From 922a239079aefb78a05f1234f8883d8096f46c62 Mon Sep 17 00:00:00 2001
From: mrsdizzie <info@mrsdizzie.com>
Date: Tue, 28 Apr 2020 11:45:32 -0400
Subject: [PATCH] Disable new signal-based asynchronous goroutine preemption
from GO 1.14 in git env (#11237)
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As seen in trouble shooting #11032 the new feature of Go 1.14 is causing several second delays in startup in certain situations. Debugging shows it spending several seconds handling SIGURG commands during init:
```
6922:04:51.984234 trace init() ./modules/queue/unique_queue_wrapped.go
remote: ) = 69 <0.000012>
remote: [pid 15984] 22:04:51 write(1, "\ttime taken: 236.761\302\265s\n\n", 25 time taken: 236.761µs
remote:
remote: ) = 25 <0.000011>
remote: [pid 15984] 22:04:51 --- SIGURG {si_signo=SIGURG, si_code=SI_TKILL, si_pid=15984, si_uid=0} ---
remote: [pid 15984] 22:04:52 --- SIGURG {si_signo=SIGURG, si_code=SI_TKILL, si_pid=15984, si_uid=0} ---
remote: [pid 15984] 22:04:52 --- SIGURG {si_signo=SIGURG, si_code=SI_TKILL, si_pid=15984, si_uid=0} ---
```
This causes up to 20 seconds added to a push in some cases as it happens for each call of the gitea hook command. This is likely the cause of #10661 as well and would start to effect users once we release 1.12 which would be the first release compiled with Go 1.14. I suspect this is just a slight issue with the upstream implementatation as there have been a few very similar bugs fixed and reported:
https://github.com/golang/go/issues/37741
https://github.com/golang/go/issues/37942
We should revisit this in the future and see if a newer version of Go has solved it, but for now disable this option in the environment that gitea hook runs in to avoid it.
---
modules/git/command.go | 2 ++
1 file changed, 2 insertions(+)
diff --git a/modules/git/command.go b/modules/git/command.go
index c1f3860731..53a04f64be 100644
--- a/modules/git/command.go
+++ b/modules/git/command.go
@@ -119,6 +119,8 @@ func (c *Command) RunInDirTimeoutEnvFullPipelineFunc(env []string, timeout time.
cmd.Env = env
cmd.Env = append(cmd.Env, fmt.Sprintf("LC_ALL=%s", DefaultLocale))
}
+
+ cmd.Env = append(cmd.Env, "GODEBUG=asyncpreemptoff=1")
cmd.Dir = dir
cmd.Stdout = stdout
cmd.Stderr = stderr