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Use a separate thread for epoll

Simplest, but absolutely inefficient, way to test openonload epoll
openonload
Vitaliy Filippov 1 year ago
parent
commit
85010fed38
  1. 2
      Makefile
  2. 92
      osd.cpp
  3. 8
      osd.h

2
Makefile

@ -18,7 +18,7 @@ OSD_OBJS := osd.o osd_secondary.o msgr_receive.o msgr_send.o osd_peering.o osd_f
osd_primary.o osd_primary_subops.o etcd_state_client.o messenger.o osd_cluster.o http_client.o pg_states.o \
osd_rmw.o json11.o base64.o timerfd_manager.o
osd: ./libblockstore.so osd_main.cpp osd.h osd_ops.h $(OSD_OBJS)
g++ $(CXXFLAGS) -o $@ osd_main.cpp $(OSD_OBJS) ./libblockstore.so -ltcmalloc_minimal -luring
g++ $(CXXFLAGS) -o $@ osd_main.cpp $(OSD_OBJS) ./libblockstore.so -ltcmalloc_minimal -luring -lpthread
stub_osd: stub_osd.o rw_blocking.o
g++ $(CXXFLAGS) -o $@ stub_osd.o rw_blocking.o -ltcmalloc_minimal

92
osd.cpp

@ -1,5 +1,6 @@
#include <sys/socket.h>
#include <sys/epoll.h>
#include <sys/eventfd.h>
#include <sys/poll.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
@ -43,6 +44,11 @@ osd_t::osd_t(blockstore_config_t & config, blockstore_t *bs, ring_loop_t *ringlo
{
throw std::runtime_error(std::string("epoll_create: ") + strerror(errno));
}
event_fd = eventfd(0, EFD_NONBLOCK);
if (event_fd < 0)
{
throw std::runtime_error(std::string("eventfd: ") + strerror(errno));
}
this->tfd = new timerfd_manager_t(ringloop);
this->tfd->set_fd_handler = [this](int fd, std::function<void(int, int)> handler) { set_fd_handler(fd, handler); };
@ -60,17 +66,40 @@ osd_t::osd_t(blockstore_config_t & config, blockstore_t *bs, ring_loop_t *ringlo
consumer.loop = [this]() { loop(); };
ringloop->register_consumer(&consumer);
epoll_thread = new std::thread([this]()
{
int nfds;
epoll_event events[MAX_EPOLL_EVENTS];
while (1)
{
nfds = epoll_wait(epoll_fd, events, MAX_EPOLL_EVENTS, -1);
{
std::lock_guard<std::mutex> guard(epoll_mutex);
for (int i = 0; i < nfds; i++)
{
int fd = events[i].data.fd;
int ev = events[i].events;
epoll_ready[fd] |= ev;
}
uint64_t n = 1;
write(event_fd, &n, 8);
}
}
});
}
osd_t::~osd_t()
{
close(epoll_fd);
epoll_thread->join();
delete epoll_thread;
if (tfd)
{
delete tfd;
tfd = NULL;
}
ringloop->unregister_consumer(&consumer);
close(epoll_fd);
close(event_fd);
close(listen_fd);
}
@ -189,8 +218,13 @@ void osd_t::bind_socket()
{
close(listen_fd);
close(epoll_fd);
throw std::runtime_error(std::string("epoll_ctl: ") + strerror(errno));
throw std::runtime_error(std::string("epoll_ctl (add listen_fd): ") + strerror(errno));
}
epoll_handlers[listen_fd] = [this](int peer_fd, int epoll_events)
{
c_cli.accept_connections(listen_fd);
};
}
bool osd_t::shutdown()
@ -205,10 +239,23 @@ bool osd_t::shutdown()
void osd_t::loop()
{
if (!wait_state)
std::map<int,int> cur_epoll;
{
handle_epoll_events();
wait_state = 1;
std::lock_guard<std::mutex> guard(epoll_mutex);
cur_epoll.swap(epoll_ready);
}
