File 3544-erts-Fix-auto-connect-from-net_kernel.patch of Package erlang

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File 3544-erts-Fix-auto-connect-from-net_kernel.patch of Package erlang

From 38968760804c522e0aa1b82f02834f28d6d24633 Mon Sep 17 00:00:00 2001
From: Rickard Green <rickard@erlang.org>
Date: Tue, 4 Apr 2023 20:00:57 +0200
Subject: [PATCH] [erts] Fix auto connect from net_kernel

This bug was harmless. Prior to ff7daaca438743cc14b79ed73c2fd6a1e7b46307
(on master prior to OTP-26.0-rc3) net_kernel never triggered auto connect
itself. After that commit, when net_kernel triggered auto connect, the
runtime system would try-lock the main-lock on net_kernel while executing
net_kernel when sending a message to net_kernel. An assertion would trigger,
but in the optimized runtime this would just cause the try-lock to fail
and the message to unnecessarily to be placed in a heap-fragment.
---
 erts/emulator/beam/dist.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/erts/emulator/beam/dist.c b/erts/emulator/beam/dist.c
index daf07e5fa7..ca6aa40185 100644
--- a/erts/emulator/beam/dist.c
+++ b/erts/emulator/beam/dist.c
@@ -5589,6 +5589,9 @@ int erts_auto_connect(DistEntry* dep, Process *proc, ErtsProcLocks proc_locks)
             return 0;
         }
 
+        if (proc == net_kernel)
+            nk_locks |= ERTS_PROC_LOCK_MAIN;
+
         /*
          * Send {auto_connect, Node, DHandle} to net_kernel
          */
@@ -5599,6 +5602,10 @@ int erts_auto_connect(DistEntry* dep, Process *proc, ErtsProcLocks proc_locks)
         msg = TUPLE3(hp, am_auto_connect, dep->sysname, dhandle);
         ERL_MESSAGE_TOKEN(mp) = am_undefined;
         erts_queue_proc_message(proc, net_kernel, nk_locks, mp, msg);
+
+        if (proc == net_kernel)
+            nk_locks &= ~ERTS_PROC_LOCK_MAIN;
+
         erts_proc_unlock(net_kernel, nk_locks);
     }
 
-- 
2.35.3

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File 3544-erts-Fix-auto-connect-from-net_kernel.patch of Package erlang

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