Summary: Fix shadown warning for xplat builds

Reviewed By: yfeldblum

Differential Revision: D7811636

fbshipit-source-id: 609b5acaca3cfdd11059ed1ebbaa969e281487a2

Summary:
Calling connect on the UDP socket can avoid route lookups
on the write path. This would be an optimization that would be
useful for clients.

There are several caveats of using connect() which we discovered
during testing. These are documented and unit tests have been written
for each of them.

Reviewed By: yfeldblum

Differential Revision: D7802389

fbshipit-source-id: 09b71373a3a95c5dab73ee9345db0dbbf66d4ec5

Summary: Some links are complaining of multiple definitions. Move to the cpp file to resolve.

Reviewed By: yfeldblum

Differential Revision: D7806874

fbshipit-source-id: f25342d647505b676ba3659400c63d6a59344024

Summary: This header is no longer needed since D7687476.

Reviewed By: yfeldblum

Differential Revision: D7804756

fbshipit-source-id: 6596f5296965b593ab5b0decf4c67203e19b03c8

Summary: As title

Reviewed By: tageorgiou

Differential Revision: D7804647

fbshipit-source-id: 9a58de258cd49a4d15ded05163975304c0e7e83b

Summary: This worked in clang but not in gcc. Quick fix

Differential Revision: D7800576

fbshipit-source-id: fcd04c0779f8a176043f3dede61289830a1ef607

Summary: Introduces two QuantileEstimators. Both estimators use the TDigest for estimating quantiles, and giving accurate sum, count, and mean. One estimator uses a single digest, and the other uses a SlidingWindow of 60 digests. All writes to the data structure are buffered for 1 second.

Reviewed By: anakryiko

Differential Revision: D7645824

fbshipit-source-id: 4f1f2c25388c3280f148591502449f857c6467d3

Summary: [Folly] Use `invoke_result` v.s. `std::result_of`, which is deprecated.

Reviewed By: aary, ericniebler

Differential Revision: D7771480

fbshipit-source-id: 1d89d489be98bfbe2014f2d6b5fc037f02147876

Summary: [Folly] Cut unused alias `isFutureResult`.

Reviewed By: Orvid

Differential Revision: D7787146

fbshipit-source-id: 44ed51e9e04c71530f67fc6dceb76b247dcadb55

Summary:
The test was missing a `main` meaning that it would fail even if libc++ was in use, making all the rest fail on macos for example.
Closes https://github.com/facebook/folly/pull/831

Reviewed By: Orvid

Differential Revision: D7787115

Pulled By: yfeldblum

fbshipit-source-id: 4a10323298be3f26f783fa1257cbde2483fb75b9

Summary:
The libstdc++ implementation of `std::unordered_map|set` determines whether to
cache a per-node hash code based on (1) whether the supplied hasher is fast
(true by default) and (2) whether the hashing operation will throw.

Mark the `operator()` of hashers of numeric types (integral, float, enum)
`noexcept`, such that stl unordered containers won't cache a hash code. This is
essentially free memomy savings, as comparing the cached hash code is as
expensive as comparing the numerical types directly.

Reviewed By: luciang

Differential Revision: D7784214

fbshipit-source-id: 020e1c38265f33a482b6ba913a11f1a383e840f8

Reviewed By: yfeldblum

Differential Revision: D7765404

fbshipit-source-id: 3f09d6806d0fb98cb59529adc6ea2d51fa7ccbbb

Summary:
BufferedStat hooks up the DigestBuilder and a Digest or a SlidingWindow

Every windowDuration time, the DigestBuilder builds a new digest that will be merged into the central data structure (either a digest or a sliding window of digests).

This diff removes the shared buffer from DigestBuilder, as the concurrency model was getting overly complex with it.

Reviewed By: simpkins

Differential Revision: D7629082

fbshipit-source-id: 54027363d37c0fdced287550eea5b12caf6b8138

Summary: [Folly] Use `is_invocable_r` in `MapUtil` v.s. reimplementing it.

Reviewed By: aary

Differential Revision: D7771481

fbshipit-source-id: 41565a06198ed2289206f01a088c3c1b3a01bc8e

Summary: [Folly] Use `is_invocable_r` in `FunctionRef` v.s. reimplementing it.

