<p>On these systems we preload the mimalloc shared library so all calls to the standard <code>malloc</code> interface are resolved to the <em>mimalloc</em> library.</p>
<p>You can set extra environment variables to check that mimalloc is running, like: </p><divclass="fragment"><divclass="line">env MIMALLOC_VERBOSE=1 LD_PRELOAD=/usr/lib/libmimalloc.so myprogram</div></div><!-- fragment --><p> or run with the debug version to get detailed statistics: </p><divclass="fragment"><divclass="line">env MIMALLOC_SHOW_STATS=1 LD_PRELOAD=/usr/lib/libmimalloc-debug.so myprogram</div></div><!-- fragment --><h3>MacOS</h3>
<p>On macOS we can also preload the mimalloc shared library so all calls to the standard <code>malloc</code> interface are resolved to the <em>mimalloc</em> library.</p>
<p>Note that certain security restrictions may apply when doing this from the <ahref="https://stackoverflow.com/questions/43941322/dyld-insert-libraries-ignored-when-calling-application-through-bash">shell</a>.</p>
<p>Overriding on Windows is robust and has the particular advantage to be able to redirect all malloc/free calls that go through the (dynamic) C runtime allocator, including those from other DLL's or libraries.</p>
<p>The overriding on Windows requires that you link your program explicitly with the mimalloc DLL and use the C-runtime library as a DLL (using the <code>/MD</code> or <code>/MDd</code> switch). Also, the <code>mimalloc-redirect.dll</code> (or <code>mimalloc-redirect32.dll</code>) must be available in the same folder as the main <code>mimalloc-override.dll</code> at runtime (as it is a dependency). The redirection DLL ensures that all calls to the C runtime malloc API get redirected to mimalloc (in <code>mimalloc-override.dll</code>).</p>
<p>To ensure the mimalloc DLL is loaded at run-time it is easiest to insert some call to the mimalloc API in the <code>main</code> function, like <code>mi_version()</code> (or use the <code>/INCLUDE:mi_version</code> switch on the linker). See the <code>mimalloc-override-test</code> project for an example on how to use this. For best performance on Windows with C++, it is also recommended to also override the <code>new</code>/<code>delete</code> operations (by including <ahref="https://github.com/microsoft/mimalloc/blob/master/include/mimalloc-new-delete.h"><code>mimalloc-new-delete.h</code></a> a single(!) source file in your project).</p>
<p>The environment variable <code>MIMALLOC_DISABLE_REDIRECT=1</code> can be used to disable dynamic overriding at run-time. Use <code>MIMALLOC_VERBOSE=1</code> to check if mimalloc was successfully redirected.</p>
<p>(Note: in principle, it is possible to even patch existing executables without any recompilation if they are linked with the dynamic C runtime (<code>ucrtbase.dll</code>) – just put the <code>mimalloc-override.dll</code> into the import table (and put <code>mimalloc-redirect.dll</code> in the same folder) Such patching can be done for example with <ahref="https://ntcore.com/?page_id=388">CFF Explorer</a>).</p>
<p>On Unix systems, you can also statically link with <em>mimalloc</em> to override the standard malloc interface. The recommended way is to link the final program with the <em>mimalloc</em> single object file (<code>mimalloc-override.o</code>). We use an object file instead of a library file as linkers give preference to that over archives to resolve symbols. To ensure that the standard malloc interface resolves to the <em>mimalloc</em> library, link it as the first object file. For example:</p>
<divclass="fragment"><divclass="line">gcc -o myprogram mimalloc-<spanclass="keyword">override</span>.o myfile1.c ...</div></div><!-- fragment --><h2>List of Overrides:</h2>
<p>The specific functions that get redirected to the <em>mimalloc</em> library are:</p>
