Summary: This is the first of a series of diffs to get folly, fbthrift, and bistro to run on Ubuntu 12.04 LTS, which is what powers Travis CI.

It's important for folly to be easily usable with Travis CI, since everything C++ depends on it, and we really want all FB open-source projects to be monitored via continuous integration to avoid breaking their OSS builds.

Thanks to @int's work on `mcrouter`, this was considerably easier than it would have been otherwise.

This puts us a hop and a skip away from actually running folly's `make && make check && make install` on Travis CI. Do y'all think this is useful?

Reviewed By: @yfeldblum

Differential Revision: D2217441

Summary: Another stab at D2111063 now that we have the go ahead to actually open up the wangle github repo

Reviewed By: @djwatson, @mdordal

Differential Revision: D2178291

Summary: Drop those `const_cast<>` hacks.

Reviewed By: @ot

Differential Revision: D2217629

Summary: This is a documentation dump, with updates from the past couple weeks. Most notably, the new information about `Future<Unit>` replacing `Future<void>`.

Reviewed By: @​hannesr

Differential Revision: D2211135

Summary: [Folly] Lift thrift/lib/cpp/test/TNotificationQueueTest.

`NotificationQueue` is already moved into folly; move its accompanying test suite as well.

Reviewed By: @simpkins

Differential Revision: D2207104

Summary: Got this ifdef wrong in my last change here.

Reviewed By: @paulbiss

Differential Revision: D2213708

Summary: If you try to make a future or promise of `void`, you will get this nice error message telling you to use `Unit` instead.

Reviewed By: @djwatson

Differential Revision: D2211239

Summary: The Homebrew setup fails to compile on OSX.

Reviewed By: @paulbiss

Differential Revision: D2212084

Summary: [Folly] folly::Unit::Drop.

Antisymmetric to folly::Unit::Lift.

Reviewed By: @fugalh

Differential Revision: D2211725

Summary: Fix so `Timekeeper::at(now() - something)` works. Also introduce a test which explicitly tests when <= now codepath, which wasn't broken per se here, but which test also tickled this bug.

Reviewed By: @jsedgwick

Differential Revision: D2209166

Reviewed By: @yfeldblum

Differential Revision: D2209095

Summary: This is three codemods:

* `(folly::(Future|Promise|Try))<void>` -> `\1<folly::Unit>`
* `(Future|Promise|Try)<void>` -> `\1<Unit>`
* add `using folly::Unit` statements where needed

Then
* undo false positives in javascript files and fibers::Promise

cf D2201259, which this will land with

Reviewed By: @djwatson

Differential Revision: D2201801

Summary: Mostly this is `s/(Promise|Future|Try)<void>/\1<Unit>/`

Reviewed By: @djwatson

Differential Revision: D2201272

Summary: Nuke Future<void> in favor of Future<Unit>, for the `folly/futures` subdirectory.

Reviewed By: @djwatson

Differential Revision: D2201259

Summary: The current #if directive is a laundry list of
"strerror_r defaults to XSI style on these platforms",
and we keep missing some, so let's just do a proper test
and simplify the code directives.

Closes #232

Reviewed By: @paulbiss

Differential Revision: D2208843

Reviewed By: @yfeldblum

Differential Revision: D2209197

Summary: Implemented a BitVector Encoder and BitVector Reader with the same interface as EliasFanoCoding.h

Reviewed By: @ot, @philippv

Differential Revision: D2198935

Summary: Apparently this test sometimes fails. @Gownta suggests it's because we're
storing temproaries in StringPiece. Change it to store in a std::string, which
should hopefully fix it.

Reviewed By: @Gownta

Differential Revision: D2208643

Summary: More people are starting to use Rx. Yay! But they're trying to use `wangle/rx`. So make sure there's no doubt about its deprecated status.

Reviewed By: @yfeldblum

Differential Revision: D2196273

Summary: flock() expects sys/file.h which on many platforms
is getting included as a side-effect, but on at least one
this isn't the case.

