Summary:
Trying to use `ZeroSizeMutex` in `CallOnce.h` causes a circular dependency:
```
//folly/synchronization:call_once ->
//folly/synchronization:call_once-module ->
//folly/synchronization:call_once-module-helper ->
//folly/synchronization:zero_size_mutex ->
//folly/synchronization:baton ->
//folly/detail:memory_idler ->
//folly/synchronization:call_once
```
The benefits of `folly::once_flag` are as follows:
https://www.internalfb.com/intern/diffusion/FBS/browse/master/fbcode/folly/synchronization/CallOnce.h?commit=d0211e9462c39c4655a7d2ff9d313f6fb433d74a&lines=37-42

A fast path is not necessary here because it's just logging within an error case.
Exception-proof behavior is not needed because glog does not throw.

Reviewed By: yfeldblum, andriigrynenko

Differential Revision: D25797067

fbshipit-source-id: 4de20235ff4115b73ab8a2689e7697fc9fe4ba65

Summary: This allows `try_emplace_with` to receive objects by copy-ellision or specific moves; without it, any attempts to pass an object would result in a copy.

Reviewed By: praihan, luciang

Differential Revision: D26008949

fbshipit-source-id: b43d2dc941c7415e2189668a2b577cc0f1165665

Summary: `constexpr` is known to be broken in MSVC causing errors when using format string compilation so disable `FMT_COMPILE` there.

Reviewed By: neildhar

Differential Revision: D26019769

fbshipit-source-id: b823b24d4e73fcf9632f8e648ebb9a4e73c43bb1

Summary: As per title, as fmt doesn't currently handle them well.

Reviewed By: vitaut

Differential Revision: D26004515

fbshipit-source-id: dbbd1e6550fa10c4a6fcb0fc5597887c9411ca70

Differential Revision: D25985696

fbshipit-source-id: 52ede8dc494f8bf1991dbfed455fbc6bbba83d87

Summary:
It wasn't guarded at all, which is causing issues for non-sanitizer builds on platforms without shared library support.

Ref: https://github.com/facebook/folly/issues/1507

Reviewed By: meyering

Differential Revision: D25970872

fbshipit-source-id: f710e752fdf8ebc5529314d335f4559e690b787a

Summary: Switch to format string compilation to prevent pulling in too many symbols from the {fmt} library into `folly/detail:ip_address`. This change saves ~64k (fixed cost) in opt mode compared to the current master or ~36k compared to the old code using Folly Format. This doesn't matter for server projects especially since {fmt} will likely be linked anyway but matters for some mobile ones.

Reviewed By: Orvid

Differential Revision: D25904078

fbshipit-source-id: 56473cf9bf4456a3cb3c5aa375c16393e144b6e1

Summary: Allows us to use new APIs in libbpf

Reviewed By: anakryiko

Differential Revision: D25933787

fbshipit-source-id: f0988caae351760b814eba74f6f716db51f728bd

Summary:
Previously the `EXPECT_THROW_RE()` macro required the regular expression be
passed in as a `const char*`.  This updates the code to accept a
`std::string_view` instead.

This allows the API to accept either `const char*` arguments, `std::string`,
or `std::string_view` objects.

Reviewed By: yfeldblum

Differential Revision: D25837542

fbshipit-source-id: e6fb00034046ad7f2810367f946f0135858ed065

Summary: Handle values different from pending_

Reviewed By: kevin-vigor

Differential Revision: D25968014

fbshipit-source-id: fd70dd6339d02a6325b237e6c9401d8962b17b51

Summary:
This diff moves the gdb related test into `folly/support/test` (as opposed to
`tests`) so that CMake rules
[here](https://github.com/facebook/folly/blob/194b7732bd65d56b4afb58b6d9e411c1b014b3e3/CMakeLists.txt#L155)
will exclude these files from OSS library builds--also to maintain consistency
with other test folder names under folly.

I still separated out the auto gdb breakpoint functionality into GdbUtil.h so
that if MSVC users want to manually compile and use the gdb script tests, they
have the option to do so.

Re: asm syntax on MSVC:
https://gcc.godbolt.org/z/1rMh4v

Fixes #1515.

Reviewed By: Orvid

Differential Revision: D25947735

fbshipit-source-id: 97e75e972fcf8eea280df804c98c400f03c37496

Summary: Adding protobuf manifest, which will be used to compile f4d/velox.

