Summary:
Many dynamic operations, including its move constructor, are
noexcept but not labeled so. Labeled some important functions as
noexcept.

Test Plan: run unit tests

Reviewed By: delong.j@fb.com

Subscribers: tudorb, philipp, sdwilsh, njormrod, folly-diffs@

FB internal diff: D1644380

Tasks: 5486739

Signature: t1:1644380:1414618757:fb910d8a3fe3e634da4215c432577edf7371be61

Summary:
Fixed unsigned/signed compares.

I had to suppress the warning in one place, but don't worry, clang
supports `#pragma GCC diagnostic ...` (see http://clang.llvm.org/docs/UsersManual.html#controlling-diagnostics-via-pragmas)

Test Plan: unit tests

Reviewed By: afrind@fb.com

Subscribers: alandau, mshneer, trunkagent, doug, jdperlow, bmatheny, njormrod, cgheorghe, folly-diffs@

FB internal diff: D1624249

Tasks: 5140804

Signature: t1:1624249:1414620209:5399e8d90d8ca32b30794a7b2a4a7c2d7d437dda

Summary:
Add a hidden option to suppress ###define [keyword]##, which is
occasionally appropriate.

Test Plan:
Build flint, run it on FBString.h, see no error.
Ran flint tests locally, see no errors.

Reviewed By: andrei.alexandrescu@fb.com

Subscribers: sdwilsh, louisk, njormrod, folly-diffs@

FB internal diff: D1644182

Tasks: 5486739

Signature: t1:1644182:1414616294:4b6004d358cba865455366f5a943644b3542ae51

Summary:
In certain circumstances, it is appropriate to omit and include
guard. Add an option to allow this to be overriden.

Test Plan: Build flint, run it on folly, see no include-guard errors.

Reviewed By: andrei.alexandrescu@fb.com

Subscribers: sdwilsh, louisk, njormrod, folly-diffs@

FB internal diff: D1644170

Tasks: 5486739

Signature: t1:1644170:1414616595:7ac52f474c1312a0c28e89255b1151d56c680acf

Summary:
Add a hidden nolint option to suppress this lint warning. It is
appropriate in this case.

Test Plan:
Build flint, run it on ExceptionWrapperTest.cpp, see no catch
lint failure

Reviewed By: andrei.alexandrescu@fb.com

Subscribers: sdwilsh, louisk, njormrod, folly-diffs@

FB internal diff: D1644165

Tasks: 5486739

Signature: t1:1644165:1414616664:a6b9dc34660df84b33ed8faaf48ec048a02bad01

Summary:
The compiler is able to make some nice optimizations when it
knows that move constructors are noexcept. (In particular, it helps a
lot inside of std::vector if you don't need to worry about the
possibility of exception during reallocation.) Some move constructors in
folly are obviously moveable: change them.

Test Plan: unit tests

Reviewed By: delong.j@fb.com

Subscribers: trunkagent, sdwilsh, njormrod, folly-diffs@

FB internal diff: D1644296

Tasks: 5486739

Signature: t1:1644296:1414618605:d9a0db5193c82650b96e9c62b019d5da218b15c5

Summary:
variants of then() that bypass Try and forward any exceptions up to the next future. like next() from http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n3865.pdf

this could go a long way towards reducing spurious rethrows wherever people don't ever actually catch exceptions in their continuations, which is probably often enough.

anyone know if there's something in folly or standard library that does what my silly VoidWrapper struct does?

there's a lot of copypasta here but i'm not sure consolidating into helpers would actually be useful considering the amount of template crap, i don't feel strongly about it though.

Test Plan: added unit

Reviewed By: hans@fb.com

Subscribers: trunkagent, sammerat, fugalh, njormrod, folly-diffs@, bmatheny

FB internal diff: D1641776

Signature: t1:1641776:1414610434:c742563b8061a748fca9292fc2765081edcf9d52

Summary:
The previous diff added the safety check but didn't actually
remove the compiler warning. This is what I get for doing an incremental
compile.

