Summary:
The fallback implementation of F14 does a clever trick in its implementation of `find()` to support heterogeneous lookup. But this trick is UB and its implementation assumes that the key-equal type is empty, not specially-aligned, and not final. Relax these constraints.

As it turns out, fbthrift streaming uses an F14 map with a stateful key-equal, triggering this UB in the fallback implementation: `StreamMap` uses key-equal type `StreamMapEquals`, which is nonempty and has a `StreamIdResolver` field, which itself is empty but which causes `StreamMapEquals` not to be empty. The simplest fix is, of course, to switch to using `StreamIdResolver` as a base, but this would be a bug in the F14 fallback regardless.

`BottomKeyEqual` must have the same size, alignment, emptiness, and finality as `KeyEqual`.

Reviewed By: aary

Differential Revision: D26905527

fbshipit-source-id: 023feb3963fc7b2e779fb591e737ea4b70ded476

Summary:
Heterogeneous access is described [here](https://github.com/facebook/folly/blob/master/folly/container/F14.md#heterogeneous-key-type-with-transparent-hash-and-equality) and this diff adds this capability to EvictingCacheMap.

See `HeterogeneousAccess` test from EvictingCacheMapTest.cpp for usage example.

Reviewed By: yfeldblum

Differential Revision: D26879601

fbshipit-source-id: 027352f2daa6773ab981b924732e1056550f6ea2

Summary:
This diff adds new capability to calculate statistics efficiently in a single pass. In particular, it uses Welford's algorithm to track an internal state such that variance and standard deviation can be obtained at O(1).

The following statistics are available:
- count
- minimum
- maximum
- mean
- sample and population variance
- sample and population standard deviation

Reviewed By: yfeldblum

Differential Revision: D26667517

fbshipit-source-id: c4eb31e93646b9cff2f6516039170c8d88a5bf33

Summary:
Version of `GENERATOR` that we're already using in a few places where
it doesn't leave its original scope.

Reviewed By: ddrcoder, luciang

Differential Revision: D26909115

fbshipit-source-id: 5fbae8bd44c62d4d96427a4fd3ef60a8d9cb40e3

Summary: All dependencies have migrated to folly/io/coro/Transport.h

Reviewed By: yairgott

Differential Revision: D26837064

fbshipit-source-id: abc46819e4d9bdec6ff5898d0295731781c7925d

Summary: This also renames the file and creates a Socket.h shim for compatabilty.

Reviewed By: yairgott

Differential Revision: D26837068

fbshipit-source-id: 47c8f7b410540d1ad0aa03f4bc96816f8a93ef1c

Summary: This allows coro::Socket to be used with non-socket AsyncTransports, notably Fizz.  A subsequent diff renames the class and file, and creates a shim for callers.

Reviewed By: yairgott

Differential Revision: D26610473

fbshipit-source-id: d64597ef0de3c90ab084249b20e85d97b34857a6

Reviewed By: zertosh

Differential Revision: D26908037

fbshipit-source-id: 5c636fd281066f1d9af0d92f6f0b015ebf77437b

Summary:
When using folly::ThreadLocal<> to create thread-local variables, if a thread-local is set from two different libraries which are compiled with -fvisibility=hidden and using libc++, then a nullptr dereference is seen when attempting to set the thread-local from the second DLL.

This is due to StaticMetaBase (which should be a singleton) getting created twice. This results in the thread local metadata getting corrupted and hence attempting to dereference a nullptr.

Fix by marking StaticMeta as FOLLY_EXPORT, so only a single instance exists at runtime.

Fixes https://github.com/facebook/folly/issues/1431

Pull Request resolved: https://github.com/facebook/folly/pull/1533

Reviewed By: yfeldblum

Differential Revision: D26818467

Pulled By: Orvid

fbshipit-source-id: 6b22627bc51060260e653885bdeb0df111207617

Summary: Some use-cases can be sensitive to inline code size, so reduce the inline code size of `Executor::invokeCatchingExns` just in case.

Reviewed By: vitaut, zhxchen17

Differential Revision: D26875990

fbshipit-source-id: 0b822f7425bb47c98837faf08216092b49a7ed38

Summary:
The `Fetch128()` function is only used in `#ifdef` sections that check for
either `can_use_sse42` or `can_use_sse41 && x86_64`.  On Android builds this
function was defined as a static function that was never used, causing
compiler errors when compiled with `-Werror -Wunused-function`

Reviewed By: mzlee

Differential Revision: D26865431

fbshipit-source-id: 5cd7ce12aa614f3d904df40ba21842223502a9ec

Summary:
If there is an active async operation on the current thread, then the signal
handler will also print the async stack trace as well. Note that an async stack
trace can have a mix of both non-async and async frames. This is an example
of what an async stack trace might print:

```
funcF      <- non async, top of stack
funcE      <- non async
co_funcD   <- async
funcC      <- non async, blocking call. Second async stack root here
co_funcB   <- async
co_funcA   <- async
main       <- non async. First async stack root here
```

If there is no async operation in progress, there is no change in behavior
(only normal stack trace is printed).

