Summary:
Rather than have a single main.yml file containing all off the different
builds, split that up so that we have one file per build environment
(linux, mac, windows).

This has a couple of advantages:

* It is quicker to see the status of just one of the platforms
* Artifact collection for one platform is not blocked pending completion
  of the builds for all systems
* It's a little easier to understand what is happening for a single platform

To support having multiple files I've changed the output-file option to
be an output-dir.

I've included the rm of main.yml in this commit.  Once this gets
imported back to the FB internal system I'll amend in an update to
the helper script that updates all of our opensource builds and run
and amend that.
Pull Request resolved: https://github.com/facebook/folly/pull/1360

Test Plan:
the GH action status on this PR should show three different
actions running, one for each platform.

I updated and ran
`fbcode/opensource/fbcode_builder/getdeps/facebook/update-all-github-actions.sh`
to regenerate all the actions files for FB.

Reviewed By: yfeldblum

Differential Revision: D21310991

Pulled By: wez

fbshipit-source-id: 604ef652c8f746781a4b410c6b996cdee4524e0d

Summary:
This commit resolves an issue with our zipapp executables
on Windows that meant that the only reliable way to start them was
to use the fully path to the executable.

The root cause is that the __wargv array is produced by parsing the
process command line into an array, and if you ran `watchman-wait -h`
__wargv[0] would have `watchman-wait` rather than the fully qualified
path to the executable that the zipapp plumbing requires.

The fix is to ask the system for the fully qualified path and ensure that
that gets set as both argv[0] AND argv[1].

Reviewed By: xavierd

Differential Revision: D21190350

fbshipit-source-id: eeb95084592d30a028a93b2b03877f8cc6c72729

Summary:
The environment changed since I tested  D20740410 and now it appears
that we'll need to re-export a versioned variable in order for cmake
to detect boost on the GH actions hosts.
Pull Request resolved: https://github.com/facebook/folly/pull/1359

Test Plan:
the GH actions status of this diff.

The workflow was updated via:

```
python3 build/fbcode_builder/getdeps.py generate-github-actions folly --output-file .github/workflows/main.yml
```

Reviewed By: yfeldblum

Differential Revision: D21307640

Pulled By: yfeldblum

fbshipit-source-id: 1555cbcade822775379cd9054be37fdbc17b4d93

Summary:
From the outset, we wanted to be sure that getdeps was able
to source and build the dependencies so that we knew that we'd have
a repeatable build.  This came at the cost of build times: having
to build boost on each CI run is a bit of a chore.

This commit adds three new elements to the manifest files:

* `rpms` - a list of RPM names that are all required to be present
  in order to consider the dependency satisfied
* `debs` - like `rpms` above, but scoped to debian package names
* `preinstalled.env` - a list of environment variables that if they
  are all set and non-empty will satisfy the dependency.

A new `--allow-system-packages` option to getdeps enables the new
logic that looks for system packages; it is off by default, but
enabled in the generated GitHub Actions workflows.

A new `install-system-deps` subcommand is provided that will attempt
to install the system packages needed to satisfy the build.  This
typically needs to be run via sudo and is thus broken out separately
from the main getdeps build flow.

I made a pass over the manifest files and added package names that
satisfy the build on ubuntu-18 and fedora-31.

shri-khare: I renamed the `Python3.7.6` manifest to just `python` as
part of this change; the version of python that it pulls in through
the normal build is the same and I believe that an equal or newer
version of python3 is available in the GH actions builder.

The `preinstalled.env` is used only by the boost manifest: it references
the name of an environment variable that is set by the github
windows hosts and that points to a pre-built and pre-installed
copy of boost.  Since there is no package manager that we can
easily query for this sort of thing, probing from the environment
seems like a reasonable and fast way to check for this.  We
may need to evolve this over time to become more feature rich,
but this seems like a good starting point.

This commit has the potential to save 20 minutes of build time
from each public CI build just due to the boost dependency alone!

Refs: https://github.com/facebook/watchman/pull/797

Reviewed By: yfeldblum

Differential Revision: D20740410

fbshipit-source-id: 6c38019449c54465127656c3d18a6ff1f30adaea

Summary:
The MSVC compiler was complaining that an implicit conversion from intmax_t
to long was being performed. Let's use static_cast to silence it.

Reviewed By: simpkins

Differential Revision: D21267752

fbshipit-source-id: e466f107ca8e861c12e0abd1f8fa7448f22adfd9

Summary:
The MSVC compiler complains about a potential lossy conversion happening,
which feels mostly right due to Iterators being potentially far apart.

