Fix data race in unix.BoundEndpoint.UnidirectionalConnect.

Data race is:

Read:
(*connectionlessEndpoint).UnidirectionalConnect:
writeQueue: e.receiver.(*queueReceiver).readQueue,

Write:
(*connectionlessEndpoint).Close:
e.receiver = nil

The problem is that (*connectionlessEndpoint).UnidirectionalConnect assumed
that baseEndpoint.receiver is immutable which is explicitly not the case.
Fixing this required two changes:
1. Add synchronization around access of baseEndpoint.receiver in
   (*connectionlessEndpoint).UnidirectionalConnect.
2. Check for baseEndpoint.receiver being nil in
   (*connectionlessEndpoint).UnidirectionalConnect.

PiperOrigin-RevId: 207984402
Change-Id: Icddeeb43805e777fa3ef874329fa704891d14181

0 files changed, 0 insertions, 0 deletions