new feature: hardware watchdog support [optional]

opencv-motion-detect/evdaemon.cpp

@@ -15,6 +15,8 @@ update: 2019/09/10
 #include <unistd.h>
 #include <sys/wait.h>
 #include <fstream>
+#include <fcntl.h>
+#include <termios.h>
 
 #include "inc/tinythread.hpp"
 #include "inc/httplib.h"
@@ -1067,14 +1069,132 @@ public:
     ~EvDaemon() {};
 };
 
+#define EV_WATCHDOG_STOP uint8_t(0xFD)
+class EvWatchDog {
+    private:
+    int fd_dog = 0;
+    string tty;
+    bool disabled = false;
+    int watchdog_init(string ttyPath)
+    {
+        const char *tty = ttyPath.c_str();
+
+        struct termios tio;
+        int tty_fd;
+        memset(&tio,0,sizeof(tio));
+        tio.c_iflag=0;
+        tio.c_oflag=0;
+        tio.c_cflag=CS8|CREAD|CLOCAL; // 8n1, see termios.h for more information
+        tio.c_lflag=0;
+        tio.c_cc[VMIN]=1;
+        tio.c_cc[VTIME]=5;
+
+        tty_fd=open(tty, O_RDWR | O_NONBLOCK);
+        if(tty_fd == -1) {
+            spdlog::error("evdaemon failed to open tty {}", tty);
+            return -1;
+        }
+
+        cfsetospeed(&tio,B115200); // 115200 baud  
+        //cfsetispeed(&tio,B115200);
+
+        if(-1 == tcsetattr(tty_fd,TCSANOW,&tio)){
+            spdlog::error("evdaemon failed to set tty {}", tty);
+            return -1;
+        }
+
+        return tty_fd;
+    }
+    
+    int watchdog_feed(int fd, uint8_t intervalMs){
+        if(fd <=0) {
+            spdlog::error("evdaemon invalid watchdog fd");
+            return -1;
+        }
+        uint8_t check = ~intervalMs;
+        uint8_t data[] = {0xFE, 0xFE, intervalMs, check, 0xEF};
+        spdlog::info("evdaemon feed watch dog: {}, {}", intervalMs, check);
+        if( -1 == write(fd,data,5)){
+            spdlog::error("evdaemon failed to write watchdog fd");
+            return -1;
+        }else{
+            return 0;
+        }
+    }
+
+    int _EV_WATCHDOG_STOP(int fd){
+        return watchdog_feed(fd, EV_WATCHDOG_STOP);
+    }
+
+    int watchdog_close(int fd) {
+        spdlog::info("evdaemon disabling watch dog..");
+        if(fd > 0) {
+            _EV_WATCHDOG_STOP(fd);
+            close(fd);
+        }
+        return 0;
+    }
+    public:
+    EvWatchDog() = delete;
+    EvWatchDog(string tty):tty(tty){
+        if((fd_dog = watchdog_init(tty)) < 0) {
+            spdlog::error("evdaemon can't open watchdog tty, ignore watchdog");
+            fd_dog = 0;
+        }
+    }
+
+    thread run(){
+        thread th = thread([this](){
+            uint8_t intval = 10;
+            if(this->fd_dog > 0) {
+                while(!this->disabled) {
+                    watchdog_feed(this->fd_dog, intval);
+                    this_thread::sleep_for(chrono::milliseconds(intval/2*100));
+                }
+                watchdog_close(this->fd_dog);
+                this->fd_dog = 0;
+            }else{
+                this->fd_dog = 0;
+            }
+        });
+       return th;
+    }
+
+    void stop(){
+        if(fd_dog > 0 && !disabled) {
+            disabled = true;
+            while(fd_dog != 0) {
+                spdlog::info("evdaemon waiting watchdog to stop");
+                this_thread::sleep_for(chrono::milliseconds(500));
+            }
+        }
+    }
+};
+
+EvWatchDog gWatchDog = EvWatchDog("/dev/ttyS1");
+
 void cleanup(int signal)
 {
+    // STOP watch dog
+    spdlog::warn("evdaemon received control signal {}, waiting to stop watch dog", signal);
+    gWatchDog.stop();
+    spdlog::info("evdaemon watchdog stopped, exiting");
+
     while (waitpid((pid_t) (-1), 0, WNOHANG) > 0) {}
+    exit(signal);
 }
 
 int main()
 {
     signal(SIGCHLD, cleanup);
+    signal(SIGINT, cleanup);
+    signal(SIGTERM, cleanup);
+    signal(SIGKILL, cleanup);
+
+    thread t = gWatchDog.run();
+    if(t.joinable()){
+        t.detach();
+    }
     //sigignore(SIGCHLD);
     EvDaemon srv;
     srv.run();