Mercurial > hg > truffle
view src/share/vm/asm/codeBuffer.cpp @ 15583:d331b7c3d7c4
[single-pass-iter] start of evolution towards a node iterator less memory-hungry
author | Miguel Garcia <miguel.m.garcia@oracle.com> |
---|---|
date | Fri, 09 May 2014 16:22:54 +0200 |
parents | 4ca6dc0799b6 |
children | 89152779163c |
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/* * Copyright (c) 1997, 2012, 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 "asm/codeBuffer.hpp" #include "compiler/disassembler.hpp" #include "memory/gcLocker.hpp" #include "oops/methodData.hpp" #include "oops/oop.inline.hpp" #include "utilities/copy.hpp" #include "utilities/xmlstream.hpp" // The structure of a CodeSection: // // _start -> +----------------+ // | machine code...| // _end -> |----------------| // | | // | (empty) | // | | // | | // +----------------+ // _limit -> | | // // _locs_start -> +----------------+ // |reloc records...| // |----------------| // _locs_end -> | | // | | // | (empty) | // | | // | | // +----------------+ // _locs_limit -> | | // The _end (resp. _limit) pointer refers to the first // unused (resp. unallocated) byte. // The structure of the CodeBuffer while code is being accumulated: // // _total_start -> \ // _insts._start -> +----------------+ // | | // | Code | // | | // _stubs._start -> |----------------| // | | // | Stubs | (also handlers for deopt/exception) // | | // _consts._start -> |----------------| // | | // | Constants | // | | // +----------------+ // + _total_size -> | | // // When the code and relocations are copied to the code cache, // the empty parts of each section are removed, and everything // is copied into contiguous locations. typedef CodeBuffer::csize_t csize_t; // file-local definition // External buffer, in a predefined CodeBlob. // Important: The code_start must be taken exactly, and not realigned. CodeBuffer::CodeBuffer(CodeBlob* blob) { initialize_misc("static buffer"); initialize(blob->content_begin(), blob->content_size()); verify_section_allocation(); } void CodeBuffer::initialize(csize_t code_size, csize_t locs_size) { // Compute maximal alignment. int align = _insts.alignment(); // Always allow for empty slop around each section. int slop = (int) CodeSection::end_slop(); assert(blob() == NULL, "only once"); set_blob(BufferBlob::create(_name, code_size + (align+slop) * (SECT_LIMIT+1))); if (blob() == NULL) { // The assembler constructor will throw a fatal on an empty CodeBuffer. return; // caller must test this } // Set up various pointers into the blob. initialize(_total_start, _total_size); assert((uintptr_t)insts_begin() % CodeEntryAlignment == 0, "instruction start not code entry aligned"); pd_initialize(); if (locs_size != 0) { _insts.initialize_locs(locs_size / sizeof(relocInfo)); } verify_section_allocation(); } CodeBuffer::~CodeBuffer() { verify_section_allocation(); // If we allocate our code buffer from the CodeCache // via a BufferBlob, and it's not permanent, then // free the BufferBlob. // The rest of the memory will be freed when the ResourceObj // is released. for (CodeBuffer* cb = this; cb != NULL; cb = cb->before_expand()) { // Previous incarnations of this buffer are held live, so that internal // addresses constructed before expansions will not be confused. cb->free_blob(); } // free any overflow storage delete _overflow_arena; #ifdef ASSERT // Save allocation type to execute assert in ~ResourceObj() // which is called after this destructor. assert(_default_oop_recorder.allocated_on_stack(), "should be embedded object"); ResourceObj::allocation_type at = _default_oop_recorder.get_allocation_type(); Copy::fill_to_bytes(this, sizeof(*this), badResourceValue); ResourceObj::set_allocation_type((address)(&_default_oop_recorder), at); #endif } void CodeBuffer::initialize_oop_recorder(OopRecorder* r) { assert(_oop_recorder == &_default_oop_recorder && _default_oop_recorder.is_unused(), "do this once"); DEBUG_ONLY(_default_oop_recorder.freeze()); // force unused OR to be frozen _oop_recorder = r; } void CodeBuffer::initialize_section_size(CodeSection* cs, csize_t size) { assert(cs != &_insts, "insts is the memory provider, not the consumer"); csize_t slop = CodeSection::end_slop(); // margin between sections int align = cs->alignment(); assert(is_power_of_2(align), "sanity"); address start = _insts._start; address limit = _insts._limit; address