malloc-perf.cpp

#include <memory>
#include <thread>
#include <benchmark/benchmark.h>

void f1(bool shouldMallocInLoop)
{
    auto n = 0;
    void *c = nullptr;
    for (int i = 0; i < 10; ++i) {
        if (shouldMallocInLoop)
            c = malloc(10);
        ++n;
        auto d = (void*)(c);
        if (shouldMallocInLoop)
            free(c);
    }
}

static void BM_TwoThreadsRunningNoMalloc(benchmark::State& state) 
{
    for (auto _ : state) {
        std::thread t1(f1, false);
        std::thread t2(f1, false);
        t1.join();
        t2.join();
    }
}


static void BM_TwoThreadsRunningWithMalloc(benchmark::State& state) 
{
    for (auto _ : state) {
        std::thread t1(f1, true);
        std::thread t2(f1, true);
        t1.join();
        t2.join();
    }
}

static void BM_SerialRunningWithMalloc(benchmark::State& state) 
{
    for (auto _ : state) {
        f1(true);
        f1(true);
    }
}
static void BM_SerialRunningNoMalloc(benchmark::State& state) 
{
    for (auto _ : state) {
        f1(false);
        f1(false);
    }
}

BENCHMARK(BM_TwoThreadsRunningNoMalloc);
BENCHMARK(BM_TwoThreadsRunningWithMalloc);
BENCHMARK(BM_SerialRunningNoMalloc);
BENCHMARK(BM_SerialRunningWithMalloc);

BENCHMARK_MAIN();