Reviewed By: spershin

Differential Revision: D25926384

fbshipit-source-id: 08a2dffc9e9baa0d393e5f648ce99ca032a9df5f

Summary: Adding lzo manifest, which will be used by f4d/velox

Reviewed By: amitkdutta

Differential Revision: D25926434

fbshipit-source-id: 4d7efe5eba7cdca1f682fbd4cfd6ff0337ce7c19

Summary:
The current code is calling `runInMainContext` on the FiberManager that we're scheduling to, which will do nothing if we're calling it from another fiber manager. This will assume fiber stack as a main stack which is incorrect.

This diff fixes it to call `folly::fibers::runInMainContext` that would properly call `runInMainContext` on the active FiberManager.

Reviewed By: andriigrynenko

Differential Revision: D25116215

fbshipit-source-id: 1d13f436a0599c077e7531dc1fe75f3a143e3478

Summary: The implementation doesn't need explicit locking or condition variables, everything can be done with a single concurrent queue.

Reviewed By: yfeldblum

Differential Revision: D25919429

fbshipit-source-id: a2b1e6332305174ba41d02fd79d9525a12b82218

Summary: Make it consistent with the other executors.

Reviewed By: yfeldblum

Differential Revision: D25926045

fbshipit-source-id: ad2f101fbba918fe2a421e394870bf67c0a044b9

Summary: As title, move gdb pretty printers from internal repo to OSS repo

Reviewed By: yfeldblum

Differential Revision: D25684325

fbshipit-source-id: b7999dee1379801ee68553de64f16ac4db78b174

Summary:
This took a lot of cmake fuckery. I am guessing it will break the current travis-ci.org based build, since it no longer downloads gflags.

As I put this diff up, mvfst (a dependency of quic (a dependency of proxygen)) is not building right now due to another diff - a fix is in progress but isn't landed yet. I applied the fix locally for the test plan, but didn't include it in the diff.

Reviewed By: snarkmaster

Differential Revision: D25651851

fbshipit-source-id: b4f15ac7fa5293123710fe367c20d355c0970c42

Summary: `folly::MicroLock` is actually 4 locks, each using 2 bits. In cases we don't need all the slots, we can use the other bits to store some data which is loaded/stored atomically with locking and unlocking. There is no change in existing `MicroLock` usage behavior.

Reviewed By: davidtgoldblatt

Differential Revision: D25842148

fbshipit-source-id: 5f6ff705c35529d279629ccc256a9c210907ea5c

Summary: This was forgotten in a refactor.

Reviewed By: Mizuchi

Differential Revision: D25903164

fbshipit-source-id: 419131987a886f0d8d057b5b04b012d1162e564d

Summary:
`extra_cmake_defines` are extra flags that are passed to cmake when
compiling each one of the dependencies. For instance:
```
$ ./opensource/fbcode_builder/getdeps.py  build f4d --extra-cmake-define='{"CMAKE_CXX_FLAGS": "-mavx2 -mfma -mavx -mf16c -march=native"}'
```
It takes a json map as input, which can take a list of defines (key value
pairs).

Reviewed By: wez

Differential Revision: D25855781

fbshipit-source-id: 7f4fef2c66f4d12f23c8d7086d6a4f24fcc01ff7

Summary:
This patch performs SFINAE-friendly invocation in `FOLLY_CREATE_STATIC_MEMBER_INVOKER` in order for invocability tests to return `false` in the situation where the member is not even available. For example, given:
```
FOLLY_CREATE_STATIC_MEMBER_INVOKER(foo_invoker, foo);
```
With this diff, something like `std::is_invocable_v<foo_invoker, HasNoFoo>` yields `false` rather than a compilation error.
This brings `FOLLY_CREATE_STATIC_MEMBER_INVOKER` in line with `FOLLY_CREATE_FREE_INVOKER` and `FOLLY_CREATE_MEMBER_INVOKER`.

Reviewed By: yfeldblum

Differential Revision: D25878262

fbshipit-source-id: 150ae6b2c71941317bc02de20720fed014639bf5

Summary: The lazy initialization logic can now be simplified.

Reviewed By: andriigrynenko

Differential Revision: D25675031

fbshipit-source-id: 048328220a2b02c13a672bebe47b79521d5f5e7a

Summary: `folly::DelayedInit` serves a similar use case to `folly::Lazy` but is suitable for data members and is thread-safe. The summary in `DelayedInit.h` provides a good overview.