middle = limit - size; middle -= (intptr_t)middle & (align-1); // align the division point downward guarantee(middle - slop > start, "need enough space to divide up"); _insts._limit = middle - slop; // subtract desired space, plus slop cs->initialize(middle, limit - middle); assert(cs->start() == middle, "sanity"); assert(cs->limit() == limit, "sanity"); // give it some relocations to start with, if the main section has them if (_insts.has_locs()) cs->initialize_locs(1); } void CodeBuffer::freeze_section(CodeSection* cs) { CodeSection* next_cs = (cs == consts())? NULL: code_section(cs->index()+1); csize_t frozen_size = cs->size(); if (next_cs != NULL) { frozen_size = next_cs->align_at_start(frozen_size); } address old_limit = cs->limit(); address new_limit = cs->start() + frozen_size; relocInfo* old_locs_limit = cs->locs_limit(); relocInfo* new_locs_limit = cs->locs_end(); // Patch the limits. cs->_limit = new_limit; cs->_locs_limit = new_locs_limit; cs->_frozen = true; if (!next_cs->is_allocated() && !next_cs->is_frozen()) { // Give remaining buffer space to the following section. next_cs->initialize(new_limit, old_limit - new_limit); next_cs->initialize_shared_locs(new_locs_limit, old_locs_limit - new_locs_limit); } } void CodeBuffer::set_blob(BufferBlob* blob) { _blob = blob; if (blob != NULL) { address start = blob->content_begin(); address end = blob->content_end(); // Round up the starting address. int align = _insts.alignment(); start += (-(intptr_t)start) & (align-1); _total_start = start; _total_size = end - start; } else { #ifdef ASSERT // Clean out dangling pointers. _total_start = badAddress; _consts._start = _consts._end = badAddress; _insts._start = _insts._end = badAddress; _stubs._start = _stubs._end = badAddress; #endif //ASSERT } } void CodeBuffer::free_blob() { if (_blob != NULL) { BufferBlob::free(_blob); set_blob(NULL); } } const char* CodeBuffer::code_section_name(int n) { #ifdef PRODUCT return NULL; #else //PRODUCT switch (n) { case SECT_CONSTS: return "consts"; case SECT_INSTS: return "insts"; case SECT_STUBS: return "stubs"; default: return NULL; } #endif //PRODUCT } int CodeBuffer::section_index_of(address addr) const { for (int n = 0; n < (int)SECT_LIMIT; n++) { const CodeSection* cs = code_section(n); if (cs->allocates(addr)) return n; } return SECT_NONE; } int CodeBuffer::locator(address addr) const { for (int n = 0; n < (int)SECT_LIMIT; n++) { const CodeSection* cs = code_section(n); if (cs->allocates(addr)) { return locator(addr - cs->start(), n); } } return -1; } address CodeBuffer::locator_address(int locator) const { if (locator < 0) return NULL; address start = code_section(locator_sect(locator))->start(); return start + locator_pos(locator); } bool CodeBuffer::is_backward_branch(Label& L) { return L.is_bound() && insts_end() <= locator_address(L.loc()); } address CodeBuffer::decode_begin() { address begin = _insts.start(); if (_decode_begin != NULL && _decode_begin > begin) begin = _decode_begin; return begin; } GrowableArray<int>* CodeBuffer::create_patch_overflow() { if (_overflow_arena == NULL) { _overflow_arena = new (mtCode) Arena(); } return new (_overflow_arena) GrowableArray<int>(_overflow_arena, 8, 0, 0); } // Helper function for managing labels and their target addresses. // Returns a sensible address, and if it is not the label's final // address, notes the dependency (at 'branch_pc') on the label. address CodeSection::target(Label& L, address branch_pc) { if (L.is_bound()) { int loc = L.loc(); if (index() == CodeBuffer::locator_sect(loc)) { return start() + CodeBuffer::locator_pos(loc); } else { return outer()->locator_address(loc); } } else { assert(allocates2(branch_pc), "sanity"); address base = start(); int patch_loc = CodeBuffer::locator(branch_pc - base, index()); L.add_patch_at(outer(), patch_loc); // Need to return a pc, doesn't matter what it is since it will be // replaced during resolution later. // Don't return NULL or badAddress, since branches shouldn't overflow. // Don't return base either because that could overflow displacements // for shorter branches. It will get checked when bound. return branch_pc; } } void CodeSection::relocate(address at, RelocationHolder const& spec, int format) { Relocation* reloc = spec.reloc(); relocInfo::relocType rtype = (relocInfo::relocType) reloc->type(); if (rtype == relocInfo::none) return; // The