This also adds a helper `getAsyncStackTraceStr()` to easily dump
the async stack trace on demand. This helper is NOT async-signal-safe
and is only meant for debugging purposes.

Reviewed By: yfeldblum, andriigrynenko

Differential Revision: D26661006

fbshipit-source-id: f6e913910eb45c438a3e1e29d231e224eed15ef2

Summary:
When log verbosity is sufficiently high, the logging of AsyncSocket connection exceptions triggers the following assert:
```
  assert(typeid(ex) == typeid(std::decay_t<Ex>) ||
       !"Dynamic and static exception types don't match. Exception would "
        "be sliced when storing in exception_wrapper.");
```
Update the log to output `e.what()`, which all of the other exception logs already do.

Reviewed By: yfeldblum

Differential Revision: D26799863

fbshipit-source-id: f9d98f81a77a654e78a153bc5c23e6ec8223fa1f

Summary: Use `folly::to_ascii_decimal` in `FOLLY_SAFE_CHECK` and related facility implementations. This facility is intentionally async-signal-safe on its own and is light on its dependencies. Specifically, avoid the dependency on `folly/Conv.h` which is heavier.

Reviewed By: luciang

Differential Revision: D26597237

fbshipit-source-id: e3cf0b3a3046cdbd3da89cc8a2e0627edb5a5a85

Differential Revision: D26882407

fbshipit-source-id: f7ab479aff6b8eaced65da333415efd33112ea0a

Summary:
`std::atomic_wait()` and `std::atomic_notify_one()` are marked as unavailable.
Not really sure what that means, but it seems to be breaking some open source
builds https://github.com/facebook/folly/issues/1527.  Explicitly qualify the
calls into those functions to try and fix the build break.

Since we cannot conditionally import either of the above (because they are
marked as unavailable), we can't rely on the standard implementations.  To
prevent ADL from kicking in when the standard-library defines these, we fully
qualify these and use `tag_invoke` for the customization points used in tests.

Reviewed By: davidtgoldblatt

Differential Revision: D26742072

fbshipit-source-id: 9f44bbfd37530f5ecffa3e03d673cfb1df953299

Summary:
Generic ascii-ification functions `to_ascii` and `to_ascii_size` for varying unsigned integer types over varying integer bases.

Has minimal dependencies. Is explicitly async-signal-safe.

Reviewed By: kennyyu

Differential Revision: D26593764

fbshipit-source-id: b1432bee8ca8eb0a5304943c4e231e201425f14a

Summary: Executors just carry on after a task they are running fails, although they try to log something marginally useful. Deduplicate the logic.

Reviewed By: aary, ot, philippv

Differential Revision: D26745058

fbshipit-source-id: 90fa558c89591b8a2d08e6820388970dee8811be

Summary:
This just fixes the include order within groups of includes, so is significantly less aggressive than the other codemod which regroups includes.

I've manually ensured that:
- groups are split when trivial.
- glog is not reordered relative to other folly headers (seems to cause down stream issues)
- portability headers are not reordered (seems to cause down stream issues)
other diffs will finish the regrouping and ordering of those groups.

Reviewed By: yfeldblum

Differential Revision: D26405757

fbshipit-source-id: 9b79a91a41a4e6ac677ed0cb7fb24dfb7c8093d2

Summary: Tag all inline-like executors, so that there's a single way to detect them in places where we don't want inline executors.

Differential Revision: D26564118

fbshipit-source-id: 1a55c03bee0a0a56328175c016d3880a86eab8b1

Summary: Folly may assume all compilers have `__has_include`. Remove the single case of testing for it before using it.

Reviewed By: simpkins

Differential Revision: D26788728

fbshipit-source-id: a11b47f6730700d81141d14c627e9d414ee6f68d

Summary: This diff is part of a series cleaning up coro::Socket

Reviewed By: yairgott

Differential Revision: D26837067

fbshipit-source-id: e7ef587a6f859a167404b3eb2c8399544aa1d092

Reviewed By: yfeldblum

Differential Revision: D26848785

fbshipit-source-id: 441aeac55f51ee8ec5e2316288f2c1f778a60dda

Summary:
Allows waiting for a range of SemiAwaitables while receiving progress incrementally.
Often requested as a repeatedly-invokable collectAll.

Uses an external AsyncScope to avoid the following sharp edge with using an internal scope (demonstrated in V1 of this diff): if the AsyncGenerator is destroyed without being fully drained we'd have to block on the scope, which can deadlock.

Reviewed By: helfman

Differential Revision: D25924855

fbshipit-source-id: 46dd7c64d58560f57a7c18e35c159beb984286a7

Summary: Mod all such cases not to pass any exception type list since such cases presumably want to catch all exceptions.

Reviewed By: ericniebler

Differential Revision: D26712856

fbshipit-source-id: 1b5de869da5701a6bec85770f11c88195d7e62d8

Summary:
D24094832 (https://github.com/facebook/folly/commit/842ecea531e8d6a90559f213be3793f7cd36781b) enabled code blocks which were currently not supported with SGX build mode, resulting in fbenclave build errs [T85891699].

