Summary:
As titled.

FBOSS depends on Python3.7.6, subsequent diff in the stack adds Python3.7.6
depedency for FBOSS.

Differential Revision: D20064316

fbshipit-source-id: 27b328dc25e326f3927ea6cb003fb7bb45732d61

Summary:
Add function `get_process_phase` that returns indicators of process phases:
- `ProcessPhase::Init`: Not all global variables may have been initialized.
- `ProcessPhase::Regular`: All globals have been initialized and have not been destroyed.
- `ProcessPhase::Exit`: Some globals may have been destroyed.

Add function `set_process_phases` and calls to it from `folly::init` and `common/init/Init.cpp` wherever `SingletonVault::singleton()->registrationComplete` is called.

Will add calls to `set_process_phases` in separate diffs to other places that call `registrationComplete ` directly.

See Section 6.9.3 Start and termination [basic.start] of the C++ Standard Working Draft [N4849](https://github.com/cplusplus/draft/releases/download/n4849/n4849.pdf).

In general this addition is useful for simplifying cases of dependence on the existence of certain globals during main, where it is safe to ignore such globals at shutdown.
For example, the destructor of `hazptr_obj_cohort` normally needs to access the default `hazptr_domain`, but it is safe to skip that access at shutdown.

Reviewed By: yfeldblum

Differential Revision: D19567170

fbshipit-source-id: a44cbd3301aa9dc77a1e992922403635a3ff6552

Summary: (Note: this ignores all push blocking failures!)

Reviewed By: farnz

Differential Revision: D19948740

fbshipit-source-id: 9d0cfc4ccbcb3c08bb969f23229ed3096470fa86

Summary:
Having the fallbacks in the public header files makes searching for classes/methods cumbersome, and some people have mistakenly assumed that F14 classes inherit from `unordered_*` because they landed on the wrong line.

In addition, when the fallback implementation is used, any compilation errors will come from the `*Fallback.h` files, making it clear that the main implementation is not being selected.

Reviewed By: yfeldblum

Differential Revision: D19926873

fbshipit-source-id: 492b0c252f33c0cbbf3c22dae38fa0bd63825f72

Summary: Capacity is known in almost all the modes (except when it's inferred from `malloc_usable_size`, which is probably something we should not do in the first place), so we can easily plug in sized deallocation.

Reviewed By: yfeldblum

Differential Revision: D19976657

fbshipit-source-id: cb03f7107195af614514645c88d12ac4999dea53

Summary:
rootid is the thing we use to correlate running Thrift requests with a folly::RequestContext. The problem is that today rootid is unique only for active requests but not unique throughout the lifetime of the process - as a consequence we see some subtle bugs like mistakenly attributing threads to already finished requests. The root cause of rootid collisions is that default implementation of rootid is just an address of folly::RequestContext - so once request finishes the address is reused.

The solution suggested here is to assign rootids explicitly when folly::RequestContext is set for the request. To construct such rootid we pack two counters:
* 12 MSB are dedicated to an ID of Cpp2Worker (should be more than enough)
* 51 LSB are dedicated to a running counter within Cpp2Worker.

(Note: this ignores all push blocking failures!)

Reviewed By: andriigrynenko

Differential Revision: D20036950

fbshipit-source-id: 76687db12a32f33c82ce86accb4cdaab3e981458

Summary:
generic API for setting socket options on a UDP socket

(Note: this ignores all push blocking failures!)

Reviewed By: yangchi

Differential Revision: D19763927

fbshipit-source-id: d1a7720b04c24592e98c6e30c93c26e650ccd0b0

Summary: delete the folly::AsyncSocket::OptionMap/OptionKey/emptyOptionMap aliases

Reviewed By: yangchi

Differential Revision: D19963346

fbshipit-source-id: 6beae0961a82d12efd4d784ec390031d9445cd2b

Summary: base diff to move AsyncSocket::OptionMap into SocketOptionMap. folly only changes and an alias for previous usages of AsyncSocket::OptionMap

Reviewed By: yangchi

Differential Revision: D19961899

fbshipit-source-id: fab060cc73409c77ea07ced663fbd0ee15a35be7

Summary:
We need to add a separate manifest for SAI 1.4 and build that too, but that is
for later diffs, for now, we need 1.5, so change it.

Differential Revision: D20019016

fbshipit-source-id: 8630340ac7c8b7d94e6b768a2efa96266b2cc3e0

Summary: Pull Request resolved: https://github.com/facebook/folly/pull/1319

Reviewed By: yfeldblum, lnicco

Differential Revision: D19951699

Pulled By: afrind

fbshipit-source-id: b71d96020ca486139472512726183ae4d3555b28

Summary: Use sdallocx for IOBuf::releaseStorage

Reviewed By: marksantaniello

Differential Revision: D19925485

fbshipit-source-id: 142276fb64e570e10bfd0b6e22d8c83b204d1c2b

Summary:
Add FOLLY_CLANG_DISABLE_WARNING for Unistd.h

(Note: this ignores all push blocking failures!)