Reviewed By: ot

Differential Revision: D7769745

fbshipit-source-id: 3cb7bf9908cc6e93c7d19ace9a91c69ba14cdfae

Summary:
OpenSSL 1.1.0 renamed and deprecated X509_CRL_get_lastUpdate -> X509_CRL_get0_lastUpdate
along with X509_CRL_get_nextUpdate -> X509_CRL_get0_nextUpdate

Reviewed By: ngoyal, anirudhvr, Orvid

Differential Revision: D7782339

fbshipit-source-id: 63f04284bb54da87d4235a02890107db8abaa4b4

Summary:
This was exposed by the latest clang with -Wreturn-std-move enabled:
```lang=bash
folly/FBString.h:2487:12: error: local variable 'rhs' will be copied despite being returned by name [-Werror,-Wreturn-std-move]
    return rhs;
           ^~~
folly/test/FBStringTest.cpp:1294:23: note: in instantiation of function template specialization 'folly::operator+<char, std::char_traits<char>, std::allocator<char>, folly::fbstring_core<char> >' requested here
    auto test1 = '\0' + std::move(s1);
                      ^
folly/FBString.h:2487:12: note: call 'std::move' explicitly to avoid copying
    return rhs;
           ^~~
           std::move(rhs)
2 errors generated.
```

Reviewed By: Orvid

Differential Revision: D7776805

fbshipit-source-id: f11ae5a1fc416b8838b8ea74d7f6b488f07cab38

Summary: Need to also allow calling this function with a writeLock.

Reviewed By: magedm

Differential Revision: D7477326

fbshipit-source-id: 403e2667a3f77be4c1d7d06dbd5f36218a659abc

Summary: The test is intended to verify the handling of trailing space.

Reviewed By: yfeldblum

Differential Revision: D7761229

fbshipit-source-id: 0196f57e6c76562562ef1b724f6dff1c7bfd5d81

Summary:
Rename folly/Logging.h to folly/GLog.h.  This header primarily exists to just
include <glog/logging.h>, and it also defines a single `FB_LOG_EVERY_MS()`
macro.

I plan to move the folly/experimental/logging/ directory to folly/logging/
soon, and I want to avoid confusing between this `Logging.h` header and the
separate `folly/logging/` code.

Reviewed By: yfeldblum

Differential Revision: D7754543

fbshipit-source-id: c91b8016d303cd0fae9e688e8782b22d095a6554

Summary:
D7642870 accidentally broke linking of folly when libunwind is available.
It change the code to use the contents of `${FOLLY_LINK_LIBRARIES}` in
folly-deps.cmake, but libunwind was added to `${FOLLY_LINK_LIBRARIES}` after
folly-deps.cmake was included, in FollyConfigChecks.cmake.

This moves the check for libunwind to folly-deps.cmake to fix this issue.  All
of the other checks for external libraries are already in folly-deps.cmake.

Reviewed By: yfeldblum

Differential Revision: D7764762

fbshipit-source-id: 922459a7eefcbd92d3d77c02e9c215bb1a5467cc

Summary: This allows using a keep-alive token in places where Executor* was previously used.

Reviewed By: yfeldblum

Differential Revision: D7751516

fbshipit-source-id: af2cb31191a78306439408dbee78dcd923492e30

Summary:
`PRETTY_TIME_HMS` extends `PRETTY_TIME` by adding additional minutes
and hours units which are more useful for human-reporting of time intervals.

Reviewed By: yfeldblum

Differential Revision: D7762524

fbshipit-source-id: 881936916db182c163a3df14196f4f11fb649527

Summary: [Folly] Avoid using gmock private macros - instead, use only the public interface.

Reviewed By: knekritz

Differential Revision: D7752463

fbshipit-source-id: 625465e7ec93613869e259fe1fe0b08aee7bb7d0

Summary:
This diff adds a method to calculate the amount of memory allocated by F14
sets. It mimics the node structure in `std::unordered_map` to calculate the
results. For certain keys and hashers, the libstdc++ implementation of
`std::unordered_map` caches a hash code in the node. libcpp seems to do this
for everything.

https://github.com/gcc-mirror/gcc/blob/9ce5a00d2d3b8b107cb1ca0e23bf1e31a095f9b6/libstdc%2B%2B-v3/include/bits/hashtable.h#L45-L49
https://github.com/llvm-mirror/libcxx/blob/58bcf28c63e0cf2ee5828e7811829c98bd244dda/include/__hash_table#L117

Depends on D7715573.

Reviewed By: nbronson

Differential Revision: D7728281

fbshipit-source-id: 0aa3ab60c746d3ab6bdb7c879f2f987110e0329d

Summary: Because not everyone is at C++17 yet.

Reviewed By: yfeldblum

Differential Revision: D7751672

fbshipit-source-id: bcca4d4da67d56be0217a940144977f1cc98e5a1

Summary: Add the currency tests to the CMake build so they can be built in open-source.