assertion below has been adjusted, to also work for // relocation for fixup. Sometimes we want to put relocation // information for the next instruction, since it will be patched // with a call. assert(start() <= at && at <= end()+1, "cannot relocate data outside code boundaries"); if (!has_locs()) { // no space for relocation information provided => code cannot be // relocated. Make sure that relocate is only called with rtypes // that can be ignored for this kind of code. assert(rtype == relocInfo::none || rtype == relocInfo::runtime_call_type || rtype == relocInfo::internal_word_type|| rtype == relocInfo::section_word_type || rtype == relocInfo::external_word_type, "code needs relocation information"); // leave behind an indication that we attempted a relocation DEBUG_ONLY(_locs_start = _locs_limit = (relocInfo*)badAddress); return; } // Advance the point, noting the offset we'll have to record. csize_t offset = at - locs_point(); set_locs_point(at); // Test for a couple of overflow conditions; maybe expand the buffer. relocInfo* end = locs_end(); relocInfo* req = end + relocInfo::length_limit; // Check for (potential) overflow if (req >= locs_limit() || offset >= relocInfo::offset_limit()) { req += (uint)offset / (uint)relocInfo::offset_limit(); if (req >= locs_limit()) { // Allocate or reallocate. expand_locs(locs_count() + (req - end)); // reload pointer end = locs_end(); } } // If the offset is giant, emit filler relocs, of type 'none', but // each carrying the largest possible offset, to advance the locs_point. while (offset >= relocInfo::offset_limit()) { assert(end < locs_limit(), "adjust previous paragraph of code"); *end++ = filler_relocInfo(); offset -= filler_relocInfo().addr_offset(); } // If it's a simple reloc with no data, we'll just write (rtype | offset). (*end) = relocInfo(rtype, offset, format); // If it has data, insert the prefix, as (data_prefix_tag | data1), data2. end->initialize(this, reloc); } void CodeSection::initialize_locs(int locs_capacity) { assert(_locs_start == NULL, "only one locs init step, please"); // Apply a priori lower limits to relocation size: csize_t min_locs = MAX2(size() / 16, (csize_t)4); if (locs_capacity < min_locs) locs_capacity = min_locs; relocInfo* locs_start = NEW_RESOURCE_ARRAY(relocInfo, locs_capacity); _locs_start = locs_start; _locs_end = locs_start; _locs_limit = locs_start + locs_capacity; _locs_own = true; } void CodeSection::initialize_shared_locs(relocInfo* buf, int length) { assert(_locs_start == NULL, "do this before locs are allocated"); // Internal invariant: locs buf must be fully aligned. // See copy_relocations_to() below. while ((uintptr_t)buf % HeapWordSize != 0 && length > 0) { ++buf; --length; } if (length > 0) { _locs_start = buf; _locs_end = buf; _locs_limit = buf + length; _locs_own = false; } } void CodeSection::initialize_locs_from(const CodeSection* source_cs) { int lcount = source_cs->locs_count(); if (lcount != 0) { initialize_shared_locs(source_cs->locs_start(), lcount); _locs_end = _locs_limit = _locs_start + lcount; assert(is_allocated(), "must have copied code already"); set_locs_point(start() + source_cs->locs_point_off()); } assert(this->locs_count() == source_cs->locs_count(), "sanity"); } void CodeSection::expand_locs(int new_capacity) { if (_locs_start == NULL) { initialize_locs(new_capacity); return; } else { int old_count = locs_count(); int old_capacity = locs_capacity(); if (new_capacity < old_capacity * 2) new_capacity = old_capacity * 2; relocInfo* locs_start; if (_locs_own) { locs_start = REALLOC_RESOURCE_ARRAY(relocInfo, _locs_start, old_capacity, new_capacity); } else { locs_start = NEW_RESOURCE_ARRAY(relocInfo, new_capacity); Copy::conjoint_jbytes(_locs_start, locs_start, old_capacity * sizeof(relocInfo)); _locs_own = true; } _locs_start = locs_start; _locs_end = locs_start + old_count; _locs_limit = locs_start + new_capacity; } } /// Support for emitting the code to its final location. /// The pattern is the same for all functions. /// We iterate over all the sections, padding each to alignment. csize_t CodeBuffer::total_content_size() const { csize_t size_so_far = 0; for (int n = 0; n < (int)SECT_LIMIT; n++) { const CodeSection* cs = code_section(n); if (cs->is_empty()) continue; // skip trivial section size_so_far = cs->align_at_start(size_so_far); size_so_far += cs->size(); } return size_so_far; } void