/* sbrk for windows */
extern void
*win_sbrk (long size) {
static long g_pagesize, g_my_pagesize;
static long g_regionsize, g_my_regionsize;
static region_list_entry *g_last;
void *result = SBRK_FAILURE;
/* Wait for spin lock */
slwait (&g_sl);
/* First time initialization */
if (! g_pagesize) {
g_pagesize = getpagesize ();
g_my_pagesize = g_pagesize << SBRK_SCALE;
}
if (! g_regionsize) {
g_regionsize = getregionsize ();
g_my_regionsize = g_regionsize << SBRK_SCALE;
}
if (! g_last) {
if (! region_list_append (&g_last, 0, 0))
goto sbrk_exit;
}
/* Allocation requested? */
if (size >= 0) {
/* Allocation size is the requested size */
long allocate_size = size;
/* Compute the size to commit */
long to_reserve = (char *) g_last->top_allocated + allocate_size - (char *) g_last->top_reserved;
/* Do we reach the commit limit? */
if (to_reserve > 0) {
/* Now we are going to search and reserve. */
int contiguous = -1;
int found = FALSE;
MEMORY_BASIC_INFORMATION memory_info;
void *base_reserved;
long reserve_size;
do {
/* Assume contiguous memory */
contiguous = TRUE;
/* Round size to reserve */
reserve_size = CEIL (to_reserve, g_my_regionsize);
/* Start with the current region's top */
memory_info.BaseAddress = g_last->top_reserved;
while (VirtualQuery (memory_info.BaseAddress, &memory_info, sizeof (memory_info))) {
/* Region is free, well aligned and big enough: we are done */
if (memory_info.State == MEM_FREE &&
(unsigned) memory_info.BaseAddress % g_regionsize == 0 &&
memory_info.RegionSize >= (unsigned) reserve_size) {
found = TRUE;
break;
}
/* From now on we can't get contiguous memory! */
contiguous = FALSE;
/* Recompute size to reserve */
reserve_size = CEIL (allocate_size, g_my_regionsize);
memory_info.BaseAddress = (char *) memory_info.BaseAddress + memory_info.RegionSize;
}
/* Search failed? */
if (! found)
goto sbrk_exit;
/* Try to reserve this */
base_reserved = VirtualAlloc (memory_info.BaseAddress, reserve_size,
MEM_RESERVE | MEM_COMMIT, PAGE_READWRITE);
if (! base_reserved) {
int rc = GetLastError ();
if (rc != ERROR_INVALID_ADDRESS)
goto sbrk_exit;
}
/* A null pointer signals (hopefully) a race condition with another thread. */
/* In this case, we try again. */
} while (! base_reserved);
/* Check returned pointer for consistency */
if (memory_info.BaseAddress && base_reserved != memory_info.BaseAddress)
goto sbrk_exit;
/* Did we get contiguous memory? */
if (contiguous) {
long start_size = (char *) g_last->top_reserved - (char *) g_last->top_allocated;
/* Adjust allocation size */
allocate_size -= start_size;
/* Adjust the regions allocation top */
g_last->top_allocated = g_last->top_reserved;
}
/* Append the new region to the list */
if (! region_list_append (&g_last, base_reserved, reserve_size))
goto sbrk_exit;
}
/* Adjust the regions allocation top */
g_last->top_allocated = (char *) g_last->top_allocated + allocate_size;
result = (char *) g_last->top_allocated - size;
/* Deallocation requested? */
} else if (size < 0) {
long deallocate_size = - size;
/* As long as we have a region to release */
while ((char *) g_last->top_allocated - deallocate_size < (char *) g_last->top_reserved - g_last->reserve_size) {
/* Get the size to release */
long release_size = g_last->reserve_size;
/* Get the base address */
void *base_reserved = (char *) g_last->top_reserved - release_size;
/* Release this */
int rc = VirtualFree (base_reserved, 0,
MEM_RELEASE);
/* Check returned code for consistency */
if (! rc)
goto sbrk_exit;
/* Adjust deallocation size */
