platform_bionic/benchmarks/stdio_benchmark.cpp
Elliott Hughes 8c4994bbc1 Implement __fsetlocking.
The old __isthreaded hack was never very useful on Android because all user
code runs in a VM where there are lots of threads running. But __fsetlocking
lets a caller say "I'll worry about the locking for this FILE*", which is
useful for the normal case where you don't share a FILE* between threads
so you don't need any locking.

Bug: 17154740
Bug: 18593728
Change-Id: I2a8dddc29d3edff39a3d7d793387f2253608a68d
2015-01-21 10:33:30 -08:00

89 lines
2.6 KiB
C++

/*
* Copyright (C) 2014 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "benchmark.h"
#include <stdio.h>
#include <stdio_ext.h>
#define KB 1024
#define MB 1024*KB
#define AT_COMMON_SIZES \
Arg(1)->Arg(2)->Arg(3)->Arg(4)->Arg(8)->Arg(16)->Arg(32)->Arg(64)->Arg(512)-> \
Arg(1*KB)->Arg(4*KB)->Arg(8*KB)->Arg(16*KB)->Arg(64*KB)
template <typename Fn>
static void ReadWriteTest(int iters, int chunk_size, Fn f, bool buffered) {
StopBenchmarkTiming();
FILE* fp = fopen("/dev/zero", "rw");
__fsetlocking(fp, FSETLOCKING_BYCALLER);
char* buf = new char[chunk_size];
StartBenchmarkTiming();
if (!buffered) {
setvbuf(fp, 0, _IONBF, 0);
}
for (int i = 0; i < iters; ++i) {
f(buf, chunk_size, 1, fp);
}
StopBenchmarkTiming();
SetBenchmarkBytesProcessed(int64_t(iters) * int64_t(chunk_size));
delete[] buf;
fclose(fp);
}
static void BM_stdio_fread(int iters, int chunk_size) {
ReadWriteTest(iters, chunk_size, fread, true);
}
BENCHMARK(BM_stdio_fread)->AT_COMMON_SIZES;
static void BM_stdio_fwrite(int iters, int chunk_size) {
ReadWriteTest(iters, chunk_size, fwrite, true);
}
BENCHMARK(BM_stdio_fwrite)->AT_COMMON_SIZES;
static void BM_stdio_fread_unbuffered(int iters, int chunk_size) {
ReadWriteTest(iters, chunk_size, fread, false);
}
BENCHMARK(BM_stdio_fread_unbuffered)->AT_COMMON_SIZES;
static void BM_stdio_fwrite_unbuffered(int iters, int chunk_size) {
ReadWriteTest(iters, chunk_size, fwrite, false);
}
BENCHMARK(BM_stdio_fwrite_unbuffered)->AT_COMMON_SIZES;
static void FopenFgetsFclose(int iters, bool no_locking) {
char buf[1024];
for (int i = 0; i < iters; ++i) {
FILE* fp = fopen("/proc/version", "re");
if (no_locking) __fsetlocking(fp, FSETLOCKING_BYCALLER);
fgets(buf, sizeof(buf), fp);
fclose(fp);
}
}
static void BM_stdio_fopen_fgets_fclose_locking(int iters) {
FopenFgetsFclose(iters, false);
}
BENCHMARK(BM_stdio_fopen_fgets_fclose_locking);
static void BM_stdio_fopen_fgets_fclose_no_locking(int iters) {
FopenFgetsFclose(iters, true);
}
BENCHMARK(BM_stdio_fopen_fgets_fclose_no_locking);