Summary:
Here I try to populate the writes done as part of a Haxl computation
in an IORef inside the Environment.
`IVar` which is the synchornisation point,
also acts as the point where we store intermediate writes for Haxl
computations, so they can be memoized and reused whenever a memoized
computation is done again. This is done inside `getIVarWithWrites` function.
This works, because we create new IVars when running a memo computation
or a data fetch, and it is only at these places where we need to create a new
environment with empty writes to run the computation in. So I run every memoized
computation in a new environment (with empty writes) and populate the writes in this new
environment. At the end of the memoized computation, I look up these writes from the `IVar`
and also add them to the original environment. This way ultimately all writes are correctly
propagated upwards to the top level environment user passes to `runHaxl`.
This logic lives inside `execMemoNow`.
Reviewed By: simonmar
Differential Revision: D14342181
fbshipit-source-id: a410dae1a477f27b480804b67b2212e7500997ab
Summary: I noticed this test was broken in `cabal test` recently.
Reviewed By: mic47
Differential Revision: D6857296
fbshipit-source-id: ca7d15ba841f1dc79acccf1cd4999e8fcea994c8
Summary:
This isn't pretty, but it's the least intrusive and most efficient way
I could find to do it.
The tricky part is that when doing multiple putResults in the same
child thread, we have to ensure the *last* one (and only the last one)
is putResultFromChildThread.
Reviewed By: xich
Differential Revision: D6519631
fbshipit-source-id: 1c3c40f311031ac4cc8ed82daefcb7740b91541e
