From 0f1d29252759fe40ed1e6fad19b7835e8326bfd1 Mon Sep 17 00:00:00 2001
From: Gavin King <gavin@hibernate.org>
Date: Thu, 15 Apr 2021 12:50:03 +0200
Subject: [PATCH 1/2] proposed fix for #707

make sure that queued requests use the right session and entity args
---
 .../reactive/id/impl/BlockingIdentifierGenerator.java  | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/hibernate-reactive-core/src/main/java/org/hibernate/reactive/id/impl/BlockingIdentifierGenerator.java b/hibernate-reactive-core/src/main/java/org/hibernate/reactive/id/impl/BlockingIdentifierGenerator.java
index e02108cb2..e30112d4b 100644
--- a/hibernate-reactive-core/src/main/java/org/hibernate/reactive/id/impl/BlockingIdentifierGenerator.java
+++ b/hibernate-reactive-core/src/main/java/org/hibernate/reactive/id/impl/BlockingIdentifierGenerator.java
@@ -38,7 +38,7 @@ public abstract class BlockingIdentifierGenerator implements ReactiveIdentifierG
     private int loValue;
     private long hiValue;
 
-    private volatile List<CompletableFuture<Long>> queue = null;
+    private volatile List<Runnable> queue = null;
 
     protected synchronized long next() {
         return loValue>0 && loValue<getBlockSize()
@@ -70,7 +70,7 @@ public CompletionStage<Long> generate(ReactiveConnectionSupplier session, Object
                     // go off and fetch the next hi value from db
                     nextHiValue(session).thenAccept( id -> {
 //						Vertx.currentContext().runOnContext(v -> {
-                        List<CompletableFuture<Long>> list;
+                        List<Runnable> list;
                         synchronized (this) {
                             // clone ref to the queue
                             list = queue;
@@ -79,14 +79,14 @@ public CompletionStage<Long> generate(ReactiveConnectionSupplier session, Object
                             result.complete( next(id) );
                         }
                         // send waiting streams back to try again
-                        list.forEach( completion -> generate(session, entity)
-                                .thenAccept(completion::complete) );
+                        list.forEach(Runnable::run);
 //						} );
                     } );
                 }
                 else {
                     // wait for the concurrent fetch to complete
-                    queue.add(result);
+                    // note that we carefully capture the right session,entity here!
+                    queue.add( () -> generate(session, entity).thenAccept(result::complete) );
                 }
                 return result;
             }

From 09f2d74014c1c8dc92fb4d649b052ca390fcee03 Mon Sep 17 00:00:00 2001
From: Gavin King <gavin@hibernate.org>
Date: Thu, 15 Apr 2021 13:35:22 +0200
Subject: [PATCH 2/2] when we're not using blocking, just go direct to the
 database

related to discussion around #707

This seems right for sequences. I'm not sure about tables though.
---
 .../reactive/id/impl/BlockingIdentifierGenerator.java        | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/hibernate-reactive-core/src/main/java/org/hibernate/reactive/id/impl/BlockingIdentifierGenerator.java b/hibernate-reactive-core/src/main/java/org/hibernate/reactive/id/impl/BlockingIdentifierGenerator.java
index e30112d4b..02cb88b5a 100644
--- a/hibernate-reactive-core/src/main/java/org/hibernate/reactive/id/impl/BlockingIdentifierGenerator.java
+++ b/hibernate-reactive-core/src/main/java/org/hibernate/reactive/id/impl/BlockingIdentifierGenerator.java
@@ -54,6 +54,11 @@ protected synchronized long next(long hi) {
 
     @Override
     public CompletionStage<Long> generate(ReactiveConnectionSupplier session, Object entity) {
+        if ( getBlockSize()<=1 ) {
+            //special case where we're not using blocking at all
+            return nextHiValue(session);
+        }
+
         long local = next();
         if ( local >= 0 ) {
             // We don't need to update or initialize the hi