deallocate_size -= (char *) g_last->top_allocated - (char *) base_reserved;
/* Remove the old region from the list */
if (! region_list_remove (&g_last))
goto sbrk_exit;
}
/* Adjust regions allocate top */
g_last->top_allocated = (char *) g_last->top_allocated - deallocate_size;
/* Check for underflow */
if ((char *) g_last->top_reserved - g_last->reserve_size > (char *) g_last->top_allocated ||
g_last->top_allocated > g_last->top_reserved) {
/* Adjust regions allocate top */
g_last->top_allocated = (char *) g_last->top_reserved - g_last->reserve_size;
goto sbrk_exit;
}
result = g_last->top_allocated;
}
sbrk_exit:
/* Release spin lock */
slrelease (&g_sl);
return result;
}
/* sbrk for windows */
static void *sbrk (INTERNAL_INTPTR_T size) {
static INTERNAL_INTPTR_T g_pagesize, g_my_pagesize;
static INTERNAL_INTPTR_T g_regionsize, g_my_regionsize;
static region_list_entry *g_last;
void *result = (void *) MORECORE_FAILURE;
#ifdef TRACE
printf ("sbrk %d\n", size);
#endif
/* Wait for spin lock */
slwait (&g_sl);
/* First time initialization */
if (! g_pagesize) {
g_pagesize = getpagesize ();
g_my_pagesize = g_pagesize << SBRK_SCALE;
}
if (! g_regionsize) {
g_regionsize = getregionsize ();
g_my_regionsize = g_regionsize << SBRK_SCALE;
}
if (! g_last) {
if (! region_list_append (&g_last, 0, 0))
goto sbrk_exit;
}
/* Assert invariants */
assert (g_last);
assert ((char *) g_last->top_reserved - g_last->reserve_size <= (char *) g_last->top_allocated &&
g_last->top_allocated <= g_last->top_committed);
assert ((char *) g_last->top_reserved - g_last->reserve_size <= (char *) g_last->top_committed &&
g_last->top_committed <= g_last->top_reserved &&
(unsigned) g_last->top_committed % g_pagesize == 0);
assert ((unsigned) g_last->top_reserved % g_regionsize == 0);
assert ((unsigned) g_last->reserve_size % g_regionsize == 0);
/* Allocation requested? */
if (size >= 0) {
/* Allocation size is the requested size */
INTERNAL_INTPTR_T allocate_size = size;
/* Compute the size to commit */
INTERNAL_INTPTR_T to_commit = (char *) g_last->top_allocated + allocate_size - (char *) g_last->top_committed;
/* Do we reach the commit limit? */
if (to_commit > 0) {
/* Round size to commit */
INTERNAL_INTPTR_T commit_size = CEIL (to_commit, g_my_pagesize);
/* Compute the size to reserve */
INTERNAL_INTPTR_T to_reserve = (char *) g_last->top_committed + commit_size - (char *) g_last->top_reserved;
/* Do we reach the reserve limit? */
if (to_reserve > 0) {
/* Compute the remaining size to commit in the current region */
INTERNAL_INTPTR_T remaining_commit_size = (char *) g_last->top_reserved - (char *) g_last->top_committed;
if (remaining_commit_size > 0) {
/* Assert preconditions */
assert ((unsigned) g_last->top_committed % g_pagesize == 0);
assert (0 < remaining_commit_size && remaining_commit_size % g_pagesize == 0);
{
/* Commit this */
void *base_committed = VirtualAlloc (g_last->top_committed, remaining_commit_size,
MEM_COMMIT, PAGE_READWRITE);
/* Check returned pointer for consistency */
if (base_committed != g_last->top_committed)
goto sbrk_exit;
/* Assert postconditions */
assert ((unsigned) base_committed % g_pagesize == 0);
#ifdef TRACE
printf ("Commit %p %d\n", base_committed, remaining_commit_size);
#endif
/* Adjust the regions commit top */
g_last->top_committed = (char *) base_committed + remaining_commit_size;
}
} {
/* Now we are going to search and reserve. */
int contiguous = -1;
int found = FALSE;
MEMORY_BASIC_INFORMATION memory_info;
void *base_reserved;
INTERNAL_INTPTR_T reserve_size;
