Posted also at
http://stackoverflow.com/questions/29219314/how-to-break-out-libevents-dispatch-loop
<http://stackoverflow.com/questions/29219314/how-to-break-out-libevents-dispatch-loop>
I've implemented a tiny webserver in a separate thread using the nice libevent
library. The webserver runs event_base_dispatch() to process all events. What I
need is a way to break out this dispatch loop from the main thread.
It boils down to the following C++ code:
#include <stdlib.h>
#include <signal.h>
#include <thread>
#include <evhttp.h>
struct event_base *eb;
std::thread t;
static volatile sig_atomic_t bailout = false;
void my_signal_handler(int) {
bailout = true;
}
void onRequest(evhttp_request *req, void *) {
struct evbuffer *OutBuf = evhttp_request_get_output_buffer(req);
evbuffer_add_printf(OutBuf, "<html><body>Testing
1-2-3</body></html>");
evhttp_send_reply(req, HTTP_OK, "OK", OutBuf);
}
void dispatch() {
eb = event_base_new();
struct evhttp *http = evhttp_new(eb);
evhttp_set_gencb(http, &onRequest, NULL);
evhttp_bind_socket_with_handle(http, "0.0.0.0", 5555);
event_base_dispatch(eb);
}
int main() {
struct sigaction sigIntHandler;
sigIntHandler.sa_handler = my_signal_handler;
sigemptyset(&sigIntHandler.sa_mask);
sigIntHandler.sa_flags = 0;
sigaction(SIGINT, &sigIntHandler, NULL);
t = std::thread { &dispatch };
while ( ! bailout ) {
std::this_thread::sleep_for(std::chrono::seconds(1));
}
event_base_loopexit(eb, NULL);
t.join();
}
The behavior is that if you run the program, request a page, abort the program
by Ctrl-C, the event_base_dispatch() keeps running *until* you fetch another
web page. Only then the loop aborts and the program terminates. What I need is
that the dispatch loop is exited immediately, not after the next page request.
Is this possible?
Thanks,
Mark
