fix(esp_http_server): Async handler example stack overflow fix

1. In async handler example, on hitting /long URI and closing the
connection forcefully from client (example ctrl + c) cause more stack
size (almost 200 bytes) than successfull request.
2. The connection should be closed from the server as soon as the client
closes the connect (i.e. handler should return ESP_FAIL to close the
connection)

Author: hrushikesh430

examples/protocols/http_server/async_handlers/main/Kconfig.projbuild

@@ -7,4 +7,10 @@ menu "Example Configuration"
             The maximum number of simultaneous async requests that the
             web server can handle.
 
+    config EXAMPLE_ASYNC_WORKER_TASK_STACK_SIZE
+        int "Async Worker Task Stack Size"
+        default 2560
+        help
+            The stack size allocated for each async worker task.
+
 endmenu

examples/protocols/http_server/async_handlers/main/main.c

@@ -32,7 +32,7 @@
  */
 
 #define ASYNC_WORKER_TASK_PRIORITY      5
-#define ASYNC_WORKER_TASK_STACK_SIZE    2048
+#define ASYNC_WORKER_TASK_STACK_SIZE    CONFIG_EXAMPLE_ASYNC_WORKER_TASK_STACK_SIZE
 
 static const char *TAG = "example";
 
@@ -104,7 +104,11 @@ static esp_err_t long_async(httpd_req_t *req)
     // send a request count
     char s[100];
     snprintf(s, sizeof(s), "<div>req: %u</div>\n", req_count);
-    httpd_resp_sendstr_chunk(req, s);
+    esp_err_t err = httpd_resp_sendstr_chunk(req, s);
+    if (err != ESP_OK) {
+        ESP_LOGE(TAG, "Failed to send string chunk: %s", esp_err_to_name(err));
+        return err;
+    }
 
     // then every second, send a "tick"
     for (int i = 0; i < 60; i++) {
@@ -116,11 +120,19 @@ static esp_err_t long_async(httpd_req_t *req)
 
         // send a tick
         snprintf(s, sizeof(s), "<div>%u</div>\n", i);
-        httpd_resp_sendstr_chunk(req, s);
+        err = httpd_resp_sendstr_chunk(req, s);
+        if (err != ESP_OK) {
+            ESP_LOGE(TAG, "Failed to send string chunk: %s", esp_err_to_name(err));
+            return err;
+        }
     }
 
     // send "complete"
-    httpd_resp_sendstr_chunk(req, NULL);
+    err = httpd_resp_sendstr_chunk(req, NULL);
+    if (err != ESP_OK) {
+        ESP_LOGE(TAG, "Failed to send string chunk: %s", esp_err_to_name(err));
+        return err;
+    }
 
     return ESP_OK;
 }