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android / platform / libcore / 8153779ad32 / . / hotspot / src / share / vm / asm / codeBuffer.cpp
blob: a8b19abb3a7f4c565f10b9326c538011dfc18c7f [file] [log] [blame]
/*
* Copyright 1997-2007 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
* CA 95054 USA or visit www.sun.com if you need additional information or
* have any questions.
*
*/
# include "incls/_precompiled.incl"
# include "incls/_codeBuffer.cpp.incl"
// 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 or other buffer area
// Important: The code_start must be taken exactly, and not realigned.
CodeBuffer::CodeBuffer(address code_start, csize_t code_size) {
assert(code_start != NULL, "sanity");
initialize_misc("static buffer");
initialize(code_start, code_size);
assert(verify_section_allocation(), "initial use of buffer OK");
}
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)code_begin() % CodeEntryAlignment == 0, "instruction start not code entry aligned");
pd_initialize();
if (locs_size != 0) {
_insts.initialize_locs(locs_size / sizeof(relocInfo));
}
assert(verify_section_allocation(), "initial use of blob is OK");
}
CodeBuffer::~CodeBuffer() {
// 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.
assert(verify_section_allocation(), "final storage configuration still OK");
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();
}
#ifdef ASSERT
Copy::fill_to_bytes(this, sizeof(*this), badResourceValue);
#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.oop_size()); // 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");
#ifdef ASSERT
for (int n = (int)SECT_INSTS+1; n < (int)SECT_LIMIT; n++) {
CodeSection* prevCS = code_section(n);
if (prevCS == cs) break;
assert(!prevCS->is_allocated(), "section allocation must be in reverse order");
}
#endif
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->instructions_begin();
address end = blob->instructions_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;
_insts._start = _insts._end = badAddress;
_stubs._start = _stubs._end = badAddress;
_consts._start = _consts._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_INSTS: return "insts";
case SECT_STUBS: return "stubs";
case SECT_CONSTS: return "consts";
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);
}
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 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.)
return base;
}
}
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_bytes(_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_code_size() const {
csize_t code_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
code_size_so_far = cs->align_at_start(code_size_so_far);
code_size_so_far += cs->size();
}
return code_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_code_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 = 0; n < (int)SECT_LIMIT; n++) {
// figure compact layout of each section
const CodeSection* cs = code_section(n);
address cstart = cs->start();
address cend = cs->end();
csize_t csize = cend - cstart;
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_CONSTS) {
// 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_code_size(), "sanity");
assert(dest->verify_section_allocation(), "final configuration works");
}
csize_t CodeBuffer::total_offset_of(address addr) const {
csize_t code_size_so_far = 0;
for (int n = 0; n < (int)SECT_LIMIT; n++) {
const CodeSection* cs = code_section(n);
if (!cs->is_empty()) {
code_size_so_far = cs->align_at_start(code_size_so_far);
}
if (cs->contains2(addr)) {
return code_size_so_far + (addr - cs->start());
}
code_size_so_far += cs->size();
}
#ifndef PRODUCT
tty->print_cr("Dangling address " PTR_FORMAT " in:", addr);
((CodeBuffer*)this)->print();
#endif
ShouldNotReachHere();
return -1;
}
csize_t CodeBuffer::total_relocation_size() const {
csize_t lsize = copy_relocations_to(NULL); // dry run only
csize_t csize = total_code_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 = 0; 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_bytes(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_code_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->instructions_begin(),
dest_blob->instructions_size());
assert(dest_blob->instructions_size() >= total_code_size(), "good sizing");
this->compute_final_layout(&dest);
relocate_code_to(&dest);
// transfer comments from buffer to blob
dest_blob->set_comments(_comments);
// Done moving code bytes; were they the right size?
assert(round_to(dest.total_code_size(), oopSize) == dest_blob->instructions_size(), "sanity");
// Flush generated code
ICache::invalidate_range(dest_blob->instructions_begin(),
dest_blob->instructions_size());
}
// Move all my code into another code buffer.
