray()) { // create a HPROF_GC_PRIM_ARRAY_DUMP record for each type array DumperSupport::dump_prim_array(writer(), typeArrayOop(o)); mark_end_of_record(); } } // The VM operation that performs the heap dump class VM_HeapDumper : public VM_GC_Operation { private: static VM_HeapDumper* _global_dumper; static DumpWriter* _global_writer; DumpWriter* _local_writer; JavaThread* _oome_thread; Method* _oome_constructor; bool _gc_before_heap_dump; GrowableArray* _klass_map; ThreadStackTrace** _stack_traces; int _num_threads; // 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 skip_operation() const; // writes a HPROF_LOAD_CLASS record static void do_load_class(Klass* k); // writes a HPROF_GC_CLASS_DUMP record for the given class // (and each array class too) static void do_class_dump(Klass* k); // writes a HPROF_GC_CLASS_DUMP records for a given basic type // array (and each multi-dimensional array too) static void do_basic_type_array_class_dump(Klass* k); // HPROF_GC_ROOT_THREAD_OBJ records int do_thread(JavaThread* thread, u4 thread_serial_num); void do_threads(); void add_class_serial_number(Klass* k, int serial_num) { _klass_map->at_put_grow(serial_num, k); } // HPROF_TRACE and HPROF_FRAME records void dump_stack_traces(); public: VM_HeapDumper(DumpWriter* writer, bool gc_before_heap_dump, bool oome) : VM_GC_Operation(0 /* total collections, dummy, ignored */, GCCause::_heap_dump /* GC Cause */, 0 /* total full collections, dummy, ignored */, gc_before_heap_dump) { _local_writer = writer; _gc_before_heap_dump = gc_before_heap_dump; _klass_map = new (ResourceObj::C_HEAP, mtInternal) GrowableArray(INITIAL_CLASS_COUNT, true); _stack_traces = NULL; _num_threads = 0; if (oome) { assert(!Thread::current()->is_VM_thread(), "Dump from OutOfMemoryError cannot be called by the VMThread"); // get OutOfMemoryError zero-parameter constructor InstanceKlass* oome_ik = SystemDictionary::OutOfMemoryError_klass(); _oome_constructor = oome_ik->find_method(vmSymbols::object_initializer_name(), vmSymbols::void_method_signature()); // get thread throwing OOME when generating the heap dump at OOME _oome_thread = JavaThread::current(); } else { _oome_thread = NULL; _oome_constructor = NULL; } } ~VM_HeapDumper() { if (_stack_traces != NULL) { for (int i=0; i < _num_threads; i++) { delete _stack_traces[i]; } FREE_C_HEAP_ARRAY(ThreadStackTrace*, _stack_traces); } delete _klass_map; } VMOp_Type type() const { return VMOp_HeapDumper; } // used to mark sub-record boundary void check_segment_length(); void doit(); }; VM_HeapDumper* VM_HeapDumper::_global_dumper = NULL; DumpWriter* VM_HeapDumper::_global_writer = NULL; bool VM_HeapDumper::skip_operation() const { return false; } // writes a HPROF_HEAP_DUMP_SEGMENT record void DumperSupport::write_dump_header(DumpWriter* writer) { if (writer->is_open()) { writer->write_u1(HPROF_HEAP_DUMP_SEGMENT); writer->write_u4(0); // current ticks // record the starting position for the dump (its length will be fixed up later) writer->set_dump_start(writer->current_offset()); writer->write_u4(0); } } // fixes up the length of the current dump record void DumperSupport::write_current_dump_record_length(DumpWriter* writer) { if (writer->is_open()) { julong dump_end = writer->bytes_written() + writer->bytes_unwritten(); julong dump_len = writer->current_record_length(); // record length must fit in a u4 if (dump_len > max_juint) { warning("record is too large"); } // seek to the dump start and fix-up the length assert(writer->dump_start() >= 0, "no dump start recorded"); writer->seek_to_offset(writer->dump_start()); writer->write_u4((u4)dump_len); // adjust the total size written to keep the bytes written correct. writer->adjust_bytes_written(-((jlong) sizeof(u4))); // seek to dump end so we can continue writer->seek_to_offset(dump_end); // no