Summary:
clang (>=3.6?) reports potential object slicing bug when MPMCQueue is used for
polymorphic class as the queue item, e.g. as in P19814469. This can be false
positive however, since the choice is based on the type trait already.  This
diff uses tag dispatch to selectively compile the overload that will be
executed, therefore if there is no-throw move ctor supplied clang will not
examine the simulated relocation code.

This doesn't avoid object slicing bug however if the client insists to use
MPMCQueue to hold base class while enqueue and dequeue with subclassed item.

Test Plan: compile with --clang

Reviewed By: tudorb@fb.com

Subscribers: folly-diffs@, yfeldblum, chalfant

FB internal diff: D2029949

Signature: t1:2029949:1430264357:af479117adf90bc1915c071e7376a30aacb72f46

Summary:
Cleans up bootstrap a bit at the expense of a more complex Pipeline interface
This doesn't have to go in, lmk either way as I want to move on to reorganizing this code into inl headers etc

Test Plan: unit

Reviewed By: davejwatson@fb.com

Subscribers: fugalh, folly-diffs@, jsedgwick, yfeldblum, chalfant

FB internal diff: D2034634

Signature: t1:2034634:1430414670:c91712fb26353987cb471e35a54f55c869ae7cf1

Summary: Also, instead of throwing on finalize() if there's no inbound/outbound handler in the pipeline, log a warning and throw when the operations are attempted. This was necessary for CodecTest which doesn't use outbound handlers.

Test Plan: unit

Reviewed By: davejwatson@fb.com

Subscribers: trunkagent, fugalh, folly-diffs@, jsedgwick, yfeldblum, chalfant

FB internal diff: D2028176

Tasks: 6836580

Signature: t1:2028176:1430346333:fdd645a535e8158d780cfd1119e27803995b663f

Summary:
Much less copypasta this time around. I wonder if the getters and setters for write flags and read buffer settings are necessary in the new handler types, or even if they belong in the bidirectional handler

I'm all ears for more suggestions on reducing copypasta

I'm going to reorg the code (inl headers etc) in a subsequent diff once this is in - easier to review this way

Test Plan: existing unit, thinking about tests for these changes

Reviewed By: davejwatson@fb.com

Subscribers: fugalh, folly-diffs@, jsedgwick, yfeldblum, chalfant

FB internal diff: D2026522

Tasks: 6836580

Signature: t1:2026522:1430346145:bd7f7770eddce0470e2ac72440fc001cf128df08

Summary:
I think this is the best I can do to minimize whjat must be copied for InboundHandler, InboundHandlerContext, InboundContextImpl, outbound equivalents, etc

Test Plan: unit

Reviewed By: davejwatson@fb.com

Subscribers: fugalh, folly-diffs@, jsedgwick, yfeldblum, chalfant

FB internal diff: D2025612

Tasks: 6836580

Signature: t1:2025612:1430346200:bc06162711bbc52b17574297a3569736f7973a7c

Summary:
This diff is based on https://github.com/facebook/folly/pull/95
by gitbug user mikekap.

It changes the struct/class naming of forward declarations to match
their definitions.

Test Plan:
fbconfig -r folly && fbmake runtests

Reviewed By: markisaa@fb.com

Subscribers: fugalh, folly-diffs@, jsedgwick, yfeldblum, chalfant

FB internal diff: D2032995

Tasks: 6783581

Signature: t1:2032995:1430339337:79193fd8409b73e8a9155133f326b7cee534244d

Summary: It looks like the ubuntu version of gtest complains about this?

Test Plan:
Will watch jenkins fbthrift and proxygen builds

previous jenkins break:
https://ci-builds.fb.com/job/folly/2178/console

Reviewed By: bmatheny@fb.com

Subscribers: doug, folly-diffs@, yfeldblum, chalfant

FB internal diff: D2032761

Tasks: 6913742

Signature: t1:2032761:1430337624:ec65b26cf8da7d0d8c7e449f235de7147d4f17d6

Blame Revision: D2029802

Test Plan: contbuild

Reviewed By: chip@fb.com

Subscribers: wormhole-diffs@, trunkagent, hphp-diffs@, jan, simpkins, configerator-diffs@, fbcode-common-diffs@, chaoyc, bill, search-fbcode-diffs@, agallagher, nli, marcelo, ckwalsh, mcduff, hitesh, mshneer, unicorn-diffs@, vighnesh, fugalh, andreib, bmatheny, tw-eng@, tanmoyc, zhuohuang, rvm4, antonl, acampi, alikhtarov, hdoshi, rsethi, panin, folly-diffs@, lins, kennyyu, hannesr, jsedgwick, dominik, yfeldblum, songhao, raghavpi, labrams, lyang, chalfant, #preselection, macsyz, nimishshah

