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/*
* Copyright (C) 2013 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "compiler_internals.h"
#include "dex_file-inl.h"
#include "arena_allocator.h"
#include "base/logging.h"
namespace art {
static const char* alloc_names[ArenaAllocator::kNumAllocKinds] = {
"Misc ",
"BasicBlock ",
"LIR ",
"MIR ",
"DataFlow ",
"GrowList ",
"GrowBitMap ",
"Dalvik2SSA ",
"DebugInfo ",
"Successor ",
"RegAlloc ",
"Data ",
"Preds ",
};
ArenaAllocator::ArenaAllocator(size_t default_size)
: default_size_(default_size),
block_size_(default_size - sizeof(ArenaMemBlock)),
arena_head_(NULL),
current_block_(NULL),
num_arena_blocks_(0),
malloc_bytes_(0),
lost_bytes_(0),
num_allocations_(0) {
memset(&alloc_stats_[0], 0, sizeof(alloc_stats_));
// Start with an empty arena.
arena_head_ = current_block_ = EmptyArenaBlock();
num_arena_blocks_++;
}
ArenaAllocator::~ArenaAllocator() {
// Reclaim all the arena blocks allocated so far.
ArenaMemBlock* head = arena_head_;
while (head != NULL) {
ArenaMemBlock* p = head;
head = head->next;
free(p);
}
arena_head_ = NULL;
num_arena_blocks_ = 0;
}
// Return an arena with no storage for use as a sentinal.
ArenaAllocator::ArenaMemBlock* ArenaAllocator::EmptyArenaBlock() {
ArenaMemBlock* res = static_cast<ArenaMemBlock*>(malloc(sizeof(ArenaMemBlock)));
malloc_bytes_ += sizeof(ArenaMemBlock);
res->block_size = 0;
res->bytes_allocated = 0;
res->next = NULL;
return res;
}
// Arena-based malloc for compilation tasks.
void* ArenaAllocator::NewMem(size_t size, bool zero, ArenaAllocKind kind) {
DCHECK(current_block_ != NULL);
DCHECK(arena_head_ != NULL);
size = (size + 3) & ~3;
alloc_stats_[kind] += size;
ArenaMemBlock* allocation_block = current_block_; // Assume we'll fit.
size_t remaining_space = current_block_->block_size - current_block_->bytes_allocated;
if (remaining_space < size) {
/*
* Time to allocate a new block. If this is a large allocation or we have
* significant space remaining in the current block then fulfill the allocation
* request with a custom-sized malloc() - otherwise grab a new standard block.
*/
size_t allocation_size = sizeof(ArenaMemBlock);
if ((remaining_space >= ARENA_HIGH_WATER) || (size > block_size_)) {
allocation_size += size;
} else {
allocation_size += block_size_;
}
ArenaMemBlock *new_block = static_cast<ArenaMemBlock*>(malloc(allocation_size));
if (new_block == NULL) {
LOG(FATAL) << "Arena allocation failure";
}
malloc_bytes_ += allocation_size;
new_block->block_size = allocation_size - sizeof(ArenaMemBlock);
new_block->bytes_allocated = 0;
new_block->next = NULL;
num_arena_blocks_++;
/*
* If the new block is completely full, insert it into the head of the list so we don't
* bother trying to fit more and won't hide the potentially allocatable space on the
* last (current_block_) block. TUNING: if we move to a mark scheme, revisit
* this code to keep allocation order intact.
*/
if (new_block->block_size == size) {
new_block->next = arena_head_;
arena_head_ = new_block;
} else {
int lost = (current_block_->block_size - current_block_->bytes_allocated);
lost_bytes_ += lost;
current_block_->next = new_block;
current_block_ = new_block;
}
allocation_block = new_block;
}
void* ptr = &allocation_block->ptr[allocation_block->bytes_allocated];
allocation_block->bytes_allocated += size;
if (zero) {
memset(ptr, 0, size);
}
num_allocations_++;
return ptr;
}
// Dump memory usage stats.
void ArenaAllocator::DumpMemStats(std::ostream& os) const {
size_t total = 0;
for (int i = 0; i < kNumAllocKinds; i++) {
total += alloc_stats_[i];
}
os << " MEM: used: " << total << ", allocated: " << malloc_bytes_
<< ", lost: " << lost_bytes_ << "\n";
os << "Number of blocks allocated: " << num_arena_blocks_ << ", Number of allocations: "
<< num_allocations_ << ", avg: " << total / num_allocations_ << "\n";
os << "===== Allocation by kind\n";
for (int i = 0; i < kNumAllocKinds; i++) {
os << alloc_names[i] << std::setw(10) << alloc_stats_[i] << "\n";
}
}
} // namespace art
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