Summary:
[Folly] `Synchronized::exchange`, for assigning a new value and returning the old value.

(Note: this ignores all push blocking failures!)

Differential Revision: D6653482

fbshipit-source-id: 68f4bd330bc2cf37bb92aff98b8ce3221334112e

Summary: [Folly] Fix copyright lines in `folly/synchronization/Baton.h`.

Reviewed By: meyering

Differential Revision: D6665595

fbshipit-source-id: 84aa0c475f01c858d543a047103437c083b3a4ed

Summary: Adds wording indicating that it is safe to call this function multiple times.

Reviewed By: yfeldblum

Differential Revision: D6625530

fbshipit-source-id: 2305f7b8e3451a6663003d23230b22c6f65a3729

Summary: [Folly] Cut `glog` include from `folly/synchronization/RWSpinLock.h`.

Reviewed By: meyering

Differential Revision: D6659300

fbshipit-source-id: 0f1b79d98be0656694f57667252a16acd54e2414

Summary: [Folly] Move `folly/RWSpinLock.h` to `folly/synchronization/`.

Reviewed By: elsteveogrande

Differential Revision: D6659265

fbshipit-source-id: 307723e22f42ceb104f26657aed8b34f7e183afb

Summary:
[Folly] Extract `WaitOptions` from `SaturatingSemaphore`.

This type may prove useful in the future for a variety of similar cases, and so does not need to be locked up inside `SaturatingSemaphore`.

Additionally:
* Extract and redraft a comment from `Baton`.
* Rename `pre_block` to `spin_max`.

Reviewed By: djwatson, aary

Differential Revision: D6632875

fbshipit-source-id: 6b7faeeb6e1ac2011a037c2b560def0ee2e9f3d4

Summary: [Folly] Move `folly/BitIterator.h` to `folly/container/`.

Reviewed By: djwatson

Differential Revision: D6648357

fbshipit-source-id: 5617e3210f58435fcbf3ef07fa745da47dbce475

Summary: [Folly] Move `InPlaceConstruction` test in `folly/test/SynchronizedTest.cpp`.

Differential Revision: D6653481

fbshipit-source-id: f0eadfd6c2f41e9f597a666d01e40d5553447c70

Summary: [Folly] Fix copyright lines for `folly/Synchronized.h`.

Reviewed By: meyering

Differential Revision: D6664326

fbshipit-source-id: 71a0fc17358e41dfc751b8bcb0736c288975a4a0

Summary: Add methods to create a X509StoreUniquePtr from a ca file or buffer.

Reviewed By: yfeldblum

Differential Revision: D6662538

fbshipit-source-id: 646f61596f2787756b2fa5998a43f36d75a91d90

Summary:
This breaks while building on aarch64 each time because the headers aren't
in the repo. I did a quick grep and I don't see anything in folly that
uses OptionalAwaitable or OptionalPromise so perhaps it's possible to
remove instead, can do that if preferred.  Depends on D6611609 to complete
build of tests cleanly.

Reviewed By: yfeldblum

Differential Revision: D6643759

fbshipit-source-id: f480d50383f85fbe905daaad74198b6557609347

Summary:
[Folly] Avoid allocs in dtors in futures `collect`.

`CollectContext`, a detail helper type, allocates storage for a results vector in its dtor. This is an awkward situation and should be avoided.

Reviewed By: ericniebler

Differential Revision: D6649299

fbshipit-source-id: 87746fcc78fa080f63505d7bb864aca6c4a3d7cb

Summary:
While trying to build folly on aarch64 found that the SharedMutexTest
wouldn't build because it uses RWTicketSpinLock which was only available
on x86 platforms.  Updated to allow build on aarch64 after suggestion by Orvid

Reviewed By: yfeldblum

Differential Revision: D6611609

fbshipit-source-id: 8ec477cdedac0f0a705608bbac42dd63b3efb919

Summary: Complete set of get and getVia methods including addition of a result operation on FutureBase that provides functionality of the old getTry on Future by returning a Try by reference.

Reviewed By: yfeldblum

Differential Revision: D6640056

fbshipit-source-id: 3ac01f7bc4b128e641f08d9a99280a18ffce82f9

Summary: [Folly] Remove `SingletonVault` C bindings. They are not generally needed.

Reviewed By: spalamarchuk

Differential Revision: D6632104

fbshipit-source-id: 3aecb35277bc76a2171487404d6994a5ea296afc

Summary:
[Folly] Use member-invoke traits in `LockTraits`.

V.s. spelling out the SFINAE manually.

Reviewed By: Orvid

Differential Revision: D6637380

fbshipit-source-id: 212e0cc5e54503b31e458b6bda93b2a3b24e6c59

Summary:
[Folly] `invoke` and member-`invoke` tweaks.

* Direct `static_cast` v.s. `std::forward` is okay.
* Implement member-`invoke` in terms of `invoke` and extract most of it to a helper type, minimizing the code directly generated by the preprocessor.

Reviewed By: spalamarchuk

Differential Revision: D6644119

fbshipit-source-id: e58a83d7ff2dd71b0377d864ef089c34e0239c8d

Summary: [Folly] Add `ColdClassTest.cpp` to oss builds.

Reviewed By: spalamarchuk

Differential Revision: D6648831

fbshipit-source-id: f8d8a727d63e4e8b83391db454de990027f1bad4

Summary: [Folly] Fix copyright lines for `Bits.h` and move `BitsBenchmark.cpp`.

Reviewed By: spalamarchuk

Differential Revision: D6648828

fbshipit-source-id: 5eed558ac2d47a1497d64173bc84a4ca27d79764

Summary:
[Folly] Fix some copyright lines in `folly/`.

(Note: this ignores all push blocking failures!)

Reviewed By: Orvid

Differential Revision: D6648215

fbshipit-source-id: 6fc446028ff79aa44116424e86ad454077717f8e

Summary:
[Folly] Fix some copyright lines in `folly/lang/`.

(Note: this ignores all push blocking failures!)

Reviewed By: Orvid

Differential Revision: D6648214

fbshipit-source-id: fa2afdb8369252b74b914622ad39f7f27261d2c1

Summary:
[Folly] Fix some copyright lines in `folly/experimental/symbolizer/`.

(Note: this ignores all push blocking failures!)

Reviewed By: Orvid

Differential Revision: D6648183

fbshipit-source-id: 36f9df5af91400a37dfa5ee2b209ffd47d5069df

Summary:
[Folly] `constexpr_pow`.

The power function. Initially, supports nonnegative integers only.

Reviewed By: spalamarchuk

Differential Revision: D6646376

fbshipit-source-id: 33a5a45f496b6f3be52d0cd7e3a5f2cd7edb3026

Summary:
[Folly] Give detail functions in `ConstexprMath.h` decorated names.

So that other code also in `namespace folly::detail` which invokes the non-detail functions will result in ambiguity.

Reviewed By: spalamarchuk

Differential Revision: D6646313

fbshipit-source-id: 679e4cfe1c90f494acacef8b2a38a453db4d79d5

Summary: The rename is to bring it closer in line with the naming conventions in the standard library, and the move is because it doesn't make sense to have clocks defined in stop_watch.

Reviewed By: Orvid

Differential Revision: D6329551

fbshipit-source-id: 09d9a48eb47b8fd3761a1bd4350d9ca748fe1f96

Summary:
It was missing, so it wasn't being installed.

Fixes https://github.com/facebook/folly/issues/727

Reviewed By: Orvid

Differential Revision: D6642322

fbshipit-source-id: 70c10e1265410f73b6c0cd759ce51a5176bfef83

Summary:
[Folly] Tweaks to `folly::call_once` and `folly::once_flag`.

In particular:
* Move the template class out of `detail`.
* Add parameterization by the atomic type.
* Expand the comments.

