+ return heap;
+}
+
+/* Override the malloc-like functions if MC is activated at compile time */
+#if SIMGRID_HAVE_MC
+
+/* ***** Temporary allocator
+ *
+ * This is used before we have found the real malloc implementation with dlsym.
+ */
+
+#ifdef __FreeBSD__ /* FreeBSD require more memory, other might */
+# define BUFFER_SIZE 256
+#else /* Valid on: Linux */
+# define BUFFER_SIZE 32
+#endif
+static size_t fake_alloc_index;
+static uint64_t buffer[BUFFER_SIZE];
+
+/* Fake implementations, they are used to fool dlsym:
+ * dlsym used calloc and falls back to some other mechanism
+ * if this fails.
+ */
+static void* mm_fake_malloc(size_t n)
+{
+ // How many uint64_t do w need?
+ size_t count = n / sizeof(uint64_t);
+ if (n % sizeof(uint64_t))
+ count++;
+ // Check that we have enough available memory:
+ if (fake_alloc_index + count >= BUFFER_SIZE)
+ exit(127);
+ // Allocate it:
+ uint64_t* res = buffer + fake_alloc_index;
+ fake_alloc_index += count;
+ return res;
+}
+
+static void* mm_fake_calloc(size_t nmemb, size_t size)
+{
+ // This is fresh .bss data, we don't need to clear it:
+ size_t n = nmemb * size;
+ return mm_fake_malloc(n);
+}
+
+static void* mm_fake_realloc(XBT_ATTRIB_UNUSED void* p, size_t s)
+{
+ return mm_fake_malloc(s);
+}
+
+static void mm_fake_free(XBT_ATTRIB_UNUSED void* p)
+{
+ // Nothing to do
+}
+
+/* Function signatures for the main malloc functions: */
+typedef void* (*mm_malloc_t)(size_t size);
+typedef void (*mm_free_t)(void*);
+typedef void* (*mm_calloc_t)(size_t nmemb, size_t size);
+typedef void* (*mm_realloc_t)(void *ptr, size_t size);
+
+/* Function pointers to the real/next implementations: */
+static mm_malloc_t mm_real_malloc;
+static mm_free_t mm_real_free;
+static mm_calloc_t mm_real_calloc;
+static mm_realloc_t mm_real_realloc;
+
+static int mm_initializing;
+static int mm_initialized;
+
+/** Constructor functions used to initialize the malloc implementation
+ */
+XBT_ATTRIB_CONSTRUCTOR(101) static void mm_legacy_constructor()
+{
+ if (mm_initialized)
+ return;
+ mm_initializing = 1;
+ __malloc_use_mmalloc = getenv(MC_ENV_VARIABLE) ? 1 : 0;
+ if (__malloc_use_mmalloc) {
+ __mmalloc_current_heap = mmalloc_preinit();
+ } else {
+#if HAVE_DLFUNC
+ mm_real_realloc = (void *(*)(void *, size_t))dlfunc(RTLD_NEXT, "realloc");
+ mm_real_malloc = (void *(*)(size_t))dlfunc(RTLD_NEXT, "malloc");
+ mm_real_free = (void (*)(void *))dlfunc(RTLD_NEXT, "free");
+ mm_real_calloc = (void *(*)(size_t, size_t))dlfunc(RTLD_NEXT, "calloc");
+#else
+ mm_real_realloc = dlsym(RTLD_NEXT, "realloc");
+ mm_real_malloc = dlsym(RTLD_NEXT, "malloc");
+ mm_real_free = dlsym(RTLD_NEXT, "free");
+ mm_real_calloc = dlsym(RTLD_NEXT, "calloc");
+#endif
+ }
+ mm_initializing = 0;
+ mm_initialized = 1;
+}
+
+/* ***** malloc/free implementation
+ *
+ * They call either the underlying/native/RTLD_NEXT implementation (non MC mode)
+ * or the mm implementation (MC mode).
+ *
+ * If we are initializing the malloc subsystem, we call the fake/dummy `malloc`
+ * implementation. This is necessary because `dlsym` calls `malloc` and friends.
+ */
+
+#define GET_HEAP() __mmalloc_current_heap
+
+void* malloc_no_memset(size_t n)
+{
+ if (!mm_initialized) {
+ if (mm_initializing)
+ return mm_fake_malloc(n);
+ mm_legacy_constructor();
+ }
+
+ if (!__malloc_use_mmalloc) {
+ return mm_real_malloc(n);
+ }
+
+ xbt_mheap_t mdp = GET_HEAP();
+ if (!mdp)
+ return NULL;
+
+ LOCK(mdp);
+ void *ret = mmalloc_no_memset(mdp, n);
+ UNLOCK(mdp);
+ return ret;