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#include "mem.h"
#include "test.h"
#define NUM_BLOCKS 10
DEF_MEM(test_mem, int, NUM_BLOCKS)
static int count(test_mem* mem) {
int count = 0;
mem_foreach(mem, n, { count++; });
return count;
}
static int sum(test_mem* mem) {
int sum = 0;
mem_foreach(mem, n, { sum += *n; });
return sum;
}
// Create a statically-backed allocator.
TEST_CASE(mem_create) {
test_mem mem;
mem_make(&mem);
}
// Create a dynamically-backed allocator.
TEST_CASE(mem_create_dyn) {
DEF_MEM_DYN(dyn_mem, int);
dyn_mem mem;
mem_make_dyn(&mem, NUM_BLOCKS, sizeof(int));
}
// Allocate N chunks of 1 block each.
TEST_CASE(mem_fully_allocate) {
test_mem mem;
mem_make(&mem);
for (int i = 0; i < NUM_BLOCKS; ++i) {
const int* block = mem_alloc(&mem, 1);
TEST_TRUE(block != 0);
}
}
// Allocate N chunks of 1 block each, then free them.
TEST_CASE(mem_fill_then_free) {
test_mem mem;
mem_make(&mem);
int* blocks[NUM_BLOCKS] = {0};
for (int i = 0; i < NUM_BLOCKS; i++) {
blocks[i] = mem_alloc(&mem, 1);
TEST_TRUE(blocks[i] != 0);
}
for (int i = 0; i < NUM_BLOCKS; i++) {
mem_free(&mem, &blocks[i]);
TEST_EQUAL(blocks[i], 0); // Pointer should be set to 0 on free.
}
TEST_EQUAL(count(&mem), 0);
}
// Attempt to allocate blocks past the maximum allocator size.
// The allocator should handle the failed allocations gracefully.
TEST_CASE(mem_allocate_beyond_max_size) {
test_mem mem;
mem_make(&mem);
// Fully allocate the mem.
for (int i = 0; i < NUM_BLOCKS; ++i) {
TEST_TRUE(mem_alloc(&mem, 1) != 0);
}
// Past the end.
for (int i = 0; i < NUM_BLOCKS; ++i) {
TEST_EQUAL(mem_alloc(&mem, 1), 0);
}
}
// Free blocks should always remain zeroed out.
// This tests the invariant right after creating the allocator.
TEST_CASE(mem_zero_free_blocks_after_creation) {
test_mem mem;
mem_make(&mem);
const int zero = 0;
for (int i = 0; i < NUM_BLOCKS; ++i) {
const int* block = (const int*)(mem.blocks) + i;
TEST_EQUAL(memcmp(block, &zero, sizeof(int)), 0);
}
}
// Free blocks should always remain zeroed out.
// This tests the invariant after freeing a block.
TEST_CASE(mem_zero_free_block_after_free) {
test_mem mem;
mem_make(&mem);
int* val = mem_alloc(&mem, 1);
TEST_TRUE(val != 0);
*val = 177;
int* old_val = val;
mem_free(&mem, &val); // val pointer is set to 0.
TEST_EQUAL(*old_val, 0); // Block is zeroed out after free.
}
// Traverse an empty allocator.
TEST_CASE(mem_traverse_empty) {
test_mem mem;
mem_make(&mem);
TEST_EQUAL(count(&mem), 0);
}
// Traverse a partially full allocator.
TEST_CASE(mem_traverse_partially_full) {
const int N = NUM_BLOCKS / 2;
test_mem mem;
mem_make(&mem);
for (int i = 0; i < N; ++i) {
int* val = mem_alloc(&mem, 1);
TEST_TRUE(val != 0);
*val = i + 1;
}
TEST_EQUAL(sum(&mem), (N) * (N + 1) / 2);
}
// Traverse a full allocator.
TEST_CASE(mem_traverse_full) {
test_mem mem;
mem_make(&mem);
for (int i = 0; i < NUM_BLOCKS; ++i) {
int* val = mem_alloc(&mem, 1);
TEST_TRUE(val != 0);
*val = i + 1;
}
TEST_EQUAL(sum(&mem), (NUM_BLOCKS) * (NUM_BLOCKS + 1) / 2);
}
// Get the ith (allocated) chunk.
TEST_CASE(mem_get_block) {
test_mem mem;
mem_make(&mem);
for (int i = 0; i < NUM_BLOCKS; ++i) {
int* block = mem_alloc(&mem, 1);
TEST_TRUE(block != 0);
*block = i;
TEST_EQUAL(mem_get_chunk_handle(&mem, block), (size_t)i);
}
for (int i = 0; i < NUM_BLOCKS; ++i) {
TEST_EQUAL(*mem_get_chunk(&mem, i), i);
}
}
// Test merging.
// 1. Allocate chunks of variable sizes.
// 2. Free them in a different order.
// 3. Then we should be able to allocate 1 chunk of N blocks.
TEST_CASE(mem_fragmentation) {
test_mem mem;
mem_make(&mem);
int* blocks[NUM_BLOCKS] = {0};
int next_block = 0;
#define ALLOC(num_blocks) \
blocks[next_block] = mem_alloc(&mem, num_blocks); \
TEST_TRUE(blocks[next_block] != 0); \
next_block++;
#define FREE(block_idx) mem_free(&mem, &blocks[block_idx])
// 5 total allocations of variable chunk sizes.
ALLOC(2); // 2; idx = 0
ALLOC(3); // 5; idx = 1
ALLOC(1); // 6; idx = 2
ALLOC(3); // 9; idx = 3
ALLOC(1); // 10; idx = 4
// Free the 5 allocations in a different order.
FREE(1);
FREE(3);
FREE(4);
FREE(2);
FREE(0);
// Should be able to allocate 1 chunk of N blocks.
const void* chunk = mem_alloc(&mem, NUM_BLOCKS);
TEST_TRUE(chunk != 0);
}
// Clear and re-use an allocator.
TEST_CASE(mem_clear_then_reuse) {
test_mem mem;
mem_make(&mem);
// Allocate chunks, contents not important.
for (int i = 0; i < NUM_BLOCKS; ++i) {
int* chunk = mem_alloc(&mem, 1);
TEST_TRUE(chunk != 0);
}
mem_clear(&mem);
// Allocate chunks and assign values 0..N.
for (int i = 0; i < NUM_BLOCKS; ++i) {
int* chunk = mem_alloc(&mem, 1);
TEST_TRUE(chunk != 0);
*chunk = i + 1;
}
TEST_EQUAL(sum(&mem), NUM_BLOCKS * (NUM_BLOCKS + 1) / 2);
}
// Stress test.
//
// 1. Allocate the mem, either fully or partially. If fully, attempt to
// allocate some items past the end.
//
// 2. Free all allocated items in some random order.
int main() { return 0; }
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