--- /dev/null
+++ libmalloc/libmalloc-283.100.6/tests/MallocBenchTest/MALLOC_BENCH/MallocBench/stress.cpp
@@ -0,0 +1,163 @@
+/*
+ * Copyright (C) 2014 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
+ */
+
+#include "Benchmark.h"
+#include "CPUCount.h"
+#include "stress.h"
+#include <array>
+#include <cassert>
+#include <chrono>
+#include <cstdlib>
+#include <memory>
+#include <stddef.h>
+#include <vector>
+
+#include "mbmalloc.h"
+
+static const size_t kB = 1024;
+static const size_t MB = kB * kB;
+
+struct Object {
+    Object(void* pointer, size_t size, long uuid)
+        : pointer(pointer)
+        , size(size)
+        , uuid(uuid)
+    {
+    }
+
+    void* pointer;
+    size_t size;
+    long uuid;
+};
+
+class SizeStream {
+public:
+    SizeStream()
+        : m_state(Small)
+        , m_count(0)
+    {
+    }
+
+    size_t next()
+    {
+        switch (m_state) {
+        case Small: {
+            if (++m_count == smallCount) {
+                m_state = Medium;
+                m_count = 0;
+            }
+            return random() % smallMax;
+        }
+                
+        case Medium: {
+            if (++m_count == mediumCount) {
+                m_state = Large;
+                m_count = 0;
+            }
+            return random() % mediumMax;
+        }
+                
+        case Large: {
+            if (++m_count == largeCount) {
+                m_state = Small;
+                m_count = 0;
+            }
+            return random() % largeMax;
+        }
+        }
+        assert(0);
+        return 0;
+    }
+
+private:
+    static const size_t smallCount = 1000;
+    static const size_t smallMax = 16 * kB;
+
+    static const size_t mediumCount = 100;
+    static const size_t mediumMax = 512 * kB;
+    
+    static const size_t largeCount = 10;
+    static const size_t largeMax = 4 * MB;
+
+    enum { Small, Medium, Large } m_state;
+    size_t m_count;
+};
+
+Object allocate(size_t size)
+{
+    Object object(mbmalloc(size), size, random());
+    for (size_t i = 0; i < size / sizeof(long); ++i)
+        (static_cast<long*>(object.pointer))[i] = object.uuid;
+    return object;
+}
+
+void deallocate(const Object& object)
+{
+    for (size_t i = 0; i < object.size / sizeof(long); ++i) {
+        if ((static_cast<long*>(object.pointer))[i] != object.uuid)
+            abort();
+    }
+
+    mbfree(object.pointer, object.size);
+}
+
+void benchmark_stress(CommandLine&)
+{
+    const size_t heapSize = 100 * MB;
+    const size_t churnSize = .05 * heapSize;
+    const size_t churnCount = 100;
+    
+    srandom(1); // For consistency between runs.
+
+    std::vector<Object> objects;
+    
+    SizeStream sizeStream;
+    
+    size_t size = 0;
+    for (size_t remaining = heapSize; remaining; remaining -= std::min(remaining, size)) {
+        size = sizeStream.next();
+        objects.push_back(allocate(size));
+    }
+    
+    for (size_t i = 0; i < churnCount; ++i) {
+        std::vector<Object> objectsToFree;
+        for (size_t remaining = churnSize; remaining; remaining -= std::min(remaining, size)) {
+            size = sizeStream.next();
+            Object object = allocate(size);
+
+            size_t index = random() % objects.size();
+            objectsToFree.push_back(objects[index]);
+            objects[index] = object;
+        }
+
+        for (auto& object : objectsToFree)
+            deallocate(object);
+        
+        mbscavenge();
+    }
+    
+    for (auto& object : objects)
+        mbfree(object.pointer, object.size);
+}