/*
* Input: Mem_T structure, unsigned integer
* Output: void
* Purpose: Unmaps a segment from memory at the given segment index and frees
* all memory associated with it.
*/
void unmap_segment(Mem_T memory, unsigned segIndex)
{
Seg_T unmapped_segment = Mem_arr_put(memory->segment_seq, NULL, segIndex);
Seg_free(unmapped_segment);
//fprintf(stderr, "about to push onto stack\n");
memory->reusable_indices = Stack_push(memory->reusable_indices, segIndex);
//fprintf(stderr, "pushing onto stack\n");
}
/* free the mem */
void free_mem(Mem* myMem)
{
assert(myMem != NULL);
for (int i = 0; i < Seq_length((*myMem)->segs); i++) {
Seg_free(Seq_get((*myMem)->segs, i));
}
Seq_free(&((*myMem)->segs));
Stack_free(&((*myMem)->unmapped));
free(*myMem);
}
/*
* Input: Mem_T structure, unsigned integer
* Ouput: void
* Purpose: Copies the segment located at segIndex and stores it in segment 0
* The segment previously at index 0 is freed.
*/
void load_program(Mem_T memory, unsigned segIndex)
{
/*Segment that will become new program*/
Seg_T program_to_load = Mem_arr_get(memory->segment_seq, segIndex);
Seg_T duplicate_segment = Seg_duplicate(program_to_load);
/*Copies program_to_load_temp to program_to_load*/
Seg_T old_program = Mem_arr_put(memory->segment_seq, duplicate_segment, 0);
Seg_free(old_program);
}
/*
* create a segment with the size of nums, and return the index of the segs of
* the mapped segment. There are two conditons, if the unmapped stack is not
* empty, we reuse the segment index stored in unmapped stack and pop that out.
* otherwise we just create a new segments and addhi into segs, the return index
* is the length of segs.
*/
uint32_t map_segment(Mem myMem, uint32_t nums)
{
assert(myMem != NULL);
Segment_T newSeg = Seg_new(nums);
for (uint32_t i = 0; i < nums; i++) {
Seq_addhi((Seq_T)newSeg, (void*) (uintptr_t) 0);
}
uint32_t index;
if (Stack_empty(myMem->unmapped) == 1) {
Seq_addhi(myMem->segs, (void*) newSeg);
index = Seq_length(myMem->segs) - 1;
} else {
index = (int) (uintptr_t) Stack_pop(myMem->unmapped);
Seg_free(Seq_put(myMem->segs, index, (void*) newSeg));
};
return index;
}