FB internal diff: D2012267

Tasks: 5676394

Signature: t1:2012267:1430334667:eaad0262b35ffbfae86df5bdb45bf057ac62c51b

Summary:
THeader.h went from 1.8s to 0.5s.
Total build of sample project doing thrift client and server stuff went
down 1.5-3% from

```
(run 1)
real    5m25.059s
user    130m30.853s
sys     10m18.642s

(run 2)
real    5m29.483s
user    129m12.209s
sys     10m14.762s
```

to
```
(run 1)
real    5m23.292s
user    125m44.318s
sys     10m7.103s

(run 2)
real    5m20.999s
user    127m4.969s
sys     10m10.118s
```

Test Plan:
fbmake --distcc off --ccache off dbg
Will also watch contbuild, since some files might be missing includes

Reviewed By: haijunz@fb.com

Subscribers: jmarg, anca, reachfrequency-eng@, jhunt, yanli, jgeller, chaoyc, search-fbcode-diffs@, net-systems@, zeus-diffs@, vikas, jcoens, unicorn-diffs@, ldbrandy, jteller, atlas2-eng@, everstore-dev@, leis, benj, laser-diffs@, zhguo, jying, wanghuan, jeremyfein, dbolcioni, jacekm, maxwellsayles, osmith, pallotron, fbcode-common-diffs@, davejwatson, andrewcox, marcelo, ckwalsh, mcduff, hitesh, mshneer, fugalh, alandau, bmatheny, folly-diffs@, jsedgwick, yfeldblum, haijunz, chalfant

FB internal diff: D2029911

Signature: t1:2029911:1430261056:9ae688c50585a6454479f810d80b2c1c79b60e04

Summary: just a lowly non-erroring semantic merge conflict

Test Plan: builds

Reviewed By: jsedgwick@fb.com

Subscribers: trunkagent, exa, folly-diffs@, jsedgwick, yfeldblum, chalfant

FB internal diff: D2029593

Signature: t1:2029593:1430319785:2cd96927b9080fe18b168ab95ad201afc4f00857

Summary:
Adds get_or_throw map helper (get a value, or throw with the specified
exception type) and get_optional (get an Optional<Value>). This is a folly
backport of some util helpers in experimental.

Test Plan: Unit tests

Reviewed By: wez@fb.com

Subscribers: folly-diffs@, yfeldblum, chalfant

FB internal diff: D2029802

Tasks: 4332480

Signature: t1:2029802:1430280249:3efbb2fb9394e31b3fbe6d5bd209d12ebb7ed587

Summary:
This should help executing sync thrift handlers on fibers. This allows the handler methods to achieve concurrency by awaiting.

Test Plan: Chimera unit tests (which also accesses running FacebookBase methods in fiber context!)

Reviewed By: davejwatson@fb.com

Subscribers: trunkagent, hannesr, andrii, folly-diffs@, jsedgwick, haijunz, yfeldblum, alandau, chalfant

FB internal diff: D2015886

Signature: t1:2015886:1430156870:a84499e0e781f5e6e77f48f1f3063f53d0968698

Summary:
add a free system memory limit to Load Shed Configuration for dynamic shedding

Test Plan:
tested on edge241.01.ams3, works as expected. Once the free memory is less than 23G (picked on purpose for testing),  new connections are shedded.   But the shedding rate is totally wrong.  I will explain and address it in another diff.

https://fburl.com/103620501
https://fburl.com/103620701

Reviewed By: afrind@fb.com

Subscribers: trunkagent, fugalh, bmatheny, nimishshah, folly-diffs@, jsedgwick, yfeldblum, chalfant, xning, alexkr

FB internal diff: D2026477

Tasks: 4604893

Signature: t1:2026477:1430176828:65eadd82efa3189a1bebcb8518efaf56cd36beed

Summary: Unit is a bit special because it's just something special to use instead of `Promise<void>`, so let's offer the same sugar that `Promise<void>` has (`p.setValue()` instead of `p.setValue(Unit())`)

Test Plan: New unit tests. Look, a pun!

Reviewed By: jsedgwick@fb.com

Subscribers: exa, folly-diffs@, jsedgwick, yfeldblum, chalfant, davejwatson, hannesr

FB internal diff: D2014139

Tasks: 6847876

Signature: t1:2014139:1430159950:1484ee420c6d7f0f794a546b78ef1601c2eec45c

Summary: Calling `folly::gen::orderBy()` without arguments causes a compilation error because the first template argument cannot be deduced. This diff fixes it.