for (auto p: cur_epoll)
{
auto cb_it = epoll_handlers.find(p.first);
if (cb_it != epoll_handlers.end())
{
cb_it->second(p.first, p.second);
}
}
if (!(wait_state & 2))
{
handle_eventfd();
wait_state = wait_state | 2;
}
handle_peers();
c_cli.read_requests();
@ -226,7 +273,7 @@ void osd_t::set_fd_handler(int fd, std::function<void(int, int)> handler)
ev.events = EPOLLOUT | EPOLLIN | EPOLLRDHUP | EPOLLET;
if (epoll_ctl(epoll_fd, exists ? EPOLL_CTL_MOD : EPOLL_CTL_ADD, fd, &ev) < 0)
{
throw std::runtime_error(std::string("epoll_ctl: ") + strerror(errno));
throw std::runtime_error(std::string(exists ? "epoll_ctl (mod fd): " : "epoll_ctl (add fd): ") + strerror(errno));
}
epoll_handlers[fd] = handler;
}
@ -234,49 +281,36 @@ void osd_t::set_fd_handler(int fd, std::function<void(int, int)> handler)
{
if (epoll_ctl(epoll_fd, EPOLL_CTL_DEL, fd, NULL) < 0 && errno != ENOENT)
{
throw std::runtime_error(std::string("epoll_ctl: ") + strerror(errno));
throw std::runtime_error(std::string("epoll_ctl (remove fd): ") + strerror(errno));
}
epoll_handlers.erase(fd);
}
}
void osd_t::handle_epoll_events()
void osd_t::handle_eventfd()
{
io_uring_sqe *sqe = ringloop->get_sqe();
if (!sqe)
{
throw std::runtime_error("can't get SQE, will fall out of sync with EPOLLET");
throw std::runtime_error("can't get SQE, will fall out of sync with eventfd");
}
ring_data_t *data = ((ring_data_t*)sqe->user_data);
my_uring_prep_poll_add(sqe, epoll_fd, POLLIN);
my_uring_prep_poll_add(sqe, event_fd, POLLIN);
data->callback = [this](ring_data_t *data)
{
if (data->res < 0)
{
throw std::runtime_error(std::string("epoll failed: ") + strerror(-data->res));
}
handle_epoll_events();
handle_eventfd();
};
ringloop->submit();
int nfds;
epoll_event events[MAX_EPOLL_EVENTS];
restart:
nfds = epoll_wait(epoll_fd, events, MAX_EPOLL_EVENTS, 0);
for (int i = 0; i < nfds; i++)
{
if (events[i].data.fd == listen_fd)
{
c_cli.accept_connections(listen_fd);
}
else
{
auto & cb = epoll_handlers[events[i].data.fd];
cb(events[i].data.fd, events[i].events);
}
}
if (nfds == MAX_EPOLL_EVENTS)
uint64_t n = 0;
size_t res = read(event_fd, &n, 8);
if (res == 8)
{
goto restart;
// No need to do anything, the loop has already woken up
ringloop->wakeup();
}
}

8
osd.h

@ -12,6 +12,8 @@
#include <set>
#include <deque>
#include <mutex>
#include <thread>
#include "blockstore.h"
#include "ringloop.h"
@ -114,6 +116,10 @@ class osd_t
int wait_state = 0;
int epoll_fd = 0;
int event_fd = 0;
std::thread *epoll_thread = NULL;
std::mutex epoll_mutex;
std::map<int, int> epoll_ready;
int listening_port = 0;
int listen_fd = 0;
ring_consumer_t consumer;
@ -150,7 +156,7 @@ class osd_t
// event loop, socket read/write
void loop();
void set_fd_handler(int fd, std::function<void(int, int)> handler);
void handle_epoll_events();
void handle_eventfd();
// peer handling (primary OSD logic)
void parse_test_peer(std::string peer);

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