Function dumping_thread

src/bvar/variable.cpp:730–860

The background thread to export all bvar periodically.

// The background thread to export all bvar periodically.
static void* dumping_thread(void*) {
    // NOTE: this variable was declared as static <= r34381, which was
    // destructed when program exits and caused coredumps.
    butil::PlatformThread::SetNameSimple("bvar_dumper");
    const std::string command_name = read_command_name();
    std::string last_filename;
    std::string mbvar_last_filename;
    while (1) {
        // We can't access string flags directly because it's thread-unsafe.
        std::string filename;
        DumpOptions options;
        std::string prefix;
        std::string tabs;
        std::string mbvar_filename;
        std::string mbvar_prefix;
        std::string mbvar_format;
        if (!GFLAGS_NAMESPACE::GetCommandLineOption("bvar_dump_file", &filename)) {
            LOG(ERROR) << "Fail to get gflag bvar_dump_file";
            return NULL;
        }
        if (!GFLAGS_NAMESPACE::GetCommandLineOption("bvar_dump_include",
                                          &options.white_wildcards)) {
            LOG(ERROR) << "Fail to get gflag bvar_dump_include";
            return NULL;
        }
        if (!GFLAGS_NAMESPACE::GetCommandLineOption("bvar_dump_exclude",
                                          &options.black_wildcards)) {
            LOG(ERROR) << "Fail to get gflag bvar_dump_exclude";
            return NULL;
        }
        if (!GFLAGS_NAMESPACE::GetCommandLineOption("bvar_dump_prefix", &prefix)) {
            LOG(ERROR) << "Fail to get gflag bvar_dump_prefix";
            return NULL;
        }
        if (!GFLAGS_NAMESPACE::GetCommandLineOption("bvar_dump_tabs", &tabs)) {
            LOG(ERROR) << "Fail to get gflags bvar_dump_tabs";
            return NULL;
        }

        // We can't access string flags directly because it's thread-unsafe.
        if (!GFLAGS_NAMESPACE::GetCommandLineOption("mbvar_dump_file", &mbvar_filename)) {
            LOG(ERROR) << "Fail to get gflag mbvar_dump_file";
            return NULL;
        }
        if (!GFLAGS_NAMESPACE::GetCommandLineOption("mbvar_dump_prefix", &mbvar_prefix)) {
            LOG(ERROR) << "Fail to get gflag mbvar_dump_prefix";
            return NULL;
        }
        if (!GFLAGS_NAMESPACE::GetCommandLineOption("mbvar_dump_format", &mbvar_format)) {
            LOG(ERROR) << "Fail to get gflag mbvar_dump_format";
            return NULL;
        }

        if (FLAGS_bvar_dump && !filename.empty()) {
            // Replace first <app> in filename with program name. We can't use
            // pid because a same binary should write the data to the same 
            // place, otherwise restarting of app may confuse noah with a lot 
            // of *.data. noah takes 1.5 days to figure out that some data is