Reviewed By: yfeldblum

Differential Revision: D7750783

fbshipit-source-id: a6e7f9490e0b88bcfab8b2aa706e1504f2a28c66

Summary:
This looked like a copypasta error. Since there is no duration passed
in, there is no notion of timeout.

Reviewed By: shixiao, Orvid

Differential Revision: D7747574

fbshipit-source-id: 279992d237dd0924ea0be9deafab94c1aef48838

Summary: [Folly] Fix autotools build afte removing `folly/Optional.cpp`.

Reviewed By: akrieger

Differential Revision: D7737170

fbshipit-source-id: 1a9286f240bf5a15ee08b707b69377f8d3cfdb48

Summary:
OpenSSL 1.1.0 uses a fiber-based (makecontext/swapcontext) API to do
asynchronous operations. When some operation deep inside the stack calls
ASYNC_pause_job, SSL_accept returns -1 with error SSL_ERROR_WANT_ASYNC.
OpenSSL chose to use fds to wait on, so after SSL_accept returns, we create an
AsyncPipeReader to restart SSL_accept when the pipe becomes readable, which is our
indication that the async job processing has finished.

Also implemented a test to kick off an async job in a different thread that creates a pipe
and gives the read end back to the SSL* before calling ASYNC_pause_job

Reviewed By: yfeldblum

Differential Revision: D5977514

fbshipit-source-id: 3aba2e45b9357dc28cf7cf785654072f8ba8dd65

Summary: On top of the recent/big EventBaseLoopController cleanup away from most EventBase internal, this is unecessary

Reviewed By: andriigrynenko

Differential Revision: D7734236

fbshipit-source-id: df38cc30fc52df929f096fb878bc1a4b6894850a

Summary:
We don't have a way to get the metadata associated with a given setting name
from outside. This is useful to know the expected type associated with a
given setting name.

Reviewed By: alikhtarov

Differential Revision: D7721340

fbshipit-source-id: e9ad07dd03c172f6f2d4bde5164614ca987c4fd8

Summary: [Folly] Use `throw_exception` in `Optional`, which also respects all stated reasons why the `throw` statement is moved to a separate `.cpp` - to outline it and to permit replacement of its implementation with a call to `std::terminate`.

Reviewed By: akrieger

Differential Revision: D7728129

fbshipit-source-id: 0539f9d16a719b52f5a81b13b5d2ce2b61d36de0

Summary:
The sorting approach used in TDigest is inefficient because it is not leveraging the fact that there are k sorted subarrays. This diff leverages inplace_merge to improve performance.

The cost of merging k digests of size m used to be O(km * log(km)). It is now O(km * log(k)).

Reviewed By: anakryiko

Differential Revision: D7690143

fbshipit-source-id: 1307db153b3cae0bb952d4b872aede8c40ce292c

Summary:
The issue is that std::swap must have the same type for both parameters but the member .swap() for PolyVal takes Poly and then uses std::swap(*this, that).

the fix uses static_cast to change the Poly to a PolyVal for std::swap

Reviewed By: ericniebler

Differential Revision: D7730948

fbshipit-source-id: 8dd93fc3c86b87938a7c0c12ccb3b5209a593730

Summary: Further performance improvements to TDigest by diverging from the algorithm in the paper slightly, but in a manner that does not impact the results at all.

Reviewed By: anakryiko

Differential Revision: D7687476

fbshipit-source-id: f71884b0fb21c9e78418643b82b099b01e96e4c9

Summary:
[Folly] Fix build failures in `folly/io/async/test/AsyncUDPSocketTest.cpp`, which uses private gmock macros to try to override base-class member functions marked `noexcept`.

Using private macros belonging to another library is not the way to go.

Reviewed By: siyengar

Differential Revision: D7728285

fbshipit-source-id: 84c96826f25679dfb8dd0ec5e5985c3cc19f6e3d

Summary:
I suspect the algorithm in the tdigest paper is slightly off. Instead of setting boundaries at k = 1, 2, 3...d, it sets boundaries at k_last_elem + 1. This results in two issues:

1) It is possible to have more than d elements in the digest. Now, that is no longer possible, and we can properly reserve the right number of elements.
2) Additional floating point operations are computed than necessary.

Reviewed By: anakryiko

Differential Revision: D7654147

fbshipit-source-id: 131184d456353a9d936c4ed385e2b5e75d468676

Reviewed By: yfeldblum

Differential Revision: D7726522

fbshipit-source-id: fa5ad9fc29152b52c5256849c2822885acd49c23

Summary: [Folly] Cut dead reference to `executorLock_` in Futures test - this field was recently removed.

Reviewed By: LeeHowes

Differential Revision: D7725446

fbshipit-source-id: a522b66da77bbefeb69970bee20feea46dcc72a5