Summary:
The DetachedInlineTask coroutine type now has its own AsyncStackFrame.

While this is largely an internal implementation detail used only
for the TaskWithExecutor's `.start()` family of methods, this now
means that detached tasks launched using TaskWithExecutor's
`.start()` methods will now record the return-address of the call to
`.start()` in the stack-trace and will also have the async-stack begin
with the `detached_task` frame at the top-level.

Reviewed By: andriigrynenko

Differential Revision: D24440817

fbshipit-source-id: 861f1ca46ec4a28b5b7e388bb8b243e4d597ee0d

Summary:
AsyncGenerator coroutines now have their own AsyncStackFrame and so can
participate in async call-stack tracing.

AsyncGenerator now applies co_withAsyncStack() to all awaitables
awaited from within the generator coroutine.

The NextAwaiter now implements the co_withAsyncStack() CPO to advertise
that it will save/restore the awaiting coroutine's AsyncStackFrame if
it provides one.

This allows the AsyncGenerator to symmetric-transfer to awaited Task
coroutines and vica-versa. This fixes some stack-overflow issues with
some synchronously-completing use-cases of AsyncGenerator.

Reviewed By: andriigrynenko

Differential Revision: D24437278

fbshipit-source-id: f9612d54558b961bb023460d4a118a773022737b

Summary:
`BarrierTask` and `DetachedBarrierTask` coroutines now have their own `AsyncStackFrame`.

This means that when a `Task` executes `co_await barrier.arriveAndWait()` that we
can use symmetric transfer to resume the `Task` since the `BarrierTask` will
already have an active `AsyncStackRoot` that we can reuse.

This fixes the test for stack-overflow of synchronously completing coroutines that
use `collectAll()` algorithms (which internally use `BarrierTask`).

Reviewed By: andriigrynenko

Differential Revision: D24435340

fbshipit-source-id: 87b622e8083f6c8f2b12f6b2f4b0bccd8bd5a595

Summary:
Initial diff that adds support for tracing through a chain of folly::coro::Task coroutines.

This adds some scaffolding that handles saving/restoring the active AsyncStackFrame
when a Task awaits some awaitable type that does not know about AsyncStackFrame
objects but also allows awaitables to opt-in to AsyncStackFrame awareness by
customising the new `folly::coro::co_withAsyncStack()` CPO.

Currently only `Task` and `TaskWithExecutor` awaiters have customised this CPO.

Also updated the awaiters for `Task` and `TaskWithExecutor` to handle being awaited
from coroutines that are not async-stack aware - in which case they just record a
null parent-frame for the Task.

The Task's `final_suspend()` then either deactivates or pops the frame depending
on whether there was a parent frame recorded.

BUG: This change currently breaks the symmetric-transfer stack-overflow avoidance
when awaiting synchronously-completing coroutines from an AsyncGenerator or from
a BarrierTask (eg. inside collectAll implementations).

Reviewed By: andriigrynenko

Differential Revision: D24428736

fbshipit-source-id: 5722e511ad10d95198ae70a5afe567d83cb06285

Summary:
Paths are not necessarily legal glob syntax. In particular, backslash
is used for escaping. This caused problems on Windows, where we tried
to pass a backslash-delimited path into `eden prefetch --no-prefetch`.

Reviewed By: xavierd

Differential Revision: D25072784

fbshipit-source-id: 9ce8e5ccc8f28581512c39d04922889da0bc1bf6

Differential Revision: D25018383

fbshipit-source-id: eefc622ad60d663efd174ad341df7697c548b3bd

Summary: Fix a double delete issue

Reviewed By: danobi

Differential Revision: D25005179

fbshipit-source-id: 03ae8f0722316294979ec7511ef9ac794196a7ce

Summary: Fix for: https://github.com/facebook/wdt/issues/203

Reviewed By: vitaut

Differential Revision: D24954835

fbshipit-source-id: 92f29f71cd6eef9bdcbe92ed1ecb8f1f5d24326e

Reviewed By: andriigrynenko

Differential Revision: D24880761

fbshipit-source-id: 643da2b0fd461955ea33b4ba48f377c30720d442

Summary: The worker thread just needed to be killed before the `AcceptCallback`. `AsyncServerSocket` calls a method on this callback class in its dtor, so it must either be alive or removed using `removeAcceptCallback`.

Differential Revision: D24972293

fbshipit-source-id: 2c7b6d64c2b9b8c00d03107002fa31e565df2a01

Summary:
Added a timestamp to `AsyncServerSocket::QueueMessage` so that `NotificationQueue` can ignore new connection messages which are deemed *expired*. Expired messages represent sockets which have *probably* timed out already.

