Parameter 'fd' is always -1 for xbt_mheap_new. Kill dead code.

[simgrid.git] / src / xbt / mmalloc / mm_module.c

diff --git a/src/xbt/mmalloc/mm_module.c b/src/xbt/mmalloc/mm_module.c
index b1c1551..5c95f1a 100644 (file)
--- a/src/xbt/mmalloc/mm_module.c
+++ b/src/xbt/mmalloc/mm_module.c
@@ -1,6 +1,6 @@
 /* Initialization for access to a mmap'd malloc managed region. */
 
 /* Initialization for access to a mmap'd malloc managed region. */
 

-/* Copyright (c) 2012-2019. The SimGrid Team.
+/* Copyright (c) 2012-2021. The SimGrid Team.

  * All rights reserved.                                                     */
 
 /* This program is free software; you can redistribute it and/or modify it
  * All rights reserved.                                                     */
 
 /* This program is free software; you can redistribute it and/or modify it


@@ -32,35 +32,14 @@
 #include <fcntl.h>              /* After sys/types.h, at least for dpx/2.  */
 #include <sys/stat.h>
 #include <string.h>
 #include <fcntl.h>              /* After sys/types.h, at least for dpx/2.  */
 #include <sys/stat.h>
 #include <string.h>

-#if HAVE_UNISTD_H
-#include <unistd.h>             /* Prototypes for lseek */
-#endif

 #include "mmprivate.h"
 #include "xbt/ex.h"
 #include "mmprivate.h"
 #include "xbt/ex.h"

-#include "src/xbt_modinter.h" /* declarations of mmalloc_preinit and friends that live here */
-
-#ifndef SEEK_SET
-#define SEEK_SET 0
-#endif
+#include "xbt/xbt_modinter.h" /* declarations of mmalloc_preinit and friends that live here */

 
 /* Initialize access to a mmalloc managed region.
 
 
 /* Initialize access to a mmalloc managed region.
 

-   If FD is a valid file descriptor for an open file then data for the
-   mmalloc managed region is mapped to that file, otherwise an anonymous
-   map is used if supported by the underlying OS. In case of running in
-   an OS without support of anonymous mappings then "/dev/zero" is used
-   and in both cases the data will not exist in any filesystem object.
-
-   If the open file corresponding to FD is from a previous use of
-   mmalloc and passes some basic sanity checks to ensure that it is
-   compatible with the current mmalloc package, then its data is
-   mapped in and is immediately accessible at the same addresses in
-   the current process as the process that created the file (ignoring
-   the BASEADDR parameter).
-
-   For non valid FDs or empty files ones the mapping is established
-   starting at the specified address BASEADDR in the process address
-   space.
+   The mapping is established starting at the specified address BASEADDR
+   in the process address space.

 
    The provided BASEADDR should be chosen carefully in order to avoid
    bumping into existing mapped regions or future mapped regions.
 
    The provided BASEADDR should be chosen carefully in order to avoid
    bumping into existing mapped regions or future mapped regions.


@@ -72,116 +51,26 @@
 
    On failure returns NULL. */
 
 
    On failure returns NULL. */
 

-xbt_mheap_t xbt_mheap_new(int fd, void *baseaddr)
-{
-  return xbt_mheap_new_options(fd, baseaddr, 0);
-}
-
-xbt_mheap_t xbt_mheap_new_options(int fd, void *baseaddr, int options)
+xbt_mheap_t xbt_mheap_new(void* baseaddr, int options)

