Summary: Merely a terminology thing. An object returned by `co_await` is an awaiter, not an awaitable.

Reviewed By: yfeldblum, lewissbaker

Differential Revision: D24524929

fbshipit-source-id: ee9b7c8807972e78fff97f055d498977048d0c48

Summary:
Allocation of InlineTaskDetached coroutines now call through to the
folly_coro_async_malloc() and folly_coro_async_free() functions so that
their allocations can be correctly accounted for as coroutine allocations.

Reviewed By: yfeldblum

Differential Revision: D24574568

fbshipit-source-id: 9bece3f8e6f6d221bca021a50fe02e1eed88f07b

Summary:
The previous implementation was calculating an address within the
detached_task() function by just adding the constant +2 to the
function-pointer. This was causing some issues with some of the
tools used to optimise binaries.

Reworked this implementation to instead actually return a true
return-address obtained from the compiler builtin so that it's
hopefully less problematic for those tools.

Reviewed By: maksfb

Differential Revision: D24506346

fbshipit-source-id: c41bd55ab09ebc70d040d355556ed4992243c14f

Summary:
D24542292 fixed a problem introduced by D24505812 (https://github.com/facebook/folly/commit/af8630489dc8318f72d18358591bc3fa0be304ff) with gcc version 6.

Unfortunately this broke some python code generation.

I didn't fully root cause the issue but it appears that the macro expansion of FMT_BEGIN_NAMESPACE is inconsistent.

The original diff D24505812 (https://github.com/facebook/folly/commit/af8630489dc8318f72d18358591bc3fa0be304ff) hardcoded the fmt namespace I changed it to what the fmt lib used when declaring the formatter template.

Reverting the change to use the macro back to hardcoding the fmt namespace fixes the test and still works around the gcc 6 compler problem.

Reviewed By: vitaut

Differential Revision: D24542292

fbshipit-source-id: cfaecf8bb94f3c6fc084ebae79886ad3e2b58539

Summary:
The TaskTests::FutureRoundtrip and TaskTests::StartInlineUnsafe tests were
incorrectly using stateful lambdas in a way that leads to the coroutines
having a dangling reference to a destructed temporary lambda. This was causing
ASAN failures.

This changes those usages to instead use stateless lambdas.

Reviewed By: lxfind

Differential Revision: D24542508

fbshipit-source-id: 034d397b79e0553094a14d2cb6d00fe3816b4b92

Summary:
The document titles should be explicitly passed, otherwise pandoc generates a warning and tries to guess

Before:
```
folly/folly/docs on  master
❯ make Format.html
/usr/bin/pandoc -s -H style.css -f markdown -t html --toc -o Format.html Format.md
[WARNING] This document format requires a nonempty <title> element.
  Defaulting to 'Format' as the title.
  To specify a title, use 'title' in metadata or --metadata title="...".

folly/folly/docs on  master
❯ make index.html
/usr/bin/pandoc -s -H style.css -f markdown -t html --toc -o index.html *.md
[WARNING] This document format requires a nonempty <title> element.
  Defaulting to 'AtomicHashMap' as the title.
  To specify a title, use 'title' in metadata or --metadata title="...".
```

After:
```
folly/folly/docs on  fix-docs [!]
❯ make Format.html
/usr/bin/pandoc -s -H style.css -f markdown -t html --toc -o Format.html Format.md --metadata title="folly/Format.h"

folly/folly/docs on  fix-docs [!]
❯ make index.html
/usr/bin/pandoc -s -H style.css -f markdown -t html --toc -o index.html *.md --metadata title="Folly API Documentation"
```

Reviewed By: danobi

Differential Revision: D24546374

fbshipit-source-id: 818e6ce39f361695a5f94c7662953062ea2f2868

Summary: Using the FunctionScheduler with PoissonDistribution will not work if we supply an interval of 36min+. This is around 2^31 so looks like it's hitting some integer limit. Also, there is no failure message and the behavior is that the function scheduler just never executes the function even for the first time after startup interval. Fixing this by using the proper type in the disribution.

