wsry opened a new pull request #17030:
URL: https://github.com/apache/flink/pull/17030


   ## What is the purpose of the change
       
       Previously, The buffer listeners are not notified when the the local 
buffer pool receives available notification from the global pool. This may 
cause potential deadlock issue:
       
       1. A LocalBufferPool is created but there is no available buffers in the 
global NetworkBufferPool.
       2. The LocalBufferPool registers an available buffer listener to the 
global NetworkBufferPool.
       3. The BufferManager requests buffers from the LocalBufferPool but no 
buffer is available. As a result, it registers an available buffer listener to 
the LocalBufferPool.
       4. A buffer is recycled to the global NetworkBufferPool and the 
LocalBufferPool is notified about the available buffer.
       5. The LocalBufferPool requests the available buffer from the global 
NetworkBufferPool but the registered available buffer listener of BufferManager 
is not notified and it can never get a chance to be notified so deadlock occurs.
       
       This patch fixes this issue by notifying the buffer listeners when the 
local buffer pool receives available notification from the global pool.
   
   
   ## Brief change log
   
     - Notify the buffer listeners when the local buffer pool receives 
available notification from the global pool.
   
   
   ## Verifying this change
   
   This change added tests.
   
   ## Does this pull request potentially affect one of the following parts:
   
     - Dependencies (does it add or upgrade a dependency): (yes / **no**)
     - The public API, i.e., is any changed class annotated with 
`@Public(Evolving)`: (yes / **no**)
     - The serializers: (yes / **no** / don't know)
     - The runtime per-record code paths (performance sensitive): (yes / **no** 
/ don't know)
     - Anything that affects deployment or recovery: JobManager (and its 
components), Checkpointing, Kubernetes/Yarn, ZooKeeper: (yes / **no** / don't 
know)
     - The S3 file system connector: (yes / **no** / don't know)
   
   ## Documentation
   
     - Does this pull request introduce a new feature? (yes / **no**)
     - If yes, how is the feature documented? (**not applicable** / docs / 
JavaDocs / not documented)
   


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