duke@435: /*
coleenp@4037:  * Copyright (c) 1998, 2012, Oracle and/or its affiliates. All rights reserved.
duke@435:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@435:  *
duke@435:  * This code is free software; you can redistribute it and/or modify it
duke@435:  * under the terms of the GNU General Public License version 2 only, as
duke@435:  * published by the Free Software Foundation.
duke@435:  *
duke@435:  * This code is distributed in the hope that it will be useful, but WITHOUT
duke@435:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@435:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
duke@435:  * version 2 for more details (a copy is included in the LICENSE file that
duke@435:  * accompanied this code).
duke@435:  *
duke@435:  * You should have received a copy of the GNU General Public License version
duke@435:  * 2 along with this work; if not, write to the Free Software Foundation,
duke@435:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@435:  *
trims@1907:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
trims@1907:  * or visit www.oracle.com if you need additional information or have any
trims@1907:  * questions.
duke@435:  *
duke@435:  */
duke@435: 
stefank@2314: #include "precompiled.hpp"
stefank@2314: #include "code/debugInfoRec.hpp"
stefank@2314: #include "code/scopeDesc.hpp"
stefank@2314: #include "prims/jvmtiExport.hpp"
duke@435: 
duke@435: // Private definition.
duke@435: // There is one DIR_Chunk for each scope and values array.
duke@435: // A chunk can potentially be used more than once.
duke@435: // We keep track of these chunks in order to detect
duke@435: // repetition and enable sharing.
duke@435: class DIR_Chunk {
duke@435:   friend class DebugInformationRecorder;
duke@435:   int  _offset; // location in the stream of this scope
duke@435:   int  _length; // number of bytes in the stream
duke@435:   int  _hash;   // hash of stream bytes (for quicker reuse)
duke@435: 
duke@435:   void* operator new(size_t ignore, DebugInformationRecorder* dir) {
duke@435:     assert(ignore == sizeof(DIR_Chunk), "");
duke@435:     if (dir->_next_chunk >= dir->_next_chunk_limit) {
duke@435:       const int CHUNK = 100;
duke@435:       dir->_next_chunk = NEW_RESOURCE_ARRAY(DIR_Chunk, CHUNK);
duke@435:       dir->_next_chunk_limit = dir->_next_chunk + CHUNK;
duke@435:     }
duke@435:     return dir->_next_chunk++;
duke@435:   }
duke@435: 
duke@435:   DIR_Chunk(int offset, int length, DebugInformationRecorder* dir) {
duke@435:     _offset = offset;
duke@435:     _length = length;
duke@435:     unsigned int hash = 0;
duke@435:     address p = dir->stream()->buffer() + _offset;
duke@435:     for (int i = 0; i < length; i++) {
duke@435:       if (i == 6)  break;
duke@435:       hash *= 127;
duke@435:       hash += p[i];
duke@435:     }
duke@435:     _hash = hash;
duke@435:   }
duke@435: 
duke@435:   DIR_Chunk* find_match(GrowableArray<DIR_Chunk*>* arr,
duke@435:                         int start_index,
duke@435:                         DebugInformationRecorder* dir) {
duke@435:     int end_index = arr->length();
duke@435:     int hash = this->_hash, length = this->_length;
duke@435:     address buf = dir->stream()->buffer();
duke@435:     for (int i = end_index; --i >= start_index; ) {
duke@435:       DIR_Chunk* that = arr->at(i);
duke@435:       if (hash   == that->_hash &&
duke@435:           length == that->_length &&
duke@435:           0 == memcmp(buf + this->_offset, buf + that->_offset, length)) {
duke@435:         return that;
duke@435:       }
duke@435:     }
duke@435:     return NULL;
duke@435:   }
duke@435: };
duke@435: 
duke@435: static inline bool compute_recording_non_safepoints() {
duke@435:   if (JvmtiExport::should_post_compiled_method_load()
duke@435:       && FLAG_IS_DEFAULT(DebugNonSafepoints)) {
duke@435:     // The default value of this flag is taken to be true,
duke@435:     // if JVMTI is looking at nmethod codes.
duke@435:     // We anticipate that JVMTI may wish to participate in profiling.
duke@435:     return true;
duke@435:   }
duke@435: 
duke@435:   // If the flag is set manually, use it, whether true or false.
duke@435:   // Otherwise, if JVMTI is not in the picture, use the default setting.
duke@435:   // (This is true in debug, just for the exercise, false in product mode.)
duke@435:   return DebugNonSafepoints;
duke@435: }
duke@435: 
duke@435: DebugInformationRecorder::DebugInformationRecorder(OopRecorder* oop_recorder)
duke@435:   : _recording_non_safepoints(compute_recording_non_safepoints())
duke@435: {
duke@435:   _pcs_size   = 100;
duke@435:   _pcs        = NEW_RESOURCE_ARRAY(PcDesc, _pcs_size);
duke@435:   _pcs_length = 0;
duke@435: 
duke@435:   _prev_safepoint_pc = PcDesc::lower_offset_limit;
duke@435: 
duke@435:   _stream = new DebugInfoWriteStream(this, 10 * K);
duke@435:   // make sure that there is no stream_decode_offset that is zero
duke@435:   _stream->write_byte((jbyte)0xFF);
duke@435: 
duke@435:   // make sure that we can distinguish the value "serialized_null" from offsets
duke@435:   assert(_stream->position() > serialized_null, "sanity");
duke@435: 
duke@435:   _oop_recorder = oop_recorder;
duke@435: 
duke@435:   _all_chunks    = new GrowableArray<DIR_Chunk*>(300);
duke@435:   _shared_chunks = new GrowableArray<DIR_Chunk*>(30);
duke@435:   _next_chunk = _next_chunk_limit = NULL;
duke@435: 
duke@435:   add_new_pc_offset(PcDesc::lower_offset_limit);  // sentinel record
duke@435: 
duke@435:   debug_only(_recording_state = rs_null);
duke@435: }
duke@435: 
duke@435: 
duke@435: void DebugInformationRecorder::add_oopmap(int pc_offset, OopMap* map) {
duke@435:   // !!!!! Preserve old style handling of oopmaps for now
duke@435:   _oopmaps->add_gc_map(pc_offset, map);
duke@435: }
duke@435: 
duke@435: void DebugInformationRecorder::add_safepoint(int pc_offset, OopMap* map) {
duke@435:   assert(!_oop_recorder->is_complete(), "not frozen yet");
duke@435:   // Store the new safepoint
duke@435: 
duke@435:   // Add the oop map
duke@435:   add_oopmap(pc_offset, map);
duke@435: 
duke@435:   add_new_pc_offset(pc_offset);
duke@435: 
duke@435:   assert(_recording_state == rs_null, "nesting of recording calls");
duke@435:   debug_only(_recording_state = rs_safepoint);
duke@435: }
duke@435: 
duke@435: void DebugInformationRecorder::add_non_safepoint(int pc_offset) {
duke@435:   assert(!_oop_recorder->is_complete(), "not frozen yet");
duke@435:   assert(_recording_non_safepoints, "must be recording non-safepoints");
duke@435: 
duke@435:   add_new_pc_offset(pc_offset);
duke@435: 
duke@435:   assert(_recording_state == rs_null, "nesting of recording calls");
duke@435:   debug_only(_recording_state = rs_non_safepoint);
duke@435: }
duke@435: 
duke@435: void DebugInformationRecorder::add_new_pc_offset(int pc_offset) {
duke@435:   assert(_pcs_length == 0 || last_pc()->pc_offset() < pc_offset,
duke@435:          "must specify a new, larger pc offset");
duke@435: 
duke@435:   // add the pcdesc
duke@435:   if (_pcs_length == _pcs_size) {
duke@435:     // Expand
duke@435:     int     new_pcs_size = _pcs_size * 2;
duke@435:     PcDesc* new_pcs      = NEW_RESOURCE_ARRAY(PcDesc, new_pcs_size);
duke@435:     for (int index = 0; index < _pcs_length; index++) {
duke@435:       new_pcs[index] = _pcs[index];
duke@435:     }
duke@435:     _pcs_size = new_pcs_size;
duke@435:     _pcs      = new_pcs;
duke@435:   }
duke@435:   assert(_pcs_size > _pcs_length, "There must be room for after expanding");
duke@435: 
duke@435:   _pcs[_pcs_length++] = PcDesc(pc_offset, DebugInformationRecorder::serialized_null,
duke@435:                                DebugInformationRecorder::serialized_null);
duke@435: }
duke@435: 
duke@435: 
duke@435: int DebugInformationRecorder::serialize_monitor_values(GrowableArray<MonitorValue*>* monitors) {
duke@435:   if (monitors == NULL || monitors->is_empty()) return DebugInformationRecorder::serialized_null;
duke@435:   assert(_recording_state == rs_safepoint, "must be recording a safepoint");
duke@435:   int result = stream()->position();
duke@435:   stream()->write_int(monitors->length());
duke@435:   for (int index = 0; index < monitors->length(); index++) {
duke@435:     monitors->at(index)->write_on(stream());
duke@435:   }
duke@435:   assert(result != serialized_null, "sanity");
duke@435: 
duke@435:   // (See comment below on DebugInformationRecorder::describe_scope.)