Reviewed By: yfeldblum

Differential Revision: D24505727

fbshipit-source-id: ad050cf82bcf5a39383ffc601b52ad05d3d54f44

Summary: Original commit changeset: 578dd8981922

Reviewed By: jalopezsilva, pdubovitsky

Differential Revision: D24531203

fbshipit-source-id: 573ccd55a4d8f3b6841cc533e25c84b18fe24d4d

Summary:
Some llvm toolsets mis-parse the function-like C-style casts in ConstexprMath.h as function declarations, resulting in strange compiler errors. Prefer `static_cast` to eliminate the ambiguity.

Note: We cannot use brace-initialization syntax, because that would error on narrowing conversions.

Reviewed By: ispeters, Mizuchi

Differential Revision: D24463342

fbshipit-source-id: 5d5aabb08cd20e91a1a5f5460cc4505cafb3cdfc

Summary: This is a quick and dirty hack that works around a wasm dependency issue. The issue manifests itself in a compile error when including fmt headers during a wasm build.

Reviewed By: shodoco

Differential Revision: D24516599

fbshipit-source-id: 578dd8981922a97702992a8c30b88b47fef1706e

Summary: gcc versions 5 & 6 do not support template specializations outside the original namespace of the template even if the namespace is explicitly included in the template specialization.

Differential Revision: D24505812

fbshipit-source-id: 693e93de5bc5074866fdea713436a06d35762cb7

Summary:
taskExecuteCount_ can be incremented from a single thread, but reading it from another thread is still technically a data race. Mark it as atomic to make TSAN happy.
Also make sure we never return < 0 when called from a non-consumer thread (since we only have the synchronization guarantee on the consumer thread).

Differential Revision: D24523284

fbshipit-source-id: 6185125e132d71a83a3f29c909b7e4eab09e6e79

Summary:
Glog v0.4.0 when configured with Debug build type adds a 'd' suffix to
the library file. This results in FindGlog.cmake failing to locate it.

Update FindGlog.cmake to use check for 'glogd', and use
select_library_configurations() to set GLOG_LIBRARY to the correct
found filename.

(Note: this has no effect if a non-Debug type is used.)

Pull Request resolved: https://github.com/facebook/folly/pull/1479

Reviewed By: yfeldblum

Differential Revision: D24503510

Pulled By: Orvid

fbshipit-source-id: 705df05a4a3d7df2df8af3bb66c319fb044adbce

Summary: This also splits queue size counter into two to make sure we do fewer atomic operations on the consumer thread.

Differential Revision: D24490151

fbshipit-source-id: 69297a2fd0c5fddcd7355a28fe600b72320e81cd

Summary: Following up on some comments on the initial diff.

Differential Revision: D24489715

fbshipit-source-id: baea66c7b811ebabf4476d7fd6a1136ab9ec2282

Differential Revision: D24414496

fbshipit-source-id: ad552d3dd58b6c351c99e5f8c9056c5829c4c095

Summary: Add an {fmt} formatter for `StringPiece`. This is much faster than going through ostream `operator<<` which we fallback to otherwise.

Reviewed By: yfeldblum

Differential Revision: D24337424

fbshipit-source-id: c6f1775cf83cfa6bcaa25cb4f6b665a76672e7c3

Summary:
A lot of these imports with specialization is not necessary. Clean up them to use generic functions instead.

(Note: this ignores all push blocking failures!)

Reviewed By: yfeldblum

Differential Revision: D24236181

fbshipit-source-id: fe6e6c41f680561c625b263bc6adeba738ddb252

Summary: Inform LifecycleObservers when an EventBase is attached or detached from an AsyncSocket.

Reviewed By: bschlinker

Differential Revision: D24294292

fbshipit-source-id: 652ec438d0b6213a78742b8a8ef0d24d55ac9816

Summary: Implement a thread local Observer that optimizes on the shared_ptr copy by using ReadMostlySharedPtr

Reviewed By: andriigrynenko

Differential Revision: D24439652

fbshipit-source-id: 9174be7f3f2fc34bdc79bd83eab571972b0c057d

Summary: Construction of ReadMostlyMainPtr is much slower than shared_ptr

Reviewed By: yfeldblum

Differential Revision: D24350176

fbshipit-source-id: 55730192f79288e7ad848b4cec6483bc0c1711b6

Summary:
This is a lock-free replacement for NotificationQueue. Unlike notification queue it supports only one consumer, which allows simplifying the internal structure a lot and avoiding any use of spin locks.
Another improvement comparing to NotificationQueue is the use of epoll edge-triggered events. This allows completely eliminating read syscals, since we don't need to drain eventfd to stop it from waking up the epoll loop.

