allow limiting number of scan retries (fixes 1013)

src/ebusd/main.cpp

@@ -92,6 +92,7 @@ static struct options s_opt = {
 
   false,  // scanConfig
   0,  // initialScan
+  5,  // scanRetries
   getenv("LANG"),  // preferLanguage
   false,  // checkConfig
   OF_NONE,  // dumpConfig
@@ -165,7 +166,8 @@ static const char argpdoc[] =
 
 #define O_INISND -2
 #define O_DEVLAT (O_INISND-1)
-#define O_CFGLNG (O_DEVLAT-1)
+#define O_SCNRET (O_DEVLAT-1)
+#define O_CFGLNG (O_SCNRET-1)
 #define O_CHKCFG (O_CFGLNG-1)
 #define O_DMPCFG (O_CHKCFG-1)
 #define O_DMPCTO (O_DMPCFG-1)
@@ -223,6 +225,7 @@ static const struct argp_option argpoptions[] = {
       "\"off\" for not picking CSV files by scan result (default when configpath is given).\n"
       "If combined with --checkconfig, you can add scan message data as "
       "arguments for checking a particular scan configuration, e.g. \"FF08070400/0AB5454850303003277201\".", 0 },
+  {"scanretries",    O_SCNRET, "COUNT",    0, "Retry scanning devices COUNT times [5]", 0 },
   {"configlang",     O_CFGLNG, "LANG",     0,
       "Prefer LANG in multilingual configuration files [system default language]", 0 },
   {"checkconfig",    O_CHKCFG, nullptr,    0, "Check config files, then stop", 0 },
@@ -361,6 +364,14 @@ error_t parse_opt(int key, char *arg, struct argp_state *state) {
     s_scanConfigOrPathSet = true;
     break;
   }
+  case O_SCNRET:  // --scanretries=10
+    value = parseInt(arg, 10, 0, 100, &result);
+    if (result != RESULT_OK) {
+      argp_error(state, "invalid scanretries");
+      return EINVAL;
+    }
+    opt->scanRetries = value;
+    break;
   case O_CFGLNG:  // --configlang=LANG
     opt->preferLanguage = arg;
     break;

src/ebusd/main.h

@@ -49,6 +49,7 @@ typedef struct options {
    * else: single slave address.
    */
   symbol_t initialScan;
+  int scanRetries;  //!< number of retries for scanning devices [10]
   const char* preferLanguage;  //!< preferred language in configuration files
   bool checkConfig;  //!< check config files, then stop
   OutputFormat dumpConfig;  //!< dump config files, then stop

src/ebusd/mainloop.cpp

@@ -109,8 +109,8 @@ MainLoop::MainLoop(const struct options& opt, Device *device, MessageMap* messag
   Queue<Request*>* requestQueue)
   : Thread(), m_device(device), m_reconnectCount(0), m_userList(opt.accessLevel), m_messages(messages),
     m_scanHelper(scanHelper), m_address(opt.address), m_scanConfig(opt.scanConfig),
-    m_initialScan(opt.readOnly ? ESC : opt.initialScan), m_scanStatus(SCAN_STATUS_NONE),
+    m_initialScan(opt.readOnly ? ESC : opt.initialScan), m_scanRetries(opt.scanRetries),
-    m_polling(opt.pollInterval > 0), m_enableHex(opt.enableHex),
+    m_scanStatus(SCAN_STATUS_NONE), m_polling(opt.pollInterval > 0), m_enableHex(opt.enableHex),
     m_shutdown(false), m_runUpdateCheck(opt.updateCheck), m_httpClient(), m_requestQueue(requestQueue) {
   m_device->setListener(this);
   // open Device
@@ -228,6 +228,7 @@ void MainLoop::run() {
   symbol_t lastScanAddress = 0;  // 0 is known to be a master
   scanStatus_t lastScanStatus = m_scanStatus;
   int scanCompleted = 0;
+  int scanRetry = 0;
   time(&now);
   start = now;
   lastTaskRun = now;
@@ -261,7 +262,7 @@ void MainLoop::run() {
         m_busHandler->reconnect();
         m_reconnectCount++;
       }
-      if (m_scanConfig) {
+      if (m_scanConfig && scanRetry <= m_scanRetries) {
         bool loadDelay = false;
         if (m_initialScan != ESC && reload && m_busHandler->hasSignal()) {
           loadDelay = true;
@@ -312,6 +313,8 @@ void MainLoop::run() {
             scanCompleted++;
             if (scanCompleted > SCAN_REPEAT_COUNT) {  // repeat failed scan only every Nth time
               scanCompleted = 0;
+              scanRetry++;
+              logNotice(lf_main, "scan completed %d time(s), %s", scanRetry, scanRetry <= m_scanRetries ? "check again" : "end");
             }
           } else {
             m_scanStatus = SCAN_STATUS_RUNNING;
@@ -424,7 +427,11 @@ void MainLoop::run() {
     bool connected = true;
     if (!req->empty()) {
       req->log();
+      bool currentReload = reload;
       result_t result = decodeRequest(req, &connected, &reqMode, &user, &reload, &ostream);
+      if (reload && !currentReload) {
+        scanRetry = 0;  // restart scan counting
+      }
       if (!req->isHttp() && (ostream.tellp() == 0 || result != RESULT_OK)) {
         if (reqMode.listenMode != lm_direct) {
           ostream.str("");

src/ebusd/mainloop.h

@@ -416,6 +416,9 @@ class MainLoop : public Thread, DeviceListener {
    * (@a ESC=none, 0xfe=broadcast ident, @a SYN=full scan, else: single slave address). */
   const symbol_t m_initialScan;
 
+  /** number of retries for scanning a device. */
+  const int m_scanRetries;
+
   /** the current scan status. */
   scanStatus_t m_scanStatus;