Summary:
Change the hazptr_hoklder function names get_protected and reset to (the names in [WG21 P1121](http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2021/p1121r3.pdf)) protect and reset_protection, respectively.

The primary change is in folly/synchronization/HazptrHolder.h

Reviewed By: yfeldblum

Differential Revision: D28662903

fbshipit-source-id: d074c718514716229daaf8dae14b5c275942b38a

Summary:
The guard targets its former use in `__thread` variables, which must be trivial. But it is now used in `thread_local` variables, which can have default constructors.

The relevant switch from `__thread` to `thread_local` was in {D27559375 (https://github.com/facebook/folly/commit/eeec4600b857dd70ca6b30837d14bb79cf9a2ef7)}.

Reviewed By: luciang

Differential Revision: D28683625

fbshipit-source-id: af74801a13e479a262ea50e6d3f89053e67d7ac9

Summary:
This diff adds an optional parameter to consume() and cancel(). This parameter will allow callback objects to know the source bridge that is calling them back. With this parameter, we will not need to create a separate callback object for each bridge (which saves memory).

The parameter is optional. If the parameter type is set to void, no parameter will be passed. This preserves backward compatibility with existing users of AtomicQueue that don't need a parameter.

Reviewed By: iahs

Differential Revision: D28550867

fbshipit-source-id: e7d998538c880c2a5c7649d3262cb7f8913e1439

Summary: This diff moves thrift's AtomicQueue to folly/experimental/channels/detail. This file will be shared between thrift and a new channels framework that will be added to folly/experimental/channels.

Reviewed By: iahs

Differential Revision: D28549810

fbshipit-source-id: de9d66c0f9fd73e89917df997526539b6b92f172

Summary: Guard internal compiler issue in makeCollectAllTryTask similar to collectAllTryRange

Reviewed By: iahs

Differential Revision: D28642361

fbshipit-source-id: a557e2c504b232a47f43c95d1163964652fdd435

Summary:
Reimplement `folly::exception_wrapper` thrown variant not to need to cache any pointers and rather to access the exception object and runtime type, and to perform runtime upcasting, via the platform runtime.

This both simplifies and extends the capability of the thrown variant.

Reviewed By: JunqiWang

Differential Revision: D28625444

fbshipit-source-id: 12409bc75794f5135cdb73563b07fafdf5cc44cd

Summary: Add TakeOwnershipOption::STORE_SIZE

Reviewed By: simpkins

Differential Revision: D28663081

fbshipit-source-id: 5f2b0cd5c9ebdb9a8475b35f8741bc0b17717441

Summary: Required to support RSA certificates in TLS 1.3.

Reviewed By: knekritz

Differential Revision: D28606758

fbshipit-source-id: 0b75eccf207c1327e590675137ce3289956d8771

Summary:
Add callbacks for sized free and corresponding allocations

(Note: this ignores all push blocking failures!)

Reviewed By: simpkins

Differential Revision: D28469569

fbshipit-source-id: 7d0d4c649c3494354ae8ec7cbda3e950eb3c80ed

Summary:
Add support for IOBuf::takeOwnership sizedFree

(Note: this ignores all push blocking failures!)

Reviewed By: simpkins

Differential Revision: D28510736

fbshipit-source-id: b102bd462df3d85856897d4acfff689d371ceb6c

Summary:
Similar to how CO_FAIL() was added, we could also benefit from a CO_SKIP()

Uses same definition as [GTEST_SKIP_](https://github.com/google/googletest/blob/master/googletest/include/gtest/internal/gtest-internal.h#L1354-L1355) but with co_return instead.

Reviewed By: ispeters, capickett

Differential Revision: D28645478

fbshipit-source-id: e92a23b91f8238247ad9d29b67c1a2954f43a38a

Summary:
Add Dockerfile build for openr.thrift python module.

