Initial chekpoint Feature Request - Add support for a ForkJoinPool type

Signed-off-by: Srikanth Padakanti <[email protected]>

Author: Srikanth Padakanti

server/src/main/java/org/opensearch/threadpool/ThreadPool.java

@@ -1039,22 +1039,31 @@ public XContentBuilder toXContent(XContentBuilder builder, Params params) throws
                 builder.field("core", min);
                 assert max != -1;
                 builder.field("max", max);
+                if (keepAlive != null) {
+                    builder.field("keep_alive", keepAlive.toString());
+                }
+                if (queueSize == null) {
+                    builder.field("queue_size", -1);
+                } else {
+                    builder.field("queue_size", queueSize.singles());
+                }
             } else if (type == ThreadPoolType.FORK_JOIN) {
                 builder.field("size", -1);
                 builder.field("min", -1);
                 builder.field("max", -1);
                 builder.field("keep_alive", (Object) null);
+                builder.field("queue_size", -1);
             } else {
                 assert max != -1;
                 builder.field("size", max);
-            }
-            if (keepAlive != null) {
-                builder.field("keep_alive", keepAlive.toString());
-            }
-            if (queueSize == null) {
-                builder.field("queue_size", -1);
-            } else {
-                builder.field("queue_size", queueSize.singles());
+                if (keepAlive != null) {
+                    builder.field("keep_alive", keepAlive.toString());
+                }
+                if (queueSize == null) {
+                    builder.field("queue_size", -1);
+                } else {
+                    builder.field("queue_size", queueSize.singles());
+                }
             }
             builder.endObject();
             return builder;

server/src/test/java/org/opensearch/threadpool/ThreadPoolSerializationTests.java

@@ -130,7 +130,12 @@ public void testThatToXContentWritesInteger() throws Exception {
         assertThat(map, hasKey("foo"));
         map = (Map<String, Object>) map.get("foo");
         assertThat(map, hasKey("queue_size"));
-        assertThat(map.get("queue_size").toString(), is("1000"));
+        if (threadPoolType == ThreadPool.ThreadPoolType.FORK_JOIN) {
+            // ForkJoinPool always writes queue_size as -1
+            assertThat(map.get("queue_size").toString(), is("-1"));
+        } else {
+            assertThat(map.get("queue_size").toString(), is("1000"));
+        }
     }
 
     public void testThatThreadPoolTypeIsSerializedCorrectly() throws IOException {