X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/c74d55b12793e78341f96550544c4a4061b714ca..41c54c2772412935a5c8fc9f2d09e623c0383ae7:/src/xbt/mmalloc/mm_legacy.c

diff --git a/src/xbt/mmalloc/mm_legacy.c b/src/xbt/mmalloc/mm_legacy.c
index b5457e1649..e9e250fa23 100644
--- a/src/xbt/mmalloc/mm_legacy.c
+++ b/src/xbt/mmalloc/mm_legacy.c
@@ -1,4 +1,4 @@
-/* Copyright (c) 2010-2014. The SimGrid Team.
+/* Copyright (c) 2010-2015. The SimGrid Team.
  * All rights reserved.                                                     */
 
 /* This program is free software; you can redistribute it and/or modify it
@@ -11,12 +11,23 @@
 
 #include <dlfcn.h>
 
+#include "src/mc/mc_base.h"
 #include "mmprivate.h"
-#include "xbt_modinter.h"
-#include "internal_config.h"
+#include "src/xbt_modinter.h"
+#include "src/internal_config.h"
 #include <math.h>
+#include "src/mc/mc_protocol.h"
 
-//#define MM_LEGACY_VERBOSE 1 /* define this to see which version of malloc gets used */
+/* ***** Whether to use `mmalloc` of the undrlying malloc ***** */
+
+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
@@ -24,28 +35,66 @@
    backwards compatibility with the non-mmap'd version. */
 xbt_mheap_t __mmalloc_default_mdp = NULL;
 
-
-static xbt_mheap_t __mmalloc_current_heap = NULL;     /* The heap we are currently using. */
+/* 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(xbt_mheap_t new_heap)
+xbt_mheap_t mmalloc_set_current_heap(xbt_mheap_t new_heap)
 {
+  xbt_mheap_t heap = __mmalloc_current_heap;
   __mmalloc_current_heap = new_heap;
+  return heap;
 }
 
 #ifdef MMALLOC_WANT_OVERRIDE_LEGACY
 
+/* ***** Temporary allocator
+ *
+ * This is used before we have found the real malloc implementation with dlsym.
+ */
+
+#define BUFFER_SIZE 32
+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_calloc(size_t nmemb, size_t size) { return NULL; }
-static void* mm_fake_malloc(size_t n)                  { return NULL; }
-static void* mm_fake_realloc(void *p, size_t s)        { return NULL; }
+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 availabel 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(void *p, size_t s)
+{
+  return mm_fake_malloc(s);
+}
+
+static void mm_fake_free(void *p)
+{
+}
 
 /* Function signatures for the main malloc functions: */
 typedef void* (*mm_malloc_t)(size_t size);
@@ -54,54 +103,76 @@ 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   = mm_fake_malloc;
+static mm_malloc_t mm_real_malloc;
 static mm_free_t mm_real_free;
-static mm_calloc_t mm_real_calloc   = mm_fake_calloc;
-static mm_realloc_t mm_real_realloc = mm_fake_realloc;
-
-#define GET_HEAP() __mmalloc_current_heap
+static mm_calloc_t mm_real_calloc;
+static mm_realloc_t mm_real_realloc;
 
-static const char* env_name = "SIMGRID_MALLOC_USE_MM";
+static int mm_initializing;
+static int mm_initialized;
 
-int mmalloc_exec_using_mm(int argc, const char** argv)
+/** Constructor functions used to initialize the malloc implementation
+ */
+static void __attribute__((constructor(101))) mm_legacy_constructor()
 {
-  char** argv2 = (char**) malloc(sizeof(char*) * (argc+1));
-  memcpy(argv2, argv, sizeof(char*) * argc);
-  argv2[argc] = NULL;
-  if (setenv(env_name, "1", 1) >= 0) {
-    execv(argv[0], argv2);
+  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 {
+    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");
   }
-  unsetenv(env_name);
-  fprintf(stderr, "Could not restart with mm malloc\n");
-  free(argv2);
-  return -1;
+  mm_initializing = 0;
+  mm_initialized = 1;
 }
 
-void mmalloc_ensure_using_mm(int argc, const char** argv)
+/* ***** 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 (!__mmalloc_default_mdp) {
-    mmalloc_exec_using_mm(argc, argv);
+  if (!mm_initialized) {
+    if (mm_initializing)
+      return mm_fake_malloc(n);
+    mm_legacy_constructor();
   }
-}
 
-/** Constructor functions used to initialize the malloc implementation
- */
-static void __attribute__((constructor(101))) mm_legacy_constructor()
-{
-  bool use_mm = getenv(env_name);
-  if (use_mm) {
-    __mmalloc_current_heap = mmalloc_preinit();
-  } else {
-    mm_real_realloc  = (mm_realloc_t) dlsym(RTLD_NEXT, "realloc");
-    mm_real_malloc   = (mm_malloc_t)  dlsym(RTLD_NEXT, "malloc");
-    mm_real_free     = (mm_free_t)    dlsym(RTLD_NEXT, "free");
-    mm_real_calloc   = (mm_calloc_t)  dlsym(RTLD_NEXT, "calloc");
+  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;
 }
 
 void *malloc(size_t n)
 {
-  if (!__mmalloc_current_heap) {
+  if (!mm_initialized) {
+    if (mm_initializing)
+      return mm_fake_malloc(n);
+    mm_legacy_constructor();
+  }
+
+  if (!__malloc_use_mmalloc) {
     return mm_real_malloc(n);
   }
 
@@ -117,7 +188,13 @@ void *malloc(size_t n)
 
 void *calloc(size_t nmemb, size_t size)
 {
-  if (!__mmalloc_current_heap) {
+  if (!mm_initialized) {
+    if (mm_initializing)
+      return mm_fake_calloc(nmemb, size);
+    mm_legacy_constructor();
+  }
+
+  if (!__malloc_use_mmalloc) {
     return mm_real_calloc(nmemb, size);
   }
 
@@ -137,7 +214,13 @@ void *calloc(size_t nmemb, size_t size)
 
 void *realloc(void *p, size_t s)
 {
-  if (!__mmalloc_current_heap) {
+  if (!mm_initialized) {
+    if (mm_initializing)
+      return mm_fake_realloc(p, s);
+    mm_legacy_constructor();
+  }
+
+  if (!__malloc_use_mmalloc) {
     return mm_real_realloc(p, s);
   }
 
@@ -153,14 +236,20 @@ void *realloc(void *p, size_t s)
 
 void free(void *p)
 {
-  if (!p)
-    return;
+  if (!mm_initialized) {
+    if (mm_initializing)
+      return mm_fake_free(p);
+    mm_legacy_constructor();
+  }
 
-  if (!__mmalloc_current_heap) {
+  if (!__malloc_use_mmalloc) {
     mm_real_free(p);
     return;
   }
 
+  if (!p)
+    return;
+
   xbt_mheap_t mdp = GET_HEAP();
   LOCK(mdp);
   mfree(mdp, p);