Summary: Method will only be applicable for types of the form Future<Future<T>>, calling flatten() on a Future<T> where <T> != Future<R> for any <R> will result with a compile time error.

Test Plan: Added tests in FutureTest.cpp.

Reviewed By: hans@fb.com

Subscribers: ldbrandy, trunkagent, folly-diffs@, jsedgwick, yfeldblum, icanadi

FB internal diff: D1843581

Tasks: 6166903

Signature: t1:1843581:1424399517:7146924db3c238b77dd309f1d5916e44a7e81968

Summary:
Make it clear that the variable is const

Closes #139

Test Plan:
authored tested, contbuild

Reviewed By: markisaa@fb.com

Subscribers: folly-diffs@, yfeldblum

FB internal diff: D1878361

Signature: t1:1878361:1425071448:6871577ddb34f4a8dc30ea37842f9950c3825dde

Summary:
1. Split the original simple test
2. Add unit test of function: get_ref_default

Closes #138

Test Plan: authored tested, contbuild

Reviewed By: markisaa@fb.com

Subscribers: folly-diffs@, yfeldblum

FB internal diff: D1878603

Signature: t1:1878603:1425073330:914a2365fa648142d11b41b387423d78e52f2e08

Summary:
Remove one of the "one" in the comment of BENCHMARK

Closes: #140

Test Plan: Inspection.

Reviewed By: markisaa@fb.com

Subscribers: trunkagent, folly-diffs@, yfeldblum

FB internal diff: D1877997

Signature: t1:1877997:1425063475:c53c09d105809de9a9070f464fb0571a4dd1e5d1

Summary:
Basically a ripoff of Dave's D1483148 but with ChannelPipeline instead of rx.
There's going to be a long tail of unit tests here, this is still pretty broken...

Not convinced that this is the way to go but I wanted to get a feel for what it would be like to plug it into an IRL system.
I think the simplicity/clarity of the handler implementations and to some extent the pipeline spec is an improvement over the rx way
but I'm less sure about everything else.

Test Plan: compiles and kind of works some of the time but not really

Reviewed By: alandau@fb.com

Subscribers: wormhole-diffs@, mcduff, hitesh, doug, yfeldblum, folly-diffs@, jsedgwick, subodh, andrewcox, njormrod, trunkagent, fugalh, alandau, bmatheny, mshneer

FB internal diff: D1618704

Tasks: 5981284

Signature: t1:1618704:1424980854:83c6193b1156be2ec65cf79f9f2ad1af670da7f8

Summary: Added willEqual function and wrote unit tests for it.

Test Plan: fbconfig --clang folly/futures && fbmake runtests

Reviewed By: hans@fb.com

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

FB internal diff: D1859840

Tasks: 6166911

Signature: t1:1859840:1424967149:865ee96ab4d3f5dbf17eb371b2ac3ccb5066ac87

Summary:
This diff gives IndexedMemPool<T> emplace-like semantics when T
is not trivial.

Test Plan:
1. new unit tests
2. LifoSem benchmark

Reviewed By: march@fb.com

Subscribers: folly-diffs@, yfeldblum

FB internal diff: D1874941

Signature: t1:1874941:1424987308:61bbe7b7e5e6df625a6208cd873c65e523a79fa0

Summary:
Update copyright notices in folly to 2015

find folly/ -type f | xargs sed -i 's/Copyright 2014 Facebook, Inc./Copyright 2015 Facebook, Inc./g'find . -type f | xargs sed -i 's/Copyright 2014 Facebook, Inc./Copyright 2015 Facebook, Inc./g'

Test Plan:
fbconfig -r folly && fbmake runtests

Reviewed By: markisaa@fb.com

Subscribers: ldbrandy, shilin, sdwilsh, fugalh, njormrod, folly-diffs@, jsedgwick, yfeldblum

FB internal diff: D1869183

Signature: t1:1869183:1424823514:a2dd33741a86bf099d5c9e3d8702e6cca6dd672f

Summary:
EventBase::runAfterDelay to throw an exception in case it fails to
schedule a proper execution of the given callback
(instead of silently returning false)

it appears to be the right thing to do, since:
@davejwatson: Digging through the layers of code, it appears this can only fail if
epoll_ctl() with EPOLL_CTL_ADD fails. Ignoring libevent bugs, it looks
like the only relevant errors could be ENOMEM or ENOSPC. So
nonrecoverable

