src/gc/allocator/dlmalloc.cc

/*
 * Copyright (C) 2012 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 "dlmalloc.h"

#include "base/logging.h"

// ART specific morecore implementation defined in space.cc.
#define MORECORE(x) art_heap_morecore(m, x)
extern "C" void* art_heap_morecore(void* m, intptr_t increment);

// Custom heap error handling.
#define PROCEED_ON_ERROR 0
static void art_heap_corruption(const char* function);
static void art_heap_usage_error(const char* function, void* p);
#define CORRUPTION_ERROR_ACTION(m) art_heap_corruption(__FUNCTION__)
#define USAGE_ERROR_ACTION(m,p) art_heap_usage_error(__FUNCTION__, p)

// Ugly inclusion of C file so that ART specific #defines configure dlmalloc for our use for
// mspaces (regular dlmalloc is still declared in bionic).
#pragma GCC diagnostic ignored "-Wempty-body"
#pragma GCC diagnostic ignored "-Wstrict-aliasing"
#include "../../../bionic/libc/upstream-dlmalloc/malloc.c"
#pragma GCC diagnostic warning "-Wstrict-aliasing"
#pragma GCC diagnostic warning "-Wempty-body"


static void art_heap_corruption(const char* function) {
  LOG(FATAL) << "Corrupt heap detected in: " << function;
}

static void art_heap_usage_error(const char* function, void* p) {
  LOG(FATAL) << "Incorrect use of function '" << function << "' argument " << p << " not expected";
}

#include "globals.h"
#include "utils.h"
#include <sys/mman.h>

using namespace art;
extern "C" void DlmallocMadviseCallback(void* start, void* end, size_t used_bytes, void* arg) {
  // Is this chunk in use?
  if (used_bytes != 0) {
    return;
  }
  // Do we have any whole pages to give back?
  start = reinterpret_cast<void*>(RoundUp(reinterpret_cast<uintptr_t>(start), kPageSize));
  end = reinterpret_cast<void*>(RoundDown(reinterpret_cast<uintptr_t>(end), kPageSize));
  if (end > start) {
    size_t length = reinterpret_cast<byte*>(end) - reinterpret_cast<byte*>(start);
    int rc = madvise(start, length, MADV_DONTNEED);
    if (UNLIKELY(rc != 0)) {
      errno = rc;
      PLOG(FATAL) << "madvise failed during heap trimming";
    }
    size_t* reclaimed = reinterpret_cast<size_t*>(arg);
    *reclaimed += length;
  }
}