C++ (Cpp) region_alloc_nothrow Examples

Example #1

File: region.c Project: diafour/tarantool

void
region_test_truncate()
{
	header();

	struct region region;

	region_create(&region, &cache);

	void *ptr = region_alloc_nothrow(&region, 10);

	fail_unless(ptr);

	size_t size = region_used(&region);

	region_alloc_nothrow(&region, 10000);
	region_alloc_nothrow(&region, 10000000);

	region_truncate(&region, size);

	fail_unless(region_used(&region) == size);

	region_free(&region);

	footer();
}

Example #2

File: region.c Project: diafour/tarantool

void
region_basic()
{
	header();

	struct region region;

	region_create(&region, &cache);

	fail_unless(region_used(&region) == 0);

	void *ptr = region_alloc_nothrow(&region, 10);

	fail_unless(ptr);

	fail_unless(region_used(&region) == 10);

	ptr = region_alloc_nothrow(&region, 10000000);
	fail_unless(ptr);

	fail_unless(region_used(&region) == 10000010);

	region_free(&region);

	fail_unless(region_used(&region) == 0);

	printf("name of a new region: %s.\n", region_name(&region));

	region_set_name(&region, "region");

	printf("set new region name: %s.\n", region_name(&region));

	region_set_name(&region, "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
			"aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
			"aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa");

	printf("region name is truncated: %s.\n", region_name(&region));

	footer();
}

Example #3

File: region.c Project: nunb/tarantool

void *
region_join_nothrow(struct region *region, size_t size)
{
	if (rlist_empty(&region->slabs.slabs)) {
		assert(size == 0);
		return region_alloc_nothrow(region, 0);
	}
	struct rslab *slab = rlist_first_entry(&region->slabs.slabs,
					       struct rslab,
					       slab.next_in_list);

	if (slab->used >= size) {
		/* Don't move stuff if it's in a single chunk. */
		return (char *) rslab_data(slab) + slab->used - size;
	}
	/**
	 * Use region_reserve() to ensure slab->size is not
	 * changed when the joined region is in the same slab
	 * as the final chunk.
	 */
	char *ptr = region_reserve_nothrow(region, size);
	size_t offset = size;
	if (ptr == NULL)
		return NULL;
	/*
	 * Copy data from last chunk to first, i.e. in the reverse order.
	 */
	while (offset > 0 && slab->used <= offset) {
		memcpy(ptr + offset - slab->used, rslab_data(slab), slab->used);
		offset -= slab->used;
		slab = rlist_next_entry(slab, slab.next_in_list);
	}
	if (offset > 0)
		memcpy(ptr, rslab_data(slab) + slab->used - offset, offset);
	region_alloc_nothrow(region, size);
	return ptr;
}