The python module is built by:
1. Building and installing Facebook libraries with fbcode_builder
2. Building Open/R
3. Generating Cython files from thrift files with the FB thrift compiler
4. Generating C++ files from the Cython modules with the Cython compiler
5. Compiling the C++ modules into shared objects

Future work for building and distributing Breeze:

- Fix the hacks in build_breeze.sh, see comments therein
- Use a staged Dockerfile build for the Open/R and Breeze build
- Install openr.thrift. The openr.thrift shared objects are build and
  stored in the Docker image generated by Dockerfile, but are unused.
- Install all the openr python submodules in a single openr site-package
- Add cross-compilation to the openr.thrift build. This is needed for
  Terragraph
- Upload the openr python package to PyPi

Reviewed By: saifhhasan

Differential Revision: D28614443

fbshipit-source-id: 38b7e7c5594fd4bb5a338f19c69e5fc3b3b95863

Summary: TSAN reports race condition in `LOG_FIRST_N`. Replacing it with thread-safe alternatives.

Reviewed By: yfeldblum

Differential Revision: D28541027

fbshipit-source-id: 7054a82c7b26df395a25cd7cd7f921a9c636ffbc

Summary:
Another approach to fixing the exception-ptr accessors for libc++.

This time, just define mimics of `__cxa_exception` both ways, and test to find out which way to cast.

Reviewed By: JunqiWang

Differential Revision: D28561635

fbshipit-source-id: d27430d8fe2d73205bf1a8c31321be4c76808df8

Summary: Improve documentation and make the description of synchronous reclamation  consistent with the current implementation.

Reviewed By: yfeldblum

Differential Revision: D28575528

fbshipit-source-id: e8f37e02d18b12a0e653264c128492a98cba6a1d

Summary:
* `VirtualGen` gains a move-only counterpart, `VirtualGenMoveOnly`
* `virtualize` added as an operator to type-erase generator names, particularly for making errors and stack traces more legible.
* `FunctionRef` used to avoid heap allocations where short-lived references are sufficient.

Differential Revision: D28167691

fbshipit-source-id: 5beaab3f613666ffafc7ac1951be1933c2863d3f

Summary: `ConcurrentHashMap` has a `DCHECK` for use-after-destruction. One of these has a comment explaining what it's for, but `DCHECK` supports taking a message to show the user. Make it a message.

Reviewed By: yfeldblum, magedm

Differential Revision: D28609176

fbshipit-source-id: ea6e57b7650ad597f45ea3efc2fa0fb62d5de40e

Summary: Add sendmsg/recmsg io_uring support

Reviewed By: yfeldblum

Differential Revision: D27148068

fbshipit-source-id: efb9174fb40f5f5bf0d0318db12cb61075866381

Summary:
Use the new ConstructorCallback class to allow exterior functions/classes
to get a callback for each new AsyncSocket()

Implications:
This adds an optional and an atomic int to the size of each AsyncSocket so
there is a very small increase in mem usage even if this is unused (which will
be most code, at least initially).

There is also a very small amount of additional CPU on constructing an
AsyncSocket: checking the std::option to see if it's non-nullopt.

Reviewed By: bschlinker

Differential Revision: D27516379

fbshipit-source-id: 56f4411afcd404dcf0092cce562230e5c0dcdf17

Summary: Original commit changeset: ce083cec4c31

Differential Revision: D28558687

fbshipit-source-id: 5cf4ac838c80428902280f3f9ccdd1174410fbe6

Summary:
It is safe to expose `size()` without requirement to go through
accessor (which adds reference tracking overhead).

Reviewed By: yfeldblum

Differential Revision: D28591686

fbshipit-source-id: ea0be2a34df01488402e53fdfbe232ee710f03f7

Reviewed By: igorsugak

Differential Revision: D28582083

fbshipit-source-id: 9beedfccfd1fc6b9dc4f7ff8ab0139282bd285ab

Summary:
## Description

Hi!
I wanted to fix a build of folly on Android.

Trying to use folly's `MPMCQueue` on Android triggers the following error:
```
{xxx}/rnfbjni/android/app/build/third-party-ndk/folly/folly/Subprocess.cpp:542:19: error: use of undeclared identifier 'getdtablesize'; did you mean 'getpagesize'?
```
where `{xxx}` is a local path on my machine.