duke@435:   int shared_result = find_sharable_decode_offset(result);
duke@435:   if (shared_result != serialized_null) {
duke@435:     stream()->set_position(result);
duke@435:     result = shared_result;
duke@435:   }
duke@435: 
duke@435:   return result;
duke@435: }
duke@435: 
duke@435: 
duke@435: int DebugInformationRecorder::serialize_scope_values(GrowableArray<ScopeValue*>* values) {
duke@435:   if (values == NULL || values->is_empty()) return DebugInformationRecorder::serialized_null;
duke@435:   assert(_recording_state == rs_safepoint, "must be recording a safepoint");
duke@435:   int result = stream()->position();
duke@435:   assert(result != serialized_null, "sanity");
duke@435:   stream()->write_int(values->length());
duke@435:   for (int index = 0; index < values->length(); index++) {
duke@435:     values->at(index)->write_on(stream());
duke@435:   }
duke@435: 
duke@435:   // (See comment below on DebugInformationRecorder::describe_scope.)
duke@435:   int shared_result = find_sharable_decode_offset(result);
duke@435:   if (shared_result != serialized_null) {
duke@435:     stream()->set_position(result);
duke@435:     result = shared_result;
duke@435:   }
duke@435: 
duke@435:   return result;
duke@435: }
duke@435: 
duke@435: 
duke@435: #ifndef PRODUCT
duke@435: // These variables are put into one block to reduce relocations
duke@435: // and make it simpler to print from the debugger.
duke@435: static
duke@435: struct dir_stats_struct {
duke@435:   int chunks_queried;
duke@435:   int chunks_shared;
duke@435:   int chunks_reshared;
duke@435:   int chunks_elided;
duke@435: 
duke@435:   void print() {
duke@435:     tty->print_cr("Debug Data Chunks: %d, shared %d+%d, non-SP's elided %d",
duke@435:                   chunks_queried,
duke@435:                   chunks_shared, chunks_reshared,
duke@435:                   chunks_elided);
duke@435:   }
duke@435: } dir_stats;
duke@435: #endif //PRODUCT
duke@435: 
duke@435: 
duke@435: int DebugInformationRecorder::find_sharable_decode_offset(int stream_offset) {
duke@435:   // Only pull this trick if non-safepoint recording
duke@435:   // is enabled, for now.
duke@435:   if (!recording_non_safepoints())
duke@435:     return serialized_null;
duke@435: 
duke@435:   NOT_PRODUCT(++dir_stats.chunks_queried);
duke@435:   int stream_length = stream()->position() - stream_offset;
duke@435:   assert(stream_offset != serialized_null, "should not be null");
duke@435:   assert(stream_length != 0, "should not be empty");
duke@435: 
duke@435:   DIR_Chunk* ns = new(this) DIR_Chunk(stream_offset, stream_length, this);
duke@435: 
duke@435:   // Look in previously shared scopes first:
duke@435:   DIR_Chunk* ms = ns->find_match(_shared_chunks, 0, this);
duke@435:   if (ms != NULL) {
duke@435:     NOT_PRODUCT(++dir_stats.chunks_reshared);
duke@435:     assert(ns+1 == _next_chunk, "");
duke@435:     _next_chunk = ns;
duke@435:     return ms->_offset;
duke@435:   }
duke@435: 
duke@435:   // Look in recently encountered scopes next:
duke@435:   const int MAX_RECENT = 50;
duke@435:   int start_index = _all_chunks->length() - MAX_RECENT;
duke@435:   if (start_index < 0)  start_index = 0;
duke@435:   ms = ns->find_match(_all_chunks, start_index, this);
duke@435:   if (ms != NULL) {
duke@435:     NOT_PRODUCT(++dir_stats.chunks_shared);
duke@435:     // Searching in _all_chunks is limited to a window,
duke@435:     // but searching in _shared_chunks is unlimited.
