/* Return segment holding given code address. */
static msegmentptr
segment_holding_code (mstate m, char* addr)
{
msegmentptr sp = &m->seg;
for (;;) {
if (addr >= add_segment_exec_offset (sp->base, sp)
&& addr < add_segment_exec_offset (sp->base, sp) + sp->size)
return sp;
if ((sp = sp->next) == 0)
return 0;
}
}
/* Release memory at the given address, as well as the corresponding
executable page if it's separate. */
static int
dlmunmap (void *start, size_t length)
{
/* We don't bother decreasing execsize or truncating the file, since
we can't quite tell whether we're unmapping the end of the file.
We don't expect frequent deallocation anyway. If we did, we
could locate pages in the file by writing to the pages being
deallocated and checking that the file contents change.
Yuck. */
msegmentptr seg = segment_holding (gm, start);
void *code;
#if FFI_CLOSURE_TEST
printf ("unmapping %zi\n", length);
#endif
if (seg && (code = add_segment_exec_offset (start, seg)) != start)
{
int ret = munmap (code, length);
if (ret)
return ret;
}
return munmap (start, length);
}
/* Allocate a chunk of memory with the given size. Returns a pointer
to the writable address, and sets *CODE to the executable
corresponding virtual address. */
void *
ffi_closure_alloc (size_t size, void **code)
{
void *ptr;
if (!code)
return NULL;
ptr = dlmalloc (size);
if (ptr)
{
msegmentptr seg = segment_holding (gm, ptr);
*code = add_segment_exec_offset (ptr, seg);
}
return ptr;
}
