Add some signal handling

I put the main app in a seperate class for it, because it was easier.

Add some signal handling
I put the main app in a seperate class for it, because it was easier.
Wiebe Cazemier
1 parent a6333881
Showing 6 changed files with 258 additions and 150 deletions
CMakeLists.txt
main.cpp
mainapp.cpp
mainapp.h
threaddata.cpp
threaddata.h
@@ -7,6 +7,7 @@ set(CMAKE_CXX_STANDARD_REQUIRED ON)
 add_executable(FlashMQ
+    mainapp.cpp
     main.cpp
     utils.cpp
     threaddata.cpp
 #include <iostream>
-#include <sys/socket.h>
-#include <stdexcept>
-#include <netinet/in.h>
-#include <sys/epoll.h>
-#include <fcntl.h>
-#include <thread>
-#include <vector>
+#include <signal.h>
+#include <memory>
+#include <string.h>
+#include "mainapp.h"
-#include "utils.h"
-#include "threaddata.h"
-#include "client.h"
-#include "mqttpacket.h"
-#include "subscriptionstore.h"
+static MainApp mainApp;
-#define MAX_EVENTS 1024
-#define NR_OF_THREADS 4
-
-
-
-void do_thread_work(ThreadData *threadData)
+static void signal_handler(int signal)
 {
-    int epoll_fd = threadData->epollfd;
-
-    struct epoll_event events[MAX_EVENTS];
-    memset(&events, 0, sizeof (struct epoll_event)*MAX_EVENTS);
-
-    std::vector<MqttPacket> packetQueueIn;
-
-    uint64_t eventfd_value = 0;
-
-    while (1)
+    if (signal == SIGPIPE)
+    {
+        return;
+    }
+    if (signal == SIGHUP)
     {
-        if (eventfd_value > 0)
-        {
-            for (Client_p client : threadData->getReadyForDequeueing())
-            {
-                //client->queuedMessagesToBuffer();
-                client->writeBufIntoFd();
-            }
-            threadData->clearReadyForDequeueing();
-            eventfd_value = 0;
-        }
-
-        // TODO: do all the buftofd here, not spread out over
-
-        int fdcount = epoll_wait(epoll_fd, events, MAX_EVENTS, 100);
-
-        if (fdcount > 0)
-        {
-            for (int i = 0; i < fdcount; i++)
-            {
-                struct epoll_event cur_ev = events[i];
-                int fd = cur_ev.data.fd;
-
-                // If this thread was actively woken up.
-                if (fd == threadData->event_fd)
-                {
-                    read(fd, &eventfd_value, sizeof(uint64_t));
-                    continue;
-                }
-
-                Client_p client = threadData->getClient(fd);
-
-                if (client)
-                {
-                    if (cur_ev.events & EPOLLIN)
-                    {
-                        bool readSuccess = client->readFdIntoBuffer();
-                        client->bufferToMqttPackets(packetQueueIn, client);
-
-                        if (!readSuccess)
-                        {
-                            std::cout << "Disconnect: " << client->repr() << std::endl;
-                            threadData->removeClient(client);
-                        }
-                    }
-                    if (cur_ev.events & EPOLLOUT)
-                    {
-                        if (!client->writeBufIntoFd())
-                            threadData->removeClient(client);
-                    }
-                }
-            }
-        }
-        for (MqttPacket &packet : packetQueueIn)
-        {
-            packet.handle(threadData->getSubscriptionStore());
-        }
-        packetQueueIn.clear();
+    }
+    else if (signal == SIGTERM || signal == SIGINT)
+    {
+        mainApp.quit();
+    }
+    else
+    {
+        std::cerr << "Received signal " << signal << std::endl;
     }
 }
-int main()
+int register_signal_handers()
 {
-    int listen_fd = socket(AF_INET, SOCK_STREAM, 0);
-
-    // Not needed for now. Maybe I will make multiple accept threads later, with SO_REUSEPORT.