duke@435:     _shared_chunks->append(ms);
duke@435:     assert(ns+1 == _next_chunk, "");
duke@435:     _next_chunk = ns;
duke@435:     return ms->_offset;
duke@435:   }
duke@435: 
duke@435:   // No match.  Add this guy to the list, in hopes of future shares.
duke@435:   _all_chunks->append(ns);
duke@435:   return serialized_null;
duke@435: }
duke@435: 
duke@435: 
duke@435: // must call add_safepoint before: it sets PcDesc and this routine uses
duke@435: // the last PcDesc set
duke@435: void DebugInformationRecorder::describe_scope(int         pc_offset,
duke@435:                                               ciMethod*   method,
duke@435:                                               int         bci,
cfang@1335:                                               bool        reexecute,
twisti@1570:                                               bool        is_method_handle_invoke,
kvn@1688:                                               bool        return_oop,
duke@435:                                               DebugToken* locals,
duke@435:                                               DebugToken* expressions,
duke@435:                                               DebugToken* monitors) {
duke@435:   assert(_recording_state != rs_null, "nesting of recording calls");
duke@435:   PcDesc* last_pd = last_pc();
duke@435:   assert(last_pd->pc_offset() == pc_offset, "must be last pc");
duke@435:   int sender_stream_offset = last_pd->scope_decode_offset();
duke@435:   // update the stream offset of current pc desc
duke@435:   int stream_offset = stream()->position();
duke@435:   last_pd->set_scope_decode_offset(stream_offset);
duke@435: 
twisti@1570:   // Record flags into pcDesc.
cfang@1366:   last_pd->set_should_reexecute(reexecute);
twisti@1570:   last_pd->set_is_method_handle_invoke(is_method_handle_invoke);
kvn@1688:   last_pd->set_return_oop(return_oop);
cfang@1366: 
duke@435:   // serialize sender stream offest
duke@435:   stream()->write_int(sender_stream_offset);
duke@435: 
duke@435:   // serialize scope
coleenp@4037:   Metadata* method_enc = (method == NULL)? NULL: method->constant_encoding();
duke@435:   stream()->write_int(oop_recorder()->find_index(method_enc));
cfang@1366:   stream()->write_bci(bci);
duke@435:   assert(method == NULL ||
duke@435:          (method->is_native() && bci == 0) ||
duke@435:          (!method->is_native() && 0 <= bci && bci < method->code_size()) ||
twisti@3969:          (method->is_compiled_lambda_form() && bci == -99) ||  // this might happen in C1
duke@435:          bci == -1, "illegal bci");
duke@435: 
duke@435:   // serialize the locals/expressions/monitors
duke@435:   stream()->write_int((intptr_t) locals);
duke@435:   stream()->write_int((intptr_t) expressions);
duke@435:   stream()->write_int((intptr_t) monitors);
duke@435: 
duke@435:   // Here's a tricky bit.  We just wrote some bytes.
duke@435:   // Wouldn't it be nice to find that we had already
duke@435:   // written those same bytes somewhere else?
duke@435:   // If we get lucky this way, reset the stream
duke@435:   // and reuse the old bytes.  By the way, this
duke@435:   // trick not only shares parent scopes, but also
duke@435:   // compresses equivalent non-safepoint PcDescs.
duke@435:   int shared_stream_offset = find_sharable_decode_offset(stream_offset);
duke@435:   if (shared_stream_offset != serialized_null) {
duke@435:     stream()->set_position(stream_offset);
duke@435:     last_pd->set_scope_decode_offset(shared_stream_offset);
duke@435:   }
duke@435: }
duke@435: 
duke@435: void DebugInformationRecorder::dump_object_pool(GrowableArray<ScopeValue*>* objects) {
duke@435:   guarantee( _pcs_length > 0, "safepoint must exist before describing scopes");
duke@435:   PcDesc* last_pd = &_pcs[_pcs_length-1];
duke@435:   if (objects != NULL) {
duke@435:     for (int i = objects->length() - 1; i >= 0; i--) {
duke@435:       ((ObjectValue*) objects->at(i))->set_visited(false);
duke@435:     }
duke@435:   }
duke@435:   int offset = serialize_scope_values(objects);
duke@435:   last_pd->set_obj_decode_offset(offset);
duke@435: }
duke@435: 
duke@435: void DebugInformationRecorder::end_scopes(int pc_offset, bool is_safepoint) {
duke@435:   assert(_recording_state == (is_safepoint? rs_safepoint: rs_non_safepoint),
duke@435:          "nesting of recording calls");
duke@435:   debug_only(_recording_state = rs_null);
duke@435: 
duke@435:   // Try to compress away an equivalent non-safepoint predecessor.
