void ProxyThread::proxyThreadRun() {
FBI_ASSERT(proxy->router != nullptr);
mcrouter_set_thread_name(pthread_self(), proxy->router->opts, "mcrpxy");
while(!proxy->router->shutdownStarted()) {
mcrouterLoopOnce(proxy->eventBase);
}
while (proxy->fiberManager.hasTasks()) {
mcrouterLoopOnce(proxy->eventBase);
}
proxy->stopAwriterThreads();
// Delete the proxy from the proxy thread so that the clients get
// deleted from the same thread where they were created.
folly::EventBase *eventBase = proxy->eventBase;
std::unique_lock<std::mutex> lk(mux);
// This is to avoid a race condition where proxy is deleted
// before the call to stopAndJoin is made.
cv.wait(lk,
[this]() {
return this->isSafeToDeleteProxy;
});
delete proxy;
if (eventBase != nullptr) {
delete eventBase;
}
}
void ConfigApi::configThreadRun() {
mcrouter_set_thread_name(pthread_self(), opts_, "mcrcfg");
if (opts_.constantly_reload_configs) {
while (!finish_) {
LOG(INFO) << "Reload config due to constantly_reload_configs";
callbacks_.notify();
usleep(10000);
}
return;
}
while (!finish_) {
bool hasUpdate;
try {
hasUpdate = checkFileUpdate();
} catch (const std::exception& e) {
LOG(ERROR) << "Check for config update failed: " << e.what();
return;
} catch (...) {
LOG(ERROR) << "Check for config update failed with unknown error";
return;
}
// There are a couple of races that can happen here
// First, the IN_MODIFY event can be fired before the write is complete,
// resulting in a malformed JSON error. Second, text editors may do
// some of their own shuffling of the file (e.g. between .swp and the
// real thing in Vim) after the write. This may can result in a file
// access error router_configure_from_file below. That's just a theory,
// but that error does happen. Race 1 can be fixed by changing the
// watch for IN_MODIFY to IN_CLOSE_WRITE, but Race 2 has no apparent
// elegant solution. The following jankiness fixes both.
sleep(1);
if (hasUpdate) {
callbacks_.notify();
}
// Otherwise there was nothing to read, so check that we aren't shutting
// down, and wait on the FD again.
}
}