Test Plan: fbmake clean ; fbmake dbg with clang:dev

Reviewed By: meyering@fb.com

Subscribers: trunkagent, mathieubaudet, njormrod, folly-diffs@, bmatheny, ranjeeth, subodh, kmdent, fma, benyluo

FB internal diff: D1646519

Signature: t1:1646519:1414602292:cfb908ae094caaef02e64eb2c42544fd34fa1389

Summary: @override-unit-failures

Test Plan: n/a

Reviewed By: rhysparry@fb.com

Subscribers: sdwilsh, njormrod, folly-diffs@

FB internal diff: D1644139

Tasks: 5486739

Signature: t1:1644139:1414553949:626fdca07a583c3d5017abe19408a5e6f6d7674a

Summary:
Add nolint comments to appropriate multiply-included files.
Removed raw duplicates from StlVectorTest.

Test Plan:
fbconfig -r folly && fbmake runtests

Ran arc lint, see no "included multiple times" messages

Reviewed By: robbert@fb.com

Subscribers: sdwilsh, njormrod, folly-diffs@

FB internal diff: D1644144

Tasks: 5486739

Signature: t1:1644144:1414599280:1e403ea3675d2173b249c4ce6db0dad621a139bc

Summary:
Among all of the implicit conversions, conversion to bool is
particularly tricky. For this reason, it has a special call-out in flint
among the casts, and canno be overriden.

However, there are legitimate use cases for operator bool. In this case,
we have a iterator that logically represents a bool but in practice
represents a packed integral. This class needs to be implicitly
convertible to bool, and warrants an override.

Push blocking tests have had over a day to complete, but haven't.
Further, the folly change is comment-only.

Test Plan:
Build flint, run it on BitIteratorDetail.h, see no more lint
errors

Reviewed By: andrei.alexandrescu@fb.com

Subscribers: sdwilsh, louisk, njormrod, folly-diffs@

FB internal diff: D1644141

Tasks: 5486739

Signature: t1:1644141:1414607351:29740da758b75187f4f7b6b5a5ad28a523e7080d

Summary: See D1508946 for the rationale behind this lint message.

Test Plan:
fbconfig -r folly && fbmake dbg

Reviewed By: hans@fb.com

Subscribers: sdwilsh, fugalh, njormrod, folly-diffs@

FB internal diff: D1644190

Tasks: 5486739

Signature: t1:1644190:1414532704:87d5851f363cf37c58f7e7c3d57c8210a792d4a1

Summary: So when we re-generate code we don't cause clang test failures (until #4412111 is done)

Test Plan: git diff

Reviewed By: jsedgwick@fb.com

Subscribers: net-systems@, fugalh, mathieubaudet, exa, njormrod, folly-diffs@

FB internal diff: D1644550

Tasks: 4412111

Signature: t1:1644550:1414604128:8184e7ce1f3e417c170ef67346d553caecc1f013

Summary:

Test Plan:

Reviewed By: dcsommer@fb.com

Subscribers: trunkagent, mcduff, hitesh, doug, alandau, bmatheny, njormrod, mshneer, folly-diffs@

FB internal diff: D1644071

Signature: t1:1644071:1414526899:c41dd55e2957a7e1fcc54508e20cdb4a9c8c30d4

Summary:
This has been bothering me for a while when I've been trying to
verify builds with clang. This generates a ton of spew and the current
code can't actually handle non-default negatives so let's just throw if
we see one.

Test Plan: fbmake runtests

Reviewed By: meyering@fb.com

Subscribers: mathieubaudet, njormrod, folly-diffs@, bmatheny, benyluo, shikong, kmdent, fma, ranjeeth, subodh

FB internal diff: D1643881

Signature: t1:1643881:1414523777:085035ce8c280fbd6481b2ce0354b53b96fdc50e

Test Plan: This diff is actually the test plan. It was contbuild bait. I fixed things that broke (in separate diffs), and then I rebased this on top, everything is green, and we pulled the trigger.

Reviewed By: davejwatson@fb.com

Subscribers: trunkagent, net-systems@, fugalh, exa, njormrod, folly-diffs@

FB internal diff: D1632937

Tasks: 5409538

Signature: t1:1632937:1414531009:4dbaa9513fbfba45a9c63e7be3de3646a6e926a2

Summary:
Idle memory in IO threads.   If loop is unused for a period of time, free associated memory, and call epoll again.