CodeBuffer::compute_final_layout(CodeBuffer* dest) const { address buf = dest->_total_start; csize_t buf_offset = 0; assert(dest->_total_size >= total_content_size(), "must be big enough"); { // not sure why this is here, but why not... int alignSize = MAX2((intx) sizeof(jdouble), CodeEntryAlignment); assert( (dest->_total_start - _insts.start()) % alignSize == 0, "copy must preserve alignment"); } const CodeSection* prev_cs = NULL; CodeSection* prev_dest_cs = NULL; for (int n = (int) SECT_FIRST; n < (int) SECT_LIMIT; n++) { // figure compact layout of each section const CodeSection* cs = code_section(n); csize_t csize = cs->size(); CodeSection* dest_cs = dest->code_section(n); if (!cs->is_empty()) { // Compute initial padding; assign it to the previous non-empty guy. // Cf. figure_expanded_capacities. csize_t padding = cs->align_at_start(buf_offset) - buf_offset; if (padding != 0) { buf_offset += padding; assert(prev_dest_cs != NULL, "sanity"); prev_dest_cs->_limit += padding; } #ifdef ASSERT if (prev_cs != NULL && prev_cs->is_frozen() && n < (SECT_LIMIT - 1)) { // Make sure the ends still match up. // This is important because a branch in a frozen section // might target code in a following section, via a Label, // and without a relocation record. See Label::patch_instructions. address dest_start = buf+buf_offset; csize_t start2start = cs->start() - prev_cs->start(); csize_t dest_start2start = dest_start - prev_dest_cs->start(); assert(start2start == dest_start2start, "cannot stretch frozen sect"); } #endif //ASSERT prev_dest_cs = dest_cs; prev_cs = cs; } debug_only(dest_cs->_start = NULL); // defeat double-initialization assert dest_cs->initialize(buf+buf_offset, csize); dest_cs->set_end(buf+buf_offset+csize); assert(dest_cs->is_allocated(), "must always be allocated"); assert(cs->is_empty() == dest_cs->is_empty(), "sanity"); buf_offset += csize; } // Done calculating sections; did it come out to the right end? assert(buf_offset == total_content_size(), "sanity"); dest->verify_section_allocation(); } // Append an oop reference that keeps the class alive. static void append_oop_references(GrowableArray<oop>* oops, Klass* k) { oop cl = k->klass_holder(); if (cl != NULL && !oops->contains(cl)) { oops->append(cl); } } void CodeBuffer::finalize_oop_references(methodHandle mh) { No_Safepoint_Verifier nsv; GrowableArray<oop> oops; // Make sure that immediate metadata records something in the OopRecorder for (int n = (int) SECT_FIRST; n < (int) SECT_LIMIT; n++) { // pull code out of each section CodeSection* cs = code_section(n); if (cs->is_empty()) continue; // skip trivial section RelocIterator iter(cs); while (iter.next()) { if (iter.type() == relocInfo::metadata_type) { metadata_Relocation* md = iter.metadata_reloc(); if (md->metadata_is_immediate()) { Metadata* m = md->metadata_value(); if (oop_recorder()->is_real(m)) { if (m->is_methodData()) { m = ((MethodData*)m)->method(); } if (m->is_method()) { m = ((Method*)m)->method_holder(); } if (m->is_klass()) { append_oop_references(&oops, (Klass*)m); } else { // XXX This will currently occur for MDO which don't // have a backpointer. This has to be fixed later. m->print(); ShouldNotReachHere(); } } } } } } if (!oop_recorder()->is_unused()) { for (int i = 0; i < oop_recorder()->metadata_count(); i++) { Metadata* m = oop_recorder()->metadata_at(i); if (oop_recorder()->is_real(m)) { if (m->is_methodData()) { m = ((MethodData*)m)->method(); } if (m->is_method()) { m = ((Method*)m)->method_holder(); } if (m->is_klass()) { append_oop_references(&oops, (Klass*)m); } else { m->print(); ShouldNotReachHere(); } } } } // Add the class loader of Method* for the nmethod itself append_oop_references(&oops, mh->method_holder()); // Add any oops that we've found Thread* thread = Thread::current(); for (int i = 0; i < oops.length(); i++) { oop_recorder()->find_index((jobject)thread->handle_area()->allocate_handle(oops.at(i))); } } csize_t CodeBuffer::total_offset_of(CodeSection* cs) const { csize_t size_so_far = 0; for (int n = (int) SECT_FIRST; n < (int) SECT_LIMIT; n++) { const CodeSection* cur_cs = code_section(n); if (!cur_cs->is_empty()) { size_so_far = cur_cs->align_at_start(size_so_far); } if (cur_cs->index() == cs->index()) { return size_so_far; } size_so_far += cur_cs->size(); } ShouldNotReachHere(); return -1; } csize_t CodeBuffer::total_relocation_size() const { csize_t lsize = copy_relocations_to(NULL); // dry run only csize_t csize = total_content_size(); csize_t total = RelocIterator::locs_and_index_size(csize, lsize); return (csize_t) align_size_up(total, HeapWordSize); } csize_t CodeBuffer::copy_relocations_to(CodeBlob* dest) const { address buf = NULL; csize_t buf_offset = 0; csize_t buf_limit = 0; if (dest != NULL) { buf = (address)dest->relocation_begin(); buf_limit = (address)dest->relocation_end() - buf; assert((uintptr_t)buf % HeapWordSize == 0, "buf must be fully aligned"); assert(buf_limit % HeapWordSize == 0, "buf must be evenly sized"); } // if dest == NULL, this is just the sizing pass csize_t code_end_so_far = 0; csize_t code_point_so_far = 0; for (int n = (int) SECT_FIRST; n < (int)SECT_LIMIT; n++) { // pull relocs out of each section const CodeSection* cs = code_section(n); assert(!(cs->is_empty() && cs->locs_count() > 0), "sanity"); if (cs->is_empty()) continue; // skip trivial section relocInfo* lstart = cs->locs_start(); relocInfo* lend = cs->locs_end(); csize_t lsize = (csize_t)( (address)lend - (address)lstart ); csize_t csize = cs->size(); code_end_so_far = cs->align_at_start(code_end_so_far); if (lsize > 0) { // Figure out how to advance the combined relocation point // first to the beginning of this section. // We'll insert one or more filler relocs to span that gap. // (Don't bother to improve this by editing the first reloc's offset.) csize_t new_code_point = code_end_so_far; for (csize_t jump; code_point_so_far < new_code_point; code_point_so_far += jump) { jump = new_code_point - code_point_so_far; relocInfo filler = filler_relocInfo(); if (jump >= filler.addr_offset()) { jump = filler.addr_offset(); } else { // else shrink the filler to fit filler = relocInfo(relocInfo::none, jump); } if (buf != NULL) { assert(buf_offset + (csize_t)sizeof(filler) <= buf_limit, "filler in bounds"); *(relocInfo*)(buf+buf_offset) = filler; } buf_offset += sizeof(filler); } // Update code point and end to skip past this section: csize_t last_code_point = code_end_so_far + cs->locs_point_off(); assert(code_point_so_far <= last_code_point, "sanity"); code_point_so_far = last_code_point; // advance past this guy's relocs } code_end_so_far += csize; // advance past this guy's instructions too // Done with filler; emit the real relocations: if (buf != NULL && lsize != 0) { assert(buf_offset + lsize <= buf_limit, "target in bounds"); assert((uintptr_t)lstart % HeapWordSize == 0, "sane start"); if (buf_offset % HeapWordSize == 0) { // Use wordwise copies if possible: Copy::disjoint_words((HeapWord*)lstart, (HeapWord*)(buf+buf_offset), (lsize + HeapWordSize-1) / HeapWordSize); } else { Copy::conjoint_jbytes(lstart, buf+buf_offset, lsize); } } buf_offset += lsize; } // Align end of relocation info in target. while (buf_offset % HeapWordSize != 0) { if (buf != NULL) { relocInfo padding = relocInfo(relocInfo::none, 0); assert(buf_offset + (csize_t)sizeof(padding) <= buf_limit, "padding in bounds"); *(relocInfo*)(buf+buf_offset) = padding; } buf_offset += sizeof(relocInfo); } assert(code_end_so_far == total_content_size(), "sanity"); // Account for index: if (buf != NULL) { RelocIterator::create_index(dest->relocation_begin(), buf_offset / sizeof(relocInfo), dest->relocation_end()); } return buf_offset; } void CodeBuffer::copy_code_to(CodeBlob* dest_blob) { #ifndef PRODUCT if (PrintNMethods && (WizardMode || Verbose)) { tty->print("done with CodeBuffer:"); ((CodeBuffer*)this)->print(); } #endif //PRODUCT CodeBuffer dest(dest_blob); assert(dest_blob->content_size() >= total_content_size(), "good sizing"); this->compute_final_layout(&dest); relocate_code_to(&dest); // transfer strings and comments from buffer to blob dest_blob->set_strings(_strings); // Done moving code bytes; were they the right size? assert(round_to(dest.total_content_size(), oopSize) == dest_blob->content_size(), "sanity"); // Flush generated code ICache::invalidate_range(dest_blob->code_begin(), dest_blob->code_size()); } // Move all my code into another code buffer. Consult applicable // relocs to repair embedded addresses. The layout in the destination // CodeBuffer is different to the source CodeBuffer: the destination // CodeBuffer gets the final layout (consts, insts, stubs in order of // ascending address). void CodeBuffer::relocate_code_to(CodeBuffer* dest) const { address