+
+/**
+ * @brief The allocator function for "user" allocation
+ *
+ * Should only be used for allocations which will not disturb the allocation
+ * patterns of a user thread.
+ */
+static void * user_malloc(size_t size)
+{
+ void *tmp = mspace_malloc(user_snapshot_space, size);
+ ASSERT(tmp);
+ return tmp;
+}
+
+/**
+ * @brief Snapshotting malloc implementation for user programs
+ *
+ * Do NOT call this function from a model-checker context. Doing so may disrupt
+ * the allocation patterns of a user thread.
+ */
+void *malloc(size_t size)
+{
+ if (user_snapshot_space) {
+ /* Only perform user allocations from user context */
+ ASSERT(!model || thread_current());
+ return user_malloc(size);
+ } else
+ return HandleEarlyAllocationRequest(size);
+}
+
+/** @brief Snapshotting free implementation for user programs */
+void free(void * ptr)
+{
+ if (!DontFree(ptr))
+ mspace_free(user_snapshot_space, ptr);
+}
+
+/** @brief Snapshotting realloc implementation for user programs */
+void *realloc(void *ptr, size_t size)
+{
+ void *tmp = mspace_realloc(user_snapshot_space, ptr, size);
+ ASSERT(tmp);
+ return tmp;
+}
+
+/** @brief Snapshotting calloc implementation for user programs */
+void * calloc(size_t num, size_t size)
+{
+ if (user_snapshot_space) {
+ void *tmp = mspace_calloc(user_snapshot_space, num, size);
+ ASSERT(tmp);
+ return tmp;
+ } else {
+ void *tmp = HandleEarlyAllocationRequest(size * num);
+ memset(tmp, 0, size * num);
+ return tmp;
+ }
+}
+
+/** @brief Snapshotting allocation function for use by the Thread class only */
+void * Thread_malloc(size_t size)
+{
+ return user_malloc(size);
+}
+
+/** @brief Snapshotting free function for use by the Thread class only */
+void Thread_free(void *ptr)
+{
+ free(ptr);
+}
+
+/** @brief Snapshotting new operator for user programs */
+void * operator new(size_t size) throw(std::bad_alloc)
+{
+ return malloc(size);
+}
+
+/** @brief Snapshotting delete operator for user programs */
+void operator delete(void *p) throw()
+{
+ free(p);
+}
+
+/** @brief Snapshotting new[] operator for user programs */
+void * operator new[](size_t size) throw(std::bad_alloc)
+{
+ return malloc(size);
+}
+
+/** @brief Snapshotting delete[] operator for user programs */
+void operator delete[](void *p, size_t size)
+{
+ free(p);
+}
+
+#else /* !USE_MPROTECT_SNAPSHOT */
+
+/** @brief Snapshotting allocation function for use by the Thread class only */
+void * Thread_malloc(size_t size)
+{
+ return malloc(size);
+}
+
+/** @brief Snapshotting free function for use by the Thread class only */
+void Thread_free(void *ptr)
+{
+ free(ptr);
+}
+
+#endif /* !USE_MPROTECT_SNAPSHOT */