Had to add a new list of callbacks that don't make the loop nonblocking (i.e. using runInLoop() instead would use the nonblocking version of epoll).

Could bake this in to EventBase directly, but that seems like the wrong abstraction, since EventBase doesn't actually control the thread - for example, that approach would also free up memory for stack-allocated EventBases where they are used synchronously by clients.

This diff doesn't change IO scheduling at all - current IO work is round robin, so this probably only helps if the whole server is idle (at least until we add smarter scheduling)

Test Plan:
Based on top of D1585087.

fbconfig thrift/perf/cpp; fbmake dbg
_bin/thrift/perf/cpp/ThriftServer
_bin/thrift/perf/cpp/loadgen -num_threads=100 -weight_sendrecv=1 -cpp2 -async

Ran loadgen for a while, watched res memory in top.  Stopped loadgen.  After ~5 sec, res memory was much reduced.

Reviewed By: jsedgwick@fb.com

Subscribers: trunkagent, doug, fugalh, njormrod, folly-diffs@

FB internal diff: D1641057

Tasks: 5002425

Summary:

Test Plan:

Reviewed By: cgheorghe@fb.com

Subscribers:

FB internal diff: D1642334

Blame Revision: D1587625

Summary:
Add an operator()(StringPiece) method to Appender, so it can be used
directly with folly::Formatter objects.  Also add printf() and vprintf()
methods to Appender, for places that need to use existing printf-style
formatting.

This also includes versions of push() and pushAtMost() that accept
ByteRange objects.  Previously we only had push() implementations that
took separate buffer and size arguments.

Test Plan: Added new unit tests to IOBufCursorTest.cpp

Reviewed By: davejwatson@fb.com

Subscribers: trunkagent, doug, net-systems@, exa, njormrod

FB internal diff: D1583684

Summary: Jenkins ci build was broken for a while, so we missed these  in contbuild results

Test Plan: watch ci build for fbthrift

Reviewed By: hans@fb.com

Subscribers: doug, fugalh, njormrod, folly-diffs@

FB internal diff: D1641515

Summary:
Move async socket to folly.

Changes:
* Made an AsyncSocketException type instead of TTransportException: Some of the exceptions didn't fit nicely in to std::exception types (like TIMED_OUT).  There are some wrappers in thrift/lib/cpp/async to convert back to TTransportException, so all existing code still compiles.
* Moved read/write callbacks out of AsyncTransport: filters are going to want to do the read/write stuff separately (see revproxy/tunnel/filters, and discussions in D1483148).

Test Plan:
fbconfig -r thrift; fbmake runtests
contbuild should catch everything else - exception types shouldn't change for existing code

Reviewed By: dcsommer@fb.com

Subscribers: mshneer, folly-diffs@, trunkagent, doug, alandau, bmatheny, njormrod, fugalh, jsedgwick

FB internal diff: D1587625

Summary:
In D1618240 I introduced a race condition in `detachOne()`, where `detached_` is incremented and then tested. If the promise and future are racing, they can both see `detached_ == 2` in the conditional, and then they'll both try to free the Core object. This fixes that.

It also fixes a related problem (which actually showed up more often with the test I wrote), where we transition into the Done state before setting the value, and then `maybeCallback()` observes the state is Done (because we're just reading an atomic, not grabbing the lock, which is intentional), tries to execute the callback, but `folly::Optional` throws an exception because the value hasn't been set yet (at least in debug it does). I should have listened to my gut and kept the state assignment after the transition action in the first place.

Test Plan: New unit test

Reviewed By: jsedgwick@fb.com

Subscribers: trunkagent, net-systems@, fugalh, exa, njormrod, folly-diffs@, mnd

FB internal diff: D1636490

Tasks: 5438209

Blame Revision: D1618240

Summary: Reverts D1633874. Companion to D1636490 which fixes the bug.