 {
 {

-  struct mdesc mtemp;
-  xbt_mheap_t mdp;
-  void *mbase;
-  struct stat sbuf;
-
-  /* First check to see if FD is a valid file descriptor, and if so, see
-     if the file has any current contents (size > 0).  If it does, then
-     attempt to reuse the file.  If we can't reuse the file, either
-     because it isn't a valid mmalloc produced file, was produced by an
-     obsolete version, or any other reason, then we fail to attach to
-     this file. */
-
-  if (fd >= 0) {
-    if (fstat(fd, &sbuf) < 0)
-      return (NULL);
-
-    else if (sbuf.st_size > 0) {
-      /* We were given an valid file descriptor on an open file, so try to remap
-         it into the current process at the same address to which it was previously
-         mapped. It naturally have to pass some sanity checks for that.
-
-         Note that we have to update the file descriptor number in the malloc-
-         descriptor read from the file to match the current valid one, before
-         trying to map the file in, and again after a successful mapping and
-         after we've switched over to using the mapped in malloc descriptor
-         rather than the temporary one on the stack.
-
-         Once we've switched over to using the mapped in malloc descriptor, we
-         have to update the pointer to the morecore function, since it almost
-         certainly will be at a different address if the process reusing the
-         mapped region is from a different executable.
-
-         Also note that if the heap being remapped previously used the mmcheckf()
-         routines, we need to update the hooks since their target functions
-         will have certainly moved if the executable has changed in any way.
-         We do this by calling mmcheckf() internally.
-
-         Returns a pointer to the malloc descriptor if successful, or NULL if
-         unsuccessful for some reason. */
-
-      struct mdesc newmd;
-      struct mdesc* mdptr   = NULL;
-      struct mdesc* mdptemp = NULL;
-
-      if (lseek(fd, 0L, SEEK_SET) != 0)
-        return NULL;
-      if (read(fd, (char *) &newmd, sizeof(newmd)) != sizeof(newmd))
-        return NULL;
-      if (newmd.headersize != sizeof(newmd))
-        return NULL;
-      if (strcmp(newmd.magic, MMALLOC_MAGIC) != 0)
-        return NULL;
-      if (newmd.version > MMALLOC_VERSION)
-        return NULL;
-
-      newmd.fd = fd;
-      if (__mmalloc_remap_core(&newmd) == newmd.base) {
-        mdptr = (struct mdesc *) newmd.base;
-        mdptr->fd = fd;
-        if(!mdptr->refcount){
-          pthread_mutex_init(&mdptr->mutex, NULL);
-          mdptr->refcount++;
-        }
-      }
-
-      /* Add the new heap to the linked list of heaps attached by mmalloc */
-      mdptemp = __mmalloc_default_mdp;
-      while(mdptemp->next_mdesc)
-        mdptemp = mdptemp->next_mdesc;
-
-      LOCK(mdptemp);
-      mdptemp->next_mdesc = mdptr;
-      UNLOCK(mdptemp);
-
-      return mdptr;
-    }
-  }
-

   /* NULL is not a valid baseaddr as we cannot map anything there. C'mon, user. Think! */
   if (baseaddr == NULL)
   /* NULL is not a valid baseaddr as we cannot map anything there. C'mon, user. Think! */
   if (baseaddr == NULL)

-    return (NULL);
+    return NULL;

 
   /* We start off with the malloc descriptor allocated on the stack, until we build it up enough to
    * call _mmalloc_mmap_morecore() to allocate the first page of the region and copy it there.  Ensure that it is
    * zero'd and then initialize the fields that we know values for. */
 
 
   /* We start off with the malloc descriptor allocated on the stack, until we build it up enough to
    * call _mmalloc_mmap_morecore() to allocate the first page of the region and copy it there.  Ensure that it is
    * zero'd and then initialize the fields that we know values for. */
 

-  mdp = &mtemp;
+  struct mdesc mtemp;
+  xbt_mheap_t mdp = &mtemp;

   memset((char *) mdp, 0, sizeof(mtemp));
   strncpy(mdp->magic, MMALLOC_MAGIC, MMALLOC_MAGIC_SIZE);
   mdp->headersize = sizeof(mtemp);
   mdp->version = MMALLOC_VERSION;
   memset((char *) mdp, 0, sizeof(mtemp));
   strncpy(mdp->magic, MMALLOC_MAGIC, MMALLOC_MAGIC_SIZE);
   mdp->headersize = sizeof(mtemp);
   mdp->version = MMALLOC_VERSION;

-  mdp->fd = fd;

   mdp->base = mdp->breakval = mdp->top = baseaddr;
   mdp->next_mdesc = NULL;
   mdp->base = mdp->breakval = mdp->top = baseaddr;
   mdp->next_mdesc = NULL;

-  mdp->refcount = 1;

   mdp->options = options;
 
   mdp->options = options;
 

-  /* If we have not been passed a valid open file descriptor for the file
-     to map to, then we go for an anonymous map */
-
-  if (mdp->fd < 0){
-    mdp->flags |= MMALLOC_ANONYMOUS;
-  }

   pthread_mutex_init(&mdp->mutex, NULL);
   /* If we have not been passed a valid open file descriptor for the file
      to map to, then open /dev/zero and use that to map to. */
   pthread_mutex_init(&mdp->mutex, NULL);
   /* If we have not been passed a valid open file descriptor for the file
      to map to, then open /dev/zero and use that to map to. */


@@ -190,12 +79,12 @@ xbt_mheap_t xbt_mheap_new_options(int fd, void *baseaddr, int options)
    * this new copy.  If the mapping fails, then close the file descriptor if it was opened by us, and arrange to return
    * a NULL. */
 
    * this new copy.  If the mapping fails, then close the file descriptor if it was opened by us, and arrange to return
    * a NULL. */
 