-    //int optval = 1;
-    //check<std::runtime_error>(setsockopt(listen_fd, SOL_SOCKET, SO_REUSEADDR | SO_REUSEPORT, &optval, sizeof(optval)));
+    struct sigaction sa;
+    memset(&sa, 0, sizeof (struct sigaction));
+    sa.sa_handler = &signal_handler;
+    sigemptyset(&sa.sa_mask);
+    sa.sa_flags = SA_RESTART;
-    int flags = fcntl(listen_fd, F_GETFL);
-    check<std::runtime_error>(fcntl(listen_fd, F_SETFL, flags | O_NONBLOCK ));
-
-    struct sockaddr_in in_addr;
-    in_addr.sin_family = AF_INET;
-    in_addr.sin_addr.s_addr = INADDR_ANY;
-    in_addr.sin_port = htons(1883);
-
-    check<std::runtime_error>(bind(listen_fd, (struct sockaddr *)(&in_addr), sizeof(struct sockaddr_in)));
-    check<std::runtime_error>(listen(listen_fd, 1024));
-
-    int epoll_fd_accept = check<std::runtime_error>(epoll_create(999));
-
-    struct epoll_event events[MAX_EVENTS];
-    struct epoll_event ev;
-    memset(&ev, 0, sizeof (struct epoll_event));
-    memset(&events, 0, sizeof (struct epoll_event)*MAX_EVENTS);
-
-    ev.data.fd = listen_fd;
-    ev.events = EPOLLIN;
-    check<std::runtime_error>(epoll_ctl(epoll_fd_accept, EPOLL_CTL_ADD, listen_fd, &ev));
-
-    std::shared_ptr<SubscriptionStore> subscriptionStore(new SubscriptionStore());
-
-    std::vector<std::shared_ptr<ThreadData>> threads;
-
-    for (int i = 0; i < NR_OF_THREADS; i++)
+    if (sigaction(SIGHUP, &sa, nullptr) != 0 || sigaction(SIGTERM, &sa, nullptr) != 0 || sigaction(SIGINT, &sa, nullptr) != 0)
     {
-        std::shared_ptr<ThreadData> t(new ThreadData(i, subscriptionStore));
-        std::thread thread(do_thread_work, t.get());
-        t->thread = std::move(thread);
-        threads.push_back(t);
+        std::cerr << "Error registering signals" << std::endl;
+        return 1;
     }
-    std::cout << "Listening..." << std::endl;
-
-    uint next_thread_index = 0;
+    sigset_t set;
+    sigemptyset(&set);
+    sigaddset(&set,SIGPIPE);
-    while (1)
+    int r;
+    if ((r = sigprocmask(SIG_BLOCK, &set, NULL) != 0))
     {
-        int num_fds = epoll_wait(epoll_fd_accept, events, MAX_EVENTS, 100);
-
-        for (int i = 0; i < num_fds; i++)
-        {
-            int cur_fd = events[i].data.fd;
-            if (cur_fd == listen_fd)
-            {
-                std::shared_ptr<ThreadData> thread_data = threads[next_thread_index++ % NR_OF_THREADS];
-
-                std::cout << "Accepting connection on thread " << thread_data->threadnr << std::endl;
-
-                struct sockaddr addr;
-                memset(&addr, 0, sizeof(struct sockaddr));
-                socklen_t len = sizeof(struct sockaddr);
-                int fd = check<std::runtime_error>(accept(cur_fd, &addr, &len));
-
-                Client_p client(new Client(fd, thread_data));
-                thread_data->giveClient(client);
-            }
-            else
-            {
-                throw std::runtime_error("The main thread had activity on an accepted socket?");
-            }
+        return r;
+    }
-        }
+    return 0;
+}
+int main()
+{
+    try
+    {
+        check<std::runtime_error>(register_signal_handers());
+        mainApp.start();
+    }
+    catch (std::exception &ex)
+    {
+        std::cerr << ex.what() << std::endl;
+        return 1;
     }
     return 0;
+#include "mainapp.h"
+
+#define MAX_EVENTS 1024
+#define NR_OF_THREADS 4
+
+void do_thread_work(ThreadData *threadData)
+{
+    int epoll_fd = threadData->epollfd;
+
+    struct epoll_event events[MAX_EVENTS];
+    memset(&events, 0, sizeof (struct epoll_event)*MAX_EVENTS);
+
+    std::vector<MqttPacket> packetQueueIn;
+
+    uint64_t eventfd_value = 0;
+
+    while (threadData->running)
+    {
+        if (eventfd_value > 0)
+        {
+            for (Client_p client : threadData->getReadyForDequeueing())
+            {
+                //client->queuedMessagesToBuffer();
+                client->writeBufIntoFd();
+            }
+            threadData->clearReadyForDequeueing();
+            eventfd_value = 0;
+        }
+
+        // TODO: do all the buftofd here, not spread out over
+
+        int fdcount = epoll_wait(epoll_fd, events, MAX_EVENTS, 100);
+
+        if (fdcount > 0)
+        {
+            for (int i = 0; i < fdcount; i++)
+            {
+                struct epoll_event cur_ev = events[i];
+                int fd = cur_ev.data.fd;
+
+                // If this thread was actively woken up.
+                if (fd == threadData->event_fd)
+                {
+                    read(fd, &eventfd_value, sizeof(uint64_t));
+                    continue;
+                }
+
+                Client_p client = threadData->getClient(fd);
+
+                if (client)
+                {
+                    if (cur_ev.events & EPOLLIN)
+                    {
+                        bool readSuccess = client->readFdIntoBuffer();
+                        client->bufferToMqttPackets(packetQueueIn, client);
+
+                        if (!readSuccess)
+                        {
+                            std::cout << "Disconnect: " << client->repr() << std::endl;
+                            threadData->removeClient(client);
+                        }
+                    }
+                    if (cur_ev.events & EPOLLOUT)
+                    {
+                        if (!client->writeBufIntoFd())
+                            threadData->removeClient(client);
+                    }
+                }
+            }
+        }
+
+        for (MqttPacket &packet : packetQueueIn)
+        {
+            packet.handle(threadData->getSubscriptionStore());
+        }
+        packetQueueIn.clear();
+    }
+}
+
+MainApp::MainApp() :
+    subscriptionStore(new SubscriptionStore())
+{
+
+}
+
+void MainApp::start()
+{
+    int listen_fd = socket(AF_INET, SOCK_STREAM, 0);
+
+    // Not needed for now. Maybe I will make multiple accept threads later, with SO_REUSEPORT.