Test Plan:
git reverting code that was git reverted and hasn't changed in the interim
Won't be checked in without the companion bugfix diff (D1636490)

Reviewed By: davejwatson@fb.com

Subscribers: trunkagent, net-systems@, fugalh, exa, njormrod, folly-diffs@

FB internal diff: D1636487

Tasks: 5438209

Blame Revision: D1633874

Summary: EventBaseManager was moved to folly, we shouldn't have deps on apache

Test Plan: fbconfig -r folly/experimental/wangle/concurrency; fbmake runtests

Reviewed By: hans@fb.com

Subscribers: doug, fugalh, njormrod, folly-diffs@

FB internal diff: D1636006

Summary:

Test Plan:

Reviewed By: harishs@fb.com

Subscribers: net-systems@, fugalh, exa, njormrod, folly-diffs@

FB internal diff: D1633874

Tasks: 5438209

Summary: I'm still a little mystified how one makes a Future<const T> (I tried to make one explicitly in a test and failed), but this is clearly the bug @reedriley sees in https://phabricator.fb.com/D1620805#21

Test Plan:
fbconfig titan/cachius/test
fbmake

Reviewed By: reedriley@fb.com

Subscribers: trunkagent, net-systems@, fugalh, exa, njormrod, reedriley, folly-diffs@

FB internal diff: D1630378

Blame Revision: D1620805

Summary:
Changes:
* namespace to folly
* some std::chrono replacesments
* Moves shutdownSocketSet stuff to thriftserver instead of in the socket itself.
* Changes exception types.  I don't see anywhere that uses the TAsync*SERVER*socket exceptions depending on the TTransport type, but I could be wrong? I don't really know what to do about the exception types

unittests still postponed overnight.

Test Plan:
fbconfig -r thrift; fbmake runtests
fbconfig -r proxygen; fbmake runtests

Reviewed By: dcsommer@fb.com

Subscribers: hphp-diffs@, ps, folly-diffs@, anca, trunkagent, jsedgwick, fugalh, doug, alandau, bmatheny, njormrod

FB internal diff: D1579187

Summary:
fix fbthrift build, broken in D1621717

I wonder if it'd be possible to lint against this somehow. The jenkins failures are easy to miss especially on folly diffs with lots of failure noise (in this case it was still postponed)

Test Plan: wait for jenkins

Reviewed By: davejwatson@fb.com

Subscribers: njormrod, folly-diffs@

FB internal diff: D1630833

Summary: This makes it more likely that SingletonVaultDestructor won't be created after atexit calls.

Test Plan: unit test

Reviewed By: chip@fb.com

Subscribers: hphp-diffs@, ps, njormrod, folly-diffs@

FB internal diff: D1629804

Tasks: 5353022

Summary:
This would cause debug builds to do a bad thing (access the variable `this->detached_` within an assert, after `delete this`).

Test Plan: unit tests

Hopefully now that we have a dummy cpp file in `folly/wangle/detail` contbuild
will pick it up and all the dependencies will also run their tests.
Right now, we suspect maybe maelstrom (@wez) and adinvoicer and zookeeper
(@jying) and probably others are seeing this in unit test failures (esp. if
they use asan, which is rightly detecting read after free). Hoping contbuild
will catch them.

Reviewed By: davejwatson@fb.com

Subscribers: net-systems@, fugalh, exa, njormrod, folly-diffs@, wez, dcapel, jying, cgheorghe

FB internal diff: D1630301

Tasks: 5424546, 5435720

Blame Revision: D1618240

Summary: Fixing the race will take some more thought. Probably a condvar. For now, I'm turning waitFor into a spinlock instead.

Test Plan: new unit test that deadlocks before the workaround

Reviewed By: jsedgwick@fb.com

Subscribers: trunkagent, net-systems@, fugalh, exa, njormrod, folly-diffs@

FB internal diff: D1628015

Tasks: 5427828

Summary: If you try to include files in a weird (but not incorrect) order you get compilation errors. No longer!

Test Plan: new dummy `cpp_binary` target

Reviewed By: davejwatson@fb.com

Subscribers: trunkagent, folly-diffs@, net-systems@, fugalh, exa, njormrod

FB internal diff: D1621083

Summary:
Modeled very closely after Finagle's interrupts. Compare with https://github.com/twitter/util/blob/master/util-core/src/main/scala/com/twitter/util/Promise.scala if you like.
The basic idea is the promise holder can register an interrupt handler, and then interrupts will call that handler. A typical handler would fulfil the promise with an exception (or special value) indicating that it was interrupted (if it was interrupted in time).
Raising an interrupt does not prevent setting a value or callbacks executing or any of that - it is only advisory to the promise holder.

