TEST(ConcurrentQueue, ParallelPushPopAscIntegerAndCalculateTotalSum) {
tlx::ThreadPool pool(8);
ConcurrentQueue<size_t, std::allocator<size_t> > queue;
std::atomic<size_t> count(0);
std::atomic<size_t> total_sum(0);
static constexpr size_t num_threads = 4;
static constexpr size_t num_pushes = 10000;
// have threads push items
for (size_t i = 0; i != num_threads; ++i) {
pool.enqueue([&queue]() {
for (size_t i = 0; i != num_pushes; ++i) {
queue.push(i);
}
});
}
// have threads try to pop items.
for (size_t i = 0; i != num_threads; ++i) {
pool.enqueue([&]() {
while (count != num_threads * num_pushes) {
size_t item;
while (queue.try_pop(item)) {
total_sum += item;
++count;
}
}
});
}
pool.loop_until_empty();
ASSERT_TRUE(queue.empty());
ASSERT_EQ(count, num_threads * num_pushes);
// check total sum, no item gets lost?
ASSERT_EQ(total_sum, num_threads * num_pushes * (num_pushes - 1) / 2);
}
int main(int argc, char *argv[]) {
// read config.ini file
Config config;
auto nthreads = config.get<int>("nthreads");
auto device = config.get<const char *>("disk_guest");
auto traceFile = config.get<const char *>("trace_file");
auto logDir = config.get<string>("log_dir");
// parse arg, prioritize argv over config
if (argc > 1) traceFile = argv[1];
if (argc > 2) nthreads = atoi(argv[2]);
if (strstr(device, "/dev/sda")) { // avoid accidentally writing to system part
fprintf(stderr, "Error trying to write to system partition %s\n", device);
return 1;
}
// use default value if not supplied
if (strcmp(device, "") == 0) device = DEFAULT_DEVICE;
if (strcmp(traceFile, "") == 0) traceFile = DEFAULT_TRACE_FILE;
if (strcmp(logDir.c_str(), "") == 0) logDir = DEFAULT_LOG_DIR;
if (nthreads == 0) nthreads = DEFAULT_NTHREADS;
srand(time(NULL)); // initialize seed
// print configuration
printf("trace : %s\n", traceFile);
printf("nthreads : %d\n", nthreads);
printf("device : %s\n", device);
printf("log : %s\n", logDir.c_str());
printf("precision : %fms\n", Timer::getResolution());
printf("Opening device %s\n", device);
int fd = open(device, O_DIRECT | O_RDWR | O_SYNC);
if (fd < 0) {
fprintf(stderr, "Error opening device '%s'\n", device);
return 1;
}
printf("Allocating buffer\n");
void *buf;
if (posix_memalign(&buf, MEM_ALIGN, LARGEST_REQUEST_SIZE * BYTE_PER_BLOCK)) {
fprintf(stderr, "Error allocating buffer\n");
return 1;
}
//memset(buf, rand() % 256, LARGEST_REQUEST_SIZE * BYTE_PER_BLOCK);
printf("Opening trace file\n");
TraceReader trace(traceFile); // open trace file
ConcurrentQueue<TraceEvent> queue; // queue of trace events
bool readDone = false; // whether or not we're done reading trace file
printf("Start reading trace\n");
thread fileThread([&] { // thread to read trace file
TraceEvent event;
while (trace.read(event)) {
event.time = event.time * 1000; // to microseconds
event.size = event.bcount * BYTE_PER_BLOCK;
queue.push(event);
}
readDone = true;
queue.notifyAll(); // notify worker we're done
});
queue.waitUntilFull(); // wait until at least queue's full
printf("Start replaying trace\n");
vector<thread> workers(nthreads); // generate worker threads
atomic<int> lateCount(0), threadId(0); // late I/O count and threadId
for (auto& t : workers) t = thread([&] { // launch workers
int myId = ++threadId; // id for this thread
int myLateCount = 0; // local lateCount for this thread
Logger logger(logDir + traceFile + to_string(myId));
Timer timer; // mark the beginning of worker thread
while (!readDone or !queue.empty()) {
TraceEvent event;
if (not queue.pop(event)) continue; // retry
long currentTime = timer.elapsedTime(), nextIoTime = event.time;
if (currentTime <= nextIoTime) { // we're early/on-time
//printf(". next=%ld current=%ld \n", nextIoTime, currentTime);
Timer::delay(nextIoTime - currentTime); // delay until ~specified time
} else { // we're late
//printf("x next=%ld current=%ld delta=%ld\n",
// nextIoTime, currentTime, currentTime-nextIoTime);
++myLateCount;
}
performIo(fd, buf, event, logger);
}
lateCount += myLateCount; // update global lateCount
});
fileThread.join(); // wait for all threads to finish
for (auto& t : workers) t.join();
printf("Late count: %d\n", lateCount.load());
Logger logger(logDir + traceFile + to_string(0));
logger.printf("%d\n", lateCount.load());
printf("Done\n");
return 0;
}