Test Plan:
fbconfig -r folly && fbmake runtests

Reviewed By: philipp@fb.com

Subscribers: folly-diffs@, yfeldblum, chalfant

FB internal diff: D2025789

Signature: t1:2025789:1430167404:02fde7287b015d9dcbf398e8dc84cde7d74b4a5b

Summary:
[Folly] BenchmarkSuspender::dismissing.

Pass a lambda to it, and the lambda will be executed while the benchmark-suspender is dismissed. Just a bit of sugar around `BenchmarkSuspender::dismiss` and `BenchmarkSuspender::rehire`.

BENCHMARK(name_void, iters) {
BenchmarkSuspender braces;
# benchmark timer is suspended
braces.dismissing([&] {
# benchmark timer is running
doSomething();
});
# benchmark timer is suspended
}

BENCHMARK(name_value, iters) {
BenchmarkSuspender braces;
# benchmark timer is suspended
auto value = braces.dismissing([&] {
# benchmark timer is running
return doSomething();
});
# benchmark timer is suspended
}

Test Plan:
Unit tests:
* `folly/test/BenchmarkTest.cpp` (actually a benchmark)

Reviewed By: njormrod@fb.com

Subscribers: net-systems@, folly-diffs@, yfeldblum, chalfant

FB internal diff: D2024166

Signature: t1:2024166:1430163281:24df0ac98cbe36372f780372ee8f7dd3722b7868

Summary:
Only allow this if the handler is only ever attached to a single pipeline once. i.e. only ever associated with one Context

Test Plan: unit, thrift unit

Reviewed By: davejwatson@fb.com

Subscribers: fugalh, alandau, bmatheny, folly-diffs@, jsedgwick, yfeldblum, chalfant

FB internal diff: D2024007

Tasks: 6836580

Signature: t1:2024007:1430157264:efcf70ca3531c10eec5d458c9e9d6cda60c507c3

Summary:
detachPipeline always goes bottom to top
attachPipeline always goes top to bottom
now we can attachReadCallback in AsyncSocketHandler::attachPipeline()

not sure of the implications for TAsyncTransportHandler... looks like Cpp2Channel still wants to attach/detach cb manually

Test Plan: unit

Reviewed By: davejwatson@fb.com

Subscribers: fugalh, folly-diffs@, jsedgwick, yfeldblum, chalfant

FB internal diff: D2023982

Tasks: 6836580

Signature: t1:2023982:1430157500:e09a4103550a3e5721effaa1b28ac5bed071fa67

Summary:
(from @njormrod) This changes the READMEs to be .md,
appropriate for github. I viewed the docs on github, and they looked
WAY better as .md files.
Signed-off-by: Nicholas Ormrod <njormrod@fb.com>

Test Plan: view on github

Reviewed By: markisaa@fb.com

Subscribers: fugalh, folly-diffs@, jsedgwick, yfeldblum, chalfant

FB internal diff: D1999531

Tasks: 6783581

Signature: t1:1999531:1429220432:68c6d8dc70806d993c83cacce6369cb7e6e964c8

Summary:
A few things:
- Eliminate HandlerPtr by managing all handlers with shared_ptrs instead of keeping them inline in the pipeline
- Kill recursively templated ChannelPipeline accordingly
- Introduce StaticPipeline to retain the flexibility of zero-alloc pipelines
- Introduce notion of an "owning handler" to avoid destruction order issues

Test Plan: unit (will add more), thrift unit

Reviewed By: davejwatson@fb.com

Subscribers: fugalh, alandau, bmatheny, folly-diffs@, jsedgwick, yfeldblum, chalfant

FB internal diff: D2023976

Tasks: 6836580

Signature: t1:2023976:1430159578:e50e8a149e549a40670d093fb65987a4843cdd8d

Summary: Move boring preamble stuff to `Future-pre.h` and `folly::futures` and `makeFuture` and pals to `helpers.h`.

Test Plan:
tests still build and pass

Reviewed By: jsedgwick@fb.com

Subscribers: exa, folly-diffs@, jsedgwick, yfeldblum, chalfant, hannesr, davejwatson

FB internal diff: D2014330

Signature: t1:2014330:1429941589:1e2c336136f3375f9b96e5df8c06ca5820ba6aeb

Summary: as above. Only got a little messy when components within folly::wangle typedefed things to Pipeline

Test Plan: unit tests

Reviewed By: davejwatson@fb.com

Subscribers: wormhole-diffs@, fugalh, alandau, bmatheny, folly-diffs@, jsedgwick, yfeldblum, chalfant

FB internal diff: D2022181

Tasks: 6836580

Signature: t1:2022181:1430157032:df0bdfb9ca0d76b86d52c55c4ad41ea953a18cb4

Summary: Fixing oss build

Test Plan: Visual analysis.