[Here](https://github.com/karol-bisztyga/rnfbjni/tree/patch-folly-repro) is a branch of my project that reproduces the problem(I've already fixed it by patching `folly` so you can see what patch has to be removed in order to make it fail [here](https://github.com/karol-bisztyga/rnfbjni/commit/e6d8059e55efda5f88d5edbc1e932b94223b052c)).

From [the man page for `getdtablesize`](https://linux.die.net/man/2/getdtablesize):

> SVr4, 4.4BSD (the getdtablesize() function first appeared in 4.2BSD). It is not specified in POSIX.1-2001; portable applications should employ sysconf(_SC_OPEN_MAX) instead of this call.

### Related issues:
https://github.com/facebook/folly/issues/1279
https://github.com/facebook/folly/issues/918 - probably, I cannot see bug details.

Pull Request resolved: https://github.com/facebook/folly/pull/1584

Reviewed By: simpkins

Differential Revision: D28547979

Pulled By: yfeldblum

fbshipit-source-id: 3b8d882ad2a4b7cb817a2c7bbc5f9f750b35770e

Summary:
Same plan as D28395301 (https://github.com/facebook/folly/commit/99f856ae2009a80b157b5121e44b1f70f61bd7c9), but with a better implementation and tests
in the diff to make sure it actually works.

Reviewed By: bschlinker

Differential Revision: D28421062

fbshipit-source-id: d9b052b38c7b938a78bbaccd4df8d276af2b6d6c

Summary:
Pull Request resolved: https://github.com/facebook/folly/pull/1585

FreeBSD uses libc++ with libcxxrt and not with llvm's libcxxabi so handle it separately.

Fixes: https://github.com/facebook/folly/issues/1582.

Reviewed By: luciang

Differential Revision: D28528248

fbshipit-source-id: c8a1c8a5af20b40e7028e8c2d12589edd3850d32

Summary:
Original commit changeset: c9b68c6b9fac
Backout: D26916419 (https://github.com/facebook/folly/commit/b9f3d9be479d4dccdc8e5094933229e676308872)

Differential Revision: D28532140

fbshipit-source-id: 15e5eb1262234039387bfda36d280391f52cc3b2

Summary:
Switches a thread search from linear-time std::find to logarithmic-time std::binary_search.

Extracts the comparison into a separate function in ThreadList class.

Reviewed By: yfeldblum

Differential Revision: D28301992

fbshipit-source-id: 199728d82ca7d7fe8534f7163c76a6473b6f7c4b

Summary:
Pull Request resolved: https://github.com/facebook/folly/pull/1524

In particular, every file in `folly/experimental/symbolizer/` and `folly/experimental/exception_tracer/`.

Permits including `folly/experimental/exception_tracer/` in the cmake build.

Closes: https://github.com/facebook/folly/pull/1524.

Reviewed By: luciang

Differential Revision: D24797973

fbshipit-source-id: 664febf885432795e54827e580cfe9eac1e75fba

Summary:
Reimplement `folly::exception_wrapper` thrown variant not to need to cache any pointers and rather to access the exception object and runtime type, and to perform runtime upcasting, via the platform runtime.

This both simplifies and extends the capability of the thrown variant.

Reviewed By: phoad, luciang

Differential Revision: D28415741

fbshipit-source-id: ce083cec4c31a8cc98e956c247229ac765c7f983

Summary: Add a separate tag to the blocking guards, derived by default from the names available in the executors. This allows more fine-grained information when reporting blocking operations on the executors.

Reviewed By: yfeldblum

Differential Revision: D28265296

fbshipit-source-id: 98d877ab13dc73c0b0b06edbdf15ec0e06f4d74a

Summary: Use the global immutable executor by default for SerialExecutor.

Reviewed By: yfeldblum

Differential Revision: D26916419

fbshipit-source-id: c9b68c6b9facd11c8768199f8bae3d6c9276f4bd

Summary: The current signature results in an attempt to construct a `Try<semi_await_result_t<SemiAwaitable>>` from a `semi_await_try_result_t<SemiAwaitable>::element_type`. While the inner types match for Task, they don't for AsyncGenerator - the former is `AsyncGenerator<T>::NextResult`, which is not constructible from a T. (We could alternatively add that constructor, but that would result in timeout returning a `Task<AsyncGenerator<T>::NextResult>`, which is undesirably indirect).