Reviewed By: andriigrynenko

Differential Revision: D25671587

fbshipit-source-id: 1933b15fdc7207a52067658188ca4d5724d9c40b

Summary: Migrate a couple of uses of Folly Format to fmt.

Reviewed By: simpkins

Differential Revision: D20152350

fbshipit-source-id: fb9798f5ff458ee03e1c01f839dc1c55796d0eaa

Summary:
This utility is meant for usage cases where
- the same `mallctl` command is called many times, and
- performance is important.

Reviewed By: yfeldblum

Differential Revision: D23638723

fbshipit-source-id: 6cab9acb1121ef4f46bf7acbe29d3877005b66b1

Summary: All changes were automated

Reviewed By: Orvid

Differential Revision: D25507587

fbshipit-source-id: fe757e6919793e9b8b28d6c1ce6f064d7e2623fb

Summary:
See docblock in new test. If the FiberManager weakref is created after the AsyncioExecutor weakref, then the native FiberManager object may be destroyed without being drained.

Unfortunately, there's no way to enforce an ordering between the destructors here (since weakrefs are cleaned up in inverse order of creation).

This diff adds a `__dealloc__` method to AsyncioExecutor to drain the native FiberManager

Reviewed By: yfeldblum

Differential Revision: D25797920

fbshipit-source-id: d1a548ebd67e7d9153eb43b169bf009a6a986e68

Summary: Update name to match usage of Try as tri-state, since this method also throws if the Try is empty

Reviewed By: yfeldblum

Differential Revision: D25737810

fbshipit-source-id: a4166153362f07353d212216fbaf7105867eef2a

Summary: Tweak `is_coroutine_handle` detail trait. No need for leading `_` and let it be a trait variable.

Reviewed By: iahs

Differential Revision: D25864424

fbshipit-source-id: 2f0723fcb3c97c6a0972056999f1d9574695c30b

Summary:
1. Patch the test to remove racy behavior
2. Added another test for a case where the timeout is hit.

Reviewed By: yfeldblum

Differential Revision: D25854609

fbshipit-source-id: c1694e5b46b9645dc3e71a12ddc8ed12e8cf270c

Summary: Fix typo

Reviewed By: yfeldblum

Differential Revision: D25861463

fbshipit-source-id: c24a521572229cbc5892a4da10999dcff94741c7

Reviewed By: igorsugak

Differential Revision: D25849195

fbshipit-source-id: 611df723a38b5c2a7ba5184c63fdeeed1ed27025

Summary: Adds a test for ConcurrentHashMap::reserve().

Reviewed By: magedm

Differential Revision: D25853643

fbshipit-source-id: 39404105c88d6dc38cdd0b399c646affad1b26e0

Summary:
Fixes a bug when a call to reserve leads to calling rehash with a buck_count value that is not a power of two and/or less than the current count.
The rehash algorithm depends on the bucket_count being a power of two and that the count does not decrease.

The fix: Ensure that reserve calls rehash with a power of two argument and that rehash is skipped if the new count is not greater than the old one.

Reviewed By: davidtgoldblatt

Differential Revision: D25852794

fbshipit-source-id: ae1ae6cfbcbd0659becc14c703920e9505181109

Summary: All changes were automated

Reviewed By: Orvid

Differential Revision: D25507562

fbshipit-source-id: ffed8f0e41d3581242b4e8e00bfd1fa6ee3e299b

Summary: Sets out the foundation of io_uring support into fizz and enables support in the fizz tool

Reviewed By: mingtaoy

Differential Revision: D23592810

fbshipit-source-id: 6f995c99541bc2aeca3cdfb7d84ebd2d25eb1f5e

Summary: Same code as in oneIn() explicit check for arg 0, 1.

Reviewed By: yfeldblum

Differential Revision: D25838957

fbshipit-source-id: 36ead588e435f116d0870ba45a181979c591c3f2

Reviewed By: yfeldblum

Differential Revision: D25689803

fbshipit-source-id: 0d5f6093d814c58e2d90f9042b7bad65ff8d8ade

Summary: Let `folly::FunctionRef` detect empty-callable ctor arguments like `folly::Function` does. Handles pointers which may be nullptr.

Reviewed By: luciang

Differential Revision: D25840538

fbshipit-source-id: 8cfccd57aa545ffc95807876d486ecf94aba8d62