Reviewed By: yfeldblum

Differential Revision: D21280438

fbshipit-source-id: 8fcb18d865688aa1fae869a41256ad3dc3ad2a97

Summary: [Folly] `identity`, an initialized function object matching `Identity`, which is renamed `identity_fn`.

Reviewed By: markisaa, lewissbaker

Differential Revision: D21265889

fbshipit-source-id: 5cc9f2e624da9a4acd0f65985ff10a4dd306efdc

Summary:
The test cert "test-cert.pem" is signed with a SHA1 based signature algorithm, and newer distros such as
CentOS 8 will fail loading this certificate due to its default security policy.

This diff regenerates the test certificates, following the old certificates
names as closely as possible. I included the script to generate these in case
they need to be changed in the future.

Reviewed By: AjanthanAsogamoorthy

Differential Revision: D21271202

fbshipit-source-id: de4227ae81dfffaf00f8d355e83936db6eb5fe31

Summary:
Folly links explicitly links against boost statically on Windows.  However,
many downstream projects that use folly independently performed their own
discovery of boost and normally used the default option of linking against it
dynamically.  This resulted in boost being listed twice on the link line on
Windows for some downstream projects: both its static libraries and dynamic
libraries would be present.  This ends up causing linking failures due to
duplicate definitions.

This updates folly's installed CMake file to correctly call
`find_dependency(Boost)` so that downstream projects don't need to perform
their own independent discovery.  This ensures that all downstream projects
use a consistent method of linking against Boost.  I updated many downstream
projects to remove their explicit separate discovery, and rely only on this
behavior from folly.

I also added a configuration setting to allow explicitly selecting whether to
link against boost statically at folly configure time.

Reviewed By: wez

Differential Revision: D21232164

fbshipit-source-id: 9ecc3ce988add48905252297e979403c42e7e148

Summary:
## Why is this diff needed?
This diff presents an annotation framework designed to address some of the issues we've had working with fibers in NodeAPI:
- It's difficult to identify functions doing I/O. As a result, we've had I/Os happening sequentially in for loops.
- It's difficult to tell if a function is running on fibers. This is especially hard in large code bases such as ours

## What does this diff do?
The `Async<T>` type can be used as the return type of a function. This accomplishes a couple of things:
- It indicates that this function should run on fibers and that a fiber can suspend in this function (or in one of it's children)
- It forces calling functions to `await` the result of this function. When coupled with a good lint rule, this enforces annotations right to the top of the stack.

Reviewed By: A5he

Differential Revision: D21159049

fbshipit-source-id: ee922093b140b22d8e7a7587b87aa0e783055b6c

Reviewed By: wez

Differential Revision: D21238976

fbshipit-source-id: 13a6def8d6c8d25057409956cc883589b205cd04

Summary:
Declaring this method noexcept was incorrect and could unnecessarily lead to
program termination if one of the calls threw an exception.

Reviewed By: yfeldblum

Differential Revision: D21187354

fbshipit-source-id: 109a33d52659cdf42e5ced9e18be41ae4c3daf85

Summary:
I noticed that copytree was taking forever and realized
that it wasn't issuing a prefetch call so I started looking in here;
this commit teaches getdeps how to recognize and EdenFS repo on
Windows but skips calling prefetch on Windows.

Currently the prefetch implementation triggers some very slow
processing in mercurial that is slower to start than just
enumerating the files in the opensource build.

It turned out that my original problem was just that my credentials
had expired and we weren't surfacing that error on Windows yet.

Reviewed By: simpkins

Differential Revision: D20755905

fbshipit-source-id: 8d3695cdd1f04199d1d409895482b8c706285d5f

Summary:
By and large, trying to test folly::coro with gcc-10's (very green) coroutines implementation was a failure, but it did turn up a couple of issues:

* Friends of friends are not friends with gcc
* -Wshadow picks up a few more instances of shadowing
* `std::exchange` needs `#include <utility>`.

Reviewed By: lewissbaker

Differential Revision: D21190145

fbshipit-source-id: d3f3148baa26bb8a2c0c1954fc930fd8124672e1

Summary: The configerator structs are used in many top level functions in Mononoke and are required in order to build all the code on github

Reviewed By: ahornby

Differential Revision: D21130546

fbshipit-source-id: 7f17d92173f5ecf7c3406ae4202359a0db8df84a

Summary:
We're recommending collectAny as a replacement for
collectAllSemiFutures :(

Reviewed By: LeeHowes

Differential Revision: D21197163

fbshipit-source-id: 0055e0feb5cc74a767370bc1dc9fe8e4d8dffcfc

Summary:
Add support for variable number of addrs so we can send data to multiple destinations.

