tools/android/memconsumer/memconsumer_hook.cc

   1 // Copyright 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include <android/log.h>
   6 #include <jni.h>
   7 #include <stdio.h>
   8 #include <string.h>
   9
  10 extern "C" {
  11 JNIEXPORT void JNICALL
  12     Java_org_chromium_memconsumer_ResidentService_nativeUseMemory(JNIEnv* env,
  13                                                                   jobject clazz,
  14                                                                   jlong memory);
  15 }
  16
  17 namespace {
  18
  19 uint32_t get_random() {
  20   static uint32_t m_w = 1;
  21   static uint32_t m_z = 1;
  22   m_z = 36969 * (m_z & 65535) + (m_z >> 16);
  23   m_w = 18000 * (m_w & 65535) + (m_w >> 16);
  24   return (m_z << 16) + m_w;
  25 }
  26
  27 }  // namespace
  28
  29 JNIEXPORT void JNICALL
  30     Java_org_chromium_memconsumer_ResidentService_nativeUseMemory(
  31         JNIEnv* env,
  32         jobject clazz,
  33         jlong memory) {
  34   static uint32_t* g_memory = NULL;
  35   if (g_memory)
  36     free(g_memory);
  37   if (memory == 0) {
  38     g_memory = NULL;
  39     return;
  40   }
  41   g_memory = static_cast<uint32_t*>(malloc(memory));
  42   if (!g_memory) {
  43     __android_log_print(ANDROID_LOG_WARN,
  44                         "MemConsumer",
  45                         "Unable to allocate %ld bytes",
  46                         memory);
  47   }
  48   // If memory allocation failed, try to allocate as much as possible.
  49   while (!g_memory) {
  50     memory /= 2;
  51     g_memory = static_cast<uint32_t*>(malloc(memory));
  52   }
  53   for (int i = 0; i < memory / sizeof(uint32_t); ++i)
  54     *(g_memory + i) = get_random();
  55 }