current dump record writer->set_dump_start((jlong)-1); } } // used on a sub-record boundary to check if we need to start a // new segment. void VM_HeapDumper::check_segment_length() { if (writer()->is_open()) { julong dump_len = writer()->current_record_length(); if (dump_len > 2UL*G) { DumperSupport::write_current_dump_record_length(writer()); DumperSupport::write_dump_header(writer()); } } } // fixes up the current dump record and writes HPROF_HEAP_DUMP_END record void DumperSupport::end_of_dump(DumpWriter* writer) { if (writer->is_open()) { write_current_dump_record_length(writer); writer->write_u1(HPROF_HEAP_DUMP_END); writer->write_u4(0); writer->write_u4(0); } } // marks sub-record boundary void HeapObjectDumper::mark_end_of_record() { dumper()->check_segment_length(); } // writes a HPROF_LOAD_CLASS record for the class (and each of its // array classes) void VM_HeapDumper::do_load_class(Klass* k) { static u4 class_serial_num = 0; // 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); // class serial number is just a number writer()->write_u4(++class_serial_num); // class ID Klass* klass = k; writer()->write_classID(klass); // add the Klass* and class serial number pair dumper()->add_class_serial_number(klass, class_serial_num); writer()->write_u4(STACK_TRACE_ID); // class name ID Symbol* name = klass->name(); writer()->write_symbolID(name); // write a LOAD_CLASS record for the array type (if it exists) k = klass->array_klass_or_null(); } while (k != NULL); } // writes a HPROF_GC_CLASS_DUMP record for the given class void VM_HeapDumper::do_class_dump(Klass* k) { if (k->is_instance_klass()) { 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(Klass* k) { DumperSupport::dump_basic_type_array_class(writer(), k); } // Walk the stack of the given thread. // Dumps a HPROF_GC_ROOT_JAVA_FRAME record for each local // Dumps a HPROF_GC_ROOT_JNI_LOCAL record for each JNI local // // It returns the number of Java frames in this thread stack int VM_HeapDumper::do_thread(JavaThread* java_thread, u4 thread_serial_num) { JNILocalsDumper blk(writer(), thread_serial_num); oop threadObj = java_thread->threadObj(); assert(threadObj != NULL, "sanity check"); int stack_depth = 0; if (java_thread->has_last_Java_frame()) { // vframes are resource allocated Thread* current_thread = Thread::current(); ResourceMark rm(current_thread); HandleMark hm(current_thread); RegisterMap reg_map(java_thread); frame f = java_thread->last_frame(); vframe* vf = vframe::new_vframe(&f, ®_map, java_thread); frame* last_entry_frame = NULL; int extra_frames = 0; if (java_thread == _oome_thread && _oome_constructor != NULL) { extra_frames++; } while (vf != NULL) { blk.set_frame_number(stack_depth); if (vf->is_java_frame()) { // java frame (interpreted, compiled, ...) javaVFrame *jvf = javaVFrame::cast(vf); if (!(jvf->method()->is_native())) { StackValueCollection* locals = jvf->locals(); for (int slot=0; slotsize(); slot++) { if (locals->at(slot)->type() == T_OBJECT) { oop o = locals->obj_at(slot)(); if (o != NULL) { writer()->write_u1(HPROF_GC_ROOT_JAVA_FRAME); writer()->write_objectID(o); writer()->write_u4(thread_serial_num); writer()->write_u4((u4) (stack_depth + extra_frames)); } } } StackValueCollection *exprs = jvf->expressions(); for(int index = 0; index < exprs->size(); index++) { if (exprs->at(index)->type() == T_OBJECT) { oop o = exprs->obj_at(index)(); if (o != NULL) { writer()->write_u1(HPROF_GC_ROOT_JAVA_FRAME); writer()->write_objectID(o); writer()->write_u4(thread_serial_num); writer()->write_u4((u4) (stack_depth + extra_frames)); } } } } else { // native frame if (stack_depth == 0) { // JNI locals for the top frame. java_thread->active_handles()->oops_do(&blk); } else { if (last_entry_frame != NULL) { // JNI locals for the entry frame