(Note: this ignores all push blocking failures!)

Reviewed By: kevin-vigor

Differential Revision: D21032857

fbshipit-source-id: f73b98d44f5d7d92f3692dfddb9b1c76ebcc51c5

Summary:
Disable TSAN instrumentation across StaticMetaBase::onThreadExit() to avoid a shortcoming in TSAN on Linux that produces sprurious failures.

This was recently worked around by ignoring TSAN failures in ld-linux's _dl_deallocate_tsd() (D20597534), but that turns out to be insufficient, because other TSAN failures can occur on the TLS area after the dynamic linker has called free() on it.  This diff backs out the change from D20597534, and works around the problem in a more direct & complete way.

Reviewed By: yfeldblum

Differential Revision: D20671620

fbshipit-source-id: 05a74e709b620391f18467c7a5e4d14dcf9f4a1e

Summary: Fixes a copy-paste mistake from the `collectAnySemiFuture` deprecation message.

Reviewed By: Orvid

Differential Revision: D21199692

fbshipit-source-id: e61b740ea238dcbd6ca8481e1ba578a5073fe7bf

Summary: [Folly] Remove unused virtual inheritance in `AsyncSocket`.

Differential Revision: D20966977

fbshipit-source-id: 502ab00438eebed0d8ebcf32ef602af50b05df47

Summary:
Resolves these warnings:
```
folly\Singleton.cpp(102,1): warning: function declared 'noreturn' should not return [-Winvalid-noreturn]
}
^
folly\Singleton.cpp(108,1): warning: function declared 'noreturn' should not return [-Winvalid-noreturn]
}
^
folly\Singleton.cpp(126,1): warning: function declared 'noreturn' should not return [-Winvalid-noreturn]
}
^
folly\Singleton.cpp(134,1): warning: function declared 'noreturn' should not return [-Winvalid-noreturn]
}
^
folly\Singleton.cpp(145,1): warning: function declared 'noreturn' should not return [-Winvalid-noreturn]
}
```

Reviewed By: mzlee, yfeldblum

Differential Revision: D21130719

fbshipit-source-id: a0f198d69c4fde44f9a5250b6915e36b6ee68642

Summary: Android doesn't expose `malloc_usable_size` below API-level 17. Correctly reflect this in folly-config.h, and then ensure that all code paths that use `malloc_usable_size` are unreachable when compiling without it.

Reviewed By: yfeldblum

Differential Revision: D20721326

fbshipit-source-id: d60b3caa1910dc2bf8ed0844177f5cb93a9fd067

Summary: Relying on `erase()`, which must be able to move elements when erasing in front of other valid elements, causes compilation failures when trying to erase non-assignable elements at the end of the vector even though no elements actually need to be moved (and thus assigned) in that case. Here we help the compiler out and extract the destruction/resizing logic away from the moving logic.

Reviewed By: yfeldblum, ot, mkatsevVR

Differential Revision: D20718712

fbshipit-source-id: 51c4e6636bc33577494c0c10e95da5f92b58d4b6

Summary:
I think swap() is nothrow as long as value_type is_nothrow_move_constructible.  We already do this on the move c'tor.

(Note: this ignores all push blocking failures!)

Reviewed By: yfeldblum

Differential Revision: D21136202

fbshipit-source-id: a5df772c5cafa592fce95bc5ce4149dc738a984c

Summary:
`sizeof(symbolizer::FrameArray<kMaxStackTraceDepth>) = 17608`, it is quite big to put on stack. When using folly::fiber we usually only have a few KB of stack space, and will overflow when calling this function.

By putting FrameArray on heap we can avoid this issue.

Reviewed By: yfeldblum

Differential Revision: D21150720

fbshipit-source-id: 7ae1d60d47b1aa3551bf96044aadad5cc21bf914

Summary: Resolve issue here: https://fb.workplace.com/groups/560979627394613/permalink/1763417530484144/

Differential Revision: D21147181

fbshipit-source-id: 82acb7eb910deff28a722026d1f43bae855f2942

Differential Revision: D21059558

fbshipit-source-id: 588e6ec2a6fdaf70ea5c03810358c84dedf81911

Summary:
This one DCHECK is the only thing keeping Range from
being free of external deps. Lets make it not be a thing, so
people are more inclined to pull in folly because Range is an
easy gateway class to the rest of folly.

Reviewed By: yfeldblum

Differential Revision: D21121743

fbshipit-source-id: 2a54e94074135c951526c50d4bb63ebf2076a72f

Summary:
The README stated "folly requires gcc 5.1+ and a version of boost..." which
some people might thing means that folly only supports gcc.

