Why Assertion `event_.ev_base != nullptr' failed?

[gateslu]

please help, when I run a demo, it always print these information, why?

proxygen_server: /work/code/proxygen-2019.07.01.00/proxygen/folly/folly/io/async/EventHandler.cpp:43: bool folly::EventHandler::registerImpl(uint16_t, bool): Assertionevent_.ev_base != nullptr' failed. *** Aborted at 1562667593 (unix time) try "date -d @1562667593" if you are using GNU date *** PC: @ 0x0 (unknown) *** SIGABRT (@0x3e900000759) received by PID 1881 (TID 0x7fca99213700) from PID 1881; stack trace: *** @ 0x7fca9c880390 (unknown) @ 0x7fca9c4da428 gsignal @ 0x7fca9c4dc02a abort @ 0x7fca9c4d2bd7 (unknown) @ 0x7fca9c4d2c82 __assert_fail @ 0x7fca9e24bf4b folly::EventHandler::registerImpl() @ 0x7fca9e23a927 folly::EventHandler::registerInternalHandler() @ 0x7fca9e23c5c6 folly::NotificationQueue<>::Consumer::startConsumingInternal() @ 0x7fca9e23809e folly::EventBase::initNotificationQueue() @ 0x7fca9e233296 folly::EventBase::EventBase() @ 0x7fca9e1bff27 folly::EventBase::EventBase() @ 0x7fca9e24909a folly::EventBaseManager::EventBaseInfo::EventBaseInfo() @ 0x7fca9e248e3d folly::EventBaseManager::getEventBase() @ 0x7fca9e9d1cd1 proxygen::HTTPServer::start() @ 0x431190 _ZZ4mainENKUlvE_clEv @ 0x4329b2 _ZNSt12_Bind_simpleIFZ4mainEUlvE_vEE9_M_invokeIJEEEvSt12_Index_tupleIJXspT_EEE @ 0x432908 _ZNSt12_Bind_simpleIFZ4mainEUlvE_vEEclEv @ 0x432898 _ZNSt6thread5_ImplISt12_Bind_simpleIFZ4mainEUlvE_vEEE6_M_runEv @ 0x7fca9cd5ac80 (unknown) @ 0x7fca9c8766ba start_thread @ 0x7fca9c5ac41d clone @ 0x0 (unknown) `

` /*

• Copyright (c) 2015, Facebook, Inc.
• All rights reserved.
• This source code is licensed under the BSD-style license found in the
• LICENSE file in the root directory of this source tree. An additional grant
• of patent rights can be found in the PATENTS file in the same directory.

*/ #include <gflags/gflags.h> #include <folly/Memory.h> #include <folly/init/Init.h> #include <folly/Portability.h> #include <folly/io/async/EventBaseManager.h> #include <proxygen/httpserver/HTTPServer.h> #include <proxygen/httpserver/RequestHandlerFactory.h> #include <unistd.h>

#include "DemoHandler.h"

using namespace DemoService; using namespace proxygen;

using folly::EventBase; using folly::EventBaseManager; using folly::SocketAddress;

using Protocol = HTTPServer::Protocol;

DEFINE_int32(http_port, 10086, "Port to listen on with HTTP protocol"); DEFINE_string(ip, "localhost", "IP/Hostname to bind to"); DEFINE_int32(threads, 10, "Number of threads to listen on. Numbers <= 0 " "will use the number of cores on this machine.");

class DemoHandlerFactory : public RequestHandlerFactory { public: void onServerStart(folly::EventBase* evb) noexcept override { printf("on server start\n"); }

void onServerStop() noexcept override { }

RequestHandler* onRequest(RequestHandler* handler, HTTPMessage* msg) noexcept override { printf("%s\n", msg->getURL().c_str() ); return new DemoHandler(); }

private: };

int main(int argc, char* argv[]) { folly::init(&argc, &argv, true);

std::vectorHTTPServer::IPConfig IPs = { {SocketAddress(FLAGS_ip, FLAGS_http_port, true), Protocol::HTTP}, };

if (FLAGS_threads <= 0) { FLAGS_threads = sysconf(_SC_NPROCESSORS_ONLN); CHECK(FLAGS_threads > 0); }

HTTPServerOptions options; options.threads = static_cast<size_t>(FLAGS_threads); options.idleTimeout = std::chrono::milliseconds(60000); options.shutdownOn = {SIGINT, SIGTERM}; options.enableContentCompression = true; options.handlerFactories = RequestHandlerChain() .addThen<DemoHandlerFactory>() .build();

HTTPServer server(std::move(options)); server.bind(IPs);

// Start HTTPServer mainloop in a separate thread std::thread t([&] () { server.start(); });

t.join(); return 0; }

`

[baranyaib90]

Seems like same issue as: https://github.com/facebook/folly/issues/601

[xqq0629]

Seems like same issue as: facebook/folly#601

Hi, I also ran into this problem recently. I am wondering if this problem has been resolved now. If not, what should we do with it?

[baranyaib90]

Hi, use the work-around I wrote here: https://github.com/facebook/folly/issues/601#issuecomment-347100410 This problem should be resolved in libev library to separate libevent wrapper to a separate library. But as I see, it's not done yet.

[xqq0629]

Hi, use the work-around I wrote here: facebook/folly#601 (comment) This problem should be resolved in libev library to separate libevent wrapper to a separate library. But as I see, it's not done yet.

Thanks, libevent was mixed and the problem has been resolved now.