Test Plan: Unit tests

Reviewed By: anca@fb.com

Subscribers: yzhan, haijunz, simpkins, net-systems@, varunk, zeus-diffs@, nli, dfechete, fugalh, atlas2-eng@, alandau, bmatheny, everstore-dev@, zhuohuang, wormhole-diffs@, anca, mwa, jgehring, oujin, alikhtarov, fuegen, mshneer, wch, bil, sanketh, zippydb, maxwellsayles, jsedgwick, trunkagent, fbcode-common-diffs@, chaoyc, search-fbcode-diffs@, andrewcox, unicorn-diffs@, tw-eng@, xie, kennyyu, yfeldblum, folly-diffs@, davejwatson

FB internal diff: D1805125

Signature: t1:1805125:1424927912:8bebb4c3b9f1fa189c0ce97b12cdb8f95dba97ae

Summary:
Updating Folly Formatting's use of separators for Decimal Integers 'd' and Numbers 'n'.
Updated Decimal Integers 'd' use of separators to directly use commas ',' and grouping of 3 digits.
Updated Numbers use of separators and grouping to follow locale settings.

Test Plan:
Wrote unit tests to validate the insertion of thousandsSeparators works.
Note that the numbers unit test does not modify the locale since the test cases are not thread safe.

Reviewed By: lesha@fb.com

Subscribers: tudorb, trunkagent, folly-diffs@, yfeldblum, aric

FB internal diff: D1821156

Tasks: 6087521

Signature: t1:1821156:1424923837:d0fb383a07fd733375b72b1905e6112afa141265

Summary:
Manual inspection of AsyncSocket.o shows the constructors are generating ugly
(and large) code. Call the smaller constructors instead of duplicating the code. This
reduces the debug .o size from ~1.9MB to ~1.6MB.

Test Plan: existing tests

Reviewed By: benyluo@fb.com

Subscribers: mzlee, folly-diffs@, yfeldblum, mathieubaudet, subodh, pgriess, benyluo

FB internal diff: D1870896

Signature: t1:1870896:1424885638:d37fc79c0f88d04109c8bb73e632dc506b9f773b

Summary: Unconditionally execute the action, passthrough semantics.

Test Plan: new unit test

Reviewed By: bmatheny@fb.com

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

FB internal diff: D1868837

Tasks: 6166860

Signature: t1:1868837:1424820181:0e83f54b59d7091dac60ab65feb387992e8ae89c

Summary:
writeFull() returns ssize_t and without proper casting, comparing
it with data.size() triggers a compiler warning (which is
treated as an error) in the gcc-4.9-glibc-2.20 toolchain.

Test Plan: fbmake runtests

Reviewed By: mhx@fb.com

Subscribers: folly-diffs@, yfeldblum

FB internal diff: D1870710

Signature: t1:1870710:1424874592:f51026c35196d763ad4b192d43c8ccee0255b41d

Summary:
See the github pull request at https://github.com/facebook/folly/issues/135

Important optimizations: remove one of the branches and change ##empty()## to ##capacity()==0##

Test Plan:
Ran extended fbvector test suite (re-enabled in experimental/njormrod)

Also

fbconfig -r folly && fbmake runtests

Reviewed By: markisaa@fb.com

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

FB internal diff: D1869112

Tasks: 6338531

Signature: t1:1869112:1424823901:d2d7331aef82edad1e8c159005cc1c7185550d0c

Summary: Funnily, google::setThreadName is Facebook specific: it's introduced only in the FB build of glog. This diff removes the call because folly should not depend on FB's glog.

Test Plan: made sure the line was deleted

Reviewed By: ldbrandy@fb.com

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

FB internal diff: D1868249

Tasks: 6345935

Signature: t1:1868249:1424812595:2a084754d614ab9b7b6168454f33638882e3f6db

Summary:
EmulatedFutexAtomic concisely says here that it doesn't copy construct,
move construct, copy assign, or move assign.

Closes #130

Test Plan:
Inspection and all unit tests.

```
Summary (total time 66.97s):
PASS: 2029
FAIL: 0
SKIP: 0
FATAL: 0
TIMEOUT: 0
```

Reviewed By: ngbronson@fb.com

Subscribers: folly-diffs@, yfeldblum

FB internal diff: D1868033

Signature: t1:1868033:1424808823:d9dd618981b29b5949c00190d69d670d96e60e07

Summary:
encodeVarintToIOBuf and decodeVarintFromCursor are not used when
FOLLY_HAVE_LIBLZMA and FOLLY_HAVE_LIBLZ4 are false, which will trigger
-Werror,-Wunused-function on compile on mobile.

