while (a != NULL) {
a_end = a->base + a->size;
+ /* If a is freeable then there is a single freeblock in fb that
+ covers it. The end of this free block must be >= the end of
+ a, so skip anything in fb that ends before a. */
while (fb != NULL && fb->base + fb->size < a_end) {
prev_fb = fb;
fb = fb->next;
}
- fb_end = fb->base + fb->size;
- if (fb->base <= a->base) {
- /* The alloc is within the free block. Now we need to know
- if it sticks out at either end. */
- if (fb_end == a_end) {
- if (fb->base == a->base) {
- /* fb and a are identical, so just free fb */
- prev_fb->next = fb->next;
- stgFree(fb);
- fb = prev_fb->next;
+ if (fb == NULL) {
+ /* If we have nothing left in fb, then neither a nor
+ anything later in the list is freeable, so we are done. */
+ break;
+ }
+ else {
+ fb_end = fb->base + fb->size;
+ /* We have a candidate fb. But does it really cover a? */
+ if (fb->base <= a->base) {
+ /* Yes, the alloc is within the free block. Now we need
+ to know if it sticks out at either end. */
+ if (fb_end == a_end) {
+ if (fb->base == a->base) {
+ /* fb and a are identical, so just free fb */
+ prev_fb->next = fb->next;
+ stgFree(fb);
+ fb = prev_fb->next;
+ }
+ else {
+ /* fb begins earlier, so truncate it to not include a */
+ fb->size = a->base - fb->base;
+ }
}
else {
- /* fb begins earlier, so truncate it to not include a */
- fb->size = a->base - fb->base;
+ /* fb ends later, so we'll make fb just be the part
+ after a. First though, if it also starts earlier,
+ we make a new free block record for the before bit. */
+ if (fb->base != a->base) {
+ block_rec *new_fb;
+
+ new_fb = (block_rec *)stgMallocBytes(sizeof(block_rec),"osReleaseFreeMemory");
+ new_fb->base = fb->base;
+ new_fb->size = a->base - fb->base;
+ new_fb->next = fb;
+ prev_fb->next = new_fb;
+ }
+ fb->size = fb_end - a_end;
+ fb->base = a_end;
}
- }
- else {
- /* fb ends later, so we'll make fb just be the part
- after a. First though, if it also starts earlier,
- we make a new free block record for the before bit. */
- if (fb->base != a->base) {
- block_rec *new_fb;
-
- new_fb = (block_rec *)stgMallocBytes(sizeof(block_rec),"osReleaseFreeMemory");
- new_fb->base = fb->base;
- new_fb->size = a->base - fb->base;
- new_fb->next = fb;
- prev_fb->next = new_fb;
+ /* Now we can free the alloc */
+ prev_a->next = a->next;
+ if(!VirtualFree((void *)a->base, 0, MEM_RELEASE)) {
+ sysErrorBelch("freeAllMBlocks: VirtualFree MEM_RELEASE failed");
+ stg_exit(EXIT_FAILURE);
}
- fb->size = fb_end - a_end;
- fb->base = a_end;
+ stgFree(a);
+ a = prev_a->next;
}
- /* Now we can free the alloc */
- prev_a->next = a->next;
- if(!VirtualFree((void *)a->base, 0, MEM_RELEASE)) {
- sysErrorBelch("freeAllMBlocks: VirtualFree MEM_RELEASE failed");
- stg_exit(EXIT_FAILURE);
+ else {
+ /* Otherwise this alloc is not freeable, so go on to the
+ next one */
+ prev_a = a;
+ a = a->next;
}
- stgFree(a);
- a = prev_a->next;
- }
- else {
- /* Otherwise this alloc is not freeable, so go on to the
- next one */
- prev_a = a;
- a = a->next;
}
}