Attachment 341015 Details for Bug 185882 – Benchmark

Benchmark

statperf.cpp (text/x-csrc), 1.76 KB, created by Chris Dumez on 2018-05-22 13:52:09 PDT

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Creator: Chris Dumez

Created: 2018-05-22 13:52:09 PDT

Size: 1.76 KB

patch

obsolete

>// clang++ -O3 -Wall -std=c++14 statperf.cpp -o statperf
>
>#include <unistd.h>
>#include <mach/mach.h>
>#include <mach/mach_time.h>
>#include <mutex>
>#include <sys/stat.h>
>
>double now()
>{
>    static mach_timebase_info_data_t timebaseInfo;
>    static std::once_flag initializeTimerOnceFlag;
>    std::call_once(initializeTimerOnceFlag, [] {
>        mach_timebase_info(&timebaseInfo);
>    });
>
>    return (mach_absolute_time() * timebaseInfo.numer) / (1.0e9 * timebaseInfo.denom);
>}
>
>int main(int argc, const char** argv)
>{
>    if (argc < 2) {
>        fprintf(stderr, "Usage: %s <file_path>\n", argv[0]);
>        return 1;
>    }
>
>    const int runCount = 100000;
>    const char* path = argv[1];
>    double begin = now();
>    for (int i = 0; i < runCount; ++i) {
>        struct stat fileInfo;
>        if (stat(path, &fileInfo)) {
>            fprintf(stderr, "Oops, file did not exist a\n");
>            return 1;
>        }
>    }
>    printf("stat: %g (lower is better)\n", now() - begin);
>
>    begin = now();
>    for (int i = 0; i < runCount; ++i) {
>        if (access(path, F_OK) == -1) {
>            fprintf(stderr, "Oops, file did not exist b\n");
>            return 1;
>        }
>    }
>    printf("access: %g (lower is better)\n", now() - begin);
>
>    begin = now();
>    for (int i = 0; i < runCount; ++i) {
>        struct stat fileInfo;
>        if (stat(path, &fileInfo)) {
>            fprintf(stderr, "Oops, file did not exist a\n");
>            return 1;
>        }
>    }
>    printf("stat: %g (lower is better)\n", now() - begin);
>
>    begin = now();
>    for (int i = 0; i < runCount; ++i) {
>        if (access(path, F_OK) == -1) {
>            fprintf(stderr, "Oops, file did not exist b\n");
>            return 1;
>        }
>    }
>    printf("access: %g (lower is better)\n", now() - begin);
>
>    return 0;
>}

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Attachments on bug 185882: 341015 | 341017 | 341020