From 53075c0a1f9d1b1fe4498231b1de56333fab58a7 Mon Sep 17 00:00:00 2001 From: Nalin Dahyabhai Date: Wed, 22 Feb 2017 16:22:00 -0500 Subject: [PATCH] Synchronize the cursor returned by followJournal Make sure that the cursor value returned by followJournal() is the last of the values returned by its goroutine's calls to drainJournal() by waiting for it, rather than returning a value that may be superceded by another if we're singalling the goroutine that it should exit by closing a pipe. Signed-off-by: Nalin Dahyabhai Upstream-commit: d57c330617efb97cad736a3e4ede82bb46ebbbf2 Component: engine --- components/engine/daemon/logger/journald/read.go | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/components/engine/daemon/logger/journald/read.go b/components/engine/daemon/logger/journald/read.go index 541fab7055..9ccf3d4579 100644 --- a/components/engine/daemon/logger/journald/read.go +++ b/components/engine/daemon/logger/journald/read.go @@ -246,6 +246,8 @@ func (s *journald) followJournal(logWatcher *logger.LogWatcher, config logger.Re s.readers.readers[logWatcher] = logWatcher s.readers.mu.Unlock() + newCursor := make(chan *C.char) + go func() { for { // Keep copying journal data out until we're notified to stop @@ -274,6 +276,7 @@ func (s *journald) followJournal(logWatcher *logger.LogWatcher, config logger.Re s.readers.mu.Unlock() C.sd_journal_close(j) close(logWatcher.Msg) + newCursor <- cursor }() // Wait until we're told to stop. @@ -283,6 +286,8 @@ func (s *journald) followJournal(logWatcher *logger.LogWatcher, config logger.Re C.close(pfd[1]) } + cursor = <-newCursor + return cursor }