From 2569a58f0859c5a6335ddea88f3752bcc2238d45 Mon Sep 17 00:00:00 2001
From: Andreas Rumpf <rumpf_a@web.de>
Date: Sat, 24 Sep 2016 02:27:04 +0200
Subject: [PATCH] fixes #4746

---
 lib/system/channels.nim | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/lib/system/channels.nim b/lib/system/channels.nim
index 4d8bc581db..0c97bc8db0 100644
--- a/lib/system/channels.nim
+++ b/lib/system/channels.nim
@@ -242,8 +242,10 @@ proc recv*[TMsg](c: var Channel[TMsg]): TMsg =
 
 proc tryRecv*[TMsg](c: var Channel[TMsg]): tuple[dataAvailable: bool,
                                                   msg: TMsg] =
-  ## try to receives a message from the channel `c` if available. Otherwise
-  ## it returns ``(false, default(msg))``.
+  ## try to receives a message from the channel `c`, but this can fail
+  ## for all sort of reasons, including contention. If it fails,
+  ## it returns ``(false, default(msg))`` otherwise it
+  ## returns ``(true, msg)``.
   var q = cast[PRawChannel](addr(c))
   if q.mask != ChannelDeadMask:
     if tryAcquireSys(q.lock):