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role="main" class="document" itemscope="itemscope" itemtype="http://schema.org/Article"> <div itemprop="articleBody"> <section id="memory"> <h1>Memory<a class="headerlink" href="#memory" title="Link to this heading">¶</a></h1> <p>The Memory tool lets you take a snapshot of the current tab’s memory <a class="reference external" href="https://en.wikipedia.org/wiki/Memory_management#HEAP">heap</a>. It then provides a number of views of the heap that can show you which objects account for memory usage and exactly where in your code you are allocating memory.</p> <iframe width="560" height="315" src="https://www.youtube.com/embed/DJLoq5E5ww0" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe> <br/> <br/><section id="the-basics"> <h2>The basics<a class="headerlink" href="#the-basics" title="Link to this heading">¶</a></h2> <ul class="simple"> <li><p><a class="reference internal" href="basic_operations/index.html#memory-basic-operations-opening-the-memory-tool"><span class="std std-ref">Opening the memory tool</span></a></p></li> <li><p><a class="reference internal" href="basic_operations/index.html#memory-basic-operations-taking-a-heap-snapshot"><span class="std std-ref">Taking a heap snapshot</span></a></p></li> <li><p><a class="reference internal" href="basic_operations/index.html#memory-basic-operations-comparing-snapshots"><span class="std std-ref">Comparing two snapshots</span></a></p></li> <li><p><a class="reference internal" href="basic_operations/index.html#memory-basic-operations-clearing-a-snapshot"><span class="std std-ref">Deleting snapshots</span></a></p></li> <li><p><a class="reference internal" href="basic_operations/index.html#memory-basic-operations-saving-and-loading-snapshots"><span class="std std-ref">Saving and loading snapshots</span></a></p></li> <li><p><a class="reference internal" href="basic_operations/index.html#memory-basic-operations-recording-call-stacks"><span class="std std-ref">Recording call stacks</span></a></p></li> </ul> </section> <section id="analyzing-snapshots"> <h2>Analyzing snapshots<a class="headerlink" href="#analyzing-snapshots" title="Link to this heading">¶</a></h2> <p>The Tree map view is new in Firefox 48, and the Dominators view is new in Firefox 46.</p> <p>Once you’ve taken a snapshot, there are three main views the Memory tool provides:</p> <ul class="simple"> <li><p><a class="reference internal" href="tree_map_view/index.html"><span class="doc">the Tree map view</span></a> shows memory usage as a <a class="reference external" href="https://en.wikipedia.org/wiki/Treemapping">treemap</a>.</p></li> <li><p><a class="reference internal" href="aggregate_view/index.html"><span class="doc">the Aggregate view</span></a> shows memory usage as a table of allocated types.</p></li> <li><p><a class="reference internal" href="dominators_view/index.html"><span class="doc">the Dominators view</span></a> shows the “retained size” of objects: that is, the size of objects plus the size of other objects that they keep alive through references.</p></li> </ul> <p>If you’ve opted to record allocation stacks for the snapshot, the Aggregate and Dominators views can show you exactly where in your code allocations are happening.</p> </section> <section id="concepts"> <h2>Concepts<a class="headerlink" href="#concepts" title="Link to this heading">¶</a></h2> <ul class="simple"> <li><p><a class="reference internal" href="dominators_view/index.html"><span class="doc">Dominators</span></a></p></li> </ul> </section> <section id="example-pages"> <h2>Example pages<a class="headerlink" href="#example-pages" title="Link to this heading">¶</a></h2> <p>Examples used in the Memory tool documentation.</p> <ul class="simple"> <li><p><a class="reference internal" href="monster_example/index.html"><span class="doc">Monster example</span></a></p></li> <li><p><a class="reference internal" href="dom_allocation_example/index.html"><span class="doc">DOM allocation example</span></a></p></li> </ul> </section> </section> </div> </div> <footer> <hr/> <div role="contentinfo"> <p></p> </div> Built with <a href="https://www.sphinx-doc.org/">Sphinx</a> using a <a href="https://github.com/readthedocs/sphinx_rtd_theme">theme</a> provided by <a href="https://readthedocs.org">Read the Docs</a>. </footer> </div> </div> </section> </div> <script> jQuery(function () { SphinxRtdTheme.Navigation.enable(true); }); </script> </body> </html>