+    //int optval = 1;
+    //check<std::runtime_error>(setsockopt(listen_fd, SOL_SOCKET, SO_REUSEADDR | SO_REUSEPORT, &optval, sizeof(optval)));
+
+    int flags = fcntl(listen_fd, F_GETFL);
+    check<std::runtime_error>(fcntl(listen_fd, F_SETFL, flags | O_NONBLOCK ));
+
+    struct sockaddr_in in_addr;
+    in_addr.sin_family = AF_INET;
+    in_addr.sin_addr.s_addr = INADDR_ANY;
+    in_addr.sin_port = htons(1883);
+
+    check<std::runtime_error>(bind(listen_fd, (struct sockaddr *)(&in_addr), sizeof(struct sockaddr_in)));
+    check<std::runtime_error>(listen(listen_fd, 1024));
+
+    int epoll_fd_accept = check<std::runtime_error>(epoll_create(999));
+
+    struct epoll_event events[MAX_EVENTS];
+    struct epoll_event ev;
+    memset(&ev, 0, sizeof (struct epoll_event));
+    memset(&events, 0, sizeof (struct epoll_event)*MAX_EVENTS);
+
+    ev.data.fd = listen_fd;
+    ev.events = EPOLLIN;
+    check<std::runtime_error>(epoll_ctl(epoll_fd_accept, EPOLL_CTL_ADD, listen_fd, &ev));
+
+    for (int i = 0; i < NR_OF_THREADS; i++)
+    {
+        std::shared_ptr<ThreadData> t(new ThreadData(i, subscriptionStore));
+        std::thread thread(do_thread_work, t.get());
+        t->thread = std::move(thread);
+        threads.push_back(t);
+    }
+
+    std::cout << "Listening..." << std::endl;
+
+    uint next_thread_index = 0;
+
+    while (running)
+    {
+        int num_fds = epoll_wait(epoll_fd_accept, events, MAX_EVENTS, 100);
+
+        for (int i = 0; i < num_fds; i++)
+        {
+            int cur_fd = events[i].data.fd;
+            if (cur_fd == listen_fd)
+            {
+                std::shared_ptr<ThreadData> thread_data = threads[next_thread_index++ % NR_OF_THREADS];
+
+                std::cout << "Accepting connection on thread " << thread_data->threadnr << std::endl;
+
+                struct sockaddr addr;
+                memset(&addr, 0, sizeof(struct sockaddr));
+                socklen_t len = sizeof(struct sockaddr);
+                int fd = check<std::runtime_error>(accept(cur_fd, &addr, &len));
+
+                Client_p client(new Client(fd, thread_data));
+                thread_data->giveClient(client);
+            }
+            else
+            {
+                throw std::runtime_error("The main thread had activity on an accepted socket?");
+            }
+
+        }
+    }
+}
+
+void MainApp::quit()
+{
+    std::cout << "Quitting application" << std::endl;
+
+    running = false;
+
+    for(std::shared_ptr<ThreadData> &thread : threads)
+    {
+        thread->quit();
+    }
+}
+#ifndef MAINAPP_H
+#define MAINAPP_H
+
+#include <iostream>
+#include <sys/socket.h>
+#include <stdexcept>
+#include <netinet/in.h>
+#include <fcntl.h>
+#include <thread>
+#include <vector>
+
+#include "forward_declarations.h"
+
+#include "utils.h"
+#include "threaddata.h"
+#include "client.h"
+#include "mqttpacket.h"
+#include "subscriptionstore.h"
+
+
+class MainApp
+{
+    bool running = true;
+    std::vector<std::shared_ptr<ThreadData>> threads;
+    std::shared_ptr<SubscriptionStore> subscriptionStore;
+
+public:
+    MainApp();
+    void start();
+    void quit();
+};
+
+#endif // MAINAPP_H
@@ -15,6 +15,12 @@ ThreadData::ThreadData(int threadnr, std::shared_ptr&lt;SubscriptionStore&gt; &amp;subscri
     check<std::runtime_error>(epoll_ctl(epollfd, EPOLL_CTL_ADD, event_fd, &ev));
 }
+void ThreadData::quit()
+{
+    running = false;
+    thread.join();
+}
+
 void ThreadData::giveClient(Client_p client)
 {
     int fd = client->getFd();
@@ -26,6 +26,7 @@ class ThreadData
     std::mutex readForDequeuingMutex;
 public:
+    bool running = true;
     std::thread thread;
     int threadnr = 0;
     int epollfd = 0;
@@ -33,6 +34,7 @@ public:
     ThreadData(int threadnr, std::shared_ptr<SubscriptionStore> &subscriptionStore);
+    void quit();
     void giveClient(Client_p client);
     Client_p getClient(int fd);
     void removeClient(Client_p client);