Rename memory_manager to heap_manager

src/tests/heap_manager.cpp

@@ -0,0 +1,114 @@
+#include <chrono>
+#include <random>
+#include <vector>
+#include <stddef.h>
+#include <stdlib.h>
+#include <stdint.h>
+
+#include "kutil/memory.h"
+#include "kutil/heap_manager.h"
+#include "catch.hpp"
+
+using namespace kutil;
+
+
+void *memory = nullptr;
+size_t total_alloc_size = 0;
+size_t total_alloc_calls = 0;
+
+const size_t hs = 0x10; // header size
+const size_t max_block = 1 << 16;
+
+
+void grow_callback(void *start, size_t length)
+{
+	total_alloc_size += length;
+	total_alloc_calls += 1;
+}
+
+
+TEST_CASE( "Buddy blocks tests", "[memory buddy]" )
+{
+	using clock = std::chrono::system_clock;
+	unsigned seed = clock::now().time_since_epoch().count();
+	std::default_random_engine rng(seed);
+
+	memory = aligned_alloc(max_block, 4 * max_block);
+
+	heap_manager mm(memory, grow_callback);
+
+	// The ctor should have allocated an initial block
+	CHECK( total_alloc_size == max_block );
+	CHECK( total_alloc_calls == 1 );
+
+	// Blocks should be:
+	// 16: 0-64K
+
+	std::vector<void *> allocs(6);
+	for (int i = 0; i < 6; ++i)
+		allocs[i] = mm.allocate(150); // size 8
+
+	// Should not have grown
+	CHECK( total_alloc_size == max_block );
+	CHECK( total_alloc_calls == 1 );
+
+	// Blocks should be:
+	// 16: [0-64K]
+	// 15: [0-32K], 32K-64K
+	// 14: [0-16K], 16K-32K
+	// 13: [0-8K], 8K-16K
+	// 12: [0-4K], 4K-8K
+	// 11: [0-2K], 2K-4K
+	// 10: [0-1K, 1-2K]
+	//  9: [0, 512, 1024], 1536
+	//  8: [0, 256, 512, 768, 1024, 1280]
+
+	// We have free memory at 1526 and 2K, but we should get 4K
+	void *big = mm.allocate(4000); // size 12
+	REQUIRE( big == offset_pointer(memory, 4096 + hs) );
+	mm.free(big);
+
+	// free up 512
+	mm.free(allocs[3]);
+	mm.free(allocs[4]);
+
+	// Blocks should be:
+	// ...
+	//  9: [0, 512, 1024], 1536
+	//  8: [0, 256, 512], 768, 1024, [1280]
+
+	// A request for a 512-block should not cross the buddy divide
+	big = mm.allocate(500); // size 9
+	REQUIRE( big >= offset_pointer(memory, 1536 + hs) );
+	mm.free(big);
+
+	mm.free(allocs[0]);
+	mm.free(allocs[1]);
+	mm.free(allocs[2]);
+	mm.free(allocs[5]);
+	allocs.clear();
+
+	std::vector<size_t> sizes = {
+		16000, 8000, 4000, 4000, 1000, 1000, 1000, 1000, 1000, 1000, 1000, 150,
+		150, 150, 150, 150, 150, 150, 150, 150, 150, 150, 150, 48, 48, 48, 13 };
+
+	std::shuffle(sizes.begin(), sizes.end(), rng);
+
+	allocs.reserve(sizes.size());
+	for (size_t size : sizes)
+		allocs.push_back(mm.allocate(size));
+
+	std::shuffle(allocs.begin(), allocs.end(), rng);
+	for (void *p: allocs)
+		mm.free(p);
+	allocs.clear();
+
+	big = mm.allocate(64000);
+
+	// If everything was freed / joined correctly, that should not have allocated
+	CHECK( total_alloc_size == max_block );
+	CHECK( total_alloc_calls == 1 );
+
+	// And we should have gotten back the start of memory
+	CHECK( big == offset_pointer(memory, hs) );
+}