Reviewed By: yfeldblum

Differential Revision: D19652177

fbshipit-source-id: 1fcc3bb65c3b0d73870e599f9fc0463c6836cf9b

Summary:
The Buck build of RocksDB supports LZ4, so if an Eden instance's
object cache ends up compressed with LZ4 compression, the opensource
getdeps build cannot open it. Enable LZ4 in the open source getdeps
build of rocksdb.

Reviewed By: pkaush

Differential Revision: D19961878

fbshipit-source-id: 9a4f37e12bd2b40a0c5dcf2dd1684876886fae26

Reviewed By: yfeldblum

Differential Revision: D19953637

fbshipit-source-id: c2135fc24084b7bba0c9d6fc978c8b6c8f9943d4

Differential Revision:
D19848850

Original commit changeset: 21e61529d8b9

fbshipit-source-id: c490eb0024a4cda830389a359ee2631615345f2d

Summary: Previously if the loop simply failed to execute the test could pass, add some minor changes to ensure control flow is as required.

Reviewed By: andriigrynenko

Differential Revision: D19960864

fbshipit-source-id: 5a437d9e7d3b7c249cbf999fe7ea5eecfe668658

Summary: Missing includes which break modular builds.

Reviewed By: igorsugak, luciang

Differential Revision: D19738860

fbshipit-source-id: 97a0329f3e558309ca87f4dd7be8dd96e9ba09a8

Summary:
If the waited upon object throws an exception when blockingWait is called within a fiber context this can cause a SIGABT as it is not permissible to yield (due to the inner baton) in an exception context.

To fix this, instead capture the exception and permit destruction to occur outside of exception handling.

Reviewed By: andriigrynenko

Differential Revision: D19951124

fbshipit-source-id: cf1bf9a62557147863390132f551d08e20c02c2d

Summary: It was originally disabled to let test pass in ovrsource, they are now passing, enabling them back

Reviewed By: pranjalssh

Differential Revision: D19848850

fbshipit-source-id: 21e61529d8b9f519b4c8cbf4787c8e3f28b99bb1

Summary:
Add folly::sizedFree

(Note: this ignores all push blocking failures!)

Reviewed By: ot

Differential Revision: D19944311

fbshipit-source-id: b5b1a648a180662fe838237c3c3b153e42fe0617

Summary: In C++20, u8 prefixed strings are typed as `char8_t` not `char`, so we need to support that in `StringPiece`.

Reviewed By: yfeldblum

Differential Revision: D19822967

fbshipit-source-id: c3441ba718b40f0781766d4a80c3432b4514a35c

Reviewed By: yfeldblum

Differential Revision: D19768449

fbshipit-source-id: b5a259486403601cf60d4e7066640e1ed4601410

Summary:
Currently the best way to get an eager SemiFuture from an AsyncGenerator is
  folly::coro::co_invoke(
      [&]()
          -> folly::coro::Task<folly::coro::AsyncGenerator<T&&>::NextResult> {
        co_return co_await gen.next();
      })
      .scheduleOn(&ex)
      .start();
which is very verbose. This diff adds helpers to make this a simple function call.

Reviewed By: andriigrynenko

Differential Revision: D19835473

fbshipit-source-id: f6e7e72cad0e0596df375d2662c87d4412536c03

Summary: There are downstream oss builds showing build failure caused by introduction of metadata. We want to make them proceed to build so we won't get errors in CI.

Reviewed By: iahs

Differential Revision: D19900007

fbshipit-source-id: 4201448f7980b53e407fd2bc1c74ed4ffa8e18c1

Summary:
If a key type has a templated constructor that can implicitly
accept const_iterator, then a call to erase or eraseInto with a non-const
iterator results in an ambiguous overload. This diff adds an extra
overload of eraseInto to avoid the ambiguity, as well as adding unit
tests that cover the rare corner case.

Reviewed By: yfeldblum

Differential Revision: D19809069

fbshipit-source-id: 499849da2d6ad64070b13eb0a9ed86a3d49ad9b0

Summary:
It's useful to be able to move the key and value
out of a hash table as that entry is being erased. Since
std::unordered_map's extract API isn't implementable for hash tables
that perform bulk allocation, we expose similar functionality via
F14{Fast,Value,Vector,Node}Map::eraseInto.  eraseInto gives a key_type&&
and mapped_type&& to the specified callback, allowing it to move them
elsewhere before the underlying value_type is destroyed.

