Summary:
These boost macros have a longstanding warning problem, not fixed in VS 2019
```
folly\overload.h(72): warning C4003: not enough arguments for function-like macro invocation 'BOOST_PP_TUPLE_TO_LIST_1'
folly\overload.h(73): warning C4003: not enough arguments for function-like macro invocation 'BOOST_PP_TUPLE_TO_LIST_1'
```

Reviewed By: kosievdmerwe

Differential Revision: D25497039

fbshipit-source-id: 47e6555681f043d6d7a80cc0c963d6e326e70242

Summary:
ConstructorCallback enables the addition of callback functions to be called when a class constructor is called (D27056139 (https://github.com/facebook/folly/commit/d31902b958fc21c7bf812b0ec45c796b4bf9073c)). The ConstructorCallback object holds a static array with all installed callbacks. When a class constructor is called, the ConstructorCallback constructor traverses the array and executes each installed callback. The array is destroyed when all instances of the class are destroyed.

This diff fixes a potential concurrency issue when ConstructorCallbacks are destroyed: the callback array is destroyed while another thread is calling the class constructor and potentially looping through the callback array. We fix the issue by putting the callback array, the callback count, and the mutex into a struct and initializing a `createGlobal` object from the struct.

**Facebook:**

We describe the issue in more detail in T100230454.

Reviewed By: bschlinker

Differential Revision: D30910255

fbshipit-source-id: d345900dbadbf2e009719b6f930ab1d8aa284647

Summary:
Extending the current support for python futures <-> folly tasks interop to also support cancellation.

By adding a new version of `bridgeCoroTask` that also accepts a `folly::CancellationToken` we can give python code the ability to cancel the folly task.

Reviewed By: nanshu

Differential Revision: D31765430

fbshipit-source-id: 4277e94e296f56b998c9c583823a93ce5b9e7586

Summary: Fix C++20 build

Reviewed By: luciang

Differential Revision: D31786941

fbshipit-source-id: 153ffcee7b64f4c6dfafb786df90e909cee723b3

Summary: No thread id available built-in in emscripten, even though it has partial pthread support. Stub it out.

Reviewed By: boguscoder

Differential Revision: D31754569

fbshipit-source-id: 29113ba31cf6b65e7d5c52455fd99ee1e659c041

Summary: Since all the other lock utilities are there.

Differential Revision: D31523986

fbshipit-source-id: 22a071c50e51518b061980d7429d1a28755dbe40

Summary:
For MSVC, `ssize_t` and `std::make_signed_t<std::size_t>` are different types (even though both are 32 bit signed integer, `std::is_same` is false: https://godbolt.org/z/n4Wfbh3nM). This creates type mismatch between header and cpp file.

This diff changed to include `folly/portability/SysTypes.h` which defines `ssize_t` in a portable way.

Reviewed By: ot

Differential Revision: D31722673

fbshipit-source-id: c8968d5e0b5ac12d8d6ab4c141f791cb73d80686

Summary: Fix -Werror,-Wunused-result

Reviewed By: ispeters

Differential Revision: D31786026

fbshipit-source-id: 51af8e21a02f9d6f476d0cb79eb7c6d38f545f20

Summary: Fix C++20 build

Reviewed By: ispeters

Differential Revision: D31785835

fbshipit-source-id: ecfa717787546048c422084785b51e0f7d8eaa26

Reviewed By: Mizuchi

Differential Revision: D31745111

fbshipit-source-id: 45122594f59b13b8a2ab68e0dd565ded750e5e40

Reviewed By: zertosh

Differential Revision: D31753624

fbshipit-source-id: cebadddc83af19739a0ada00cb4bbfde0d640213

Differential Revision: D31755819

fbshipit-source-id: ad32b753efda887e1dae4a7a29749aefa8477e75

Summary: Workaround for -Werror,-Wambiguous-reversed-operator

Reviewed By: yfeldblum, mpark

Differential Revision: D31615526

fbshipit-source-id: 23f72e7b0aaea65d1e0cc294beef3b33d7aa985e

Summary: Adding QueueObserver to MeteredExecutor so that we are able to execute callbacks per enqueue and dequeue

Reviewed By: mshneer

Differential Revision: D30052794

fbshipit-source-id: eec2d55fcd02477791080a7b97cec98cb6ba9875

Summary:
Made the following changes AsyncTransport::LifecycleObserver callback
- added `connectAttempt()`, called for each observer when connect is invoked;
- changed `connect()` to `connectSuccess()`, called for each observer when connect is successful;

Reviewed By: bschlinker

Differential Revision: D29962337

fbshipit-source-id: f1d2c0e48b6d7e263466f74c97d701bb9df9b313

Summary: A typo in its name meant it was missing and that `dynamic::operator-(int)` was defined instead.