do {
/* Assume contiguous memory */
contiguous = TRUE;
/* Round size to reserve */
reserve_size = CEIL (to_reserve, g_my_regionsize);
/* Start with the current region's top */
memory_info.BaseAddress = g_last->top_reserved;
/* Assert preconditions */
assert ((unsigned) memory_info.BaseAddress % g_pagesize == 0);
assert (0 < reserve_size && reserve_size % g_regionsize == 0);
while (VirtualQuery (memory_info.BaseAddress, &memory_info, sizeof (memory_info))) {
/* Assert postconditions */
assert ((unsigned) memory_info.BaseAddress % g_pagesize == 0);
#ifdef TRACE
printf ("Query %p %d %s\n", memory_info.BaseAddress, memory_info.RegionSize,
memory_info.State == MEM_FREE ? "FREE":
(memory_info.State == MEM_RESERVE ? "RESERVED":
(memory_info.State == MEM_COMMIT ? "COMMITTED": "?")));
#endif
/* Region is free, well aligned and big enough: we are done */
if (memory_info.State == MEM_FREE &&
(unsigned) memory_info.BaseAddress % g_regionsize == 0 &&
memory_info.RegionSize >= (unsigned) reserve_size) {
found = TRUE;
break;
}
/* From now on we can't get contiguous memory! */
contiguous = FALSE;
/* Recompute size to reserve */
reserve_size = CEIL (allocate_size, g_my_regionsize);
memory_info.BaseAddress = (char *) memory_info.BaseAddress + memory_info.RegionSize;
/* Assert preconditions */
assert ((unsigned) memory_info.BaseAddress % g_pagesize == 0);
assert (0 < reserve_size && reserve_size % g_regionsize == 0);
}
/* Search failed? */
if (! found)
goto sbrk_exit;
/* Assert preconditions */
assert ((unsigned) memory_info.BaseAddress % g_regionsize == 0);
assert (0 < reserve_size && reserve_size % g_regionsize == 0);
/* Try to reserve this */
base_reserved = VirtualAlloc (memory_info.BaseAddress, reserve_size,
MEM_RESERVE, PAGE_NOACCESS);
if (! base_reserved) {
int rc = GetLastError ();
if (rc != ERROR_INVALID_ADDRESS)
goto sbrk_exit;
}
/* A null pointer signals (hopefully) a race condition with another thread. */
/* In this case, we try again. */
} while (! base_reserved);
/* Check returned pointer for consistency */
if (memory_info.BaseAddress && base_reserved != memory_info.BaseAddress)
goto sbrk_exit;
/* Assert postconditions */
assert ((unsigned) base_reserved % g_regionsize == 0);
#ifdef TRACE
printf ("Reserve %p %d\n", base_reserved, reserve_size);
#endif
/* Did we get contiguous memory? */
if (contiguous) {
INTERNAL_INTPTR_T start_size = (char *) g_last->top_committed - (char *) g_last->top_allocated;
/* Adjust allocation size */
allocate_size -= start_size;
/* Adjust the regions allocation top */
g_last->top_allocated = g_last->top_committed;
/* Recompute the size to commit */
to_commit = (char *) g_last->top_allocated + allocate_size - (char *) g_last->top_committed;
/* Round size to commit */
commit_size = CEIL (to_commit, g_my_pagesize);
}
/* Append the new region to the list */
if (! region_list_append (&g_last, base_reserved, reserve_size))
goto sbrk_exit;
/* Didn't we get contiguous memory? */
if (! contiguous) {
/* Recompute the size to commit */
to_commit = (char *) g_last->top_allocated + allocate_size - (char *) g_last->top_committed;
/* Round size to commit */
commit_size = CEIL (to_commit, g_my_pagesize);
}
}
}
/* Assert preconditions */
assert ((unsigned) g_last->top_committed % g_pagesize == 0);
assert (0 < commit_size && commit_size % g_pagesize == 0);
{
/* Commit this */
void *base_committed = VirtualAlloc (g_last->top_committed, commit_size,
MEM_COMMIT, PAGE_READWRITE);
/* Check returned pointer for consistency */
