From fa82ce3b1ed68aee071fe094bc5c82a168736091 Mon Sep 17 00:00:00 2001
From: Emiel Por <epor@stsci.edu>
Date: Fri, 6 Dec 2024 09:27:47 -0800
Subject: [PATCH] Add benchmarks for FreeListAllocator.

---
 benchmarks/CMakeLists.txt          |  6 ++
 benchmarks/free_list_allocator.cpp | 91 ++++++++++++++++++++++++++++++
 2 files changed, 97 insertions(+)
 create mode 100644 benchmarks/free_list_allocator.cpp

diff --git a/benchmarks/CMakeLists.txt b/benchmarks/CMakeLists.txt
index bc716bd2..695b327e 100644
--- a/benchmarks/CMakeLists.txt
+++ b/benchmarks/CMakeLists.txt
@@ -24,7 +24,13 @@ add_executable(timestamp timestamp.cpp)
 target_include_directories(timestamp PUBLIC ../catkit_core)
 target_link_libraries(timestamp PUBLIC catkit_core)
 
+# Free list allocator benchmark
+add_executable(free_list_allocator free_list_allocator.cpp)
+target_include_directories(free_list_allocator PUBLIC ../catkit_core)
+target_link_libraries(free_list_allocator PUBLIC catkit_core)
+
 # Add install files
 install(TARGETS datastream_latency DESTINATION bin)
 install(TARGETS datastream_submit DESTINATION bin)
 install(TARGETS timestamp DESTINATION bin)
+install(TARGETS free_list_allocator DESTINATION bin)
diff --git a/benchmarks/free_list_allocator.cpp b/benchmarks/free_list_allocator.cpp
new file mode 100644
index 00000000..5ffd62be
--- /dev/null
+++ b/benchmarks/free_list_allocator.cpp
@@ -0,0 +1,91 @@
+#include "FreeListAllocator.h"
+#include "Timing.h"
+#include <iostream>
+
+void benchmark_linux_scalability()
+{
+	typedef FreeListAllocator<16384, 32> Allocator;
+
+	const size_t N = 10000000;
+
+	auto *handles = new Allocator::BlockHandle[N];
+
+	Allocator allocator(size_t(32) * N);
+
+	auto start = GetTimeStamp();
+
+	for (size_t i = 0; i < N; ++i)
+	{
+		handles[i] = allocator.Allocate(16);
+	}
+
+	for (size_t i = 0; i < N; ++i)
+	{
+		allocator.Deallocate(handles[i]);
+	}
+
+	auto end = GetTimeStamp();
+
+	std::cout << "Linux Scalability:" << std::endl;
+	std::cout << "Time: " << (end - start) / 1e9 << " sec" << std::endl;
+	std::cout << "Throughput: " << 2 * N / ((end - start) / 1e9) << " ops/s" << std::endl;
+
+	delete[] handles;
+}
+
+void benchmark_larson()
+{
+	const size_t ALIGNMENT = 32;
+	typedef FreeListAllocator<16384, ALIGNMENT> Allocator;
+
+	const size_t N = 10000000;
+	const size_t M = 1000;
+	const size_t MIN_SIZE = 16;
+	const size_t MAX_SIZE = 128;
+
+	auto *handles = new Allocator::BlockHandle[M];
+	for (size_t i = 0; i < M; ++i)
+	{
+		handles[i] = -1;
+	}
+
+	auto *indices = new size_t[N];
+	auto *sizes = new size_t[N];
+	for (size_t i = 0; i < N; ++i)
+	{
+		indices[i] = rand() % M;
+		sizes[i] = (MIN_SIZE + (rand() % (MAX_SIZE - MIN_SIZE))) * ALIGNMENT;
+	}
+
+	Allocator allocator(size_t(1024) * 1024 * 1024);
+
+	auto start = GetTimeStamp();
+
+	for (size_t i = 0; i < N; ++i)
+	{
+		size_t index = indices[i];
+		size_t size = sizes[i];
+
+		if (handles[index] != -1)
+		{
+			allocator.Deallocate(handles[index]);
+		}
+
+		handles[index] = allocator.Allocate(size);
+	}
+
+	auto end = GetTimeStamp();
+	std::cout << "Larson benchmark:" << std::endl;
+	std::cout << "Time: " << (end - start) / 1e9 << " sec" << std::endl;
+	std::cout << "Throughput: " << (N * 2 - M) / ((end - start) / 1e9) << " ops/s" << std::endl;
+
+	delete[] handles;
+}
+
+int main(int argc, char **argv)
+{
+	benchmark_linux_scalability();
+	benchmark_larson();
+
+	return 0;
+}