Edit the README with more details about supported compilers and platforms.
I tried to strike a balance between informative (FB uses folly on many
platforms), conservative (the CMake build might not support all of them),
and not mentioning specific versions (likely to get outdated.)

Reviewed By: yfeldblum

Differential Revision: D21093741

fbshipit-source-id: 3a541f22b30736201361d2a10d861d61bd278e47

Summary: Unbreak -fno-exceptions support for this file.

Reviewed By: yfeldblum

Differential Revision: D21043400

fbshipit-source-id: aceea45c32d143c723ad6bae68a7403f14d7e0f2

Summary:
There are some duplicated unit test in TokenBucketTest.cpp. So this pr is intent to delete these unused unit test.
Pull Request resolved: https://github.com/facebook/folly/pull/1354

Reviewed By: yfeldblum

Differential Revision: D21061401

Pulled By: Orvid

fbshipit-source-id: ea486fc244e2be68196ef015e020b8664bb3670a

Summary: Repurpose the existing `folly::ssl::SSLSession` to be an abstraction for SSL sessions, with the internal implementation hidden. The intention is to soon move to using these abstracted sessions instead of directly using OpenSSL sessions.

Reviewed By: yfeldblum, mingtaoy

Differential Revision: D20143848

fbshipit-source-id: 01e175668c0afcf8b91d19a289368496717d3150

Summary:
Fix a bug in overwrite of null data.

Null old data should be erased so that the insert of the new data can succeed.

Reviewed By: davidtgoldblatt

Differential Revision: D20908574

fbshipit-source-id: 6873d9c76daf1289f1d5b97b001c21473c41ea3f

Summary:
Fix typo

(Note: this ignores all push blocking failures!)

Reviewed By: mokomull

Differential Revision: D21056053

fbshipit-source-id: 3bf4295f9c6be1c50cdc64f6bbdf1b34cce6bece

Summary:
- Indicate that the EDEN_VERSION_OVERRIDE environment variable affects the
  build.
- Exclude eden/config.py from the shipit  path map, as this file is
  auto-generated in open source builds.
- Include pexpect as a dependency, as this is needed for some of the
  integration tests.

Reviewed By: genevievehelsel

Differential Revision: D21000163

fbshipit-source-id: 8eec378f66487229c995f637c4787eae530c7845

Summary: We want to use observer API to correlate tasks across same Thrift request. `RequestContext::getRootId` is the thing for it.

Reviewed By: yfeldblum

Differential Revision: D20600485

fbshipit-source-id: 1a79bde0f6c5b3692b4fb3805c98f377b1b317c9

Summary: Use pre-existing cached local contexts, rather than creating our own.

Reviewed By: bimbashrestha

Differential Revision: D18890550

fbshipit-source-id: d53d0bdf35ebfcfa5dfb45da6b99a886022d5f8b

Summary:
Fix PollIoBackend compile error

(Note: this ignores all push blocking failures!)

Reviewed By: yfeldblum, kevin-vigor

Differential Revision: D20955224

fbshipit-source-id: a2c7a34d9129cb282d3652607e79dcee1ce1cc78

Summary:
This diff extracts the fbsource commit hash and the date of that
commit and maintains that in place of just the commit hash that
we were previously extracting.

This data is exported into the environment that we pass on to
builders so that it is available if they choose to use it.

In a follow on diff I'll use this to default a version number
in the watchman project.

Reviewed By: fanzeyi

Differential Revision: D20949666

fbshipit-source-id: dc12bffe5f0efc4297b15ba0140c4c67a23ab0fd

Summary:
Allow a T that derives from EnableMasterFromThis<T> to use masterLockFromThis() to get a non-owning shared_ptr to this and to use masterRefFromThis() to get a MasterPtrRef<> from this.

Adds MasterPtr::cleanup() that returns SemiFuture<Unit>. join() just does a blocking wait on the SemiFuture returned from cleanup().

Allows a T to provide a T::cleanup() method that will be composed into the MasterPtr::cleanup() work.

MasterPtr now uses SemiFuture<Unit> instead of Baton. This allows users of MasterPtr::cleanup() to compose cleanup work with other tasks.

Andrii suggested that the cleanup feature be extracted out of MasterPtr

Adds cleanup traits (that MasterPtr satisfies) and a Cleanup type that satisfies the cleanup traits and allows objects that are not heap-allocated to participate in structured concurrency by deriving from Cleanup.

Reviewed By: andriigrynenko

Differential Revision: D19584561

fbshipit-source-id: aa2d608effe613ec84b08f902a1c61561f3458bb