[GitHub] [pulsar] bschofield opened a new issue #8311: Memory leak in C client, inside function handle_producer_send()

[GitBox <gi...@apache.org>]

bschofield opened a new issue #8311:
URL: https://github.com/apache/pulsar/issues/8311


   **Describe the bug**
   
   When a message is asynchronously sent using the C client, the function *pulsar_producer_send_async()* (in file *c_Producer.cc*) will set up a shim function *handle_producer_send()* to handle the callback.
   
   Inside *handle_producer_send()*, a `pulsar_message_id_t` is created:
   
   ```C++
           pulsar_message_id_t *c_message_id = new pulsar_message_id_t;
   ```
   
   I cannot find where this memory is freed. It seems to be the source of a memory leak.
   
   Because the amount of memory leaked is so small, the issue only really becomes visible after sending tens or hundreds of millions of messages.
   
   **To Reproduce**
   
   1. Run a program using the C/C++ translation layer (e.g. anything using the golang -> C -> C++ client), using `valgrind --leak-check=full`.
   2. Look at the valgrind output. Scroll down to the last of the leak reports. There should be a report like this:
   
   ```
   ==132== 4,004,096 (1,234,208 direct, 2,769,888 indirect) bytes in 77,138 blocks are definitely lost in loss record 22,211 of 22,211
   ==132==    at 0x4835DEF: operator new(unsigned long) (vg_replace_malloc.c:334)
   ==132==    by 0x4AEEB03: handle_producer_send(pulsar::Result, pulsar::MessageId, void (*)(pulsar_result, _pulsar_message_id*, void*), void*) (c_Producer.cc:42)
   ...
   ```
   
   **Expected behavior**
   
   The C client should not leak memory in normal use.
   
   **Additional information**
   
   [Confirmed as a bug here](https://apache-pulsar.slack.com/archives/C5ZSVEN4E/p1603209067051000).
   


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[GitHub] [pulsar] bschofield commented on issue #8311: Memory leak in ~C~ golang client, inside function handle_producer_send()

[GitBox <gi...@apache.org>]

bschofield commented on issue #8311:
URL: https://github.com/apache/pulsar/issues/8311#issuecomment-713006747


   After discussion with @merlimat, it seems that the behavior of the C interface code is intended, and it has to be that way due to legacy client constraints. It is intended that clients using the C interface call *pulsar_message_id_free()* after a callback with a result of `pulsar_result_Ok`.
   
   Currently, the cgo interface appears to fail to make that call. Hence, the bug is in the pulsar cgo interface code.


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[GitHub] [pulsar] wolfstudy closed issue #8311: Memory leak in golang client (cgo interface)

[GitBox <gi...@apache.org>]

wolfstudy closed issue #8311:
URL: https://github.com/apache/pulsar/issues/8311


   


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