assert(last_entry_frame->is_entry_frame(), "checking"); last_entry_frame->entry_frame_call_wrapper()->handles()->oops_do(&blk); } } } // increment only for Java frames stack_depth++; last_entry_frame = NULL; } else { // externalVFrame - if it's an entry frame then report any JNI locals // as roots when we find the corresponding native javaVFrame frame* fr = vf->frame_pointer(); assert(fr != NULL, "sanity check"); if (fr->is_entry_frame()) { last_entry_frame = fr; } } vf = vf->sender(); } } else { // no last java frame but there may be JNI locals java_thread->active_handles()->oops_do(&blk); } return stack_depth; } // write a HPROF_GC_ROOT_THREAD_OBJ record for each java thread. Then walk // the stack so that locals and JNI locals are dumped. void VM_HeapDumper::do_threads() { for (int i=0; i < _num_threads; i++) { JavaThread* thread = _stack_traces[i]->thread(); oop threadObj = thread->threadObj(); u4 thread_serial_num = i+1; u4 stack_serial_num = thread_serial_num + STACK_TRACE_ID; writer()->write_u1(HPROF_GC_ROOT_THREAD_OBJ); writer()->write_objectID(threadObj); writer()->write_u4(thread_serial_num); // thread number writer()->write_u4(stack_serial_num); // stack trace serial number int num_frames = do_thread(thread, thread_serial_num); assert(num_frames == _stack_traces[i]->get_stack_depth(), "total number of Java frames not matched"); } } // The VM operation that dumps the heap. The dump consists of the following // records: // // HPROF_HEADER // [HPROF_UTF8]* // [HPROF_LOAD_CLASS]* // [[HPROF_FRAME]*|HPROF_TRACE]* // [HPROF_GC_CLASS_DUMP]* // [HPROF_HEAP_DUMP_SEGMENT]* // HPROF_HEAP_DUMP_END // // The HPROF_TRACE records represent the stack traces where the heap dump // is generated and a "dummy trace" record which does not include // any frames. The dummy trace record is used to be referenced as the // unknown object alloc site. // // Each HPROF_HEAP_DUMP_SEGMENT record has a length followed by sub-records. // To allow the heap dump be generated in a single pass we remember the position // of the dump length and fix it up after all sub-records have been written. // To generate the sub-records we iterate over the heap, writing // HPROF_GC_INSTANCE_DUMP, HPROF_GC_OBJ_ARRAY_DUMP, and HPROF_GC_PRIM_ARRAY_DUMP // records as we go. Once that is done we write records for some of the GC // roots. void VM_HeapDumper::doit() { HandleMark hm; CollectedHeap* ch = Universe::heap(); ch->ensure_parsability(false); // must happen, even if collection does // not happen (e.g. due to GCLocker) if (_gc_before_heap_dump) { if (GCLocker::is_active()) { warning("GC locker is held; pre-heapdump GC was skipped"); } else { ch->collect_as_vm_thread(GCCause::_heap_dump); } } // 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 - we always use 1.0.2 size_t used = ch->used(); const char* header = "JAVA PROFILE 1.0.2"; // header is few bytes long - no chance to overflow int writer()->write_raw((void*)header, (int)strlen(header)); writer()->write_u1(0); // terminator writer()->write_u4(oopSize); writer()->write_u8(os::javaTimeMillis()); // HPROF_UTF8 records SymbolTableDumper sym_dumper(writer()); SymbolTable::symbols_do(&sym_dumper); // write HPROF_LOAD_CLASS records ClassLoaderDataGraph::classes_do(&do_load_class); Universe::basic_type_classes_do(&do_load_class); // write HPROF_FRAME and HPROF_TRACE records // this must be called after _klass_map is built when iterating the classes above. dump_stack_traces(); // write HPROF_HEAP_DUMP_SEGMENT DumperSupport::write_dump_header(writer()); // Writes HPROF_GC_CLASS_DUMP records ClassLoaderDataGraph::classes_do(&do_class_dump); Universe::basic_type_classes_do(&do_basic_type_array_class_dump); check_segment_length(); // writes HPROF_GC_INSTANCE_DUMP records. // After each sub-record is written check_segment_length will be invoked // to check if the