Test Plan: unit test

Reviewed By: seanc@fb.com

Subscribers: meisner, trunkagent, seanc, folly-diffs@, yfeldblum

FB internal diff: D1864016

Signature: t1:1864016:1424702813:75535ea92ac16385ce5c272d93bba507ccbb67a1

Summary:
Previously leak-fatal could never happen because we were incorrectly checking singleton state.
Sending this diff to see how many tests will actually fail and potentially fix worst offenders.

Test Plan: unit tests

Reviewed By: stepan@fb.com

Subscribers: trunkagent, folly-diffs@, yfeldblum

FB internal diff: D1838405

Signature: t1:1838405:1424478983:94cda86ed57f38b0cf626b74804fbc168d182c66

Summary:
Add option to disable time measurement in EventBase::loopBody()
to improve performances when time measurement is not used.

Test Plan:
Unit tests, benchmarking and manual tests.

Reviewed By: pavlo@fb.com

Subscribers: trunkagent, folly-diffs@, yfeldblum

FB internal diff: D1846020

Tasks: 6086197

Signature: t1:1846020:1424459703:9686a84027e1137ee43eb0458b0baa4fee3a8abf

Summary:
This 'moves' bistro::AutoTimer into folly. I actually changed it a bit, so I'm
not migrating any existing uses in this diff, but I can do that as a followup.
We're using it in various places now, so it doesn't make sense to have it in
bistro.

Basically this class lets you conveniently time a series of things while
printing log messages, e.g.:
{
AutoTimer t("Done");
processA();
t.log("processA() complete");
}

would print
"processA() complete in XXX seconds"
"Done in YYY seconds"

I changed some things from bistro::AutoTimer:
- Use std::chrono::time_point<Clock> to store the start time.
- I removed the gflags. It seems weird to rely on those to control the timer,
since they would affect all uses of this. If a specific user of the timer
wants to actually control timing at runtime, I think it's better to use a
custom logger.
- I removed the 'min log duration'. As implemented it actually made the
constructor conflict: AutoTimer("foo", 1.2) is ambiguous. Also, it should
probably be set on the logger, so this likewise feels like a place where you
could make a custom logger.

I'm not sure that the way I use the default logger as a template argument is
best, so please suggest improvements to that.

Test Plan: unit test

Reviewed By: lesha@fb.com

Subscribers: trunkagent, folly-diffs@, yfeldblum

FB internal diff: D1860794

Signature: t1:1860794:1424458219:a2dd0d428aedf063a888b2937b1443c7142554e8

Summary: I thought this was a race, but I think now it was something to do with using a value that had been moved out or something. Anyway, this refactor is cleaner and consolidates a few methods so it's all kinds of fuzzy feelings.

Test Plan: unit tests

Reviewed By: hannesr@fb.com

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

FB internal diff: D1861376

Tasks: 6298004

Signature: t1:1861376:1424465861:736353ab3174656fec9e036e0ebd964970da38d0

Summary:
a couple of files were catching this exception and included the .cpp file :O. So we moved
to .h before realizing this was not intended to be caught. reverting the move to .h. codemod will follow.

Test Plan: fbmake -r folly && fbmake && fbmake runtests

Reviewed By: delong.j@fb.com

Subscribers: trunkagent, doug, seanc, folly-diffs@, yfeldblum

FB internal diff: D1854301

Tasks: 6245781

Signature: t1:1854301:1424375745:7e226196315fac99835752896cc5e549e91df2da

Summary:
Instead of returning a deactivated future, have `via` just set the executor. Propagate the executor from `then`. This fixes the `via().get()` problem, and has semantics similar to before for `via().then().then()`.

However, the semantics are now slightly different - each `then` goes back through the executor. This adds some overhead and tweaks the semantics (e.g. if the executor is a threadpool it might execute subsequent `then`s in another thread). However, with `futures::chain` recently introduced, and any other convenience methods that you can dream up and make a case for, we can reasonably get the old once-through-the-executor behavior when performance or other concerns demand it. e.g. `via().then(futures::chain(a, b, c))`.