Reviewed By: ot, luciang

Differential Revision: D31726709

fbshipit-source-id: 42696c958f674de806dd56c3d89ec07dd60db961

Summary:
`retryingJitteredExponentialBackoffDur()` supports `jitter_param=0` (sanctioned in tests, and widely used to disable jitter based on a runtime parameter), but `std::normal_distribution` does not, so just special-case it.

In practice, libstdc++ already returns 0.

Reviewed By: yfeldblum

Differential Revision: D31722687

fbshipit-source-id: d81b1736379c596c4fc352b0067a4ad5788b0f8c

Summary: Make them a bit shorter with a bit less repetition. Performance-wise, trades away two direct calls for one indirect but perfectly-predictable call. And continues to optimize away in non-sanitizer builds.

Reviewed By: luciang

Differential Revision: D31673074

fbshipit-source-id: f6d8b66cf45a81788d1ec0c5b58241f4fc693001

Differential Revision: D31661218

fbshipit-source-id: 48535870ab2b2f86b0d4e9286365fe906110dc3e

Summary: While the baton is used to guard associated memory, if the wait times out, the associated memory is not available. There is no corresponding load-acquire, so marking the timeout may use a store-relaxed rather than a store-release.

Reviewed By: luciang

Differential Revision: D31676286

fbshipit-source-id: dd2474db1ba053337de7e84aa88e7556e630b1ce

Summary: The stripe table, which is a table of atomics, is its own data and does not guard any associated data. It must technically be atomic to avoid technical data race, but all accesses are relaxed.

Differential Revision: D31524230

fbshipit-source-id: 782b515f3845b4567ca258fd8d096f22248d60ff

Summary:
We currently bump it for clang+tsan because the clang implementation of tsan historically implements the historical pre-c++17 rule even post-c++17. But to enable libstdc++ assertions, we must also bump it for for some versions of libstdc++ when assertions are enabled.

The assertions are removed in libstdc++ trunk: https://github.com/gcc-mirror/gcc/commit/dba1ab212292839572fda60df00965e094a11252. They remain in libstdc++11.2.

Reviewed By: ot

Differential Revision: D31593055

fbshipit-source-id: a339306e86452c4bb6d9d821cd28038ab6f49767

Summary: The AsyncSocket move constructor creates a new socket and then populates member fields, such as `byteEventHelper_` and `preReceivedData_`, with the respective values from the old socket. This happens **after** any callbacks in the AsyncSocket constructor (e.g., installed with ConstructorCallback). These callbacks may need the updated values. This diffs offers the possibility to populate new socket member variables early, by adding them to the initializer list of the AsyncSocket constructor used in the move constructor.

Reviewed By: bschlinker

Differential Revision: D31318333

fbshipit-source-id: 731d24ab4c7525e6f28c3aea4d04c9c5e98409ea

Summary:
Spinlocks in user space are generally a bad idea due to tendency to
burn CPU in outlier events. Replace it with SharedMutex instead. The common
case cost could go up a bit should be better overall.

Reviewed By: yfeldblum

Differential Revision: D31654923

fbshipit-source-id: 77d249293458cd740904f777e00be1bd6834b62f

Summary: Added another line to the rsys sample app's `main.cpp`, which forced me to enable sockets and fix errors in order to get it compile and link.

Reviewed By: usikder

Differential Revision: D30192527

fbshipit-source-id: 10eb9714900ca7f7a48c11b5d8308558ca5e8208

Summary:
`folly/io/async:async_base` is not fully migrated to XROS, mitigate futures implementation for now:
* Craft out `fibers::Baton` and `IO pool` dependencies from futures.
* Add futures to CI targets.
* Add build time test to ensure `folly::Future<Unit>` symbols are generated.

This closely follows mitigation in `AROS` branch:
https://www.internalfb.com/code/aros/[a0c19baba13b]/xros/third-party/folly/folly/futures/Future.h

(any suggestions on how to properly proceed with such change are greatly appreciated!)

