log: ensure writes are atomic. This means that any Writer can be used safely even when Output is called concurrently. Fixes issue 1302.
log: ensure writes are atomic.
This means that any Writer can be used safely
even when Output is called concurrently.
Fixes issue 1302.

R=r, nigeltao_gnome
CC=golang-dev
http://codereview.appspot.com/3300042

Committer: Rob Pike <4dc7c9ec434ed06502767136789763ec11d2c4b7@golang.org>
abustany/go,abustany/go,abustany/go,abustany/go,abustany/go,abustany/go,abustany/go