Reviewed By: pavlo@fb.com

Subscribers: folly-diffs@, yfeldblum, chalfant

FB internal diff: D2023889

Signature: t1:2023889:1430144784:e58fe9e1f1193d71527ba5f5f2c2efb60bce7a2d

Blame Revision: D2022859

Summary: title

Test Plan: tests

Reviewed By: hannesr@fb.com

Subscribers: exa, folly-diffs@, jsedgwick, yfeldblum, chalfant

FB internal diff: D2022859

Signature: t1:2022859:1429920863:0d3afce9779a790baf246de97f98812e23e1574d

Summary:
[Folly] IPAddressV6::kToFullyQualifiedSize.

The scenario: One has a string known to be a fully-qualified IPv4 or fully-qualified IPv6 address, but one does not know which of the two it is.

The dirty but fast solution: just check its size.

Test Plan: Build. Unit tests.

Reviewed By: mshneer@fb.com

Subscribers: folly-diffs@, dougw, yfeldblum, chalfant, brettp

FB internal diff: D2016634

Signature: t1:2016634:1429831808:08ecb28eab3060988f9613748ed8dabf3724bf13

Summary: Similar to Promise::fulfil -> setWith change, this name is a lot clearer

Test Plan: tests

Reviewed By: hans@fb.com

Subscribers: netego-diffs@, fugalh, mwa, jgehring, fuegen, folly-diffs@, tingy, jsedgwick, yfeldblum, chalfant

FB internal diff: D2013124

Tasks: 6837405

Signature: t1:2013124:1429735106:e8861925dfeb6d7f0662c1057cbcf2ad8dcf008c

Summary:
Change ThreadManager interface to more generic Executor interface.  Specific example of supporting fibers.  This diff would replace D1967655

Test Plan: added several unittests

Reviewed By: alandau@fb.com

Subscribers: doug, alandau, bmatheny, mshneer, folly-diffs@, jsedgwick, yfeldblum, chalfant, alikhtarov, andrii, yitingli

FB internal diff: D1994663

Signature: t1:1994663:1429640509:d729ce6f020563b680d1d549f9aa273c739eb925

Summary:
We don't need to check for void after all, and with perfect forwarding we don't need separate const& and && versions.

Test Plan: tests still pass

Reviewed By: jsedgwick@fb.com

Subscribers: exa, folly-diffs@, jsedgwick, yfeldblum, chalfant

FB internal diff: D2014264

Tasks: 6847876

Signature: t1:2014264:1429735036:01ac166399ef8d0f2f34adb51e965809022c2b64

Summary: This covers the ubiquitous case. If the approach is approved (the task mentioned changing impl to use 'auto for' so this is a bit different) i'll codemod callsites

Test Plan: unit

Reviewed By: hans@fb.com

Subscribers: trunkagent, folly-diffs@, jsedgwick, yfeldblum, chalfant

FB internal diff: D2013573

Tasks: 6779710

Signature: t1:2013573:1429735631:cfa0d3f6672a8966afc0ea18308307e2153793ce

Summary:
MIN_WRITE_SIZE is used to avoid small write calls to SSL_write. If there are
consecutive small buffers to write, then will be combined together(by being
copied to a local buffer) until total size exceeds MIN_WRITE_SIZE. This reduces
number of calls SSL_write, improving performance, and avoiding overhead in OpenSSL.

Currently, MIN_WRITE_SIZE is hard coded to be 1500 bytes.

Wormhole could benefit from this, as our average message size is several
hundreds of bytes. We could get even better throughput with larger
MIN_WRITE_SIZE.

As discussed with Adam and Alan, there is a good reason to make it
configurable, though default value is still 1500.

Test Plan: unit tests

Reviewed By: simpkins@fb.com

Subscribers: net-systems@, ssl-diffs@, folly-diffs@, yfeldblum, chalfant, thomasf

FB internal diff: D1996570

Tasks: 6784543

Signature: t1:1996570:1429667035:a661ef30a715dafec3e134a7f6af6f56ada2e8e0

Summary:
Today it's hard to create SocketAddress from IPAddress
without converting to strings and back. This change adds this capability.