duke@435:   // (This only works because we have previously recognized redundant
duke@435:   // scope trees and made them use a common scope_decode_offset.)
duke@435:   if (_pcs_length >= 2 && recording_non_safepoints()) {
duke@435:     PcDesc* last = last_pc();
duke@435:     PcDesc* prev = prev_pc();
duke@435:     // If prev is (a) not a safepoint and (b) has the same
duke@435:     // stream pointer, then it can be coalesced into the last.
duke@435:     // This is valid because non-safepoints are only sought
duke@435:     // with pc_desc_near, which (when it misses prev) will
duke@435:     // search forward until it finds last.
duke@435:     // In addition, it does not matter if the last PcDesc
duke@435:     // is for a safepoint or not.
never@1449:     if (_prev_safepoint_pc < prev->pc_offset() && prev->is_same_info(last)) {
duke@435:       assert(prev == last-1, "sane");
duke@435:       prev->set_pc_offset(pc_offset);
duke@435:       _pcs_length -= 1;
duke@435:       NOT_PRODUCT(++dir_stats.chunks_elided);
duke@435:     }
duke@435:   }
duke@435: 
duke@435:   // We have just recorded this safepoint.
duke@435:   // Remember it in case the previous paragraph needs to know.
duke@435:   if (is_safepoint) {
duke@435:     _prev_safepoint_pc = pc_offset;
duke@435:   }
duke@435: }
duke@435: 
coleenp@4037: #ifdef ASSERT
coleenp@4037: bool DebugInformationRecorder::recorders_frozen() {
coleenp@4037:   return _oop_recorder->is_complete() || _oop_recorder->is_complete();
coleenp@4037: }
coleenp@4037: 
coleenp@4037: void DebugInformationRecorder::mark_recorders_frozen() {
coleenp@4037:   _oop_recorder->freeze();
coleenp@4037: }
coleenp@4037: #endif // PRODUCT
coleenp@4037: 
duke@435: DebugToken* DebugInformationRecorder::create_scope_values(GrowableArray<ScopeValue*>* values) {
coleenp@4037:   assert(!recorders_frozen(), "not frozen yet");
duke@435:   return (DebugToken*) (intptr_t) serialize_scope_values(values);
duke@435: }
duke@435: 
duke@435: 
duke@435: DebugToken* DebugInformationRecorder::create_monitor_values(GrowableArray<MonitorValue*>* monitors) {
coleenp@4037:   assert(!recorders_frozen(), "not frozen yet");
duke@435:   return (DebugToken*) (intptr_t) serialize_monitor_values(monitors);
duke@435: }
duke@435: 
duke@435: 
duke@435: int DebugInformationRecorder::data_size() {
coleenp@4037:   debug_only(mark_recorders_frozen());  // mark it "frozen" for asserts
duke@435:   return _stream->position();
duke@435: }
duke@435: 
duke@435: 
duke@435: int DebugInformationRecorder::pcs_size() {
coleenp@4037:   debug_only(mark_recorders_frozen());  // mark it "frozen" for asserts
duke@435:   if (last_pc()->pc_offset() != PcDesc::upper_offset_limit)
duke@435:     add_new_pc_offset(PcDesc::upper_offset_limit);
duke@435:   return _pcs_length * sizeof(PcDesc);
duke@435: }
duke@435: 
duke@435: 
duke@435: void DebugInformationRecorder::copy_to(nmethod* nm) {
duke@435:   nm->copy_scopes_data(stream()->buffer(), stream()->position());
duke@435:   nm->copy_scopes_pcs(_pcs, _pcs_length);
duke@435: }
duke@435: 
duke@435: 
duke@435: void DebugInformationRecorder::verify(const nmethod* code) {
duke@435:   Unimplemented();
duke@435: }
duke@435: 
duke@435: #ifndef PRODUCT
duke@435: void DebugInformationRecorder::print_statistics() {
duke@435:   dir_stats.print();
duke@435: }
duke@435: #endif //PRODUCT