Add the explicit include to fix builds on those platforms.

Closes #232

Facebook

Unrelated runtime failures.

Reviewed By: @JoelMarcey

Differential Revision: D2196306

Summary: When doing android development, we need to compile with
FOLLY_HAVE_BITS_FUNCTEXCEPT_H set for some flavors, and
FOLLY_HAVE_BITS_FUNCTEXCEPT_H unset for others (primarily for tests
run in the local (xcode) development platform).  This diff adds some
more conditionals so it all works.

In this repro, these files are never used, so this is more or less a
noop, but this is the upstream so I'm making these changes here.

Reviewed By: @Gownta

Differential Revision: D2202107

Summary: before the first setReadCallback(), the readCallback_ is nullptr.  Thanks @siyengar for pointing out this!

Reviewed By: @siyengar

Differential Revision: D2203489

Summary: refactor D2201181

Reviewed By: @afrind

Differential Revision: D2202245

Summary: a subset of folly now compiles with Windows mingw64 toolchain

Reviewed By: @djwatson

Differential Revision: D2171872

Summary: `folly/Format.h` pulls in `folly/small_vector.h` and
`folly/FBVector.h`, which (according to @​oleksandr's analysis)
are the most expensive includes for multiple fbcode projects.

Reviewed By: @ot

Differential Revision: D2198904

Summary: Resplit violated the contract of `apply()`; it returned `false` even though the input sequence was fully consumed.

Reviewed By: @philippv

Differential Revision: D2195889

Summary: double-conversion was recently added to homebrew, making it the last
folly dependency to do so. this diff modifies the existing OS X
bootstrap tool to account for that. I also added an rm for the gtest
wget, so there wasn't a leftover zip file in your repo. alternatively,
we could remove that and add it to the gitignore.

Reviewed By: @fugalh

Differential Revision: D2196000

Pulled By: @sgolemon

Summary: If x->add() executes its lambda on a different thread and
doesn't pass the context on its own, the callback wouldn't
have the correct context set.

Reviewed By: @djwatson

Differential Revision: D2189318

Summary: make it std::atomic

Reviewed By: @tudor

Differential Revision: D2191861

Summary: [Folly] to_shared_ptr.

So you can write this:

    auto sptr = to_shared_ptr(getSomethingUnique<T>());

Instead of this:

    auto sptr = shared_ptr<T>(getSomethingUnique<T>());

Useful when `T` is long, such as `T = foobar::cpp2::FooBarServiceAsyncClient`.

Reviewed By: @meyering

Differential Revision: D2193572

Summary: this taks advantage of SSL_write_iovec and SSL_read_buf functions to improve CPU.  This eliminates one malloc+memcpy+free operation for all HTTPS traffic, and save up to two for small packets.

It saves 10~15% CPU
https://fburl.com/99681397
https://fburl.com/99427544

Reviewed By: @djwatson

Differential Revision: D1993764

Reviewed By: @ot

Differential Revision: D2188740

Summary: We have this now.

Reviewed By: @jsedgwick

Differential Revision: D2191642

Summary: Storing the new state could be a memory race according to C++ (but wasn't in practice). I only checked GCC though.

Reviewed By: @nbronson

Differential Revision: D2189287

Summary: Not 100% about the `ThreadWheelTimekeeper` test. It makes TSAN happy
though.

Reviewed By: @yfeldblum

Differential Revision: D2187901

Summary: 1) We forgot to `--attached_` if `x` throws an exception
2) `PriorityExecutor` didn't execute `Func`, causing leaks in the test (not a bug in Futures)
3) I moved up the initialization for an empty `Core` into the constructor to make it easier to see

Reviewed By: @jsedgwick

Differential Revision: D2187343

Summary: This was set to 32 which probably works fine for the
majority of FB servers, but not everyone's system is so endowed.

Closes #119

Reviewed By: @fredemmott

Differential Revision: D2187008