Our SGX targets depend on folly and are built with a custom toolchain. Because of our dep constraints we don't support all features. We typically try to toggle certain folly features, for example: https://www.internalfb.com/intern/diffusion/FBS/browsefile/master/tools/buckconfigs/fbcode/sgx.bcfg?commit=8981fc7187d8b2484a764e9277a1efa082a13f50&lines=36

We were unable to disable these blocks of code because this macro was defined to be 1. We would typically just add the compiler flag: -DFOLLY_HAVE_SO_TIMESTAMPING=0. But doing causes redefinition.

Reviewed By: bschlinker

Differential Revision: D26765404

fbshipit-source-id: 06d800efa7f23d9235a019ed7cc8fe4cde53c91c

Reviewed By: yfeldblum, philippv, luciang

Differential Revision: D26832361

fbshipit-source-id: 9f67a0af8c3c939cbfda1bd46806849e164e5354

Summary: Since most uses just specify `std::exception` and really just want to catch everything.

Reviewed By: ericniebler

Differential Revision: D26712827

fbshipit-source-id: b33c1a311a839a50d81b9bc6c2b441908130dec6

Summary: FiberManager depends on those tasks to be run to know when it's safe to shut down (i.e. all outstanding tasks should be run).

Differential Revision: D26811875

fbshipit-source-id: 98b59ad28e25e7e47197e23ad3209349fdbfbb44

Summary: Adds `pretty_formating_indent_size` option which is used to change the indentation size when used with `pretty_formatting`

Reviewed By: yfeldblum

Differential Revision: D26793086

fbshipit-source-id: 53efea33d7daa5c8f8840fc7f087d2d976ed3eda

Summary:
Revise `folly::demangle` and its test suite.

As a few items:
* Minimize preprocessor conditional compilation.
* Make the tests work for all combinations.

Differential Revision: D26551208

fbshipit-source-id: 422f6f96632c4dfc3f2e51f7b3ae8855cdb3ab30

Summary:
If we have `PATH_MAX` we can probably have `NAME_MAX` as well.

It should be exact equivalent of `NAME_MAX` on Windows:
https://docs.microsoft.com/en-us/cpp/c-runtime-library/path-field-limits?view=msvc-160

Reviewed By: Orvid

Differential Revision: D26784071

fbshipit-source-id: 1e28d5de4358efded182db85f0382939c96a4dce

Summary:
Update the check in `folly/Portability.h` to handle more recent versions of
MSVC that do support `__has_include`.  The code on the `__has_include` code
path was checking the value of `__cplusplus` rather than `_MSVC_LANG`.
Microsoft only defines `__cplusplus` correctly when the compiler is invoked
with the `/Zc:__cplusplus` flag.

This updates the code to use the `FOLLY_CPLUSPLUS` macro instead.

Reviewed By: yfeldblum

Differential Revision: D26769080

fbshipit-source-id: e40cfaef967b13d2fe1be2b40a109cb0ed39515a

Summary: Workaround for: "folly/Range.h:252:9: error: field 'b_' will be initialized after field 'e_' [-Werror,-Wreorder]"

Reviewed By: yfeldblum

Differential Revision: D26788131

fbshipit-source-id: 3664ea96adc26b0f97ad8d11259b018c39254692

Summary: Ensure that threshold is not 0, otherwise when capacity < 10, threshold is 0, which can lead to consumers never transferring credit to producers.

Differential Revision: D26791831

fbshipit-source-id: 741bcf17de18198e43471d4b36d98c79288652fb

Summary: These cause unused variable warnings on other platforms.

Reviewed By: mzlee

Differential Revision: D26771614

fbshipit-source-id: 9170c0da97375682624ee73fe422f34860f35a80

Summary:
On Apple platforms, some of the ucontext methods used here are
deprecated.

Reviewed By: yfeldblum, snufkinsnorka

Differential Revision: D26765225

fbshipit-source-id: 92c7e554b1d1e98b7b8566079a0cb3a0e8afc2d3

Summary: Depending on inlining of std library primitives (e.g. coroutine_handle) it's possible to have more frames in the stack trace.

Reviewed By: yfeldblum

Differential Revision: D26793792

fbshipit-source-id: 44fb1344353e29ec92559ee34740157373112f8f

Summary:
When the given deadline to futexWaitUntil() is less than the idle
timeout that controls purging, MemoryIdler should not purge JEMalloc arenas.
Fix a bug where if the deadline is less than the idle timeout, purging happens
100% of the time unconditionally.

Reviewed By: mogeb, davidtgoldblatt, jalatif

Differential Revision: D26784786

fbshipit-source-id: 316ef96658d0cc2263b973b0b7c345605784eb36

Summary:
With the exception of std::string, nothing else string-like can be
optimized further than a copy. So, create a generic Stringish constructor
that copies .size() elements from .data(), where .data() has a value type
of char.

Reviewed By: yfeldblum

Differential Revision: D5407445

fbshipit-source-id: acf709f07e73bb5bef3f124169c81d76edefa52c