client_subscription_loop.c 5.6 KB

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  1. /* This work is licensed under a Creative Commons CCZero 1.0 Universal License.
  2. * See http://creativecommons.org/publicdomain/zero/1.0/ for more information. */
  3. /* Enable POSIX features */
  4. #ifndef _XOPEN_SOURCE
  5. # define _XOPEN_SOURCE 600
  6. #endif
  7. #ifndef _DEFAULT_SOURCE
  8. # define _DEFAULT_SOURCE
  9. #endif
  10. /* On older systems we need to define _BSD_SOURCE.
  11. * _DEFAULT_SOURCE is an alias for that. */
  12. #ifndef _BSD_SOURCE
  13. # define _BSD_SOURCE
  14. #endif
  15. /**
  16. * Client disconnect handling
  17. * --------------------------
  18. * This example shows you how to handle a client disconnect, e.g., if the server
  19. * is shut down while the client is connected. You just need to call connect
  20. * again and the client will automatically reconnect.
  21. *
  22. * This example is very similar to the tutorial_client_firststeps.c. */
  23. #include "open62541.h"
  24. #include <signal.h>
  25. #ifdef _WIN32
  26. # include <windows.h>
  27. # define UA_sleep_ms(X) Sleep(X)
  28. #else
  29. # include <unistd.h>
  30. # define UA_sleep_ms(X) usleep(X * 1000)
  31. #endif
  32. UA_Boolean running = true;
  33. UA_Logger logger = UA_Log_Stdout;
  34. static void stopHandler(int sign) {
  35. UA_LOG_INFO(logger, UA_LOGCATEGORY_USERLAND, "Received Ctrl-C");
  36. running = 0;
  37. }
  38. static void
  39. handler_currentTimeChanged(UA_Client *client, UA_UInt32 subId, void *subContext,
  40. UA_UInt32 monId, void *monContext, UA_DataValue *value) {
  41. UA_LOG_INFO(logger, UA_LOGCATEGORY_USERLAND, "currentTime has changed!");
  42. if(UA_Variant_hasScalarType(&value->value, &UA_TYPES[UA_TYPES_DATETIME])) {
  43. UA_DateTime raw_date = *(UA_DateTime *) value->value.data;
  44. UA_DateTimeStruct dts = UA_DateTime_toStruct(raw_date);
  45. UA_LOG_INFO(logger, UA_LOGCATEGORY_USERLAND, "date is: %02u-%02u-%04u %02u:%02u:%02u.%03u",
  46. dts.day, dts.month, dts.year, dts.hour, dts.min, dts.sec, dts.milliSec);
  47. }
  48. }
  49. static void
  50. deleteSubscriptionCallback(UA_Client *client, UA_UInt32 subscriptionId, void *subscriptionContext) {
  51. UA_LOG_INFO(logger, UA_LOGCATEGORY_USERLAND, "Subscription Id %u was deleted", subscriptionId);
  52. }
  53. static void
  54. stateCallback (UA_Client *client, UA_ClientState clientState) {
  55. switch(clientState) {
  56. case UA_CLIENTSTATE_DISCONNECTED:
  57. UA_LOG_INFO(logger, UA_LOGCATEGORY_USERLAND, "The client is disconnected");
  58. break;
  59. case UA_CLIENTSTATE_CONNECTED:
  60. UA_LOG_INFO(logger, UA_LOGCATEGORY_USERLAND, "A TCP connection to the server is open");
  61. break;
  62. case UA_CLIENTSTATE_SECURECHANNEL:
  63. UA_LOG_INFO(logger, UA_LOGCATEGORY_USERLAND, "A SecureChannel to the server is open");
  64. break;
  65. case UA_CLIENTSTATE_SESSION:{
  66. UA_LOG_INFO(logger, UA_LOGCATEGORY_USERLAND, "A session with the server is open");
  67. /* A new session was created. We need to create the subscription. */
  68. /* Create a subscription */
  69. UA_CreateSubscriptionRequest request = UA_CreateSubscriptionRequest_default();
  70. UA_CreateSubscriptionResponse response = UA_Client_Subscriptions_create(client, request,
  71. NULL, NULL, deleteSubscriptionCallback);
  72. if(response.responseHeader.serviceResult == UA_STATUSCODE_GOOD)
  73. UA_LOG_INFO(logger, UA_LOGCATEGORY_USERLAND, "Create subscription succeeded, id %u", response.subscriptionId);
  74. else
  75. return;
  76. /* Add a MonitoredItem */
  77. UA_MonitoredItemCreateRequest monRequest =
  78. UA_MonitoredItemCreateRequest_default(UA_NODEID_NUMERIC(0, UA_NS0ID_SERVER_SERVERSTATUS_CURRENTTIME));
  79. UA_MonitoredItemCreateResult monResponse =
  80. UA_Client_MonitoredItems_createDataChange(client, response.subscriptionId,
  81. UA_TIMESTAMPSTORETURN_BOTH,
  82. monRequest, NULL, handler_currentTimeChanged, NULL);
  83. if(monResponse.statusCode == UA_STATUSCODE_GOOD)
  84. UA_LOG_INFO(logger, UA_LOGCATEGORY_USERLAND, "Monitoring UA_NS0ID_SERVER_SERVERSTATUS_CURRENTTIME', id %u", monResponse.monitoredItemId);
  85. }
  86. break;
  87. case UA_CLIENTSTATE_SESSION_RENEWED:
  88. UA_LOG_INFO(logger, UA_LOGCATEGORY_USERLAND, "A session with the server is open (renewed)");
  89. /* The session was renewed. We don't need to recreate the subscription. */
  90. break;
  91. }
  92. return;
  93. }
  94. int main(void) {
  95. signal(SIGINT, stopHandler); /* catches ctrl-c */
  96. UA_ClientConfig config = UA_ClientConfig_default;
  97. /* Set stateCallback */
  98. config.stateCallback = stateCallback;
  99. UA_Client *client = UA_Client_new(config);
  100. /* Endless loop runAsync */
  101. while (running) {
  102. /* if already connected, this will return GOOD and do nothing */
  103. /* if the connection is closed/errored, the connection will be reset and then reconnected */
  104. /* Alternatively you can also use UA_Client_getState to get the current state */
  105. UA_StatusCode retval = UA_Client_connect(client, "opc.tcp://localhost:4840");
  106. if(retval != UA_STATUSCODE_GOOD) {
  107. UA_LOG_ERROR(logger, UA_LOGCATEGORY_USERLAND, "Not connected. Retrying to connect in 1 second");
  108. /* The connect may timeout after 1 second (see above) or it may fail immediately on network errors */
  109. /* E.g. name resolution errors or unreachable network. Thus there should be a small sleep here */
  110. UA_sleep_ms(1000);
  111. continue;
  112. }
  113. UA_Client_runAsync(client, 1000);
  114. };
  115. /* Clean up */
  116. UA_Client_delete(client); /* Disconnects the client internally */
  117. return UA_STATUSCODE_GOOD;
  118. }