Fix IOBuf memory leak in PythonUserException exception path#9738
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banitag1 wants to merge 1 commit intofacebook:masterfrom
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Fix IOBuf memory leak in PythonUserException exception path#9738banitag1 wants to merge 1 commit intofacebook:masterfrom
banitag1 wants to merge 1 commit intofacebook:masterfrom
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Summary: CONTEXT: When a thrift-python service handler raises a user-defined exception, the exception path serializes the response into an IOBuf and wraps it in a PythonUserException. This IOBuf was being leaked on every exception. WHAT: Two issues combined to cause the leak: 1. PythonUserException defines an explicit copy constructor (which clones the IOBuf) but no move constructor, suppressing implicit move generation. This caused cmove() to fall back to copying, cloning the IOBuf unnecessarily. 2. The pattern `_cpp_obj.release()` in serverCallback_coro returned a raw pointer that was never deleted. After the copy (not move) into the promise, the original object (including its cloned IOBuf) was leaked. Fix: Add defaulted move constructor/assignment to PythonUserException, and replace the release() pattern with a cdef helper that moves the unique_ptr into a local variable whose destructor properly cleans up. Differential Revision: D96219777
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Summary:
CONTEXT: When a thrift-python service handler raises a user-defined exception,
the exception path serializes the response into an IOBuf and wraps it in a
PythonUserException. This IOBuf was being leaked on every exception.
WHAT: Two issues combined to cause the leak:
PythonUserException defines an explicit copy constructor (which clones the
IOBuf) but no move constructor, suppressing implicit move generation. This
caused cmove() to fall back to copying, cloning the IOBuf unnecessarily.
The pattern
_cpp_obj.release()in serverCallback_coro returned a rawpointer that was never deleted. After the copy (not move) into the promise,
the original object (including its cloned IOBuf) was leaked.
Fix: Add defaulted move constructor/assignment to PythonUserException, and
replace the release() pattern with a cdef helper that moves the unique_ptr
into a local variable whose destructor properly cleans up.
Differential Revision: D96219777