From e2aaef8b6c19a8d5d764ce8d40f3668e14f75e7d Mon Sep 17 00:00:00 2001
From: ed-tsn <ed@tsn.systems>
Date: Fri, 3 Jul 2026 09:08:47 +0200
Subject: [PATCH] Fix memory leak in _DynamicCapabilityClient._send_helper()
 (#398)

The heap-allocated Request object was never freed after send().
  Each RPC call leaked ~72 bytes, growing linearly with usage.

  Added del request after request.send() to free the Request once
  the RemotePromise has been constructed.
---
 capnp/lib/capnp.pyx | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/capnp/lib/capnp.pyx b/capnp/lib/capnp.pyx
index 538c46f..b5347f4 100644
--- a/capnp/lib/capnp.pyx
+++ b/capnp/lib/capnp.pyx
@@ -2320,7 +2320,9 @@ cdef class _DynamicCapabilityClient:
 
         self._set_fields(request, name, args, kwargs)
 
-        return _RemotePromise()._init(request.send(), self)
+        cdef _RemotePromise result = _RemotePromise()._init(request.send(), self)
+        del request
+        return result
 
     cpdef _request_helper(self, name, firstSegmentWordSize, args, kwargs):
         # if word_count is None: