Summary:
Make the interface consistent with the other queue algorithms.
push
try_push
try_push_for
try_push_until
pop
try_pop
try_pop_for
try_pop_until
peek
try_peek
try_peek_for
try_peek_until

Reviewed By: yfeldblum, djwatson

Differential Revision: D8262170

fbshipit-source-id: 0299e947a0069eacafd1315c920ec6e1b36675f3

Summary: Weak reference can be used if it's ok for some tasks to be dropped when Executor is destroyed.

Reviewed By: yfeldblum

Differential Revision: D8309958

fbshipit-source-id: 8ecc86a8be181a9eb695aa12305b2a30b6f4b60e

Summary:
Moved `Future::within` to `FutureBase::withinImplementation`, and changed it to return a `SemiFuture`.
`SemiFuture::within` uses it directly, and `Future::within` uses it then attaches the current executor or falls back to the inline executor to preserve existing behavior.

Reviewed By: yfeldblum

Differential Revision: D8269907

fbshipit-source-id: 76e235a2ecb2c648603961d0ac0ac17bf646d027

Summary:
[Folly] Support self-copy in `small_vector`.

And refactor move-assignment to look like the fixed copy-assignment for symmetry.

Reviewed By: Ahmed-Salama

Differential Revision: D8321122

fbshipit-source-id: 2c8b26ad6c4e538266082df29276b827cf4505fc

Summary: When vector intrinsics are not available, `visitAllocationClasses` fails to compile as it is a member function of a template class and it invokes a member function of a template base class without explicit `this->`.

Reviewed By: yfeldblum, nbronson

Differential Revision: D8300168

fbshipit-source-id: 1c1619bd1c864535648e531b218d2cf1ffef767b

Summary:
VLOG(1) shows up in Android logs, which is annoying as some of our
tools try to repeatedly connect.

Reviewed By: yfeldblum

Differential Revision: D8297987

fbshipit-source-id: 45cf4320d2e2fcf570117fee6aef133b2d9986e6

Summary:
There is no guarantee that the default branch in git is 'master'; so
    unless specified we checkout a tag along the 'dev' branch, which is not
    intended as it is the master branch that tracks releases for Zstd.

Reviewed By: jstrizich

Differential Revision: D8297843

fbshipit-source-id: 8497dc75c399ae7c86e27b28fdb73898ef4b1a4e

Summary: `s/Future/SemiFuture/` on `SemiFuture` ctor and fixed typo `s/Timeekeeper/Timekeeper/`.

Reviewed By: yfeldblum

Differential Revision: D8290658

fbshipit-source-id: 99ddbdecc0302e620bd2b4ebce74c6080cf81aec

Make Future<T>::delayed complete on correct executor 5/n: Add back Future::delayed with correct behaviour

Summary:
Overall plan to modify Future<T>::delayed to complete on the same
executor as the input future.

[folly::Futures] Make Future<T>::delayed complete on correct executor 5/n:
 * Add back future::delayed.
 * Have Future::delayed complete on input executor.
 * r-value qualify Future::delayed

Reviewed By: yfeldblum, marshallcline

Differential Revision: D8238220

fbshipit-source-id: 79afa8cc9a9fe588609ad186ad62f714ee322f7d

Summary: [Folly] Let `Sychronized` move-constructor not lock the source object, since it is an rvalue-reference and the move-constructor code may therefore be assumed to have the only live reference to the source. Same with the move-assignment operator.

Reviewed By: aary

Differential Revision: D8219883

fbshipit-source-id: f62ff87197ac4b9ceed290a73a05062ab8ed45c4

Summary:
Reusing a context can provide significant efficiency benefits.

Depends on D8172871.

Reviewed By: yfeldblum, terrelln

Differential Revision: D8287767

fbshipit-source-id: 2565e7a959b2ac0911f0a4d6e1596f9da6d12ee8

Summary:
Reusing a context can provide significant efficiency benefits.

Depends on D8172801.

Reviewed By: yfeldblum, terrelln

Differential Revision: D8172871

fbshipit-source-id: f92c85410a35643502d28922583ee0ed0b4386c9

Summary: Clear/read OpenSSL errors after certain ops.

Reviewed By: mingtaoy

Differential Revision: D8277088

fbshipit-source-id: aa436657c3bca3a081cd56858e09da57a03cda05

Summary: Use static FOLLY_TLS ThreadEntry to avoid an ASAN deadlock due to new after fork

Reviewed By: philippv

Differential Revision: D8272580

fbshipit-source-id: e2dc069e81d15f14be9f96a26d30de7482ced0cf

Summary: Replaced boost::algorithm::to_lower() with std::transform()

Reviewed By: yfeldblum

Differential Revision: D8264760

fbshipit-source-id: f6faa46c0bbced3a08c02b93eacbb58eb6927890

Summary:
* One function needed renaming
* One bug needed to be worked around (content size defaulting to 0)

Reviewed By: yfeldblum

Differential Revision: D8264565

fbshipit-source-id: 1abe5fb79b525108e64857dc28d5582372fcc165

Summary: The instance method is permitted on `const` objects, so the ADL method should also accept a `const&` input.

Reviewed By: yfeldblum

Differential Revision: D8240295

fbshipit-source-id: 960aa5567afea3f52b91c1b83566820f5ecefc4d

Summary:
IntervalRateLimiter was already operating on millisecond
granularity. coarse_steady_clock offers better performance because
it's on millisecond granularity.

Reviewed By: yfeldblum

Differential Revision: D8245042

fbshipit-source-id: 7ce0e347c0498ff2741adc727577c3bb2ce63979

Summary: Iterate only through the threads that have in use entries - v2

Reviewed By: djwatson

Differential Revision: D8143429

fbshipit-source-id: 51098ff8e1fef7aaf9f1c0f2ddbf7ebb579cbeb4

Summary:
[Folly] Cut `FOLLY_IS_TRIVIALLY_COPYABLE` macro, replacing all uses with `folly::is_trivially_copyable`.

And cut `folly::IsTriviallyCopyable` with member-type-detection support, and move `folly::traits_detail::is_trivially_copyable` to `folly::is_trivially_copyable`.

`FOLLY_IS_TRIVIALLY_COPYABLE` and `folly::IsTriviallyCopyable` were there to support gcc < 5.

Reviewed By: Orvid

Differential Revision: D8246972

fbshipit-source-id: 8af9bbdbfac8671a61ebaa200dbfd2426a40d2eb

Summary:
x86_64 chips with SSE >= 4.2 and many aarch64 chips have
CRC32-specific instructions with excellent latency.  This diff switches
the bit mixer applied to untrusted hash functions to use these instructions.
This is a noticeable win for the F14 uses that are CPU front-end bound.

Reviewed By: yfeldblum

Differential Revision: D8245688

fbshipit-source-id: f6a1c1c2a6365201178c653cd5d8c04fbac8d78e

Summary:
Overall plan to modify Future<T>::delayed to complete on the same executor as the input future.

4/n: Remove Future::delayed completely to ensure that all users are on delayedUnsafe so that when we put delayed in with correct behaviour there is no incorrect use.

Reviewed By: marshallcline

Differential Revision: D8223327

fbshipit-source-id: c675d2d51afa2131eee5871afea45f1c6cc65a77

Summary: Minor refactoring of several fbcode/folly/ classes.  Primarily constification, replacing custom code with call to boost, etc.

Reviewed By: yfeldblum

Differential Revision: D8239891

fbshipit-source-id: 14cb109b5deb27f8949b7889d195fcba29e2038c

Summary:
F14 can apply some additional optimizations for trivially
copyable and trivially destructible values in the case that the allocator
doesn't do anything special in its construct and destroy methods.
Previously this was gated based on whether the allocator was exactly
std::allocator, but that causes this optimization to be missed in some
important cases.  This diff extends the checking machinery to test if
there is actually a default construct or destroy method in the allocator
(they are optional) and to test if there is a manual override of the
conservative default check.

Reviewed By: yfeldblum

Differential Revision: D8191437

fbshipit-source-id: c55b8f32427c3f0eff5c8ef42d7b51a57b0cbd1f

Summary:
Core::hasResult() is called in lots of places:

- future.result()
- future.get()
- future.wait()
- future.within()
- future.hasValue()
- future.hasException()
- future.getTry()
- future.raise()
- future.poll()
- promise.setInterruptHandler()
- etc.

This diff improves that function as follows (source: godbolt, with optimization, on both gcc and clang):

- old: 7 instructions w/ 2 conditional jumps + 1 unconditional jump; fastest path is 4 instructions w/ 2 jumps, slowest is 7 instructions w/ 2 jumps
- new: 3 instructions w/ 0 jumps

Small improvement overall, but to a widely used function.

Reviewed By: yfeldblum

Differential Revision: D8231048

fbshipit-source-id: 83a9f5c602475c2ca7066a45635d807596ecf37d

Summary:
- Add class-level description including states & state-transitions
- Add method-level contracts to Core

Reviewed By: yfeldblum

Differential Revision: D7923362

fbshipit-source-id: f7b0f340b6a768c33068547aa4a38acc72ad7088

Summary: We are changing `folly::collectAll` to return `SemiFuture` rather than `Future` and this is needed as an interim step. After all calls to `collectAll` are changed to `collectAllSemiFuture`, we'll be renaming it back to `collectAll`.

Reviewed By: yfeldblum

Differential Revision: D8210974

fbshipit-source-id: e4a7464f4a1c3ede157b8377a4df97d943001f60

Summary:
[Folly] Simplify `folly/test/ExecutorTest.cpp`.

* `auto` is fine.
* `auto` is equivalent to `auto&&` when copy-elision is performed - in the former case, the compiler may use copy-elision to elide materialization of a temporary, whereas in the latter case, the compiler must materialize a temporary, rendering them equivalent..
* `std::addressof` is useful only for unknown types; prefix-`&` is fine for known types which do not overload that operator.

Reviewed By: Orvid

Differential Revision: D8226453

fbshipit-source-id: c987c71d65c01a2d8ca81960f796fcc6100c3484

Summary:
F14MapTest's random test checks afterward that some events
happened, but this is not assured on different platforms.  This diff
inverts the checks so that the loop is continued until all necessary
events have triggered.  Hypothetical failures of the condition checked
by the removed EXPECT_GE checks will be visible after this diff as
test timeouts.

Reviewed By: andreazevedo

Differential Revision: D8226301

fbshipit-source-id: 2ec295b0f5f47e0726cdf1eb64b81c0c23eedae2

Summary:
Container swap is not allowed to fall back to allocation + move
when allocators are not equal, which makes swap undefined in that case.
FOLLY_SAFE_CHECK it.  For zero-size allocators this check will be optimized
away at compile time.

Reviewed By: yfeldblum

Differential Revision: D8209358

fbshipit-source-id: 6555f102c51c97f1e1ecfebd0597c532849184b5

Reviewed By: yfeldblum

Differential Revision: D8208046

fbshipit-source-id: 58ae8a1df7fedd7bb8ec63bcb51c82ec7fb3c9e8

Summary:
Avoid spin-waiting for threads that may be descheduled by making steps that used to require waiting for action by a specific thread wait-free. The changed steps are:
- Allocating and linking the next segment
- Advancing tail to the next segment
- Advancing head to the next segment

For SPSC, the consumer still must wait for the producer to advance tail before it advances head.

Reviewed By: djwatson

Differential Revision: D8124279

fbshipit-source-id: 4dc9b2c1f333a71e7283175e0f9c4ab2eaeb7549

Make Future<T>::delayed complete on correct executor 2/n: Apply codemod future delayed to delayed unsafe

Summary:
Overall plan to modify Future<T>::delayed to complete on the same
executor as the input future.

2/n: Codemod Future<T>::delayed to Future<T> delayedUnsafe. Name-only change, no behaviour.

Reviewed By: yfeldblum

Differential Revision: D8217994

fbshipit-source-id: e20f861c2545f08a177b78e1dba643b267146e94

Summary: We do not want implicit copies of `KeepAlive`, because they may be accidental and they impose an overhead. However, making a copy by calling `folly::getKeepAliveToken(keep_alive.get())` does not look very nice. Also, in case that `keep_alive` is a dummy, it makes an unnecessary call to `Executor::keepAliveAcquire`, which will return false but cannot be inlined usually because it's a virtual function. This diff adds a `copy() const` method which returns a copy of the `KeepAlive` object. It only calls `Executor::keepAliveAcquire` if the original object is not a dummy.

Reviewed By: yfeldblum, andriigrynenko

Differential Revision: D8203839

fbshipit-source-id: bb595d3836405bd84e55c4214ac19127b1e0e42a

Summary:
This diff adds a simple unit test, verifying that construction
of a `KeepAlive` object (either from `Executor*` or move construction)
calls `keepAliveAcquire` and `keepAliveRelease` the correct
number of times.

Reviewed By: elsteveogrande

Differential Revision: D8203944

fbshipit-source-id: 297beeaab99c55d7284ca06edd5e6b9023e27619

Summary:
Somehow gcc49 as used in travis-ci is having a hard time deciding which
constructor to call in `folly/executors/test/ThreadPoolExecutorTest.cpp:721`.
It can't decide between `folly/executors/CPUThreadPoolExecutor.h:69` and
`folly/executors/CPUThreadPoolExecutor.h:83`.
All this diff does is give it a hint about which constructor it should
use.

Reviewed By: yfeldblum

Differential Revision: D8219425

fbshipit-source-id: d92b08efc8bad795ce4a6775efd1e0512aaa6bb5

Summary: [Folly] Cut Futures private invocability helpers, which can be replaced with invoke_result, is_invocable, etc.

Reviewed By: marshallcline

Differential Revision: D8087901

fbshipit-source-id: 17282d77aaff61350d1e7f1b0c363c25db8fb5b1

Summary: [Folly] No longer allow continuations taking non-const lvalue-ref, since that is not really necessary - callers can get all the same results using continuations taking non-const rvalue-ref instead.

Reviewed By: Orvid

Differential Revision: D8166011

fbshipit-source-id: 468d049c6034339f3caf1a82fbc8c755ec2f51e6

Summary:
Overall plan to modify Future<T>::delayed to complete on the same
executor as the input future.

1/n: Adds Future<T>::delayedUnsafe that is identical to Future<T>::delayed
but acts as a codemod target.

Reviewed By: marshallcline

Differential Revision: D8209451

fbshipit-source-id: ee9c1184de2847e142516b315140fcc6d43948c5

Summary:
`libfollylogging_example` is failing to link because it cannot find the
definition of `folly::default_domain`.
This diff adds Hazptr.cpp to the build script, which actually defines
`folly::default_domain`.

Reviewed By: yfeldblum

Differential Revision: D8217299

fbshipit-source-id: 5fb36ef2f160cf45e93c2fc4098d58d384390e5d