Add multiple receive bbe

examples/index.json

@@ -1426,6 +1426,13 @@
         "verifyOutput": true,
         "isLearnByExample": true
       },
+      {
+        "name": "Multiple receive",
+        "url": "multiple-receive",
+        "verifyBuild": true,
+        "verifyOutput": true,
+        "isLearnByExample": true
+      },
       {
         "name": "Named workers and futures",
         "url": "named-workers-and-futures",

examples/multiple-receive/multiple_receive.bal

@@ -0,0 +1,23 @@
+import ballerina/io;
+import ballerina/lang.runtime;
+
+public function main() {
+    worker w1 {
+        2 -> w3;
+    }
+
+    worker w2 {
+        runtime:sleep(2);
+        3 -> w3;
+    }
+
+    worker w3 returns map<int> {
+        // worker waits until both values are received.
+        map<int> result = <- {w1, w2};
+        return result;
+    }
+
+    map<int> results = wait w3;
+    io:println(results["w1"]);
+    io:println(results["w2"]);
+}

examples/multiple-receive/multiple_receive.md

@@ -0,0 +1,7 @@
+# Multiple receive
+
+The multiple receive action allows receiving messages from multiple workers.
+
+::: code multiple_receive.bal :::
+
+::: out multiple_receive.out :::

examples/multiple-receive/multiple_receive.metatags

@@ -0,0 +1,2 @@
+description: This BBE demonstrates the multiple receive action.
+keywords: ballerina, ballerina by example, bbe, worker, multiple receive

examples/multiple-receive/multiple_receive.out

@@ -0,0 +1,3 @@
+$ bal run multiple_receive.bal
+2
+3