if (base_committed != g_last->top_committed)
goto sbrk_exit;
/* Assert postconditions */
assert ((unsigned) base_committed % g_pagesize == 0);
#ifdef TRACE
printf ("Commit %p %d\n", base_committed, commit_size);
#endif
/* Adjust the regions commit top */
g_last->top_committed = (char *) base_committed + commit_size;
}
}
/* Adjust the regions allocation top */
g_last->top_allocated = (char *) g_last->top_allocated + allocate_size;
result = (char *) g_last->top_allocated - size;
/* Deallocation requested? */
} else if (size < 0) {
INTERNAL_INTPTR_T deallocate_size = - size;
/* As INTERNAL_INTPTR_T as we have a region to release */
while ((char *) g_last->top_allocated - deallocate_size < (char *) g_last->top_reserved - g_last->reserve_size) {
/* Get the size to release */
INTERNAL_INTPTR_T release_size = g_last->reserve_size;
/* Get the base address */
void *base_reserved = (char *) g_last->top_reserved - release_size;
/* Assert preconditions */
assert ((unsigned) base_reserved % g_regionsize == 0);
assert (0 < release_size && release_size % g_regionsize == 0);
{
/* Release this */
int rc = VirtualFree (base_reserved, 0,
MEM_RELEASE);
/* Check returned code for consistency */
if (! rc)
goto sbrk_exit;
#ifdef TRACE
printf ("Release %p %d\n", base_reserved, release_size);
#endif
}
/* Adjust deallocation size */
deallocate_size -= (char *) g_last->top_allocated - (char *) base_reserved;
/* Remove the old region from the list */
if (! region_list_remove (&g_last))
goto sbrk_exit;
} {
/* Compute the size to decommit */
INTERNAL_INTPTR_T to_decommit = (char *) g_last->top_committed - ((char *) g_last->top_allocated - deallocate_size);
if (to_decommit >= g_my_pagesize) {
/* Compute the size to decommit */
INTERNAL_INTPTR_T decommit_size = FLOOR (to_decommit, g_my_pagesize);
/* Compute the base address */
void *base_committed = (char *) g_last->top_committed - decommit_size;
/* Assert preconditions */
assert ((unsigned) base_committed % g_pagesize == 0);
assert (0 < decommit_size && decommit_size % g_pagesize == 0);
{
/* Decommit this */
int rc = VirtualFree ((char *) base_committed, decommit_size,
MEM_DECOMMIT);
/* Check returned code for consistency */
if (! rc)
goto sbrk_exit;
#ifdef TRACE
printf ("Decommit %p %d\n", base_committed, decommit_size);
#endif
}
/* Adjust deallocation size and regions commit and allocate top */
deallocate_size -= (char *) g_last->top_allocated - (char *) base_committed;
g_last->top_committed = base_committed;
g_last->top_allocated = base_committed;
}
}
/* Adjust regions allocate top */
g_last->top_allocated = (char *) g_last->top_allocated - deallocate_size;
/* Check for underflow */
if ((char *) g_last->top_reserved - g_last->reserve_size > (char *) g_last->top_allocated ||
g_last->top_allocated > g_last->top_committed) {
/* Adjust regions allocate top */
g_last->top_allocated = (char *) g_last->top_reserved - g_last->reserve_size;
goto sbrk_exit;
}
result = g_last->top_allocated;
}
/* Assert invariants */
assert (g_last);
assert ((char *) g_last->top_reserved - g_last->reserve_size <= (char *) g_last->top_allocated &&
g_last->top_allocated <= g_last->top_committed);
assert ((char *) g_last->top_reserved - g_last->reserve_size <= (char *) g_last->top_committed &&
g_last->top_committed <= g_last->top_reserved &&
(unsigned) g_last->top_committed % g_pagesize == 0);
assert ((unsigned) g_last->top_reserved % g_regionsize == 0);
assert ((unsigned) g_last->reserve_size % g_regionsize == 0);
sbrk_exit:
/* Release spin lock */
slrelease (&g_sl);
return result;
}