The TTL is configured per `AsyncServerSocket` instance and is applied to all future messages that are queued by it. By default, messages do not expire. This can be configured with `AsyncServerSocket::setQueueTimeout`.

Reviewed By: andriigrynenko

Differential Revision: D24667870

fbshipit-source-id: 0f9d6c235627393d964e280a0d5956676010c7aa

Summary:
If `Consumer::operator()` returns `AtomicNotificationQueueTaskStatus` then this value indicates if the consumer actually consumed the task, or if it should be discarded.

Enumerating all cases:

`operator()` return type is `void`:
*All tasks are considered consumed and counted towards `maxReadAtOnce`.*

`operator()` returns `AtomicNotificationQueueTaskStatus::CONSUMED`:
*Same as above.*

`operator()` returns `AtomicNotificationQueueTaskStatus::DISCARD`:
*Task does not count towards `maxReadAtOnce` and is silently discarded. The consumer is responsible for any cleanup other than calling the destructor.*

Reviewed By: andriigrynenko

Differential Revision: D24698221

fbshipit-source-id: 0da2364d18b67468addf737b67cae573c89b7e9c

Summary:
Add an API to enable setting signature algorithms in string form.
An example string form: `"ECDSA+SHA256:RSA+SHA256"`.
OpenSSL supports TLS1.3 Signature Scheme format,
e.g.; `"ecdsa_secp256r1_sha256:rsa_pss_rsae_sha256"`.

Reviewed By: mingtaoy

Differential Revision: D24745481

fbshipit-source-id: 018be0a242d922f36a81d051791679a20fe08893

Summary:
Fixes https://github.com/facebook/folly/issues/1486

Pull Request resolved: https://github.com/facebook/folly/pull/1487

Reviewed By: Orvid

Differential Revision: D24851586

Pulled By: yfeldblum

fbshipit-source-id: ae683ba73336c562a8912ed35ef2b3318ab53519

Summary: To support cases where the child process may outlive the parent process.  Detaching the process is an option as well, but in that case the pid for the child process is not captured.

Reviewed By: yfeldblum

Differential Revision: D24409176

fbshipit-source-id: f74f64e3ae21baa40468c6f39ac6b4d0152db03a

Summary:
We often run into cases where system CPU util is low but SR eventbase threads are backing up. During S213134 debugging, it took us a while to figure out that requests with http transport were expensive and causing issues on intern-rpc clients and later realized it was a known issue for http transport to be CPU intensive. We got lucky that http transport requests used different stack we could see in strobelight, but this will likely not be the case for other similar issues.

For ease of debugging these issues, one idea is to log SR Eventbase cost of each request to SR scuba. **The closest proxy for this is the wall clock time spent by SR's request-dispatch task in fiber, excluding all the preemptions.** This metric does have couple of drawbacks:

- It wont capture all the work a request does via runInMainContext. This should be Ok since SR tries not to do lot of work in mainContext of fiber manager.
- If system context switching the threads a lot and if eventbase thread is preempted by OS, we will count that time as time spent in task. I am hoping that new metric will still be useful even with this caveat.

Design: Allow fiberManager.AddTask() to optionally take in a bool `logRunningTime` to decide whether it can log the running time of the task. If `logRunningTime` is set, fiber will keep track of elapsed time since most recent run in  `currStartTime_` and track the running time of all previous runs together in  `prevDuration_`.

I looked into using ExecutionObserver for this purpose. I did not go that route because
1. ExecutionObserver's callbacks return fiber IDs, we want a callback to return function/task ID that we can tie back to Sr request.  See here https://fburl.com/diffusion/qh9ioeq3
2. Caller (SR) will need to maintain the separate cache of all outstanding tasks with their running_times and manage their lifetime, which feels more complex than current approach.

I have a way to turn off this change using new killswitch I added in SR.

Reviewed By: yfeldblum

Differential Revision: D24823396

fbshipit-source-id: 62f79b8c340cc48a22684c9cb3cdddadc260a0ab

Reviewed By: andriigrynenko

Differential Revision: D24698220

fbshipit-source-id: aab8c96440d60bb653f0c537af56081819129306

Summary:
Allowing a bounded `AtomicNotificationQueue` is helpful to migrate `AsyncSocketServer` over from `NotificationQueue`.

`AtomicNotificationQueue::tryPutMessage` is the same as `putMessage` but also accepts a `maxSize`. If the queue size is >= `maxSize`, the message will not be queued. The user of the queue is responsible maintaining state regarding the max size of the queue.

Reviewed By: andriigrynenko

Differential Revision: D24698219

fbshipit-source-id: 1e3d1dc0073c65cd1803629f6a4a9b015e111b08

Summary: Add retryingUnsafe as a duplicate of retrying that forces the return type to be a Future rather than a SemiFuture.

