Summary:
Introduce functions `exception_ptr_get_type`, `exception_ptr_get_object` for inspecting and upcasting the content of `std::exception_ptr`. Since these facilities are not exposed in any standard way, reach into the platform abi/runtime to implement them.

Includes implementations for these platforms:
* libstdc++
* libc++
* win32

Reviewed By: mzlee, luciang

Differential Revision: D26306199

fbshipit-source-id: 3b655476b69f4456f4e4f88135fbba70a8c4a2a6

Reviewed By: Orvid

Differential Revision: D27671636

fbshipit-source-id: 82cab152ecb606235ee66c026ecafecfe52a88a5

Summary:
This correctly walks the async stack traces. Previously, we were not following the async stack root
from the last async stack frame.

High level stack walking strategy is as follows:
1) Start walking the normal stack up to the first normal stack frame holding the first async stack root
2) Walk the async stack frame chain from the provided async stack root
3) When we reach the end of the current async stack frame chain, check if the last async stack frame references an async stack root R1.
   If there is one, use R1 to find the start of the next normal stack frame when walking the normal stack frame.
4) If that async stack root R1 has a next async stack root R2, the normal stack frame walk should end at the normal stack frame
   holding the next async stack root R2. Otherwise the normal stack frame walk should continue all the way until it hits nullptr.
5) The next async stack walk should begin at the top async frame referenced by the next async stack root R2.
6) Repeat until we've reached the end of both the normal and async stack frame chains.

Reviewed By: andriigrynenko

Differential Revision: D28102128

fbshipit-source-id: c412a2a253720867c257d5cbaa9a6b22e96154f2

Reviewed By: Orvid

Differential Revision: D27671208

fbshipit-source-id: 44710468544eebbb8f4ed0ecd5621bce0b56d248

Summary:
It is monomorphized but called rarely. Best to optimize for size.

The `UniqueInstance` ctor is currently called in the constructor of each translation unit for each distinct instance of `SingletonThreadLocal`.

`UniqueInstance` may be extended to more use-cases so it is worthwhile optimizing for size.

Reviewed By: luciang

Differential Revision: D27602938

fbshipit-source-id: e4077830544516219485814ccc48805b7bb38e34

Summary: Need this to migrate CO_TEST using FAIL() fully on coroutines.

Reviewed By: ispeters

Differential Revision: D28099628

fbshipit-source-id: c79658809210184d8895c3d1551e04b1baf88cae

Summary: To reduce build size, avoid creating unnecessary functions. If the provided callable is already a function-pointer, the callee will already not be inlined.

Differential Revision: D27984345

fbshipit-source-id: a5a31330541338eb04e802bd9dafd99188af3ab9

Summary: Some older versions of gcc cannot deduce the relevant types correctly, and they are still in use in corners of the codebase.

Differential Revision: D28111907

fbshipit-source-id: 0367cb102f450f0f601350308a5831c7fd68f775

Differential Revision: D27582896

fbshipit-source-id: e4228117ba02fe18bd6e8964640f293c963a8732

Summary:
Fixes warnings about implicit type truncation. By making the conversions explicit, react-native-windows will be able to remove suppressions for several warnings required per SDL.

Pull Request resolved: https://github.com/facebook/folly/pull/1565

Reviewed By: igorsugak

Differential Revision: D27964258

Pulled By: yfeldblum

fbshipit-source-id: b13f8728ecda0b38c2fd661199d6551c5ff87993

Summary: Complex expressions involving certain tokens parse at preprocessor time as multiple preprocessor arguments. Quite awkward. The trick is to change the preprocessor macro to deal in variadic arguments.

Reviewed By: ot, Orvid, luciang

Differential Revision: D27986071

fbshipit-source-id: a126fca260396418b14b7367e3e41ddeea78b7af

Summary: QueueMessage is now a variant of NewConnMessage and ErrorMessage

Reviewed By: praihan

Differential Revision: D27384053

fbshipit-source-id: a92f514b56f31e879dc329984bf0a615ed339836

Differential Revision: D27582476

fbshipit-source-id: 376fecda16de8a4836f9ba5196701a9045799ce7

Summary: So that it is possible to have both `Foo<K0, K1, X, Y>` and `Bar<K0, K1, A, B>` where both `Foo` and `Bar` use `UniqueInstance`.

Differential Revision: D27600228

fbshipit-source-id: a5d58726ea0009d7a45c0234f9cff723662a4604

Summary: Parameterises CPUThreadPoolExecutor to allow us to construct one that prohibits blocking operations on its threads. The flag is stored as a thread local and applied using a scoped guard.

