From 5aa81f04faf94361852117b7155f94473cf42a8e Mon Sep 17 00:00:00 2001
From: sdong <siying.d@fb.com>
Date: Thu, 13 Mar 2014 11:21:03 -0700
Subject: [PATCH] Fix extra compaction tasks scheduled after D16767 in some
 cases

Summary:
With D16767, there is a case compaction tasks are scheduled infinitely:
(1) no flush thread is configured and more than 1 compaction threads
(2) a flush is going on by one compaction hread
(3) the state of SST files is in the state that versions_->current()->NeedsCompaction() will generate a false positive (return true actually there is no work to be done)
In that case, a infinite loop will be formed.

This patch would fix it.

Test Plan: make all check

Reviewers: haobo, igor, ljin

Reviewed By: igor

CC: dhruba, yhchiang, leveldb

Differential Revision: https://reviews.facebook.net/D16863
---
 db/db_impl.cc | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/db/db_impl.cc b/db/db_impl.cc
index 52c538277..cc17e743d 100644
--- a/db/db_impl.cc
+++ b/db/db_impl.cc
@@ -1842,7 +1842,7 @@ void DBImpl::MaybeScheduleFlushOrCompaction() {
         // memtable flush needed
         bg_flush_scheduled_++;
         env_->Schedule(&DBImpl::BGWorkFlush, this, Env::Priority::HIGH);
-      } else {
+      } else if (options_.max_background_flushes > 0) {
         bg_schedule_needed_ = true;
       }
     }