X-Git-Url: http://bilbo.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/4c04d8355923f8323a1a3195fe3b73ac08b984ea..9a4ec91cc24a9a54ff3a060cc2828ac54d0c0c26:/src/xbt/mmalloc/mm_legacy.c

diff --git a/src/xbt/mmalloc/mm_legacy.c b/src/xbt/mmalloc/mm_legacy.c
index d126d185f8..fb22a59865 100644
--- a/src/xbt/mmalloc/mm_legacy.c
+++ b/src/xbt/mmalloc/mm_legacy.c
@@ -1,77 +1,225 @@
-/* Copyright (c) 2010. The SimGrid Team.
- * All rights reserved.                                                     */
+/* Copyright (c) 2010-2023. The SimGrid Team. All rights reserved.          */
 
 /* This program is free software; you can redistribute it and/or modify it
  * under the terms of the license (GNU LGPL) which comes with this package. */
 
 /* Redefine the classical malloc/free/realloc functions so that they fit well in the mmalloc framework */
+#define _GNU_SOURCE
 
 #include "mmprivate.h"
+#include "src/mc/mc_environ.h" // MC_ENV_SOCKET_FD
+#include <dlfcn.h>
+#include <math.h>
+#include <stdlib.h>
 
-static void *__mmalloc_current_heap=NULL; /* The heap we are currently using. */
+/* ***** Whether to use `mmalloc` of the underlying malloc ***** */
 
-void* mmalloc_get_current_heap(void) {
+static int __malloc_use_mmalloc;
+
+int malloc_use_mmalloc(void)
+{
+  return __malloc_use_mmalloc;
+}
+
+/* ***** Current heap ***** */
+
+/* The mmalloc() package can use a single implicit malloc descriptor
+   for mmalloc/mrealloc/mfree operations which do not supply an explicit
+   descriptor.  This allows mmalloc() to provide
+   backwards compatibility with the non-mmap'd version. */
+xbt_mheap_t __mmalloc_default_mdp = NULL;
+
+/* The heap we are currently using. */
+static xbt_mheap_t __mmalloc_current_heap = NULL;
+
+xbt_mheap_t mmalloc_get_current_heap(void)
+{
   return __mmalloc_current_heap;
 }
-void mmalloc_set_current_heap(void *new_heap) {
-  __mmalloc_current_heap=new_heap;
+
+/* Override the malloc-like functions if MC is activated at compile time */
+/* ***** Temporary allocator
+ *
+ * This is used before we have found the real malloc implementation with dlsym.
+ */
+
+static size_t fake_alloc_index;
+static uint64_t buffer[mmalloc_preinit_buffer_size];
+uint64_t* mmalloc_preinit_buffer = buffer;
+
+/* 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)
+{
+  mmalloc_preinit_buffer = buffer;
+
+  // 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 >= mmalloc_preinit_buffer_size) {
+    puts("mmalloc is not initialized yet, but the static buffer used as malloc replacement is already exhausted. "
+         "Please increase `mmalloc_preinit_buffer_size` in mm_legacy.c\n");
+    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);
 }
 
-#ifdef MMALLOC_WANT_OVERIDE_LEGACY
-void *malloc(size_t n) {
-  void *ret = mmalloc(__mmalloc_current_heap, n);
+static void* mm_fake_realloc(XBT_ATTRIB_UNUSED void* p, size_t s)
+{
+  return mm_fake_malloc(s);
+}
 
-  return ret;
+static void mm_fake_free(XBT_ATTRIB_UNUSED void* p)
+{
+  // Nothing to do
 }
 
-void *calloc(size_t nmemb, size_t size) {
-  size_t total_size = nmemb * size;
+/* 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_SOCKET_FD) != NULL;
+  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
+  }
 
-  void *ret = mmalloc(__mmalloc_current_heap, total_size);
+  mm_initializing = 0;
+  mm_initialized = 1;
+}
 
-  /* Fill the allocated memory with zeroes to mimic calloc behaviour */
-  memset(ret,'\0', total_size);
+/* ***** 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(size_t n)
+{
+  if (!mm_initialized) {
+    if (mm_initializing)
+      return mm_fake_malloc(n);
+    mm_legacy_constructor();
+  }
 
-  return ret;
+  if (!__malloc_use_mmalloc) {
+    return mm_real_malloc(n);
+  }
+
+  xbt_mheap_t mdp = GET_HEAP();
+  if (!mdp)
+    return NULL;
+
+  return mmalloc(mdp, n);
 }
 
-void *realloc(void *p, size_t s) {
-  void *ret = NULL;
+void *calloc(size_t nmemb, size_t size)
+{
+  if (!mm_initialized) {
+    if (mm_initializing)
+      return mm_fake_calloc(nmemb, size);
+    mm_legacy_constructor();
+  }
 
-  if (s) {
-    if (p)
-      ret = mrealloc(__mmalloc_current_heap, p,s);
-    else
-      ret = mmalloc(__mmalloc_current_heap,s);
-  } else {
-    if (p)
-      mfree(__mmalloc_current_heap,p);
+  if (!__malloc_use_mmalloc) {
+    return mm_real_calloc(nmemb, size);
   }
 
+  xbt_mheap_t mdp = GET_HEAP();
+  if (!mdp)
+    return NULL;
+
+  void *ret = mmalloc(mdp, nmemb*size);
+  // This was already done in the callee:
+  if(!(mdp->options & XBT_MHEAP_OPTION_MEMSET)) {
+    memset(ret, 0, nmemb * size);
+  }
   return ret;
 }
 
-void free(void *p) {
-  return mfree(__mmalloc_current_heap, p);
-}
-#endif
+void *realloc(void *p, size_t s)
+{
+  if (!mm_initialized) {
+    if (mm_initializing)
+      return mm_fake_realloc(p, s);
+    mm_legacy_constructor();
+  }
 
-/* Make sure it works with md==NULL */
+  if (!__malloc_use_mmalloc) {
+    return mm_real_realloc(p, s);
+  }
 
-#define HEAP_OFFSET   40960000    /* Safety gap from the heap's break address */
+  xbt_mheap_t mdp = GET_HEAP();
+  if (!mdp)
+    return NULL;
 
-void *mmalloc_get_default_md(void) {
-  xbt_assert(__mmalloc_default_mdp);
-  return __mmalloc_default_mdp;
+  return mrealloc(mdp, p, s);
 }
 
-/* Initialize the default malloc descriptor. */
-#include "xbt_modinter.h"
-void mmalloc_preinit(void) {
-  __mmalloc_default_mdp = mmalloc_attach(-1, (char *)sbrk(0) + HEAP_OFFSET);
-  xbt_assert(__mmalloc_default_mdp != NULL);
-}
-void mmalloc_postexit(void) {
-  /* Do not detach the default mdp or ldl won't be able to free the memory it allocated since we're in memory */
-  //  mmalloc_detach(__mmalloc_default_mdp);
+void free(void *p)
+{
+  if (!mm_initialized) {
+    if (mm_initializing)
+      return mm_fake_free(p);
+    mm_legacy_constructor();
+  }
+
+  if (!__malloc_use_mmalloc) {
+    mm_real_free(p);
+    return;
+  }
+
+  if (!p)
+    return;
+
+  xbt_mheap_t mdp = GET_HEAP();
+  mfree(mdp, p);
 }