Test Plan: unit tests

Reviewed By: hannesr@fb.com

Subscribers: zeus-diffs@, mmandal, steveo, rituraj, trunkagent, exa, folly-diffs@, yfeldblum, jsedgwick, davejwatson

FB internal diff: D1839691

Tasks: 6048744

Signature: t1:1839691:1424397180:ca0b0ea7b3867769ab8abd254a510059df67011e

Summary:
This reverts commit 1e407b48d379a41f32e7a980285dbdf4dadb2e33.

Test Plan: revert-hammer

Reviewed By: yitingli@fb.com

Subscribers: folly-diffs@, jsedgwick, yfeldblum

FB internal diff: D1858994

Signature: t1:1858994:1424386588:5c4608ecbe1f9ab1108ac12e506b157b54d0078b

Summary:
These were doing more assignments than necessary.
1) We don't need to set `core_` to `nullptr` and then immediately
overwrite it with `other.core_`.
2) Don't need to swap the booleans (this was actually an unitialized
memory access).

Test Plan: Ran all the tests.

Reviewed By: hans@fb.com

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

FB internal diff: D1852386

Signature: t1:1852386:1424375154:25997209e76ccd16169125597e868932a5143ffb

Summary: This diff should let us include folly/io:compression into iOS and Android projects without pulling in a lot of dependencies and should allow the use of zlib.

Test Plan: fbconfig -r folly/io/tests && fbmake runtests

Reviewed By: seanc@fb.com

Subscribers: trunkagent, bmatheny, folly-diffs@, yfeldblum, seanc, benyluo

FB internal diff: D1853058

Tasks: 6245912

Signature: t1:1853058:1424370881:2ea243d93e6041502e5e356fa430c2483f652b40

Summary:
Use server bootstrap.

* code reuse
* Allows multiple accept threads easily.

Accept now doesn't happen in the server's eventBase, but a new thread.

I think I hit all the corner cases involving existingSocket, duplex, stopListening(), etc.

There are a lot of minor changes here to support all the cases, let me know if I should split anything to separate diffs

Test Plan: fbconfig -r thrift/lib/cpp2; fbmake runtests

Reviewed By: hans@fb.com

Subscribers: haijunz, yfeldblum, ruibalp, fbcode-common-diffs@, davejwatson, jsedgwick, trunkagent, doug, alandau, bmatheny, mshneer, folly-diffs@, mcduff, andrewcox, fugalh

FB internal diff: D1732895

Tasks: 5788102

Signature: t1:1732895:1423087631:379bbb131c35ce2221801bc7cec226f87ba0b1d9

Summary: from discussion

Test Plan: unit tests

Reviewed By: hans@fb.com

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

FB internal diff: D1829282

Signature: t1:1829282:1423180907:3630dac1378750b05f316c672fbbd71138d2bc0a

Summary: They are functionaly equivalent, no need to have more than one

Test Plan: fbconfig -r realtime/voip; fbmake runtests

Reviewed By: naizhi@fb.com

Subscribers: trunkagent, doug, ps, bmatheny, folly-diffs@, yfeldblum

FB internal diff: D1828044

Tasks: 6154007

Signature: t1:1828044:1423165354:f71d2fd28ca76a8f67a597c747f8578d2909823c

Summary: After D1827390 regular get and get_weak is comparable to Meyers and static singletons, so there's no need to keey _fast APIs.

Test Plan: benchmark && fbmake

Reviewed By: mshneer@fb.com

Subscribers: trunkagent, configerator-diffs@, fbcode-common-diffs@, mcduff, hitesh, mshneer, fugalh, acampi, alikhtarov, folly-diffs@, jsedgwick, yfeldblum

FB internal diff: D1843219

Signature: t1:1843219:1424216566:f2f182a1c86bb5f0fb1f978d8c6b7a4388198f5f

Summary: This are the open-source-related additions. A separate diff will replace the current implementation in common/concurrency/ to use this one.

Test Plan: fbmake runtests

Reviewed By: simpkins@fb.com

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

FB internal diff: D1845525

Signature: t1:1845525:1424207291:d30e3c5e85222527c2aff39c1250aa1e41b9a2cf

Summary:
The continuation at the end of the line with the while
was causing gcc to complain about it because it's a
single line comment.

Reformat it into a multiline comment and wrap it to 80 chars.

Test Plan: It's just a comment...

Reviewed By: paulbiss@fb.com

Subscribers: trunkagent, folly-diffs@, yfeldblum

FB internal diff: D1850876

Signature: t1:1850876:1424124973:b2afbc2a8177ac6d11a21bf5a52093bcfd9cbb3e

Summary: I think this makes sense, especially if `interrupt_` is really rare.