Reviewed By: Orvid

Differential Revision: D6637250

fbshipit-source-id: 3806580ca0badf8464f637750c4873b2aba9f916

Summary:
std::remove_cvref is like std::decay, but without the function to
pointer and array to pointer decays

Backport of http://en.cppreference.com/w/cpp/types/remove_cvref

Reviewed By: yfeldblum

Differential Revision: D6639513

fbshipit-source-id: 2a5e252678aacc09acf6ce4565872e7efb9b48f3

Summary:
As it stands the user cannot use initializer list constructors in the
underlying type, this fixes that and provides a good interface change.
This allows them to use list initialization, which works with initializer
lists

Reviewed By: yfeldblum

Differential Revision: D6620994

fbshipit-source-id: c29199f97b434d84dd8d4cee2f00c5eccb316166

Summary:
A ParkingLot API inspired by linux futex syscall, and WebKit's parkingLot.

Extends the futex interface with lambdas, such that many different sleeping abstractions
can be built.

Reviewed By: yfeldblum, aary

Differential Revision: D6581826

fbshipit-source-id: dba741fe4ed34f27bfad5f5747adce85741441e0

Summary: Add getVia and getTryVia to SemiFuture to allow driving chains of work conveniently in the current thread.

Reviewed By: yfeldblum

Differential Revision: D6631898

fbshipit-source-id: 324ef342a44d4ef502188b3cffde17103f0e6cb2

Summary:
Move getTry from FutureBase to Future and SemiFuture.

Make SemiFuture version move the result out for consistency with get.

Reviewed By: yfeldblum

Differential Revision: D6638561

fbshipit-source-id: 551c0f06ed52ef6d8976a5971a5e90b3ab793da0

Summary: Add more detail to testing return of SemiFuture from a continuation to ensure correct behaviour.

Reviewed By: yfeldblum

Differential Revision: D6637565

fbshipit-source-id: 096a7ca140e6bdef7baab6725e86d25cf79742d8

Summary:
To ensure that we do not end up with continuable futures without attached executors we should deprecate folly::makeFuture. In most cases folly::makeSemiFuture is adequate here.

This diff only adds comments to dissuade future use.

Reviewed By: yfeldblum

Differential Revision: D6628800

fbshipit-source-id: c2b91df351cc5980c1bfb752f7536d320ef8168a

Summary: Adds getSemiFuture functionality to folly::SharedPromise. Implements getFuture in terms of this, using folly::InlineExecutor to ensure that there is no change of behaviour.

Reviewed By: yfeldblum

Differential Revision: D6628723

fbshipit-source-id: 0ce7c7773b9290998ce87f84fa5d82ba957f0313

Summary:
[Folly] Namespacing and comments in `folly/Likely.h`.

This adds `FOLLY_LIKELY` and `FOLLY_UNLIKELY`.

Reviewed By: Orvid

Differential Revision: D6636136

fbshipit-source-id: da93220201cabca91b4477ab98269a0febb735db

Summary: [Folly] Tweaks to `AtomicStruct`.

Reviewed By: Orvid

Differential Revision: D6636432

fbshipit-source-id: 274c118a732287219c569d7d3f4e170f275518f1

Summary: Returning a SemiFuture from a continuation should work by correctly checking the types and returning a folly::Future on the same executor as the original future that .then was applied to.

Reviewed By: yfeldblum

Differential Revision: D6597273

fbshipit-source-id: cf2016a344d4b29f1d31c1da20c89df5b4cfe64e

Summary:
[Folly] Remove `folly/detail/UncaughtExceptionCounter.h`.

It's a thin and unnecessary shell around `folly/UncaughtExceptions.h`.

Reviewed By: Orvid

Differential Revision: D6636260

fbshipit-source-id: cdf6fa5fefc9fd69586c1c4c1a8443c5e8543b1c

Summary: [Folly] `constexpr_log2_ceil`, like `constexpr_log2` but rounding up.

Reviewed By: Orvid

Differential Revision: D6636433

fbshipit-source-id: a10f031cc9c91cfeba7b74bbf143895a311ca772