Test Plan: I wrote some unit tests.

Reviewed By: davejwatson@fb.com

Subscribers: folly-diffs@, net-systems@, fugalh, exa, hannesr, njormrod

FB internal diff: D1620805

Tasks: 4618297

Summary:
This is a refactor of the current functionality to use a state machine (inheriting from `FSM`). This will make it easier to extend to do cancellation and Future collapsing. Performance is the same, maybe slightly faster (abt 1%). (I might be a little conservative with the atomics, it might be worth going through and reasoning about whether they all need to be atomic).

The state machine is two states, Waiting (no value), and Done (has a value). Transitioning to Done will execute the callback if it exists and we are active. Otherwise the callback will happen when it is set and active is true.

There is a subjective balancing act in place here, between making a state for every single mutable bit of information (which results in an explosion of states: hasValue X hasCallback X isActive X isCancelled …), and finding a sweet spot of expressivity. This isn't too far from the way Twitter did it, though we don't (yet) have all the states they have (and they don't have the concept of hot/cold futures). But I got there by way of replacing the `mutex_` with the state, after changing all those variables to atomics so they didn't need mutex protection (resulting in only `callback_` and `result_` needing it). I expect the state machine will morph as the rest of the functionality is added, but hopefully it will be easier to understand and keep correct (that's the idea anyway).

Test Plan: Tests still pass (and not by accident, I made several awesome mistakes along the way).

Reviewed By: davejwatson@fb.com

Subscribers: net-systems@, fugalh, exa, njormrod

FB internal diff: D1618240

Tasks: 4618297

Summary:
Just some cleaning hose in `detail::Core`.
- rename `fulfil` to `setResult`
- and `value_` to `result_`
- remove unnecessary helper methods (I can be convinced to keep them if you like them)

Test Plan: mechanical changes, tests still pass

Reviewed By: davejwatson@fb.com

Subscribers: trunkagent, folly-diffs@, net-systems@, fugalh, exa, njormrod

FB internal diff: D1618161

Summary:
Later is now superfluous. Just hold a deactivated future (e.g. one returned by `Future::via`), and then activate (or destruct) it when you're ready.
ThreadGate has proven to be too rigid and too heavyweight to be really useful. And is superfluous now with `Future::via`. e.g.
f.via(east).then(a1).then(a2).via(west).then(b1).then(b2);

This is stage one of removing these: mark them deprecated.
Stage two will be for me to change all existing usages in our code to not use them.
Stage three will be to rip these out altogether.

Test Plan:
Everything still builds and works, but now with deprecation warnings.

fbconfig -r \
common/smc/cpp/tests \
folly/wangle \
langtech/audiens \
messaging/avscan \
messaging/maelstrom \
neteng/traffic_manager \
notifications/nudge/service \
tao/client \
zeus/datashuttle
fbmake runtests

Reviewed By: jsedgwick@fb.com

Subscribers: net-systems@, fugalh, exa, njormrod, folly-diffs@

FB internal diff: D1626412

Tasks: 5409538

Summary: It was deprecated, now is unused.

Test Plan:
fbgs
check contbuild

Reviewed By: hannesr@fb.com

Subscribers: trunkagent, net-systems@, fugalh, exa, njormrod, folly-diffs@

FB internal diff: D1624221

Summary: for great contbuild

Test Plan: these projects still build. contbuild should start picking them up, based on discussion with @robbert

Reviewed By: robbert@fb.com

Subscribers: trunkagent, net-systems@, fugalh, exa, mwa, jgehring, fuegen, njormrod, folly-diffs@, robbert

FB internal diff: D1624206

Tasks: 5399744

Summary:
Like the magic macros. As it says in the comment, this can lead to nicer code.
Also added/moved a couple examples to the top of `test/FSM.cpp`.

Test Plan: new tests

Reviewed By: davejwatson@fb.com

Subscribers: trunkagent, net-systems@, fugalh, exa, njormrod

FB internal diff: D1618184