Commit graph

3 commits

Author SHA1 Message Date
Colin Cross
d7cfaeeebc Fix a bug in OncePer.Get that could return a waiter
OncePer.Get must call maybeWaitFor on the value it reads, otherwise
it could return a waiter instead of the real value.

Test: onceper_test.go
Change-Id: I7d407bd1c577dbb43bc14fa107d5f606bf2b1c67
2019-02-19 11:19:09 -08:00
Colin Cross
e5cdaf9221 Make OncePer.Once reentrant
The value constructor passed to OncePer.Once may call back into
Once.  Replace the global mutex with a temporary channel stored
in the map using the key, and have callers for the same key
wait on the channel if they find it instead of a real value.

Test: TestOncePerReentrant
Change-Id: Ifa88a3c48981b5076b83f47fbdee5d26311725c6
2019-02-12 19:03:53 +00:00
Colin Cross
571cccfcbc Prepare for a type-safe OnceKey
Add an opaque OnceKey type and use it for all calls to Once in
build/soong.  A future patch will convert the arguments to
Once* to OnceKey once users outside build/soong have been updated.

Test: onceper_test.go
Change-Id: Ifcb338e6e603e804e507203c9508d30ffb2df966
2019-02-06 01:52:41 +00:00