1 files changed, 171 insertions, 0 deletions

diff --git a/memstack/test/memstack_test.c b/memstack/test/memstack_test.c
new file mode 100644
index 0000000..2bcffcd
--- /dev/null
+++ b/memstack/test/memstack_test.c
@@ -0,0 +1,171 @@
+#include "memstack.h"
+
+#include "test.h"
+
+#define NUM_INTS 10
+#define CAPACITY (NUM_INTS * sizeof(int))
+
+// Create and destroy a statically-backed stack.
+TEST_CASE(memstack_create) {
+  int memory[CAPACITY];
+
+  memstack stack = {0};
+  memstack_make(&stack, CAPACITY, memory);
+  memstack_del(&stack);
+}
+
+// Create and destroy a dynamically-backed stack.
+TEST_CASE(memstack_create_dyn) {
+  memstack stack = {0};
+  memstack_make(&stack, CAPACITY, nullptr);
+  memstack_del(&stack);
+}
+
+// Clear an uninitialized stack.
+TEST_CASE(memstack_clear_uninitialized) {
+  memstack stack = {0};
+  memstack_clear(&stack);
+}
+
+// Allocate all N ints.
+TEST_CASE(memstack_allocate_until_full) {
+  memstack stack = {0};
+  memstack_make(&stack, CAPACITY, nullptr);
+
+  for (int i = 0; i < NUM_INTS; ++i) {
+    const int* block = memstack_alloc(&stack, sizeof(int));
+    TEST_TRUE(block != nullptr);
+  }
+
+  TEST_TRUE(memstack_size(&stack) == CAPACITY);
+
+  memstack_del(&stack);
+}
+
+// Allocate all N ints, then free them.
+TEST_CASE(memstack_fill_then_free) {
+  memstack stack = {0};
+  memstack_make(&stack, CAPACITY, nullptr);
+
+  int* blocks[NUM_INTS] = {nullptr};
+  for (int i = 0; i < NUM_INTS; ++i) {
+    blocks[i] = memstack_alloc(&stack, sizeof(int));
+    TEST_TRUE(blocks[i] != nullptr);
+  }
+
+  memstack_clear(&stack);
+
+  TEST_EQUAL(memstack_size(&stack), 0);
+
+  memstack_del(&stack);
+}
+
+// Attempt to allocate blocks past the maximum stack size.
+// The stack should handle the failed allocations gracefully.
+TEST_CASE(memstack_allocate_beyond_max_size) {
+  memstack stack = {0};
+  memstack_make(&stack, CAPACITY, nullptr);
+  memstack_enable_traps(&stack, false);
+
+  // Fully allocate the stack.
+  for (int i = 0; i < NUM_INTS; ++i) {
+    TEST_TRUE(memstack_alloc(&stack, sizeof(int)) != nullptr);
+  }
+
+  // Past the end.
+  for (int i = 0; i < NUM_INTS; ++i) {
+    TEST_EQUAL(memstack_alloc(&stack, sizeof(int)), nullptr);
+  }
+
+  TEST_TRUE(memstack_size(&stack) == CAPACITY);
+
+  memstack_del(&stack);
+}
+
+// Free blocks should always remain zeroed out.
+// This tests the invariant right after creating the stack.
+TEST_CASE(memstack_zero_free_blocks_after_creation) {
+  memstack stack = {0};
+  memstack_make(&stack, CAPACITY, nullptr);
+
+  for (int i = 0; i < NUM_INTS; ++i) {
+    const int* block = memstack_alloc(&stack, sizeof(int));
+    TEST_TRUE(block != nullptr);
+    TEST_EQUAL(*block, 0);
+  }
+
+  memstack_del(&stack);
+}
+
+// Free blocks should always remain zeroed out.
+// This tests the invariant after clearing the stack and allocating a new block.
+TEST_CASE(memstack_zero_free_block_after_free) {
+  memstack stack = {0};
+  memstack_make(&stack, CAPACITY, nullptr);
+
+  for (int i = 0; i < NUM_INTS; ++i) {
+    const int* block = memstack_alloc(&stack, sizeof(int));
+    TEST_TRUE(block != nullptr);
+    TEST_EQUAL(*block, 0);
+  }
+
+  memstack_clear(&stack);
+
+  for (int i = 0; i < NUM_INTS; ++i) {
+    const int* block = memstack_alloc(&stack, sizeof(int));
+    TEST_TRUE(block != nullptr);
+    TEST_EQUAL(*block, 0);
+  }
+
+  memstack_del(&stack);
+}
+
+// Aligned allocations should be properly aligned.
+TEST_CASE(memstack_alloc_aligned) {
+  memstack stack = {0};
+  memstack_make(&stack, CAPACITY, nullptr);
+
+  // -1 because the base address of the memory storage might be unaligned.
+  for (int i = 0; i < NUM_INTS - 1; ++i) {
+    const int* block =
+        memstack_alloc_aligned(&stack, sizeof(int), alignof(int));
+    TEST_TRUE(block != nullptr);
+    TEST_EQUAL(*block, 0);
+    TEST_EQUAL((uintptr_t)block % alignof(int), 0);
+  }
+
+  memstack_del(&stack);
+}
+
+// Get and set the watermark.
+TEST_CASE(memstack_watermark) {
+  memstack stack = {0};
+  memstack_make(&stack, CAPACITY, nullptr);
+
+  // Allocate N/2 ints.
+  for (int i = 0; i < NUM_INTS / 2; ++i) {
+    const int* block = memstack_alloc(&stack, sizeof(int));
+    TEST_TRUE(block != nullptr);
+  }
+
+  const size_t watermark = memstack_watermark(&stack);
+
+  // Allocate the remaining N/2 ints.
+  for (int i = 0; i < NUM_INTS / 2; ++i) {
+    const int* block = memstack_alloc(&stack, sizeof(int));
+    TEST_TRUE(block != nullptr);
+  }
+
+  // Now reset the watermark halfway through.
+  memstack_set_watermark(&stack, watermark);
+
+  // Allocate the remaining N/2 ints (again).
+  for (int i = 0; i < NUM_INTS / 2; ++i) {
+    const int* block = memstack_alloc(&stack, sizeof(int));
+    TEST_TRUE(block != nullptr);
+  }
+
+  memstack_del(&stack);
+}
+
+int main() { return 0; }