-/* Initialization for acces s to a mmap'd malloc managed region. */
+/* Initialization for access to a mmap'd malloc managed region. */
-/* Copyright (c) 2012-2014. The SimGrid Team.
- * All rights reserved. */
+/* Copyright (c) 2012-2023. 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. */
not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
-#include "src/internal_config.h"
#include <sys/types.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 "src/xbt_modinter.h" /* declarations of mmalloc_preinit and friends that live here */
-
-#ifndef SEEK_SET
-#define SEEK_SET 0
-#endif
/* 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 choosed carefully in order to avoid
+ The provided BASEADDR should be chosen carefully in order to avoid
bumping into existing mapped regions or future mapped regions.
On success, returns a "malloc descriptor" which is used in subsequent
so that users of the package don't have to worry about the actual
implementation details.
- On failure returns NULL. */
+ On failure, returns NULL. */
-xbt_mheap_t xbt_mheap_new(int fd, void *baseaddr)
+xbt_mheap_t xbt_mheap_new(void* baseaddr, int options)
{
- return xbt_mheap_new_options(fd, baseaddr, 0);
-}
-
-xbt_mheap_t xbt_mheap_new_options(int fd, 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, *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! */
+ /* 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;
- mdp->fd = fd;
mdp->base = mdp->breakval = mdp->top = baseaddr;
mdp->next_mdesc = NULL;
- mdp->refcount = 1;
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. */
- /* Now try to map in the first page, copy the malloc descriptor structure
- there, and arrange to return a pointer to this new copy. If the mapping
- fails, then close the file descriptor if it was opened by us, and arrange
- to return a NULL. */
+ /* Now try to map in the first page, copy the malloc descriptor structure there, and arrange to return a pointer to
+ * 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();
}
+ memcpy(mbase, mdp, sizeof(mtemp));
/* Add the new heap to the linked list of heaps attached by mmalloc */
if(__mmalloc_default_mdp){
while(mdp->next_mdesc)
mdp = mdp->next_mdesc;
- LOCK(mdp);
mdp->next_mdesc = (struct mdesc *)mbase;
- UNLOCK(mdp);
}
return mbase;
}
-
-
-/** Terminate access to a mmalloc managed region, but do not free its content.
- *
- * This is for example useful for the base region where ldl stores its data
- * because it leaves the place after us.
- */
-void xbt_mheap_destroy_no_free(xbt_mheap_t md)
-{
- struct mdesc *mdp = md;
-
- if(--mdp->refcount == 0){
- pthread_mutex_destroy(&mdp->mutex);
- }
-}
-
-/** Terminate access to a mmalloc managed region by unmapping all memory pages
- associated with the region, and closing the file descriptor if it is one
- that we opened.
+/** Terminate access to a mmalloc managed region by unmapping all memory pages associated with the region, and closing
+ * the file descriptor if it is one that we opened.
Returns NULL on success.
- Returns the malloc descriptor on failure, which can subsequently be used
- for further action, such as obtaining more information about the nature of
- the failure.
+ Returns the malloc descriptor on failure, which can subsequently be used for further action, such as obtaining more
+ information about the nature of the failure.
- Note that the malloc descriptor that we are using is currently located in
- region we are about to unmap, so we first make a local copy of it on the
- stack and use the copy. */
+ Note that the malloc descriptor that we are using is currently located in region we are about to unmap, so we first
+ make a local copy of it on the stack and use the copy. */
void *xbt_mheap_destroy(xbt_mheap_t mdp)
{
- struct mdesc mtemp, *mdptemp;
-
if (mdp != NULL) {
/* Remove the heap from the linked list of heaps attached by mmalloc */
- mdptemp = __mmalloc_default_mdp;
+ struct mdesc* mdptemp = __mmalloc_default_mdp;
while(mdptemp->next_mdesc != mdp )
mdptemp = mdptemp->next_mdesc;
mdptemp->next_mdesc = mdp->next_mdesc;
- xbt_mheap_destroy_no_free(mdp);
- mtemp = *mdp;
+ struct mdesc mtemp = *mdp;
/* Now unmap all the pages associated with this region by asking for a
negative increment equal to the current size of the region. */
if (mmorecore(&mtemp, (char *)mtemp.base - (char *)mtemp.breakval) == NULL) {
- /* Deallocating failed. Update the original malloc descriptor
- with any changes */
+ /* Deallocating failed. Update the original malloc descriptor with any changes */
*mdp = mtemp;
} else {
- if (mtemp.flags & MMALLOC_DEVZERO) {
- close(mtemp.fd);
- }
mdp = NULL;
}
}
- return (mdp);
+ return mdp;
}
/* Safety gap from the heap's break address.
