Add a new extension library: connection (#39)

samples/simple/wasm-apps/event_publisher.c

@@ -0,0 +1,57 @@
+/*
+ * Copyright (C) 2019 Intel Corporation.  All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "wasm_app.h"
+
+int num = 0;
+
+void publish_overheat_event()
+{
+    attr_container_t *event;
+
+    event = attr_container_create("event");
+    attr_container_set_string(&event, "warning", "temperature is over high");
+
+    api_publish_event("alert/overheat", FMT_ATTR_CONTAINER, event,
+            attr_container_get_serialize_length(event));
+
+    attr_container_destroy(event);
+}
+
+/* Timer callback */
+void timer1_update(user_timer_t timer)
+{
+    publish_overheat_event();
+}
+
+void start_timer()
+{
+    user_timer_t timer;
+
+    /* set up a timer */
+    timer = api_timer_create(1000, true, false, timer1_update);
+    api_timer_restart(timer, 1000);
+}
+
+void on_init()
+{
+    start_timer();
+}
+
+void on_destroy()
+{
+    /* real destroy work including killing timer and closing sensor is accomplished in wasm app library version of on_destroy() */
+}