X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/c7ff77c2e7f934ad3e6234b09b7f80047544ed7c..f43bc484f697666583ba779d3adb325f1eee498b:/src/xbt/mmalloc/mm_legacy.c?ds=sidebyside

diff --git a/src/xbt/mmalloc/mm_legacy.c b/src/xbt/mmalloc/mm_legacy.c
index 2bced98dd1..2c1a0d5d9d 100644
--- a/src/xbt/mmalloc/mm_legacy.c
+++ b/src/xbt/mmalloc/mm_legacy.c
@@ -1,166 +1,258 @@
-/* Copyright (c) 2010. The SimGrid Team.
+/* Copyright (c) 2010-2014. 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 "gras_config.h"
+#include <stdlib.h>
 
-static void *__mmalloc_current_heap = NULL;     /* The heap we are currently using. */
+#include <dlfcn.h>
 
+#include "../../mc/mc_base.h"
+#include "mmprivate.h"
 #include "xbt_modinter.h"
+#include "internal_config.h"
+#include <math.h>
+#include "../mc/mc_protocol.h"
+
+/* ***** Whether to use `mmalloc` of the undrlying 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)
+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_OVERIDE_LEGACY
-void *malloc(size_t n)
+#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_malloc(size_t n)
 {
-  void *mdp = __mmalloc_current_heap;
-#ifdef HAVE_MMAP
-  if (!mdp)
-    mmalloc_preinit();
-#endif
-  LOCK(mdp);
-  void *ret = mmalloc(mdp, n);
-  UNLOCK(mdp);
+  // 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;
+}
 
-  return ret;
+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);
 }
 
-void *calloc(size_t nmemb, size_t size)
+static void* mm_fake_realloc(void *p, size_t s)
 {
-  size_t total_size = nmemb * size;
-  void *mdp = __mmalloc_current_heap;
-#ifdef HAVE_MMAP
-  if (!mdp)
-    mmalloc_preinit();
-#endif
-  LOCK(mdp);
-  void *ret = mmalloc(mdp, total_size);
-  UNLOCK(mdp);
+  return mm_fake_malloc(s);
+}
 
-  /* Fill the allocated memory with zeroes to mimic calloc behaviour */
-  memset(ret, '\0', total_size);
+static void mm_fake_free(void *p)
+{
+}
 
-  return ret;
+/* 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
+ */
+static void __attribute__((constructor(101))) 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 {
+    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");
+  }
+  mm_initializing = 0;
+  mm_initialized = 1;
 }
 
-void *realloc(void *p, size_t s)
+/* ***** 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)
 {
-  void *ret = NULL;
-  void *mdp = __mmalloc_current_heap;
-#ifdef HAVE_MMAP
+  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)
-    mmalloc_preinit();
-#endif
+    return NULL;
+
   LOCK(mdp);
-  if (s) {
-    if (p)
-      ret = mrealloc(mdp, p, s);
-    else
-      ret = mmalloc(mdp, s);
-  } else {
-    if (p)
-      mfree(mdp, p);
-  }
+  void *ret = mmalloc_no_memset(mdp, n);
   UNLOCK(mdp);
-
   return ret;
 }
 
-void free(void *p)
+void *malloc(size_t n)
 {
-  void *mdp = __mmalloc_current_heap;
-#ifdef HAVE_GTNETS
-  if(!mdp) return;
-#endif
+  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);
-  mfree(mdp, p);
+  void *ret = mmalloc(mdp, n);
   UNLOCK(mdp);
+  return ret;
 }
-#endif
 
-/* Make sure it works with md==NULL */
+void *calloc(size_t nmemb, size_t size)
+{
+  if (!mm_initialized) {
+    if (mm_initializing)
+      return mm_fake_calloc(nmemb, size);
+    mm_legacy_constructor();
+  }
 
-/* Safety gap from the heap's break address.
- * Try to increase this first if you experience strange errors under
- * valgrind. */
-#define HEAP_OFFSET   (128UL<<20)
+  if (!__malloc_use_mmalloc) {
+    return mm_real_calloc(nmemb, size);
+  }
 
-void *mmalloc_get_default_md(void)
-{
-  xbt_assert(__mmalloc_default_mdp);
-  return __mmalloc_default_mdp;
-}
+  xbt_mheap_t mdp = GET_HEAP();
+  if (!mdp)
+    return NULL;
 
-static void mmalloc_fork_prepare(void)
-{
-  struct mdesc* mdp = NULL;
-  if ((mdp =__mmalloc_default_mdp)){
-    while(mdp){
-      LOCK(mdp);
-      if(mdp->fd >= 0){
-        mdp->refcount++;
-      }
-      mdp = mdp->next_mdesc;
-    }
+  LOCK(mdp);
+  void *ret = mmalloc(mdp, nmemb*size);
+  UNLOCK(mdp);
+  // This was already done in the callee:
+  if(!(mdp->options & XBT_MHEAP_OPTION_MEMSET)) {
+    memset(ret, 0, nmemb * size);
   }
+  return ret;
 }
 
-static void mmalloc_fork_parent(void)
+void *realloc(void *p, size_t s)
 {
-  struct mdesc* mdp = NULL;
-  if ((mdp =__mmalloc_default_mdp)){
-    while(mdp){
-      if(mdp->fd < 0)
-        UNLOCK(mdp);
-      mdp = mdp->next_mdesc;
-    }
+  if (!mm_initialized) {
+    if (mm_initializing)
+      return mm_fake_realloc(p, s);
+    mm_legacy_constructor();
   }
-}
 
-static void mmalloc_fork_child(void)
-{
-  struct mdesc* mdp = NULL;
-  if ((mdp =__mmalloc_default_mdp)){
-    while(mdp){
-      UNLOCK(mdp);
-      mdp = mdp->next_mdesc;
-    }
+  if (!__malloc_use_mmalloc) {
+    return mm_real_realloc(p, s);
   }
+
+  xbt_mheap_t mdp = GET_HEAP();
+  if (!mdp)
+    return NULL;
+
+  LOCK(mdp);
+  void* ret = mrealloc(mdp, p, s);
+  UNLOCK(mdp);
+  return ret;
 }
 
-/* Initialize the default malloc descriptor. */
-void mmalloc_preinit(void)
+void free(void *p)
 {
-  int res;
-  if (!__mmalloc_default_mdp) {
-    unsigned long mask = ~((unsigned long)getpagesize() - 1);
-    void *addr = (void*)(((unsigned long)sbrk(0) + HEAP_OFFSET) & mask);
-    __mmalloc_default_mdp = mmalloc_attach(-1, addr);
-    /* Fixme? only the default mdp in protected against forks */
-    res = xbt_os_thread_atfork(mmalloc_fork_prepare,
-			       mmalloc_fork_parent, mmalloc_fork_child);
-    if (res != 0)
-      THROWF(system_error,0,"xbt_os_thread_atfork() failed: return value %d",res);
+  if (!mm_initialized) {
+    if (mm_initializing)
+      return mm_fake_free(p);
+    mm_legacy_constructor();
   }
-  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);
-  mmalloc_pre_detach(__mmalloc_default_mdp);
+  if (!__malloc_use_mmalloc) {
+    mm_real_free(p);
+    return;
+  }
+
+  if (!p)
+    return;
+
+  xbt_mheap_t mdp = GET_HEAP();
+  LOCK(mdp);
+  mfree(mdp, p);
+  UNLOCK(mdp);
 }
+#endif /* WANT_MALLOC_OVERRIDE */