Reviewed By: yfeldblum

Differential Revision: D24707194

fbshipit-source-id: cb2a107f51d4d4dd47a41ce6f8a009c4d82e3138

Summary:
`add_fbthrift_cpp_library` should honor `BUILD_SHARED_LIBS`, and call
`add_library` with the right setting (`SHARED` if enabled, `STATIC` otherwise)

Reviewed By: yns88

Differential Revision: D24911124

fbshipit-source-id: 79df7640a758a592a3df3e9e79bb129dd57f2d47

Summary:
needed for QUIC/H3 interop

also make it possible to run getdeps build with extra arguments (--no-tests for
example)

Reviewed By: mjoras

Differential Revision: D24925777

fbshipit-source-id: fbdc1aa56e398d295ef8dac0ad0bab03bd7bd803

Reviewed By: zertosh

Differential Revision: D24880203

fbshipit-source-id: 2034cdfc2712209e86d3d05c119c58f979b05c52

Summary:
Right now proxygen hardcodes a static build when using cmake  and
ignores BUILD_SHARED_LIBS. Fix that, and enable PIE on the shared libs so they
can be linked properly

Closes: https://github.com/facebook/proxygen/issues/335

Reviewed By: mjoras, lnicco

Differential Revision: D24787944

fbshipit-source-id: 7a654af7cb43227ca913a1bed67f2432703a343d

Summary: This header is needed by python/futures.h

Reviewed By: yfeldblum

Differential Revision: D24861734

fbshipit-source-id: 913ad13e6ca155250238020538af762c2360f137

Summary: Allow recycling of std::unique_ptr<IOBuf>

Reviewed By: yfeldblum

Differential Revision: D24650191

fbshipit-source-id: 85d219052cc62c35098085abb3eed6cfe00beefc

Summary:
Honor `DESTDIR` on Unix-like platforms (important when building packages),
and use `CMAKE_INSTALL_PREFIX` instead of the default prefix.

Reviewed By: yfeldblum

Differential Revision: D24821935

fbshipit-source-id: 42a311f920ed74760597f8908cd339b914ecb92e

Summary: `exception_wrapper::handle` uses the signature of `Fn::operator()` to pick apart the function type and deduce the exception type for the handler. We use specializations of an `arg_type_` class template to do this. In C++17, `noexcept` is a part of the type system, but there were no specializations of `arg_type_` to handle `noexcept`-qualified callables.

Reviewed By: ispeters

Differential Revision: D24733871

fbshipit-source-id: 344e735e653296c9344b6c09662fccd94953e8a7

Summary:
This allows customizing the exceptions for which retry
is triggered. This is useful when we only want to retry
in case of a few specific exceptions but have others
cause the operation to fail immediately.

Reviewed By: lewissbaker

Differential Revision: D24766615

fbshipit-source-id: f97451673f575bef511399cbde6c1ad110f9493a

Summary:
Hello,
The compilation with the HEAD of gcc 11 fails:
```
FAILED: CMakeFiles/folly_base.dir/folly/TimeoutQueue.cpp.o
g++  ... -c ../folly/TimeoutQueue.cpp
../folly/TimeoutQueue.cpp: In member function 'int64_t folly::TimeoutQueue::nextExpiration() const':
../folly/TimeoutQueue.cpp:39:32: error: 'numeric_limits' is not a member of 'std'
   39 |       timeouts_.empty() ? std::numeric_limits<int64_t>::max()
      |                                ^~~~~~~~~~~~~~
../folly/TimeoutQueue.cpp:39:54: error: expected primary-expression before '>' token
   39 |       timeouts_.empty() ? std::numeric_limits<int64_t>::max()
      |                                                      ^
../folly/TimeoutQueue.cpp:39:57: error: '::max' has not been declared
   39 |       timeouts_.empty() ? std::numeric_limits<int64_t>::max()
      |                                                         ^~~
../folly/TimeoutQueue.cpp:39:57: note: suggested alternatives:
In file included from /opt/1A/toolchain/x86_64-v21.0.8/include/c++/11.0.0/functional:65,
                 from ../folly/TimeoutQueue.h:31,
                 from ../folly/TimeoutQueue.cpp:17:
/opt/1A/toolchain/x86_64-v21.0.8/include/c++/11.0.0/bits/stl_algo.h:3464:5: note:   'std::max'
 3464 |     max(initializer_list<_Tp> __l, _Compare __comp)
      |     ^~~
```
It is nothing to fix.
Regards,
Laurent

