static void *malloc_pages(size_t len, size_t alignment)
{
void *r;
size_t extra = 0;
if (!page_size)
page_size = getpagesize();
#ifndef MAP_ANON
if (!fd_created) {
fd_created = 1;
fd = open("/dev/zero", O_RDWR);
}
#endif
CHECK_USED_AGAINST_MAX(len);
/* Round up to nearest page: */
if (len & (page_size - 1))
len += page_size - (len & (page_size - 1));
/* Something from the cache, perhaps? */
r = find_cached_pages(len, alignment);
if (r)
return r;
extra = alignment;
#ifdef MAP_ANON
r = mmap(NULL, len + extra, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, -1, 0);
#else
r = mmap(NULL, len + extra, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
#endif
if (r == (void *)-1)
return NULL;
if (extra) {
/* We allocated too large so we can choose the alignment. */
void *real_r;
long pre_extra;
real_r = (void *)(((unsigned long)r + (alignment - 1)) & (~(alignment - 1)));
pre_extra = real_r - r;
if (pre_extra)
if (munmap(r, pre_extra))
GCPRINT(GCOUTF, "Unmap warning: %lx, %ld, %d\n", (long)r, pre_extra, errno);
if (pre_extra < extra)
if (munmap(real_r + len, extra - pre_extra))
GCPRINT(GCOUTF, "Unmap warning: %lx, %ld, %d\n", (long)r, pre_extra, errno);
r = real_r;
}
ACTUALLY_ALLOCATING_PAGES(len);
LOGICALLY_ALLOCATING_PAGES(len);
return r;
}
/* the VM subsystem as defined by the GC files */
static void *do_malloc_pages(size_t len, size_t alignment, int dirty_ok)
{
kern_return_t retval;
size_t extra = 0;
void *r;
if(!task_self) task_self = mach_task_self();
CHECK_USED_AGAINST_MAX(len);
/* round up to the nearest page: */
if(len & (page_size - 1))
len += page_size - (len & (page_size - 1));
r = find_cached_pages(len, alignment, dirty_ok);
if (r)
return r;
extra = alignment;
retval = vm_allocate(task_self, (vm_address_t*)&r, len + extra, TRUE);
if(retval != KERN_SUCCESS) {
GCPRINT(GCOUTF, "Couldn't allocate memory: %s\n", mach_error_string(retval));
abort();
}
if(extra) {
/* we allocated too large so we can choose the alignment */
void *real_r;
long pre_extra;
real_r = (void*)(((unsigned long)r + (alignment-1)) & (~(alignment-1)));
pre_extra = real_r - r;
if(pre_extra) {
retval = vm_deallocate(task_self, (vm_address_t)r, pre_extra);
if(retval != KERN_SUCCESS) {
GCPRINT(GCOUTF, "WARNING: couldn't deallocate pre-extra: %s\n",
mach_error_string(retval));
}
}
if(pre_extra < extra) {
if (!pre_extra) {
/* Instead of actually unmapping, put it in the cache, and there's
a good chance we can use it next time: */
ACTUALLY_ALLOCATING_PAGES(extra);
free_actual_pages(real_r + len, extra, 1);
} else {
retval = vm_deallocate(task_self, (vm_address_t)real_r + len,
extra - pre_extra);
if(retval != KERN_SUCCESS) {
GCPRINT(GCOUTF, "WARNING: couldn't deallocate post-extra: %s\n",
mach_error_string(retval));
}
}
}
r = real_r;
}
ACTUALLY_ALLOCATING_PAGES(len);
LOGICALLY_ALLOCATING_PAGES(len);
return r;
}