Reviewed By: egorich239

Differential Revision: D31497625

fbshipit-source-id: c0b2406496ca3c4f69ddadd61dbd1d75f309e8a1

Summary: Workaround for protected default constructor issue

Reviewed By: yfeldblum, mpark, luciang

Differential Revision: D31618662

fbshipit-source-id: f7e2d498f2da01971b4f67dd28897026f405c0fb

Summary: csl_iterator fix

Reviewed By: yfeldblum

Differential Revision: D31664052

fbshipit-source-id: 338b60ddc9575a7d73ee431e9cef848cecfbcdad

Summary: Async socket test workaround for -Werror,-Wsign-compare

Reviewed By: mpark, ispeters, luciang

Differential Revision: D31625210

fbshipit-source-id: 387bf6172d4e518dfd850f456b859605aa9a6d0f

Summary: Address ConstructorCallback -Werror,-Wsign-compare

Reviewed By: ispeters, luciang

Differential Revision: D31625450

fbshipit-source-id: d5be388fc0d62eb715b5a8fe8e5758a8345cbbb0

Differential Revision: D31641668

fbshipit-source-id: a733dbd2dc4e3f20e82d75514ded1a51788d378f

Summary: `DigestBuilder` is a useful companion to `TDigest` (already public), has a simple and well-defined interface, better documentation than most classes in the parent directory, tests, and benchmarks. It doesn't need to be in `detail/`, and it can be useful for use cases not covered by `BufferedStat`, for example when sub-second resolution and a precise flush schedule are required.

Reviewed By: philippv, luciang

Differential Revision: D31643638

fbshipit-source-id: 4f2f54a933942cbe02d08cd63ab5fc04f13630e3

Summary: Symmetric operators are done using free or non-member operators. This ensures that whatever conversions could happen to the RHS can also happen to the LHS, symmetrically.

Reviewed By: philippv

Differential Revision: D31582089

fbshipit-source-id: ecae61bc810ee9538b1c2b738c58d4e9e01f1483

Summary:
Pull Request resolved: https://github.com/facebook/folly/pull/1669

Similar to CO_TEST_[F|P], adding CO_TYPED_TEST which allows test cases to use co_await/co_return and blocks on the Task<> separately.

Reviewed By: iahs

Differential Revision: D31621981

fbshipit-source-id: 83618de2d106954bde819d90afde0c0140674d54

Reviewed By: iahs

Differential Revision: D31271338

fbshipit-source-id: 10cbd083c4da7461a43d4d0a9d4ab5455dcee270

Summary: While `wake()` is an accurate-enough description of what the function in question does, the actual name of the function is `post()`.

Reviewed By: luciang

Differential Revision: D31617933

fbshipit-source-id: b45f062dccada3cedab2e2b7e7734f6b0b501e63

Summary:
`hg debugapi` now provides easier ways to test edenapi endpoints.
Remove the `edenapi/tools` to reduce code bloat. This also unblocks removing
`To/FromJson` complexity so adding new endpoints become easier.

Reviewed By: yancouto

Differential Revision: D31465796

fbshipit-source-id: fdc0a47b4302c876e78455101068f27949d1b645

Summary:
[Folly] Use `relaxed_atomic` in `IOThreadPoolExecutor`.

For the `nextThread_` field, which may be mutated within `pickThread` in any number of threads concurrently. While `pickThread` is only ever called with a shared lock held, the shared lock does not actually help with concurrent mutations.

Since the mutations of `nextThread_` by `pickThread` is always a `std::atomic::fetch_add` with `std::memory_order_relaxed`, and since that case is a bit more nicely solved with `folly::relaxed_atomic`, switch to that.

Reviewed By: ot

Differential Revision: D6290451

fbshipit-source-id: e473fa6321e462c9b3df9d2bd9650967cca3444a

Summary:
we are currently capture the ID of the thread that is spawning IO threads, not
the ids of the IO threads themselves. Fix it.

Reviewed By: yfeldblum

Differential Revision: D31577084

fbshipit-source-id: 869f9ad20ad379327db513501392bd6bc1ced7e8

Summary: I'm not sure this API is actually used anywhere, but the implementations don't account for cases where the underlying socket is unreadable but setting a read callback would immediately provide data.

Reviewed By: simpkins

Differential Revision: D25324200

fbshipit-source-id: 4176432feea09a4d1387b9025f485e537a5b8da5