The keen observer will note that there is no way to move the key out
of a std::pair<key_type const,mapped_type> without relying on undefined
behavior. We already rely on this form of UB to avoid copying keys during
rehash, and perform it only when we have total control over the lifecycle
of the object and the memory backing the value_type.

eraseInto was previously implemented for F14 sets.

Reviewed By: shixiao

Differential Revision: D19777644

fbshipit-source-id: 9904224af2c6e51abeadae62cc5e66f7bf4b1ae7

Summary: This issue was only showing up in a single test, but include orders meant that stdio.h could end up being included in a way that caused it to not properly define the normal names it's supposed to, as they were getting disabled due to the `_CRT_INTERNAL_NON_STDC_NAMES` changes being made.

Reviewed By: yfeldblum

Differential Revision: D19866950

fbshipit-source-id: 9d6391f5c0e5a2ef44f0f8ba6dad064cfecf0a82

Summary: Newer versions of boost thread re-wrote how this works, so use the new way.

Reviewed By: yfeldblum

Differential Revision: D19824658

fbshipit-source-id: a3d66fd6ef781ac83c92f6313cf47a7920cfebda

Reviewed By: iahs

Differential Revision: D19873296

fbshipit-source-id: f92785feb33be09bdef4c047532b4bd3dd42972e

Summary:
g++ 8.2.1 on some platforms crashes on the gtests defined
in EventBaseTestLib.h that declare inner classes.  This diff
refactors the tests so that they can be successfully compiled.

Reviewed By: yfeldblum

Differential Revision: D19871529

fbshipit-source-id: 3e84c2983e90b7445c014c002bbac504e0366657

Summary: It is possible for blockingWait to crash if just after it leaves it's drive() method in the destructor, from another thread something releases the keep alive. If then the destructor continues it will clean up, but that other thread will then be manipulating freed data.

Reviewed By: andriigrynenko

Differential Revision: D19860616

fbshipit-source-id: 25df16b5e900f283bbc0a264233770b6d3667ba3

Summary:
Take the README.md from
https://github.com/facebookexperimental/mononoke/blob/7ead0e29e41aec0771531a4650b6170bc1ff6566/README.md
and apply it on Eden repo.

Re-add the Cargo.toml file that declares Cargo workspace.

Re-add fbcode_builder/getdeps manifest for Mononoke
Pull Request resolved: https://github.com/facebookexperimental/eden/pull/13

Test Plan:
./build/fbcode_builder/getdeps.py build mononoke
  ./build/fbcode_builder/getdeps.py test mononoke

Reviewed By: ahornby

Differential Revision: D19833059

Pulled By: lukaspiatkowski

fbshipit-source-id: fb37e13306c0b9969a7c4e52b05e1a66a577022f

Summary: When connection is reset by server it's possible for a write to fail before the read callback is called. Make sure we still try to process all the data that was received before closing the socket.

Reviewed By: rhodo

Differential Revision: D19851139

fbshipit-source-id: af50b939ccd7f25384e48bcf29b4892a23c2ef83

Summary: platform_mapping library needs RE2 lib.

Reviewed By: shri-khare

Differential Revision: D19838529

fbshipit-source-id: 71a2c06437ce05a42396a2867ddadb029e36926e

Summary: [Folly] Remove trivial-copyability requirement from `LockFreeRingBuffer` since we can rely on the compiler to optimize copy operations over types which are trivially-copyable without our code having to specify `memcpy`.

Reviewed By: yfeldblum

Differential Revision: D19844612

fbshipit-source-id: 4770e46ac8c63fa68b68598fb5012cb58896f550

Summary: [Folly] Use SingletonThreadLocal for the current fiber manager, which does not depend on whether `__thread` or `thread_local` is available.

Reviewed By: andriigrynenko

Differential Revision: D19229511

fbshipit-source-id: a92016aca89205c2842dc4f71054b1b6306b14b9

Summary: [Folly] Prefer `invoke_result_t` in `DistributedMutex` over the underlying `decltype` and `declval` implementation.

Reviewed By: aary

Differential Revision: D19321643

fbshipit-source-id: 323a0fce49447d2f009ad3bc61e285de3f311ff1

Summary: [Folly] Use invocability helper variables in preference to types.

Reviewed By: aary

Differential Revision: D18748026

fbshipit-source-id: e7a76c1238360c55dd6d41c53f763e9df4069acb

Summary:
1. Add `"-Wshorten-64-to-32"` to `_extra_clang_flags`
2. Fix warnings generated from `buck build --keep-going wangle/...`

Reviewed By: chadaustin

Differential Revision: D19647345

fbshipit-source-id: 417840fe82ed3d5c9c2d989a0acf67e12758c1f9