Test Plan: build

Reviewed By: yfeldblum@fb.com

Subscribers: ps, bmatheny, folly-diffs@, yfeldblum, chalfant

FB internal diff: D2011879

Signature: t1:2011879:1429733811:c05fc2d5ef5e9fdbbbb54ad26b4d1e3c0ad06dfa

Summary:
make future::wait() use fiber's baton, so wait works in threads or in fibers.

Much cleaner than making a new FiberRequest type in thrift

Test Plan: tests

Reviewed By: andrii@fb.com

Subscribers: doug, alandau, bmatheny, mshneer, andrii, folly-diffs@, yitingli, yfeldblum, jsedgwick, chalfant

FB internal diff: D1996283

Signature: t1:1996283:1429144165:da5dc6b1f2a053a45efd39877e79169e3fba810c

Summary: title

Test Plan: tests

Reviewed By: hans@fb.com

Subscribers: laser-diffs@, trunkagent, mhl, rhe, fbcode-common-diffs@, chaoyc, search-fbcode-diffs@, hero-diffs@, zeus-diffs@, vikas, cold-storage-diffs@, rtgw-diffs@, unicorn-diffs@, targeting-diff-backend@, netego-diffs@, apollo-diffs@, everstore-dev@, zhuohuang, zhguo, jying, darshan, apodsiadlo, alikhtarov, folly-diffs@, wch, lins, tingy, jsedgwick, thom, yfeldblum, petchean, iaroslav, qhuang, gus, san, tomasz, pknowles, lyang, chalfant, paggarw, stevenkim

FB internal diff: D2003300

Tasks: 6025255

Signature: t1:2003300:1429659170:e18999cba45e8aa9019aa94f1f29732076a274ad

Summary:
as above. it never ends.

Test Plan: added unit

Reviewed By: hans@fb.com

Subscribers: folly-diffs@, jsedgwick, yfeldblum, chalfant

FB internal diff: D2011569

Signature: t1:2011569:1429660210:930cb17682d5c86a11881a23efe0a91f4c6a36b1

Summary:
Pass an Executor to `then`, which applies only for that callback. This is on
the one hand just a convenience method, but it's a major convenience when it's
needed, because grabbing, storing, and restoring the old Executor in the
middle of a chain is very inconvenient indeed.

Test Plan:
new unit
docblock comments

Reviewed By: jsedgwick@fb.com

Subscribers: folly-diffs@, davejwatson, chalfant, yfeldblum, nkgupta, jsedgwick, exa, robbert

FB internal diff: D2011542

Tasks: 6771589, 6838553

Signature: t1:2011542:1429660204:f5959b1e0b3b36dfb8c3c7091302d19101dde93b

Summary:
this was a fun one. Add a specialized implementation that builds up the results in a map with their indices and aggregates them into a vector at the end

Test Plan: unit tests

Reviewed By: hans@fb.com

Subscribers: folly-diffs@, jsedgwick, yfeldblum, chalfant

FB internal diff: D2002444

Signature: t1:2002444:1429642589:ee5aa5e8c461db97a28642b9887b3158df317813

Summary:
simple sugary syrup, best used in conjunction with collect/whenAll

Test Plan: unit

Reviewed By: hans@fb.com

Subscribers: trunkagent, folly-diffs@, jsedgwick, yfeldblum, chalfant, cgthayer

FB internal diff: D1999047

Tasks: 6045623

Signature: t1:1999047:1429570631:62361bb43dc5489fe3d4eb31af404faf8a765402

Summary:
Rather than crashing spectacularly, if `Executor::add` throws (e.g. because the queue is full), then discard the result we got and assume the exception the executor threw instead.

Alternatively, we could pass this exceptional Try to the callback (without an executor, as it is here), but not perturb `result_`. This would mean two different world views in these two code snippets:

auto f1 = makeFuture(42).via(&crappyExecutor);
f1.value(); // 42 (no callback happened)
f1.then(...); // would see the executor's exception. Would also be ill-advised to do this after value()

auto f2 = makeFuture(42).via(&crappyExecutor)
.then([](int x) { return x * 2; }); // skipped
f2.value(); // throws executor's exception

It feels rude to throw away the result, but it feels too potentially dangerous to allow this split view of the world.

Test Plan: modified unit

Reviewed By: jsedgwick@fb.com

Subscribers: exa, folly-diffs@, jsedgwick, yfeldblum, chalfant

FB internal diff: D2007729

Tasks: 5306911

Signature: t1:2007729:1429627114:b627ce758ce9231298f1b28e203ccc1ee415ed9a