// Consult applicable relocs to repair embedded addresses.
void CodeBuffer::relocate_code_to(CodeBuffer* dest) const {
DEBUG_ONLY(address dest_end = dest->_total_start + dest->_total_size);
for (int n = 0; 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());
}
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);
{ // 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);
}
}
}
}
csize_t CodeBuffer::figure_expanded_capacities(CodeSection* which_cs,
csize_t amount,
csize_t* new_capacity) {
csize_t new_total_cap = 0;
int prev_n = -1;
for (int n = 0; n < (int)SECT_LIMIT; n++) {
const CodeSection* sect = code_section(n);
if (!sect->is_empty()) {
// Compute initial padding; assign it to the previous non-empty guy.
// 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(prev_n >= 0, "sanity");
new_capacity[prev_n] += padding;
}
prev_n = n;
}
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_INSTS; 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.
assert(verify_section_allocation(), "expanded allocation is ship-shape");
#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);
}
#ifdef ASSERT
bool CodeBuffer::verify_section_allocation() {
address tstart = _total_start;
if (tstart == badAddress) return true; // smashed by set_blob(NULL)
address tend = tstart + _total_size;
if (_blob != NULL) {
assert(tstart >= _blob->instructions_begin(), "sanity");
assert(tend <= _blob->instructions_end(), "sanity");
}
address tcheck = tstart; // advancing pointer to verify disjointness
for (int n = 0; n < (int)SECT_LIMIT; n++) {
CodeSection* sect = code_section(n);
if (!sect->is_allocated()) continue;
assert(sect->start() >= tcheck, "sanity");
tcheck = sect->start();
assert((intptr_t)tcheck % sect->alignment() == 0
|| sect->is_empty() || _blob == NULL,
"start is aligned");
assert(sect->end() >= tcheck, "sanity");
assert(sect->end() <= tend, "sanity");
}
return true;
}
#endif //ASSERT
#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) {
_comments.add_comment(offset, comment);
}
class CodeComment: public CHeapObj {
private:
friend class CodeComments;
intptr_t _offset;
const char * _comment;
CodeComment* _next;
~CodeComment() {
assert(_next == NULL, "wrong interface for freeing list");
os::free((void*)_comment);
}
public:
CodeComment(intptr_t offset, const char * comment) {
_offset = offset;
_comment = os::strdup(comment);
_next = NULL;
}
intptr_t offset() const { return _offset; }
const char * comment() const { return _comment; }
CodeComment* next() { return _next; }
void set_next(CodeComment* next) { _next = next; }
CodeComment* find(intptr_t offset) {
CodeComment* a = this;
while (a != NULL && a->_offset != offset) {
a = a->_next;
}
return a;
}
};
void CodeComments::add_comment(intptr_t offset, const char * comment) {
CodeComment* c = new CodeComment(offset, comment);
CodeComment* insert = NULL;
if (_comments != NULL) {
CodeComment* c = _comments->find(offset);
insert = c;
while (c && c->offset() == offset) {
insert = c;
c = c->next();
}
}
if (insert) {
// insert after comments with same offset
c->set_next(insert->next());
insert->set_next(c);
} else {
c->set_next(_comments);
_comments = c;
}
}
void CodeComments::assign(CodeComments& other) {
assert(_comments == NULL, "don't overwrite old value");
_comments = other._comments;
}
void CodeComments::print_block_comment(outputStream* stream, intptr_t offset) {
if (_comments != NULL) {
CodeComment* c = _comments->find(offset);
while (c && c->offset() == offset) {
stream->print(" ;; ");
stream->print_cr(c->comment());
c = c->next();
}
}
}
void CodeComments::free() {
CodeComment* n = _comments;
while (n) {
// unlink the node from the list saving a pointer to the next
CodeComment* p = n->_next;
n->_next = NULL;
delete n;
n = p;
}
_comments = NULL;
}
void CodeBuffer::decode() {
Disassembler::decode(decode_begin(), code_end());
_decode_begin = code_end();
}
void CodeBuffer::skip_decode() {
_decode_begin = code_end();
}
void CodeBuffer::decode_all() {
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