Pull Request resolved: https://github.com/facebook/folly/pull/1482

Reviewed By: yfeldblum

Differential Revision: D24757105

Pulled By: Orvid

fbshipit-source-id: 8a5382edbe5b7c11cace5a1cd4c0645dfd2a9d37

Reviewed By: Orvid

Differential Revision: D24805802

fbshipit-source-id: 5ce7ef1c32395bc7d92046335278c0249eb0aee7

Differential Revision: D24805539

fbshipit-source-id: 64a8e688310e5c8f21226c5b363928a0917da851

Reviewed By: rsunkad

Differential Revision: D24750170

fbshipit-source-id: 5c48ab812b5438a33713315faf83e7a21a3c4eae

Reviewed By: yfeldblum

Differential Revision: D24724575

fbshipit-source-id: 2d7c6dbf94ee27638c92abfb94d8084beabb3d5e

Summary:
Adds a new TrackThreadId template argument to SharedMutexImpl that when enabled, expands SharedMutex from 4 to 8 bytes (still with
4 byte alignment), and uses the extra space to record the thread ID
of a distinguished owning thread (upgrade or exclusive lock holder).
This dramatically simplifies debugging in some scenarios.  It adds enough
information that we could enforce that unlock happens on the same thread
as lock, but this diff doesn't actually add such a check.

A new TrackedSharedMutex class is added for SharedMutex with lock owner thread id tracking enabled. fb_localtime is the only user for now to reduce the risk.

Differential Revision: D24731513

fbshipit-source-id: 6b41fb05498842224feb088b1332794281b501a9

Summary: The old behaviour passed an r-value after incrementing. Some use cases take an r-value and hence depend on that behaviour. This change makes that consistent.

Reviewed By: yfeldblum

Differential Revision: D24634859

fbshipit-source-id: 872197a11197a5e60f32492f1670dd94cf78c8b8

Summary: As part of the effort to deprecate futures 0.1 in favor of 0.3 I want to create a new futures_ext crate that will contain some of the extensions that are applicable from the futures_01_ext. But first I need to reclame this crate name by renaming the old futures_ext crate. This will also make it easier to track which parts of codebase still use the old futures.

Reviewed By: farnz

Differential Revision: D24725776

fbshipit-source-id: 3574d2a0790f8212f6fad4106655cd41836ff74d

Summary:
This commit takes advantage of git 2.5.0 being able to fetch a
requested revision rather than relying on the desired revision being within the
depth limited fetch.

This relies on having git 2.5.0 on the server which is true for all
of the projects we have manifests for; this shows zero matches:

```
$ rg repo_url opensource/fbcode_builder/manifests | grep -v github
```

We've had a couple of situations recently where folks have run into issues with
the commit rate in folly being higher than then fetch depth, so this should
address that.

Refs: https://github.com/facebook/watchman/issues/866

Reviewed By: fanzeyi

Differential Revision: D24747992

fbshipit-source-id: e9b67c61dddc9f55e05d8984e8d210e7d2faabcb

Summary: We shouldn't be sleeping less that requested and return silently.

Reviewed By: lewissbaker

Differential Revision: D24633977

fbshipit-source-id: 71ef422f0f72747bc19ac8491fdb8b148598d499

Summary:
tsan reports warning in the test because the server socket writes in
a thread but closes in another thread without synchronization. This was by
design and is not a bug since implicit synchronization is done by joining client
thread, but this isn't visible to tsan. The fix is to use a port reused new
server socket to write response to client.

Reviewed By: yfeldblum

Differential Revision: D24675113

fbshipit-source-id: bdab8a5d5b6f85aa36ba84a6299e4457710625de

Summary:
There are two separate changes here.

### Use `find_package`

The old setup of "let's manually enumerate and order the libraries that Bistro depends on" worked fine, except:
 - it was a bit brittle (requiring occasional patches as deps changed), and
 - it garnered a lot of feedback to the effect of "your build is weird, so it's probably broken because of that."

Now I expect to have fewer breaks and more plausible deniability :)

 More importantly, this should make it much easier to migrate to `getdeps.py`.

## Statically link `fmt`

After `fmt` was added as a `folly` dependency, and linked into Folly code used by Bistro, its tests would fail to run with this error: `test_sqlite_task_store: error while loading shared libraries: libfmt.so.6: cannot open shared object file: No such file or directory`.

Something was getting messed up in the dynamic linking, and it wasn't clear to me what -- the way that Bistro is linking its dependencies certainly seems sensible. Most likely one of the dependencies is incompatible with dynamic linking in a subtle way. I suspect Proxygen.

The `fmt.py` change in this diff addresses this problem by forcing static linking on the offending library.

Reviewed By: yfeldblum

Differential Revision: D24604309

fbshipit-source-id: 35ecbbb277b25907ecaee493e8b0081d9f20b865