add code for raspberry-pi based p1 derotator

p1rotator/tmout.c

@@ -0,0 +1,75 @@
+/*
+ *                                                                                                  geany_encoding=koi8-r
+ * tmout.c
+ *
+ * Copyright 2018 Edward V. Emelianov <eddy@sao.ru, edward.emelianoff@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301, USA.
+ *
+ */
+
+#include <stdio.h>
+#include <pthread.h>
+#include <errno.h>
+#include <sys/select.h>
+#include <signal.h>
+
+#include "usefull_macros.h"
+
+char indi[] = "|/-\\";
+volatile int tmout = 0;
+
+static void *tmout_thread(void *buf){
+    int selfd = -1;
+    struct timeval *tv = (struct timeval *) buf;
+    errno = 0;
+    while(selfd < 0){
+        selfd = select(0, NULL, NULL, NULL, tv);
+        if(selfd < 0 && errno != EINTR){
+            WARN(_("Error while select()"));
+            tmout = 1;
+            return NULL;
+        }
+    }
+    tmout = 1;
+    return NULL;
+}
+
+/**
+ * run thread with pause [delay] (in seconds), at its end set variable tmout
+ */
+void set_timeout(double delay){
+    static int run = 0;
+    static pthread_t athread;
+    static struct timeval tv; // should be static to send this as argument of tmout_thread
+    if(delay < 0.){
+        tmout = 1;
+        return;
+    }
+    if(run && (pthread_kill(athread, 0) != ESRCH)){ // another timeout process detected - kill it
+        pthread_cancel(athread);
+        pthread_join(athread, NULL);
+    }
+    tmout = 0;
+    run = 1;
+    tv.tv_sec  = (time_t) delay;
+    tv.tv_usec = (suseconds_t)((delay - (double)tv.tv_sec)*1e6);
+    if(pthread_create(&athread, NULL, tmout_thread, (void*)&tv)){
+        WARN(_("Can't create timeout thread!"));
+        tmout = 1;
+        return;
+    }
+}