Reviewed By: yfeldblum

Differential Revision: D27893465

fbshipit-source-id: 71af1c0b7c23752f499712f498b6abb58a345979

Summary:
Similarly to `IoUringOp::getSqe()`, expose underlying submission data
structure.  The end goal is to perform certain introspection in client code to
report aggregated stats (number of IO, total size of IO, ...).

Reviewed By: ot

Differential Revision: D28022188

fbshipit-source-id: edc51420ed901f0a0d9b5b1338308ad680371298

Summary:
I have a use case where I would like to check if the
AsyncPipe is still active without pumping something in to
write(). Could set up an onClosed callback, but this would introduce
more complexity.

This adds a function to determine if the queue inside the AsyncPipe
still exists.

Reviewed By: iahs

Differential Revision: D28015007

fbshipit-source-id: 1ba37466218abd2f42eab1d8ea5677c3945e31f5

Summary: For TCP sockets, it may not be possible to query the peer address from the fd if the endpoint is no longer connected (closed with reset).  In most server cases, the peer address is known when the connection is accepted, so it can be prepopulated.

Reviewed By: mjoras

Differential Revision: D27985942

fbshipit-source-id: 630098ac00930b978fe8a9cad1894834c44d4d93

Summary:
```
folly/executors/InlineExecutor.h:29:11: error: '~InlineLikeExecutor' overrides a destructor but is not marked 'override' [-Werror,-Wsuggest-destructor-override]
  virtual ~InlineLikeExecutor() {}
          ^
folly/Executor.h:57:11: note: overridden virtual function is here
  virtual ~Executor() {}
          ^
In file included from tupperware/agent/system/Mounts.cpp:18:
In file included from folly/futures/Future.h:36:
In file included from folly/fibers/Baton.h:297:
In file included from folly/fibers/Baton-inl.h:19:
folly/fibers/FiberManagerInternal.h:588:10: error: 'timeoutExpired' overrides a member function but is not marked 'override' [-Werror,-Wsuggest-override]
    void timeoutExpired() noexcept { run(); }
         ^
folly/io/async/HHWheelTimer.h:95:18: note: overridden virtual function is here
    virtual void timeoutExpired() noexcept = 0;
                 ^
In file included from tupperware/agent/system/Mounts.cpp:18:
In file included from folly/futures/Future.h:36:
In file included from folly/fibers/Baton.h:297:
In file included from folly/fibers/Baton-inl.h:19:
folly/fibers/FiberManagerInternal.h:589:10: error: 'callbackCanceled' overrides a member function but is not marked 'override' [-Werror,-Wsuggest-override]
    void callbackCanceled() noexcept {}
         ^
folly/io/async/HHWheelTimer.h:100:18: note: overridden virtual function is here
    virtual void callbackCanceled() noexcept { timeoutExpired(); }
                 ^
3 errors generated.
```

Reviewed By: simpkins

Differential Revision: D27988235

fbshipit-source-id: 799484c52f89fa20f647ff0801b8d136b657b395

Summary:
Add a termination tag that carries through the blocking context chain. This flag notifies logging operations that they may go as far as to terminate the process if blocking operations are detected.

The flags carry through the blocking scopes so the termination flag will stay present while we enable and disable blocking - it would be sticky for a given thread once set.

Reviewed By: yfeldblum

Differential Revision: D27869075

fbshipit-source-id: 27014a3e6c9b28c0f433949a576bb6116e7c06c0

Summary: Internals are not portable between versions or across platforms.

Reviewed By: Orvid

Differential Revision: D27990286

fbshipit-source-id: b70d8d3f67a1e5262efa842f70817e3ae3972339

Reviewed By: Orvid

Differential Revision: D27582035

fbshipit-source-id: 0f0c35adca1c44dcd0ef88f2443f769d7991e6aa

Summary: Add a source file for the function bodies of `getThreadID` and `getOSThreadID`.

Differential Revision: D27698463

fbshipit-source-id: 255961954b1be07e59b19ef3006dcd6149795861

Summary: `folly/stats/StreamingStats.h` uses `std::min` and `std::max` so must `#include <algorithm>`.

Reviewed By: Orvid

Differential Revision: D27986054

fbshipit-source-id: 1c1160101e1ebb4e0b1a16d3d97fd2931db9eeb0

Summary: `StaticSingletonManager::create<T, Tag>` is larger than necessary, which may not be desirable when using many tags with the same type. Permit call-sites to use static data to shrink the functions.

