docs/html/tools/performance/comparison.jd

page.title=Memory Profilers
meta.tags="android, performance, profiling, tools, memory, memoryleaks, garbagecollection"
page.tags="android", "performance", "profiling", "tools", "memory", "memoryleaks", "garbagecollection"
page.metaDescription=Heap Viewer, Memory Monitor, and Allocation Tracker are complementary tools that visualize the memory your app uses.
page.image=tools/performance/thumbnails/tools_memory_monitor.png
page.article=true

@jd:body

<div id="tb" style="margin-left: 7px; margin-bottom: 5px;">

<h2>In this document</h2>
<ul>
  <li><a href="#MemoryMonitor">Memory Monitor</a></li>
  <li><a href="#HeapViewer">Heap Viewer</a></li>
  <li><a href="#AllocationTracker">Allocation Tracker</a></li>

</ul>

<h2>You should also read</h2>
<ul>
  <li><a href="{@docRoot}tools/performance/memory-monitor/index.html">
    Memory Monitor Walkthrough</a></li>
  <li><a href="{@docRoot}tools/performance/heap-viewer/index.html">
    Heap Viewer Walkthrough</a></li>
  <li><a href="{@docRoot}tools/performance/allocation-tracker/index.html">
    Allocation Tracker Walkthrough</a></li>
</ul>

</div>

  <p>Heap Viewer, Memory Monitor, and Allocation Tracker are complementary tools that visualize the
  memory your app uses.</p>

  <ol>
    <li>Use the
    <a href="{@docRoot}tools/performance/memory-monitor/index.html">
    Memory Monitor Tool</a> to find out whether undesirable garbage collection (GC) event patterns might
    be causing your performance problems.</li>

    <li>Run
    <a href="{@docRoot}tools/performance/heap-viewer/index.html">
    Heap Viewer</a> to identify object types that get or stay allocated
    unexpectedely or unecessarily.</li>

    <li>Use
    <a href="{@docRoot}tools/performance/allocation-tracker/index.html">
    Allocation Tracker</a> to identify where in your code the problem might be.</li>
  </ol>

  <h2 id="MemoryMonitor">Memory Monitor</h2>

<div>
  <div class="figure" style="">
    <img src="{@docRoot}images/tools/performance/compare_MemoryMonitor.png"
         alt=""
         height="" />
    <p class="img-caption">
      <strong>Figure 1. </strong>Memory Monitor.
    </p>
  </div>

  <ul>
    <li>Shows available and used memory as they both change over time <i>for your app</i> in a
    graph, with dips indicating Garbage Collection (GC) events.</li>

    <li>Provides a quick way to test whether app slowness might be related
    to excessive GC events.</li>

    <li>Provides a quick way to see whether app crashes might be related
    to running out of memory.</li>

    <li>Runs live on your application and updates about once a second.</li>

    <li>Helps quickly identify the potential of memory leaks.</li>

    <li>Helps identify GC patterns for your application and determine whether
      they are healthy and what you expect.</li>

    <li>Is easy to use, and it is easy to interpret what you see.</li>

    <li>However, Memory Monitor does not tell you which objects are the cause
      of your problems, or where in your code it might be.</li>
  </ul>

    <h2 id="HeapViewer">Heap Viewer</h2>

  <div class="figure" style="">
    <img src="{@docRoot}images/tools/performance/compare_HeapViewer.png"
         alt=""
         height="" />
    <p class="img-caption">
      <strong>Figure 2. </strong>Heap Viewer.
    </p>
  </div>

  <ul>
    <li>Shows snapshots of a number of objects allocated by type.</li>

    <li>Samples data every time a garbage collection event occurs
      naturally or triggered by you.</li>

    <li>Helps identify which object types might be involved in memory leaks.</li>

    <li>However, you have to look for changes over time yourself by tracking what's
    happening in the graph.</li>
    <br><br><br><br>
  </ul>

    <h2 id="AllocationTracker">Allocation Tracker</h2>

  <div class="figure" style="">
    <img src="{@docRoot}images/tools/performance/compare_AllocationTracker.png"
         alt=""ge
         height="" />
    <p class="img-caption">
      <strong>Figure 3. </strong>Allocation Tracker.
    </p>
  </div>

  <ul>
    <li>Shows when and where your code allocates object types, their size, allocating thread, and
    stack traces.</li>

    <li>Helps recognize memory churn through recurring allocation/deallocation patterns.</li>

    <li>Can be used in combination with Heap Viewer to track down memory leaks. For example, if you
    see a bitmap object resident on the heap, you can find its allocation location with Allocation
    Tracker.</li>

    <li>However, it takes time and experience to learn to interpret the output from this tool.</li>

  </ul>