- * Try to increase this first if you experience strange errors under
- * valgrind. */
+ * Try to increase this first if you experience strange errors under valgrind. */
#define HEAP_OFFSET (128UL<<20)
-xbt_mheap_t mmalloc_get_default_md(void)
-{
- xbt_assert(__mmalloc_default_mdp);
- return __mmalloc_default_mdp;
-}
-
-static void mmalloc_fork_prepare(void)
-{
- xbt_mheap_t mdp = NULL;
- if ((mdp =__mmalloc_default_mdp)){
- while(mdp){
- LOCK(mdp);
- if(mdp->fd >= 0){
- mdp->refcount++;
- }
- mdp = mdp->next_mdesc;
- }
- }
-}
-
-static void mmalloc_fork_parent(void)
-{
- xbt_mheap_t mdp = NULL;
- if ((mdp =__mmalloc_default_mdp)){
- while(mdp){
- if(mdp->fd < 0)
- UNLOCK(mdp);
- mdp = mdp->next_mdesc;
- }
- }
-}
-
-static void mmalloc_fork_child(void)
-{
- struct mdesc* mdp = NULL;
- if ((mdp =__mmalloc_default_mdp)){
- while(mdp){
- UNLOCK(mdp);
- mdp = mdp->next_mdesc;
- }
- }
-}
-
-/* Initialize the default malloc descriptor. */
-void *mmalloc_preinit(void)
+/* Initialize the default malloc descriptor.
+ *
+ * There is no malloc_postexit() destroying the default mdp, because it would break ldl trying to free its memory
+ */
+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);
- __mmalloc_default_mdp = xbt_mheap_new_options(-1, addr, XBT_MHEAP_OPTION_MEMSET);
- /* Fixme? only the default mdp in protected against forks */
- // This is mandated to protect the mmalloced areas through forks. Think of tesh.
- // Nah, removing the mutex isn't a good idea either for tesh
- int 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);
+ unsigned long mmalloc_pagesize = (unsigned long)sysconf(_SC_PAGESIZE);
+ unsigned long mask = ~(mmalloc_pagesize - 1);
+ void* addr = (void*)(((unsigned long)sbrk(0) + HEAP_OFFSET) & mask);
+ __mmalloc_default_mdp = xbt_mheap_new(addr, XBT_MHEAP_OPTION_MEMSET);
}
- xbt_assert(__mmalloc_default_mdp != NULL);
+ mmalloc_assert(__mmalloc_default_mdp != NULL, "__mmalloc_default_mdp cannot be NULL");
return __mmalloc_default_mdp;
}
-
-void mmalloc_postexit(void)
-{
- /* Do not destroy the default mdp or ldl won't be able to free the memory it
- * allocated since we're in memory */
- // xbt_mheap_destroy_no_free(__mmalloc_default_mdp);
-}
-
-// This is the underlying implementation of mmalloc_get_bytes_used_remote.
-// Is it used directly in order to evaluate the bytes used from a different
-// process.
-size_t mmalloc_get_bytes_used_remote(size_t heaplimit, const malloc_info* heapinfo)
-{
- int bytes = 0;
- for (size_t i=0; i < heaplimit; ++i){
- if (heapinfo[i].type == MMALLOC_TYPE_UNFRAGMENTED){
- if (heapinfo[i].busy_block.busy_size > 0)
- bytes += heapinfo[i].busy_block.busy_size;
- } else if (heapinfo[i].type > 0) {
- for (size_t j=0; j < (size_t) (BLOCKSIZE >> heapinfo[i].type); j++){
- if(heapinfo[i].busy_frag.frag_size[j] > 0)
- bytes += heapinfo[i].busy_frag.frag_size[j];
- }
- }
- }
- return bytes;
-}
-
-size_t mmalloc_get_bytes_used(const xbt_mheap_t heap){
- const struct mdesc* heap_data = (const struct mdesc *) heap;
- return mmalloc_get_bytes_used_remote(heap_data->heaplimit, heap_data->heapinfo);
-}
-
-ssize_t mmalloc_get_busy_size(xbt_mheap_t heap, void *ptr){
-
- ssize_t block = ((char*)ptr - (char*)(heap->heapbase)) / BLOCKSIZE + 1;
- if(heap->heapinfo[block].type < 0)
- return -1;
- else if(heap->heapinfo[block].type == MMALLOC_TYPE_UNFRAGMENTED)
- return heap->heapinfo[block].busy_block.busy_size;
- else{
- ssize_t frag = ((uintptr_t) (ADDR2UINT (ptr) % (BLOCKSIZE))) >> heap->heapinfo[block].type;
- return heap->heapinfo[block].busy_frag.frag_size[frag];
- }
-
-}
-
-void mmcheck(xbt_mheap_t heap) {return;
- if (!heap->heapinfo)
- return;
- malloc_info* heapinfo = NULL;
- for (size_t i=1; i < heap->heaplimit; i += mmalloc_get_increment(heapinfo)) {
- heapinfo = heap->heapinfo + i;
- switch (heapinfo->type) {
- case MMALLOC_TYPE_HEAPINFO:
- case MMALLOC_TYPE_FREE:
- if (heapinfo->free_block.size==0) {
- xbt_die("Block size == 0");
- }
- break;
- case MMALLOC_TYPE_UNFRAGMENTED:
- if (heapinfo->busy_block.size==0) {
- xbt_die("Block size == 0");
- }
- if (heapinfo->busy_block.busy_size==0 && heapinfo->busy_block.size!=0) {
- xbt_die("Empty busy block");
- }
- break;
- default:
- if (heapinfo->type<0) {
- xbt_die("Unkown mmalloc block type.");
- }
- }
- }
-}