Fix multiple issues with a driver pool#250

Merged

dennwc merged 4 commits intobblfsh:masterfrom dennwc:fix_timeout

Feb 13, 2019

+68-22

Commits on Feb 12, 2019

add a flag to enable pprof
Denys Smirnov
committed
pass the context when starting the driver - client may decide to wait
Denys Smirnov
committed
don't populate the driver pool if the driver startup fails
Denys Smirnov
committed
daemon: rw mutex for the pool; acquire the lock on Stop as well
Denys Smirnov
committed