Differential Revision: D24297158

fbshipit-source-id: 1f418d861210f6dcad52b4d663f49eb2e8f3ae8c

Summary:
`libfolly.pc` should contain the actual version of Folly, instead of just
`master`.

Reviewed By: danobi

Differential Revision: D24471074

fbshipit-source-id: 5fc29eeee25c8c317c3405f430fd079d47c441bd

Summary:
Existing test was supposed to be testing the exception, but was instead dying because of the pid check.
Have 2 separate tests and use crash message regex to make sure they actually test what they are supposed to be testing.

Differential Revision: D24461683

fbshipit-source-id: b7ef30e488d266ea17e283f9b13b5d013a4a125a

Summary:
This should make packaging folly easier, as it allows one to set the
.so version to denote ABI breaks. Specifically, we're looking to use this in
https://bugzilla.redhat.com/show_bug.cgi?id=1887621 to package folly in Fedora
and have the version match the tagged release version (i.e. treat every release
as ABI breaking).

Differential Revision: D24451669

fbshipit-source-id: f63be760c90567117f1ebbec37416c0d9d8a4736

Summary:
This reverts https://github.com/facebook/folly/pull/833 by adding back
the unconditional setting of `POSITION_INDEPENDENT_CODE` when building shared
libs. Without it, the build fails with a number of relocation errors. This was
previously reported in https://github.com/facebook/folly/issues/983

Differential Revision: D24449731

fbshipit-source-id: 6f6cb71ef545d02998afb09909772b62657c1262

Summary: These do not need to be executable

Differential Revision: D24449732

fbshipit-source-id: 5f013c62dd6bf88fe4d50782a4c5bfcec6834aec

Summary:
`frame` may be unused depending on whether it is compiled with or without asserts.

`FOLLY_MAYBE_UNUSED` is supposed to take care of this, but it does not work on Windows and trips up the comiler:

```
warning C4100: frame: unreferenced formal parameter
```

Reviewed By: johnkearney, akrieger

Differential Revision: D24451220

fbshipit-source-id: 8225640a5e8fd0ceed4ffcc53cea7422a5581d6f

Summary: [Folly] `to_shared_ptr_aliasing`, exposing the shared-ptr aliasing constructor as a free function deducing the types of its arguments.

Reviewed By: Mizuchi

Differential Revision: D24414504

fbshipit-source-id: 290e822464860b824961986211375d87f942f483

Summary:
Updates the FiberManager to make sure that it saves/restores the current-thread's
top-most active AsyncStackRoot when the coroutine is suspended/resumed.

This is required for correctness to ensure async stack traces remain functional
in the presence of fiber context-switches.

(Note: this ignores all push blocking failures!)

Reviewed By: yfeldblum

Differential Revision: D21130668

fbshipit-source-id: 4002bae0fc12a61c38836f9f099da4e6cf9183f4

Summary:
While running some unit tests which happen to call into `folly::futures::retryingPolicyCappedJitteredExponentialBackoff`, I noticed that  `retryingJitteredExponentialBackoffDur` was triggering a "float-cast-overflow" error from UndefinedBehaviorSanitizer.

It turns out that this only happened if `backoff_min` was 0 and there were at least 1025 retries. The large retry count caused the exponential term in the calculation to become `Infinity`. In floating point, Infinity multiplied by 0 was `NaN`, causing the sanitizer error.

Although `backoff_min` should typically not be set to 0 because this effectively disables all backoff, I think there may be cases, such as unit tests, where setting `backoff_min` to 0 does make sense. This commit adds an additional check to handle this unusual case.