Reviewed By: yfeldblum

Differential Revision: D28475605

fbshipit-source-id: c30a60e3ec942f801653a08b020796d47d4ef763

Summary:
The function `folly::exception_ptr_get_type` under 32-bit arm-ehabi libc++ >= v5.0.1 and < v10.0.0-rc2, is broken because the `__cxa_exception` layout is changed in an incompatible way, with an extra 4 bytes padding incorrectly preceding the unwind field. Shift the `__cxa_exception` pointer before accessing fields through it.

Major thanks to Crystal Jin <crystalj@fb.com> for help debugging the problem and testing the fix.

Differential Revision: D28423734

fbshipit-source-id: fdf67fa5c1056df921fad23f86ae965761603738

Summary: Observer initialization is blocking and is using thread-local state to detect cycles/track dependencies. When running on a fiber we have to make sure the fiber doesn't get suspended during observer initialization.

Reviewed By: yfeldblum

Differential Revision: D28306797

fbshipit-source-id: 807a4553e89f9fa807e6c745a623041dbb0e47ce

Summary: Adding `addLifecycleObserver` and `removeLifecycleObserver` to support tests.

Reviewed By: yfeldblum

Differential Revision: D27163395

fbshipit-source-id: de749b2570c71a3f98cbbc8569c2990ce2c5be0c

Summary: When multiple observers attached and one is removed, removal code can end up calling `observerDetach` on the wrong observer. Simplified and fixed removal logic and added new tests.

Reviewed By: yfeldblum

Differential Revision: D27033014

fbshipit-source-id: df84bf65207a00f3b76d8950ac2c29f477508da1

Summary:
The initial implementation of ConstructorCallback used a global (pre-main)
initialization which was deemed safe.  While likely still safe, it turns out
that when trying to land diffs that used ConstructorCallback, many code bases
compile with -Wglobal-constructor which explicitly denies this type of
initialization (even if it is safe).

Re-worked the code to prevent any non-zero initialization and still maintain
the property that we don't lock unless someone is registering a callback.

Reviewed By: bschlinker

Differential Revision: D28395301

fbshipit-source-id: 2cdd82189410b3ccea1c892560d0d0cb5b6abc34

Summary:
So it can be used in cases where data is already hashed, and
order-independent way to reduce the set of hashes is required.

Reviewed By: ot

Differential Revision: D28382187

fbshipit-source-id: 4327ddd67b49a61d0172c4676090b2f96e84c065

Summary:
To facilitate debugging.

Privacy note: now `what()` message may contain part of JSON.

parser_error `what()` message:

- before the change:
`folly::toJson: JSON object value was a NaN`

- after the change:
`folly::toJson: JSON object value was a NaN when serializing value at "outerKey"->"innerKey"`

Reviewed By: yfeldblum

Differential Revision: D27623818

fbshipit-source-id: 86e61a0fed500eddafbd3e3bb1b9ed363ba8fcae

Summary:
This introduces `__folly_memcpy`, which is an implementation of `memcpy` that uses prefetch to speed up cold copies (data absent from L1) and uses overlapping copies to avoid as much branching as possible to speed up hot copies (data present in L1).

A description of the core ideas for this memcpy is in the file comment at the top of folly_memcpy.S.

`__folly_memcpy` *does* act as a `memmove`, although it isn't optimized for that purpose for copies of 257 or more bytes. This masks some undefined behavior bugs when code calls `memcpy` on an overlapping region of data. `perf` samples will show when `memmove` is called by `__folly_memcpy`, which will help identify these undefined behavior bugs for copies of 257 bytes or more.

Reviewed By: yfeldblum

Differential Revision: D23629205

fbshipit-source-id: 61ed66122cc8edf33154ea6e8b87f4223c0ffcc0