Function waker

test/bthread_futex_unittest.cpp:152–165

butil::atomic<int> nevent(0);

void* waker(void* lock) {
    bthread_usleep(10000);
    const size_t REP = 100000;
    int nwakeup = 0;
    butil::Timer tm;
    tm.start();
    for (size_t i = 0; i < REP; ++i) {
        nwakeup += bthread::futex_wake_private(lock, 1);
    }
    tm.stop();
    EXPECT_EQ(0, nwakeup);
    printf("futex_wake nop = %" PRId64 "ns\n", tm.n_elapsed() / REP);
    return NULL;
} 

void* batch_waker(void* lock) {
    bthread_usleep(10000);