Reinstate the new signal handling; revert the revert.

[cubemap] / server.cpp

diff --git a/server.cpp b/server.cpp
index 74a20c83d2308c5a0664b2e15ad040970ab47257..6d5cce372ae9c79b81b4b755052252680ce3cf28 100644 (file)
--- a/server.cpp
+++ b/server.cpp
@@ -1,9 +1,11 @@
-#include <arpa/inet.h>
 #include <assert.h>
 #include <errno.h>
+#include <netinet/in.h>
 #include <pthread.h>
+#include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 #include <sys/epoll.h>
 #include <sys/sendfile.h>
 #include <sys/socket.h>
@@ -24,6 +26,7 @@
 #include "server.h"
 #include "state.pb.h"
 #include "stream.h"
+#include "util.h"
 
 using namespace std;
 
@@ -49,14 +52,7 @@ Server::~Server()
                delete stream_it->second;
        }
 
-       int ret;
-       do {
-               ret = close(epoll_fd);
-       } while (ret == -1 && errno == EINTR);
-
-       if (ret == -1) {
-               log_perror("close(epoll_fd)");
-       }
+       safe_close(epoll_fd);
 }
 
 vector<ClientStats> Server::get_client_stats() const
@@ -74,15 +70,17 @@ vector<ClientStats> Server::get_client_stats() const
 
 void Server::do_work()
 {
-       for ( ;; ) {
-               int nfds = epoll_wait(epoll_fd, events, EPOLL_MAX_EVENTS, EPOLL_TIMEOUT_MS);
-               if (nfds == -1 && errno == EINTR) {
-                       if (should_stop) {
-                               return;
-                       }
-                       continue;
-               }
-               if (nfds == -1) {
+       while (!should_stop()) {
+               // Wait until there's activity on at least one of the fds,
+               // or 20 ms (about one frame at 50 fps) has elapsed.
+               //
+               // We could in theory wait forever and rely on wakeup()
+               // from add_client_deferred() and add_data_deferred(),
+               // but wakeup is a pretty expensive operation, and the
+               // two threads might end up fighting over a lock, so it's
+               // seemingly (much) more efficient to just have a timeout here.
+               int nfds = epoll_pwait(epoll_fd, events, EPOLL_MAX_EVENTS, EPOLL_TIMEOUT_MS, &sigset_without_usr1_block);
+               if (nfds == -1 && errno != EINTR) {
                        log_perror("epoll_wait");
                        exit(1);
                }
@@ -111,10 +109,6 @@ void Server::do_work()
                                process_client(to_process[i]);
                        }
                }
-
-               if (should_stop) {
-                       return;
-               }
        }
 }
 
@@ -145,18 +139,21 @@ void Server::add_client_deferred(int sock)
 
 void Server::add_client(int sock)
 {
-       clients.insert(make_pair(sock, Client(sock)));
+       pair<map<int, Client>::iterator, bool> ret =
+               clients.insert(make_pair(sock, Client(sock)));
+       assert(ret.second == true);  // Should not already exist.
+       Client *client_ptr = &ret.first->second;
 
        // Start listening on data from this socket.
        epoll_event ev;
        ev.events = EPOLLIN | EPOLLET | EPOLLRDHUP;
-       ev.data.u64 = reinterpret_cast<uint64_t>(&clients[sock]);
+       ev.data.u64 = reinterpret_cast<uint64_t>(client_ptr);
        if (epoll_ctl(epoll_fd, EPOLL_CTL_ADD, sock, &ev) == -1) {
                log_perror("epoll_ctl(EPOLL_CTL_ADD)");
                exit(1);
        }
 
-       process_client(&clients[sock]);
+       process_client(client_ptr);
 }
 
 void Server::add_client_from_serialized(const ClientProto &client)
@@ -169,8 +166,10 @@ void Server::add_client_from_serialized(const ClientProto &client)
        } else {
                stream = stream_it->second;
        }
-       clients.insert(make_pair(client.sock(), Client(client, stream)));
-       Client *client_ptr = &clients[client.sock()];
+       pair<map<int, Client>::iterator, bool> ret =
+               clients.insert(make_pair(client.sock(), Client(client, stream)));
+       assert(ret.second == true);  // Should not already exist.
+       Client *client_ptr = &ret.first->second;
 
        // Start listening on data from this socket.
        epoll_event ev;
@@ -551,14 +550,7 @@ void Server::close_client(Client *client)
        access_log->write(client->get_stats());
 
        // Bye-bye!
-       int ret;
-       do {
-               ret = close(client->sock);
-       } while (ret == -1 && errno == EINTR);
-
-       if (ret == -1) {
-               log_perror("close");
-       }
+       safe_close(client->sock);
 
        clients.erase(client->sock);
 }