Reviewed By: yfeldblum

Differential Revision: D24122470

fbshipit-source-id: 48a8aede0d22e73cf001dab5eb184e841f3c23aa

Summary: Remove FOLLY_HAVE_MSG_ERRQUEUE check

Reviewed By: yfeldblum

Differential Revision: D24295244

fbshipit-source-id: 24d4a69a013951b37fe7c93539b26eedf8113360

Summary:
We were seeing the following build failures on i386:
```
In file included from folly/stats/detail/BufferedStat.h:151,
                 from folly/stats/QuantileEstimator.h:20,
                 from folly/stats/QuantileEstimator.cpp:17:
folly/stats/detail/BufferedStat-inl.h: In member function 'void folly::detail::BufferedStat<DigestT, ClockT>::doUpdate(folly::detail::BufferedStat<DigestT, ClockT>::TimePoint, const std::unique_lock<folly::SharedMutexImpl<false> >&, folly::detail::BufferedStat<DigestT, ClockT>::UpdateMode)':
folly/stats/detail/BufferedStat-inl.h:72:3: error: there are no arguments to 'DCHECK' that depend on a template parameter, so a declaration of 'DCHECK' must be available [-fpermissive]
   72 |   DCHECK(g.owns_lock());
      |   ^~~~~~
```

My best guess is some kind of argument dependent lookup complication.

This diff sidesteps the issue by using plain old `assert()` instead

Reviewed By: yfeldblum

Differential Revision: D24375147

fbshipit-source-id: d702d883fcabc548e8f4969207e265abf21acf2b

Summary: AsyncUDPSocket: use actual controllen size instead of max

Reviewed By: danobi

Differential Revision: D24368739

fbshipit-source-id: 0c1083a058d8fe0ddc212989a262f3eeebfa610c

Summary:
Pull Request resolved: https://github.com/facebookexperimental/rust-shed/pull/15

With the update from rustc 1.44 to 1.47 the doctests started to break when building a crate that depends on a different crate of the same name, see this: https://github.com/rust-lang/cargo/issues/6819

This diff also removes the TravisCI build as it was broken and unused for some time.

Reviewed By: krallin

Differential Revision: D24390815

fbshipit-source-id: fa9c78ef394640afbf8c419f8276bbf339960406

Reviewed By: zertosh

Differential Revision: D24388883

fbshipit-source-id: 6bba618c6a919cd3947d2a65954feff989bb80a2

Summary:
A number of libraries at Facebook include interval midpoint calculations; however, doing these in a mathematically precise way (without over/underflow) can be tricky. Doing them wrong can break binary searches over large datasets and give imprecise floating-point calculations.

This function provides an early opportunity to fix binary searches and other calculations which can later be updated to `std::midpoint()` when C++20 becomes available.

Reviewed By: yfeldblum

Differential Revision: D23997097

fbshipit-source-id: 373e0dc1d1ff071f697ee782be46fb0d49a2f8f7

Summary:
Windows paths can both use forward slashes as well as backslashes, and also
contain colons that folly uses to separate prefixes to strip.

The xlogStripFilename unfortunately didn't handle both of these cases leading
to log categories to always contain the full path instead of a suffix path.

Reviewed By: yfeldblum

Differential Revision: D24353208

fbshipit-source-id: ff17afe4b46f36d46bf468a5e3cf9ba9ba8412b8

Summary:
Similar to D24179337 (https://github.com/facebook/folly/commit/7cc28784d1749283b7eb78399a0f0a77594dbc14).

Though I'm not actually sure what's causing the increase... maybe the right thing to do is the debug the underlying cause, but I'm also not sure how to debug this exactly.

Reviewed By: yfeldblum

Differential Revision: D24353676

fbshipit-source-id: 12bc5eae939f95d8d091280dc5b5af638f0152a0

Summary:
The MSVC compiler complains about truncation of size_t to int:

  Z:\installed\folly\include\folly/synchronization/HazptrDomain.h(210): warning C4267: 'argument': conversion from 'size_t' to 'int', possible loss of data

MSVC being very verbose, this is followed by 25 lines of template expansion.

Since `shard` is a size_t due to `calc_shard` returning that type, let's simply
make the shard argument of hazptr_warning_list_too_large a size_t too to
silence the warning.

Reviewed By: magedm

Differential Revision: D24365556

fbshipit-source-id: b426cee7caaf593eb112691bc45b83e564342b0e