Module sync

Thread synchronization primitives.

• Parker, a thread parking primitive.
• ShardedLock, a sharded reader-writer lock with fast concurrent reads.
• WaitGroup, for synchronizing the beginning or end of some computation.

Structs

• Parker
  A thread parking primitive.
• ShardedLock
  A sharded reader-writer lock.
• ShardedLockReadGuard
  A guard used to release the shared read access of a ShardedLock when dropped.
• ShardedLockWriteGuard
  A guard used to release the exclusive write access of a ShardedLock when dropped.
• Unparker
  Unparks a thread parked by the associated Parker.
• WaitGroup
  Enables threads to synchronize the beginning or end of some computation.