dest_end = dest->_total_start + dest->_total_size; address dest_filled = NULL; for (int n = (int) SECT_FIRST; n < (int) SECT_LIMIT; n++) { // pull code out of each section const CodeSection* cs = code_section(n); if (cs->is_empty()) continue; // skip trivial section CodeSection* dest_cs = dest->code_section(n); assert(cs->size() == dest_cs->size(), "sanity"); csize_t usize = dest_cs->size(); csize_t wsize = align_size_up(usize, HeapWordSize); assert(dest_cs->start() + wsize <= dest_end, "no overflow"); // Copy the code as aligned machine words. // This may also include an uninitialized partial word at the end. Copy::disjoint_words((HeapWord*)cs->start(), (HeapWord*)dest_cs->start(), wsize / HeapWordSize); if (dest->blob() == NULL) { // Destination is a final resting place, not just another buffer. // Normalize uninitialized bytes in the final padding. Copy::fill_to_bytes(dest_cs->end(), dest_cs->remaining(), Assembler::code_fill_byte()); } // Keep track of the highest filled address dest_filled = MAX2(dest_filled, dest_cs->end() + dest_cs->remaining()); assert(cs->locs_start() != (relocInfo*)badAddress, "this section carries no reloc storage, but reloc was attempted"); // Make the new code copy use the old copy's relocations: dest_cs->initialize_locs_from(cs); } // Do relocation after all sections are copied. // This is necessary if the code uses constants in stubs, which are // relocated when the corresponding instruction in the code (e.g., a // call) is relocated. Stubs are placed behind the main code // section, so that section has to be copied before relocating. for (int n = (int) SECT_FIRST; n < (int)SECT_LIMIT; n++) { // pull code out of each section const CodeSection* cs = code_section(n); if (cs->is_empty()) continue; // skip trivial section CodeSection* dest_cs = dest->code_section(n); { // Repair the pc relative information in the code after the move RelocIterator iter(dest_cs); while (iter.next()) { iter.reloc()->fix_relocation_after_move(this, dest); } } } if (dest->blob() == NULL && dest_filled != NULL) { // Destination is a final resting place, not just another buffer. // Normalize uninitialized bytes in the final padding. Copy::fill_to_bytes(dest_filled, dest_end - dest_filled, Assembler::code_fill_byte()); } } csize_t CodeBuffer::figure_expanded_capacities(CodeSection* which_cs, csize_t amount, csize_t* new_capacity) { csize_t new_total_cap = 0; for (int n = (int) SECT_FIRST; n < (int) SECT_LIMIT; n++) { const CodeSection* sect = code_section(n); if (!sect->is_empty()) { // Compute initial padding; assign it to the previous section, // even if it's empty (e.g. consts section can be empty). // Cf. compute_final_layout csize_t padding = sect->align_at_start(new_total_cap) - new_total_cap; if (padding != 0) { new_total_cap += padding; assert(n - 1 >= SECT_FIRST, "sanity"); new_capacity[n - 1] += padding; } } csize_t exp = sect->size(); // 100% increase if ((uint)exp < 4*K) exp = 4*K; // minimum initial increase if (sect == which_cs) { if (exp < amount) exp = amount; if (StressCodeBuffers) exp = amount; // expand only slightly } else if (n == SECT_INSTS) { // scale down inst increases to a more modest 25% exp = 4*K + ((exp - 4*K) >> 2); if (StressCodeBuffers) exp = amount / 2; // expand only slightly } else if (sect->is_empty()) { // do not grow an empty secondary section exp = 0; } // Allow for inter-section slop: exp += CodeSection::end_slop(); csize_t new_cap = sect->size() + exp; if (new_cap < sect->capacity()) { // No need to expand after all. new_cap = sect->capacity(); } new_capacity[n] = new_cap; new_total_cap += new_cap; } return new_total_cap; } void CodeBuffer::expand(CodeSection* which_cs, csize_t amount) { #ifndef PRODUCT if (PrintNMethods && (WizardMode || Verbose)) { tty->print("expanding CodeBuffer:"); this->print(); } if (StressCodeBuffers && blob() != NULL) { static int expand_count = 0; if (expand_count >= 0) expand_count += 1; if (expand_count > 100 && is_power_of_2(expand_count)) { tty->print_cr("StressCodeBuffers: have expanded %d times", expand_count); // simulate an occasional allocation failure: free_blob(); } } #endif //PRODUCT // Resizing must be allowed { if (blob() == NULL) return; // caller must check for blob == NULL for (int n = 0; n < (int)SECT_LIMIT; n++) { guarantee(!code_section(n)->is_frozen(), "resizing not allowed when frozen"); } } // Figure new