Reviewed By: aary

Differential Revision: D27863037

fbshipit-source-id: 9f6ced3e7d7a85b78e671f69d7a475ab4de5eea0

Summary: By suppressing `-Wdeprecated-declarations` v.s. `-Wdeprecated`, which latter works only under clang.

Reviewed By: Orvid

Differential Revision: D27987616

fbshipit-source-id: 4bf2a225a65d8ac7c7555123343e9536759fcfcc

Summary:
Reported by clang-12:
```
folly/test/SynchronizedTestLib-inl.h:587:7: error: expression result unused [-Werror,-Wunused-value]
      SYNCHRONIZED_DUAL(lv, v, lm, m) {
      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
folly/Synchronized.h:1819:5: note: expanded from macro 'SYNCHRONIZED_DUAL'
    ::folly::detail::SYNCHRONIZED_macro_is_deprecated{};                       \
    ^                                                ~~
```

Reviewed By: chadaustin

Differential Revision: D27954777

fbshipit-source-id: bd1dba5ebf563b34b496457b980568ea1c978442

Reviewed By: Orvid

Differential Revision: D27559485

fbshipit-source-id: be2db59ef6d9b4cf178216a4b8851e27e7ecef93

Summary: The facility was renamed in gtest.

Reviewed By: praihan

Differential Revision: D27985919

fbshipit-source-id: d35795d7bfb985767b5e6c28141dac47a4b9f0ce

Summary: No risk of mismatched types.

Reviewed By: vitaut

Differential Revision: D27933275

fbshipit-source-id: 41bf921748299ead7388bb0dc4197eb4390aa007

Summary: To avoid the extra and unusual dependency in this particular case.

Differential Revision: D27933052

fbshipit-source-id: aeda0b7b5916c3fe05581f9880472d194412c461

Summary: The release order is not valid for compare-exchange-failure-load.

Reviewed By: magedm

Differential Revision: D27932613

fbshipit-source-id: 689929ecdef8feaec268dc2cd350ce001103ee75

Summary: Prefer not to have polyfills. The class `NativeSemaphore` replaces this polyfill.

Reviewed By: Orvid

Differential Revision: D27971239

fbshipit-source-id: 39bd8b2d9be895a947faee4d522420535378fdc3

Summary: Rename ForbidTag to TrackTag as a counter to PermitTag. ForbidTag did not capture the idea that in practice we simply log blocking operations. TrackTag allows for that and opens scope for a more aggressive form of tracking on top.

Reviewed By: andriigrynenko

Differential Revision: D27914911

fbshipit-source-id: d56132b7e389825167503934b7af08f9a3ccf1fe

Summary:
Thread 1:
  - Creates an eventfd X
  - Registers X with an event base
  - Closes X
  - Unregisters X from the event base

Thread 2:
  - Creates some other file descriptor (eventfd or socket or whatever); the operating system reuses file descriptor #X.

The unregistering of X from the event base in thread 1 races with the opening of reused X in thread 2.

The fix is to unregister X before closing X.

Reviewed By: yfeldblum

Differential Revision: D27962155

fbshipit-source-id: 1bcb62c7ebe0297ab9687e1a0edf37d319637fda

Summary: Replace the uses of `FOLLY_CL_USE_FOLLY_TLS` in some cases with C++ checks on `kIsMobile`.

Differential Revision: D27669672

fbshipit-source-id: 79a29896653f2fa62b10b488220d8cf83cba3d00

Summary: To use `std::atomic`, we need `#include <atomic>`.

Reviewed By: Mizuchi

Differential Revision: D27932606

fbshipit-source-id: 8d29a56a75b27ae35bac37b87a7e6d6d1661030e

Summary: The facility was renamed in gtest.

Reviewed By: praihan

Differential Revision: D27904281

fbshipit-source-id: 3f00b4371e17cd85672ad7ef706cea4ca1ba5c64

Summary: On apple platforms, posix sem is deprecated. On windows, it does not exist. So switch to the native-semaphore wrapper.

Reviewed By: chadaustin

Differential Revision: D27903002

fbshipit-source-id: d53c7762fea3123cf67cda48fdd87489a0ee496c

Summary:
A semaphore type which wraps the platform native semaphore type.

On Windows, this is the Windows semaphore type. On Apple, this is the semaphore type from libdispatch. Otherwise, this is the POSIX semaphore type, which is deprecated on Apple and unavailable on Windows.

Reviewed By: Orvid

Differential Revision: D27951114

fbshipit-source-id: e6a870f656eecd3ba41c2efed038b916c124d0e8