Test Plan:
============================================================================
folly/futures/test/Benchmark.cpp                relative  time/iter  iters/s
============================================================================
constantFuture                                             101.25ns    9.88M
promiseAndFuture                                  92.86%   109.03ns    9.17M
withThen                                          28.96%   349.65ns    2.86M
----------------------------------------------------------------------------
oneThen                                                    337.33ns    2.96M
twoThens                                          58.46%   577.06ns    1.73M
fourThens                                         32.42%     1.04us  961.23K
hundredThens                                       1.45%    23.24us   43.04K
----------------------------------------------------------------------------
no_contention                                                4.45ms   224.48
contention                                        72.89%     6.11ms   163.61
----------------------------------------------------------------------------
throwAndCatch                                                6.34us  157.77K
throwAndCatchWrapped                              95.65%     6.63us  150.91K
throwWrappedAndCatch                             142.58%     4.45us  224.95K
throwWrappedAndCatchWrapped                      488.86%     1.30us  771.27K
----------------------------------------------------------------------------
throwAndCatchContended                                        1.01s  987.01m
throwAndCatchWrappedContended                    100.03%      1.01s  987.27m
throwWrappedAndCatchContended                    148.37%   682.86ms     1.46
throwWrappedAndCatchWrappedContended            18765.19%     5.40ms   185.21
============================================================================

Compare to D1843129#31 (seems to be an improvement?)

Reviewed By: hans@fb.com

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

FB internal diff: D1847843

Signature: t1:1847843:1423855151:3602d49df245eda3f85325ab5efd63514213ca44

Summary:
Disable the -Wunevaluated-expression warning for this test:

EXPECT_EQ(typeid(ie), typeid(IntException));

Otherwise, clang warns about the unevaluated expression because
the expansion of EXPECT_EQ applies sizeof to an expression
with side effects:

folly/test/ExceptionWrapperTest.cpp:179:122: error: expression with side effects has no effect in an unevaluated context [-Werror,-Wunevaluated-expression]
switch (0) case 0: default: if (const ::testing::AssertionResult gtest_ar = (::testing::internal:: EqHelper<(sizeof(::testing::internal::IsNullLiteralHelper(typeid(ie))) == 1)>::Compare("typeid(ie)", "typeid(IntException)", typeid(ie), typeid(IntException)))) ; else ::testing::internal::AssertHelper(::testing::TestPartResult::kNonFatalFailure, "folly/test/ExceptionWrapperTest.cpp", 179, gtest_ar.failure_message()) = ::testing::Message();

Test Plan:
Ensure this compiles with clang-3.4, 3.5 and clang:dev.
I.e., ensure that this prints PASS at the end.

for i in '' 3.5 dev; do
test -n "$i" && i=--with-project-version=clang:$i
fbconfig -r --clang $i folly/test:exception_wrapper_test && fbmake dbgo
done && echo PASS

Reviewed By: mpawlowski@fb.com

Subscribers: mathieubaudet, folly-diffs@, yfeldblum

FB internal diff: D1850778

Tasks: 6244745

Signature: t1:1850778:1424111029:136478e9a3cc3a219047547d501de4c579a1a181

Summary:
* folly/wangle/channel/test/MockChannelHandler.h:
Avoiding a new warning that rendered this file uncompilable
by clang-3.5 and older.  Add cpp conditionals to protect
against that.

Test Plan:
Ensure it works with clang-3.4, 3.5 and clang:dev.
I.e., ensure that this prints PASS at the end.

for i in '' 3.5 dev; do
test -n "$i" && i=--with-project-version=clang:$i
fbconfig -r --clang $i folly/wangle/channel/test && fbmake runtests_dbgo
done && echo PASS

Reviewed By: meyering@fb.com

Subscribers: mpawlowski, fugalh, mathieubaudet, folly-diffs@, jsedgwick, yfeldblum

FB internal diff: D1849474

Tasks: 6244745

Blame Revision: D1848330
@build-break

Summary:
Clang's new -Wself-move warning dings this code:

b = std::move(b);

But in this case, that is a deliberate test of
this capability, so we suppress that particular
warning for the duration of this small test function.