capacity for each section. csize_t new_capacity[SECT_LIMIT]; csize_t new_total_cap = figure_expanded_capacities(which_cs, amount, new_capacity); // Create a new (temporary) code buffer to hold all the new data CodeBuffer cb(name(), new_total_cap, 0); if (cb.blob() == NULL) { // Failed to allocate in code cache. free_blob(); return; } // Create an old code buffer to remember which addresses used to go where. // This will be useful when we do final assembly into the code cache, // because we will need to know how to warp any internal address that // has been created at any time in this CodeBuffer's past. CodeBuffer* bxp = new CodeBuffer(_total_start, _total_size); bxp->take_over_code_from(this); // remember the old undersized blob DEBUG_ONLY(this->_blob = NULL); // silence a later assert bxp->_before_expand = this->_before_expand; this->_before_expand = bxp; // Give each section its required (expanded) capacity. for (int n = (int)SECT_LIMIT-1; n >= SECT_FIRST; n--) { CodeSection* cb_sect = cb.code_section(n); CodeSection* this_sect = code_section(n); if (new_capacity[n] == 0) continue; // already nulled out if (n != SECT_INSTS) { cb.initialize_section_size(cb_sect, new_capacity[n]); } assert(cb_sect->capacity() >= new_capacity[n], "big enough"); address cb_start = cb_sect->start(); cb_sect->set_end(cb_start + this_sect->size()); if (this_sect->mark() == NULL) { cb_sect->clear_mark(); } else { cb_sect->set_mark(cb_start + this_sect->mark_off()); } } // Move all the code and relocations to the new blob: relocate_code_to(&cb); // Copy the temporary code buffer into the current code buffer. // Basically, do {*this = cb}, except for some control information. this->take_over_code_from(&cb); cb.set_blob(NULL); // Zap the old code buffer contents, to avoid mistakenly using them. debug_only(Copy::fill_to_bytes(bxp->_total_start, bxp->_total_size, badCodeHeapFreeVal)); _decode_begin = NULL; // sanity // Make certain that the new sections are all snugly inside the new blob. verify_section_allocation(); #ifndef PRODUCT if (PrintNMethods && (WizardMode || Verbose)) { tty->print("expanded CodeBuffer:"); this->print(); } #endif //PRODUCT } void CodeBuffer::take_over_code_from(CodeBuffer* cb) { // Must already have disposed of the old blob somehow. assert(blob() == NULL, "must be empty"); #ifdef ASSERT #endif // Take the new blob away from cb. set_blob(cb->blob()); // Take over all the section pointers. for (int n = 0; n < (int)SECT_LIMIT; n++) { CodeSection* cb_sect = cb->code_section(n); CodeSection* this_sect = code_section(n); this_sect->take_over_code_from(cb_sect); } _overflow_arena = cb->_overflow_arena; // Make sure the old cb won't try to use it or free it. DEBUG_ONLY(cb->_blob = (BufferBlob*)badAddress); } void CodeBuffer::verify_section_allocation() { address tstart = _total_start; if (tstart == badAddress) return; // smashed by set_blob(NULL) address tend = tstart + _total_size; if (_blob != NULL) { guarantee(tstart >= _blob->content_begin(), "sanity"); guarantee(tend <= _blob->content_end(), "sanity"); } // Verify disjointness. for (int n = (int) SECT_FIRST; n < (int) SECT_LIMIT; n++) { CodeSection* sect = code_section(n); if (!sect->is_allocated() || sect->is_empty()) continue; guarantee((intptr_t)sect->start() % sect->alignment() == 0 || sect->is_empty() || _blob == NULL, "start is aligned"); for (int m = (int) SECT_FIRST; m < (int) SECT_LIMIT; m++) { CodeSection* other = code_section(m); if (!other->is_allocated() || other == sect) continue; guarantee(!other->contains(sect->start() ), "sanity"); // limit is an exclusive address and can be the start of another // section. guarantee(!other->contains(sect->limit() - 1), "sanity"); } guarantee(sect->end() <= tend, "sanity"); guarantee(sect->end() <= sect->limit(), "sanity"); } } void CodeBuffer::log_section_sizes(const char* name) { if (xtty != NULL) { // log info about buffer usage xtty->print_cr("<blob name='%s' size='%d'>", name, _total_size); for (int n = (int) CodeBuffer::SECT_FIRST; n < (int) CodeBuffer::SECT_LIMIT; n++) { CodeSection* sect = code_section(n); if (!sect->is_allocated() || sect->is_empty()) continue; xtty->print_cr("<sect index='%d' size='" SIZE_FORMAT "' free='" SIZE_FORMAT "'/>", n, sect->limit() - sect->start(), sect->limit() - sect->end()); } xtty->print_cr("</blob>"); } } #ifndef PRODUCT void CodeSection::dump() { address ptr = start(); for (csize_t step; ptr < end(); ptr += step) { step = end() - ptr; if (step > jintSize * 4) step = jintSize * 4; tty->print(PTR_FORMAT ": ", ptr); while (step > 0) { tty->print(" " PTR32_FORMAT, *(jint*)ptr); ptr += jintSize; } tty->cr(); } } void CodeSection::decode() { Disassembler::decode(start(), end()); } void CodeBuffer::block_comment(intptr_t offset, const char * comment) { _strings.add_comment(offset, comment); } const char* CodeBuffer::code_string(const char* str) { return _strings.add_string(str); } class CodeString: public CHeapObj<mtCode> { private: friend class CodeStrings; const char * _string; CodeString* _next; intptr_t _offset; ~CodeString() { assert(_next == NULL, "wrong interface for freeing list"); os::free((void*)_string, mtCode); } bool is_comment() const { return _offset >= 0; } public: CodeString(const char * string, intptr_t offset = -1) : _next(NULL), _offset(offset) { _string = os::strdup(string, mtCode); } const char * string() const { return _string; } intptr_t offset() const { assert(_offset >= 0, "offset for non comment?"); return _offset; } CodeString* next() const { return _next; } void set_next(CodeString* next) { _next = next; } CodeString* first_comment() { if (is_comment()) { return this; } else { return next_comment(); } } CodeString* next_comment() const { CodeString* s = _next; while (s != NULL && !s->is_comment()) { s = s->_next; } return s; } }; CodeString* CodeStrings::find(intptr_t offset) const { CodeString* a = _strings->first_comment(); while (a != NULL && a->offset() != offset) { a = a->next_comment(); } return a; } // Convenience for add_comment. CodeString* CodeStrings::find_last(intptr_t offset) const { CodeString* a = find(offset); if (a != NULL) { CodeString* c = NULL; while (((c = a->next_comment()) != NULL) && (c->offset() == offset)) { a = c; } } return a; } void CodeStrings::add_comment(intptr_t offset, const char * comment) { CodeString* c = new CodeString(comment, offset); CodeString* inspos = (_strings == NULL) ? NULL : find_last(offset); if (inspos) { // insert after already existing comments with same offset c->set_next(inspos->next()); inspos->set_next(c); } else { // no comments with such offset, yet. Insert before anything else. c->set_next(_strings); _strings = c; } } void CodeStrings::assign(CodeStrings& other) { _strings = other._strings; } void CodeStrings::print_block_comment(outputStream* stream, intptr_t offset) const { if (_strings != NULL) { CodeString* c = find(offset); while (c && c->offset() == offset) { stream->bol(); stream->print_raw(" ;; "); // Don't interpret as format strings since it could contain % stream->print_raw_cr(c->string()); c = c->next_comment(); } } } void CodeStrings::free() { CodeString* n = _strings; while (n) { // unlink the node from the list saving a pointer to the next CodeString* p = n->next(); n->set_next(NULL); delete n; n = p; } _strings = NULL; } const char* CodeStrings::add_string(const char * string) { CodeString* s = new CodeString(string); s->set_next(_strings); _strings = s; assert(s->string() != NULL, "should have a string"); return s->string(); } void CodeBuffer::decode() { ttyLocker ttyl; Disassembler::decode(decode_begin(), insts_end()); _decode_begin = insts_end(); } void CodeBuffer::skip_decode() { _decode_begin = insts_end(); } void CodeBuffer::decode_all() { ttyLocker ttyl; for (int n = 0; n < (int)SECT_LIMIT; n++) { // dump contents of each section CodeSection* cs = code_section(n); tty->print_cr("! %s:", code_section_name(n)); if (cs != consts()) cs->decode(); else cs->dump(); } } void CodeSection::print(const char* name) { csize_t locs_size = locs_end() - locs_start(); tty->print_cr(" %7s.code = " PTR_FORMAT " : " PTR_FORMAT " : " PTR_FORMAT " (%d of %d)%s", name, start(), end(), limit(), size(), capacity(), is_frozen()? " [frozen]": ""); tty->print_cr(" %7s.locs = " PTR_FORMAT " : " PTR_FORMAT " : " PTR_FORMAT " (%d of %d) point=%d", name, locs_start(), locs_end(), locs_limit(), locs_size, locs_capacity(), locs_point_off()); if (PrintRelocations) { RelocIterator iter(this); iter.print(); } } void CodeBuffer::print() { if (this == NULL) { tty->print_cr("NULL CodeBuffer pointer"); return; } tty->print_cr("CodeBuffer:"); for (int n = 0; n < (int)SECT_LIMIT; n++) { // print each section CodeSection* cs = code_section(n); cs->print(code_section_name(n)); } } #endif // PRODUCT