From: Emmanuel T Odeke <emmanuel@orijtech.com>
Date: Wed, 12 Jun 2019 15:19:31 +0000 (-0700)
Subject: os: document File's concurrent operation resource limits
X-Git-Tag: go1.13rc1~70
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=919594830f17f25c9e971934d825615463ad8a10;p=gostls13.git

os: document File's concurrent operation resource limits

Document that *os.File is subject to resource limits
for concurrent operations. We aren't documenting
a specific number of concurrent operations because that
number is OS/system dependent. This limit comes from:
    internal/poll/fd_mutex.go
where we use 20 bits to count locks.

Fixes #32544

Change-Id: I7d305d4aaba5b2dbc6f1ab8c447117fde5e31a66
Reviewed-on: https://go-review.googlesource.com/c/go/+/181841
Reviewed-by: Rob Pike <r@golang.org>
---

diff --git a/src/os/file.go b/src/os/file.go
index 96df3fb5e9..c13babe5f7 100644
--- a/src/os/file.go
+++ b/src/os/file.go
@@ -34,6 +34,10 @@
 //	}
 //	fmt.Printf("read %d bytes: %q\n", count, data[:count])
 //
+// Note: The maximum number of concurrent operations on a File may be limited by
+// the OS or the system. The number should be high, but exceeding it may degrade
+// performance or cause other issues.
+//
 package os
 
 import (