Test Plan:
Run this and note that it now compiles: (it passes the tests, too)
fbconfig --clang --with-project-version=clang:dev -r folly/test:optional_test && fbmake dbgo

Reviewed By: watashi@fb.com

Subscribers: folly-diffs@, yfeldblum

FB internal diff: D1849689

Tasks: 6244745

Signature: t1:1849689:1423877932:4f479d682bd8ba97dcabed7fc29ce0a22c013969

@build-break (using this to work around bogus push failure: https://phabricator.fb.com/P19730606)

Summary:
* folly/ExceptionWrapper.h (class_name): Clang is not yet smart enough to
see that there is no harm in dereferencing an "item_" that we've just
verified is non-NULL.  Accommodate it, to avoid this:
./folly/ExceptionWrapper.h:199:30: error: expression with side effects will be evaluated despite being used as an operand to 'typeid' [-Werror,-Wpotentially-evaluated-expression]
return demangle(typeid(*item_));
^

Test Plan:
Run these commands and note there are fewer errors than before:
fbconfig --clang --with-project-version=clang:dev -r folly && fbmake dbgo

Reviewed By: mhorowitz@fb.com

Subscribers: trunkagent, yfeldblum, folly-diffs@

FB internal diff: D1848327

Tasks: 6244745

Signature: t1:1848327:1423869597:a58c9e9e3671befb78ae07fbd274a13d08ffb2a7

Blame Revision:

Summary: [Folly] clang:dev rejects vector<atomic<T>> in EventBaseTest.cpp.

Test Plan: Build and run `folly/io/async/test/EventBaseTest.cpp` using the current `clang`; try building with `clang:dev` and verifying that at least the related failures are gone.

Reviewed By: meyering@fb.com

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

FB internal diff: D1848749

Tasks: 6244720

Signature: t1:1848749:1423866420:7b7354d4568b6a6d6a824236ae8d271f6855d90b

Summary:
This avoids warnings about e.g., sizeof(k++) that result
from macro expansion.
* folly/futures/test/ExecutorTest.cpp: Move increment out
of macro argument list.
* folly/test/FBVectorTestBenchmarks.cpp.h: Likewise.
* folly/test/LazyTest.cpp: Likewise.
Otherwise, we'd get errors like this:

folly/test/LazyTest.cpp:49:118: error: expression with side effects has no effect in an unevaluated context [-Werror,-Wunevaluated-expression]
switch (0) case 0: default: if (const ::testing::AssertionResult gtest_ar = (::testing::internal:: EqHelper<(sizeof(::testing::internal::IsNullLiteralHelper(++globalCount())) == 1)>::Compare("++globalCount()", "1", ++globalCount(), 1))) ; else ::testing::internal::AssertHelper(::testing::TestPartResult::kNonFatalFailure, "folly/test/LazyTest.cpp", 49, gtest_ar.failure_message()) = ::testing::Message();
^

Test Plan:
Run these commands and note there are fewer errors than before:
fbconfig --clang --with-project-version=clang:dev -r folly && fbmake dbgo

Reviewed By: njormrod@fb.com

Subscribers: folly-diffs@, jsedgwick, yfeldblum

FB internal diff: D1848324

Tasks: 6244745

Signature: t1:1848324:1423860890:bce44c5e0895804a21957893ae6b78e76dfbc4d3

Summary:
Upgrading to clang:dev (clang >3.6) brought in some new warnings.
This change address all of the issues exposed by the new
-Winconsistent-missing-override, usually by simply adding the
missing "override" keyword.  However, in
folly/wangle/channel/test/MockChannelHandler.h, I chose
to ignore those warnings for the mocked functions.
* folly/futures/test/ViaTest.cpp: Add missing "override"(s).
* folly/io/async/AsyncSSLSocket.h: Likewise.
* folly/io/async/AsyncSocket.h: Likewise.
* folly/io/async/EventBase.h: Likewise.
* folly/test/ExceptionWrapperTest.cpp: Likewise.
* folly/wangle/channel/AsyncSocketHandler.h: Likewise.
* folly/wangle/channel/test/MockChannelHandler.h: Ignore
the new warning for these functions.

Test Plan:
Run these commands and note there are fewer errors than before:
fbconfig --clang --with-project-version=clang:dev -r folly && fbmake dbgo

Reviewed By: hans@fb.com

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

FB internal diff: D1848330

Tasks: 6244745

Signature: t1:1848330:1423858909:b167ca220d6c9fe036d3adca08cf3053a7a9de16