current segment exceeds a threshold. If so, a new // segment is started. // The HPROF_GC_CLASS_DUMP and HPROF_GC_INSTANCE_DUMP are the vast bulk // of the heap dump. HeapObjectDumper obj_dumper(this, writer()); Universe::heap()->safe_object_iterate(&obj_dumper); // HPROF_GC_ROOT_THREAD_OBJ + frames + jni locals do_threads(); check_segment_length(); // HPROF_GC_ROOT_MONITOR_USED MonitorUsedDumper mon_dumper(writer()); ObjectSynchronizer::oops_do(&mon_dumper); check_segment_length(); // HPROF_GC_ROOT_JNI_GLOBAL JNIGlobalsDumper jni_dumper(writer()); JNIHandles::oops_do(&jni_dumper); Universe::oops_do(&jni_dumper); // technically not jni roots, but global roots // for things like preallocated throwable backtraces check_segment_length(); // HPROF_GC_ROOT_STICKY_CLASS // These should be classes in the NULL class loader data, and not all classes // if !ClassUnloading StickyClassDumper class_dumper(writer()); ClassLoaderData::the_null_class_loader_data()->classes_do(&class_dumper); // fixes up the length of the dump record and writes the HPROF_HEAP_DUMP_END record. DumperSupport::end_of_dump(writer()); // 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() { // write a HPROF_TRACE record without any frames to be referenced as object alloc sites DumperSupport::write_header(writer(), HPROF_TRACE, 3*sizeof(u4)); writer()->write_u4((u4) STACK_TRACE_ID); writer()->write_u4(0); // thread number writer()->write_u4(0); // frame count _stack_traces = NEW_C_HEAP_ARRAY(ThreadStackTrace*, Threads::number_of_threads(), mtInternal); int frame_serial_num = 0; for (JavaThreadIteratorWithHandle jtiwh; JavaThread *thread = jtiwh.next(); ) { oop threadObj = thread->threadObj(); if (threadObj != NULL && !thread->is_exiting() && !thread->is_hidden_from_external_view()) { // dump thread stack trace ThreadStackTrace* stack_trace = new ThreadStackTrace(thread, false); stack_trace->dump_stack_at_safepoint(-1); _stack_traces[_num_threads++] = stack_trace; // write HPROF_FRAME records for this thread's stack trace int depth = stack_trace->get_stack_depth(); int thread_frame_start = frame_serial_num; int extra_frames = 0; // write fake frame that makes it look like the thread, which caused OOME, // is in the OutOfMemoryError zero-parameter constructor if (thread == _oome_thread && _oome_constructor != NULL) { int oome_serial_num = _klass_map->find(_oome_constructor->method_holder()); // the class serial number starts from 1 assert(oome_serial_num > 0, "OutOfMemoryError class not found"); DumperSupport::dump_stack_frame(writer(), ++frame_serial_num, oome_serial_num, _oome_constructor, 0); extra_frames++; } for (int j=0; j < depth; j++) { StackFrameInfo* frame = stack_trace->stack_frame_at(j); Method* m = frame->method(); int class_serial_num = _klass_map->find(m->method_holder()); // the class serial number starts from 1 assert(class_serial_num > 0, "class not found"); DumperSupport::dump_stack_frame(writer(), ++frame_serial_num, class_serial_num, m, frame->bci()); } depth += extra_frames; // write HPROF_TRACE record for one thread DumperSupport::write_header(writer(), HPROF_TRACE, 3*sizeof(u4) + depth*oopSize); int stack_serial_num = _num_threads + STACK_TRACE_ID; writer()->write_u4(stack_serial_num); // stack trace serial number writer()->write_u4((u4) _num_threads); // thread serial number writer()->write_u4(depth); // frame count for (int j=1; j <= depth; j++) { writer()->write_id(thread_frame_start + j); } } } } // dump the heap to given path. int HeapDumper::dump(const char* path) { assert(path != NULL && strlen(path) > 0, "path missing"); // print message in interactive case if (print_to_tty()) { tty->print_cr("Dumping heap to %s ...", path); timer()->start(); } // create the dump writer. If the file can be opened then bail DumpWriter writer(path); if (!writer.is_open()) { set_error(writer.error()); if (print_to_tty()) { tty->print_cr("Unable to create %s: %s", path, (error() != NULL) ? error() : "reason unknown"); } return -1; } // generate the dump VM_HeapDumper dumper(&writer, _gc_before_heap_dump, _oome); 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(); set_error(writer.error()); // print message in interactive case if (print_to_tty()) { timer()->stop(); if (error() == NULL) { tty->print_cr("Heap dump file created [" JULONG_FORMAT " bytes in %3.3f secs]", writer.bytes_written(), timer()->seconds()); } else { tty->print_cr("Dump file is incomplete: %s", writer.error()); } } return (writer.error() == NULL) ? 0 : -1; } // stop timer (if still active), and free any error string we might be holding HeapDumper::~HeapDumper() { if (timer()->is_active()) { timer()->stop(); } set_error(NULL); } // returns the error string (resource allocated), or NULL char* HeapDumper::error_as_C_string() const { if (error() != NULL) { char* str = NEW_RESOURCE_ARRAY(char, strlen(error())+1); strcpy(str, error()); return str; } else { return NULL; } } // set the error string void HeapDumper::set_error(char* error) { if (_error != NULL) { os::free(_error); } if (error == NULL) { _error = NULL; } else { _error = os::strdup(error); assert(_error != NULL, "allocation failure"); } } // Called by out-of-memory error reporting by a single Java thread // outside of a JVM safepoint void HeapDumper::dump_heap_from_oome() { HeapDumper::dump_heap(true); } // 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() { HeapDumper::dump_heap(false); } void HeapDumper::dump_heap(bool oome) { static char base_path[JVM_MAXPATHLEN] = {'\0'}; static uint dump_file_seq = 0; char* my_path; const int max_digit_chars = 20; const char* dump_file_name = "java_pid"; const char* dump_file_ext = ".hprof"; // The dump file defaults to java_pid.hprof in the current working // directory. HeapDumpPath= can be used to specify an alternative // dump file name or a directory where dump file is created. if (dump_file_seq == 0) { // first time in, we initialize base_path // Calculate potentially longest base path and check if we have enough // allocated statically. const size_t total_length = (HeapDumpPath == NULL ? 0 : strlen(HeapDumpPath)) + strlen(os::file_separator()) + max_digit_chars + strlen(dump_file_name) + strlen(dump_file_ext) + 1; if (total_length > sizeof(base_path)) { warning("Cannot create heap dump file. HeapDumpPath is too long."); return; } bool use_default_filename = true; if (HeapDumpPath == NULL || HeapDumpPath[0] == '\0') { // HeapDumpPath= not specified } else { 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) { strcat(base_path, os::file_separator()); } } } } // If HeapDumpPath wasn't a file name then we append the default name if (use_default_filename) { const size_t dlen = strlen(base_path); // if heap dump dir specified jio_snprintf(&base_path[dlen], sizeof(base_path)-dlen, "%s%d%s", dump_file_name, os::current_process_id(), dump_file_ext); } const size_t len = strlen(base_path) + 1; my_path = (char*)os::malloc(len, mtInternal); if (my_path == NULL) { warning("Cannot create heap dump file. Out of system memory."); return; } strncpy(my_path, base_path, len); } else { // Append a sequence number id for dumps following the first const size_t len = strlen(base_path) + max_digit_chars + 2; // for '.' and \0 my_path = (char*)os::malloc(len, mtInternal); if (my_path == NULL) { warning("Cannot create heap dump file. Out of system memory."); return; } jio_snprintf(my_path, len, "%s.%d", base_path, dump_file_seq); } dump_file_seq++; // increment seq number for next time we dump HeapDumper dumper(false /* no GC before heap dump */, true /* send to tty */, oome /* pass along out-of-memory-error flag */); dumper.dump(my_path); os::free(my_path); }