-  if ((mbase = mmorecore(mdp, sizeof(mtemp))) != NULL) {
-    memcpy(mbase, mdp, sizeof(mtemp));
-  } else {
+  void* mbase = mmorecore(mdp, sizeof(mtemp));
+  if (mbase == NULL) {

     fprintf(stderr, "morecore failed to get some more memory!\n");
     abort();
   }
     fprintf(stderr, "morecore failed to get some more memory!\n");
     abort();
   }

+  memcpy(mbase, mdp, sizeof(mtemp));

 
   /* Add the new heap to the linked list of heaps attached by mmalloc */
   if(__mmalloc_default_mdp){
 
   /* Add the new heap to the linked list of heaps attached by mmalloc */
   if(__mmalloc_default_mdp){


@@ -222,9 +111,7 @@ void xbt_mheap_destroy_no_free(xbt_mheap_t md)
 {
   struct mdesc *mdp = md;
 
 {
   struct mdesc *mdp = md;
 

-  if(--mdp->refcount == 0){
-    pthread_mutex_destroy(&mdp->mutex);
-  }
+  pthread_mutex_destroy(&mdp->mutex);

 }
 
 /** Terminate access to a mmalloc managed region by unmapping all memory pages associated with the region, and closing
 }
 
 /** Terminate access to a mmalloc managed region by unmapping all memory pages associated with the region, and closing


@@ -258,14 +145,11 @@ void *xbt_mheap_destroy(xbt_mheap_t mdp)
       /* Deallocating failed.  Update the original malloc descriptor with any changes */
       *mdp = mtemp;
     } else {
       /* Deallocating failed.  Update the original malloc descriptor with any changes */
       *mdp = mtemp;
     } else {

-      if (mtemp.flags & MMALLOC_DEVZERO) {
-        close(mtemp.fd);
-      }

       mdp = NULL;
     }
   }
 
       mdp = NULL;
     }
   }
 

-  return (mdp);
+  return mdp;

 }
 
 /* Safety gap from the heap's break address.
 }
 
 /* Safety gap from the heap's break address.


@@ -278,9 +162,6 @@ static void mmalloc_fork_prepare(void)
   if ((mdp =__mmalloc_default_mdp)){
     while(mdp){
       LOCK(mdp);
   if ((mdp =__mmalloc_default_mdp)){
     while(mdp){
       LOCK(mdp);

-      if(mdp->fd >= 0){
-        mdp->refcount++;
-      }

       mdp = mdp->next_mdesc;
     }
   }
       mdp = mdp->next_mdesc;
     }
   }


@@ -291,8 +172,7 @@ static void mmalloc_fork_parent(void)
   xbt_mheap_t mdp = NULL;
   if ((mdp =__mmalloc_default_mdp)){
     while(mdp){
   xbt_mheap_t mdp = NULL;
   if ((mdp =__mmalloc_default_mdp)){
     while(mdp){

-      if(mdp->fd < 0)
-        UNLOCK(mdp);
+      UNLOCK(mdp);

       mdp = mdp->next_mdesc;
     }
   }
       mdp = mdp->next_mdesc;
     }
   }


@@ -310,14 +190,14 @@ static void mmalloc_fork_child(void)
 }
 
 /* Initialize the default malloc descriptor. */
 }
 
 /* Initialize the default malloc descriptor. */

-void *mmalloc_preinit(void)
+xbt_mheap_t mmalloc_preinit(void)

 {
   if (__mmalloc_default_mdp == NULL) {
     if(!xbt_pagesize)
       xbt_pagesize = getpagesize();
     unsigned long mask = ~((unsigned long)xbt_pagesize - 1);
     void *addr = (void*)(((unsigned long)sbrk(0) + HEAP_OFFSET) & mask);
 {
   if (__mmalloc_default_mdp == NULL) {
     if(!xbt_pagesize)
       xbt_pagesize = getpagesize();
     unsigned long mask = ~((unsigned long)xbt_pagesize - 1);
     void *addr = (void*)(((unsigned long)sbrk(0) + HEAP_OFFSET) & mask);

-    __mmalloc_default_mdp = xbt_mheap_new_options(-1, addr, XBT_MHEAP_OPTION_MEMSET);
+    __mmalloc_default_mdp = xbt_mheap_new(addr, XBT_MHEAP_OPTION_MEMSET);

 
     // atfork mandated at least on FreeBSD, or simgrid-mc will fail to fork the verified app
     int res = pthread_atfork(mmalloc_fork_prepare, mmalloc_fork_parent, mmalloc_fork_child);
 
     // atfork mandated at least on FreeBSD, or simgrid-mc will fail to fork the verified app
     int res = pthread_atfork(mmalloc_fork_prepare, mmalloc_fork_parent, mmalloc_fork_child);