Summary:
For dealing with sequences of pointers. Works with pointer wrappers,
and filters out nullptrs, see tests.

Test Plan: Unit tests

Reviewed By: tulloch@fb.com

FB internal diff: D914069

Summary:
`apply()` returns false if and only if the handler it was //directly//
passed returned false. `Take` didn't do this right, and `Until` was just broken.

Test Plan: More thorough unit tests.

Reviewed By: kittipat@fb.com

FB internal diff: D913185

Summary: In clang (as of 3.2) intrinsics aren't `constexpr`.

Test Plan:
fbconfig folly/test:bits_test && fbmake opt -j32
fbconfig --clang folly/test:bits_test && fbmake opt -j32

Reviewed By: lucian@fb.com

FB internal diff: D910310

Summary: Convert stream of elements to stream of fixed-sized vectors.

Test Plan: unit tests

Reviewed By: tjackson@fb.com

FB internal diff: D912290

Summary: Dave Watson put this in github a few months ago.

Test Plan: None

Reviewed By: delong.j@fb.com

FB internal diff: D912681

Summary:
Threads and fork still don't mix, but we shouldn't help you shoot yourself in
the foot if you decide to do it.

Test Plan: test added

Reviewed By: mshneer@fb.com

FB internal diff: D911224

Summary: For repeating a generator's values endlessly.

Test Plan: Unit tests

Reviewed By: kittipat@fb.com

FB internal diff: D911178

Summary:
Complains about

```
In file included from crypto/lib/cpp/CryptoException.cpp:1:
In file included from crypto/lib/cpp/CryptoException.h:5:
In file included from ./folly/Conv.h:30:
./folly/Range.h:573:19: error: redefinition of default argument
Comp eq = Comp()) {
^    ~~~~~~
./folly/Range.h:55:26: note: previous definition is here
Comp eq = Comp());
^    ~~~~~~
```

Redefinition of default arguments is not allowed in C++.

Test Plan:
```
fbconfig --clang admarket/adpublisher && fbmake dbg
```

contbuild, etc.

Reviewed By: lucian@fb.com

FB internal diff: D910800

Summary:
qfind(haystack, needle) is templated, but used a non-templated
default comparator that cast everything to char.  This works find for
8-bit types, but not for others such as the uint32_t Ranges we are
using.  Replace the default comparator with std::equal<> to use a
working comparator for whatever type is being searched.

Test Plan:
Compiles, unit tests (including a new one that fails with the
old code) pass.  Not sure how to test other users of this, or measure
performance impact. :(

Reviewed By: andrei.alexandrescu@fb.com

FB internal diff: D906311

Summary: - memrchr is GNU + Linux specific, it turns out

Test Plan: - compiled on FreeBSD, contbuild

Reviewed By: delong.j@fb.com

FB internal diff: D900935

Summary:
- fix folly compilation on FreeBSD

Github Author: Martin Matuska <martin@matuska.org>

Test Plan: - compiled

Reviewed By: tudorb@fb.com

FB internal diff: D896747

Summary:
A bunch of MPMCQueues linked together. Stage i produces exactly Ki (default 1)
outputs for each input. Ordering is preserved, even though stages might
produce (intermediate or final) results in parallel and in any order; we do
this by abusing the enqueueing mechanism in MPMCQueue. (Read the code for
details)

Test Plan: test added, more tests to be written before commit

Reviewed By: ngbronson@fb.com

FB internal diff: D892388

Summary:
Like size(), sizeGuess() is allowed to return a negative value,
so it should be ssize_t instead of uint64_t.

Test Plan: fbmake, wait for contbuild

Reviewed By: tudorb@fb.com

FB internal diff: D893075

Summary:
"Wouldn't this test case still pass if the hash function didn't depend on the value?

It would be nice to verify that different tuple values produce different hash values (or maybe there's another test that verifies that), especially since this is a tricky thing to get right."

I think there's not much chance of this failing since it's just leveraging hash_combine and that's already tested. But it's easy to add another sanity check, so here we are.

Test Plan: runtests

Reviewed By: tulloch@fb.com

FB internal diff: D890448

Blame Revision: D888796

Summary:
Add hash support for std::tuple.
See also D490478 (where a first attempt was made) and D543586 (where that attempt was deemed broken and removed).

Test Plan: unit test

Reviewed By: chip@fb.com

FB internal diff: D888796

Summary:
fix OSX compat issues

Github Author: Daniel Sloof <goapsychadelic@gmail.com>

Test Plan: - compiled

Reviewed By: pt@fb.com

FB internal diff: D877309

Summary:
Apparently the templates don't like to match the initlializer
list, so this needed to be added.  This allows for things like:

auto s = join(":", {val1, val2, val3, val4, val4});

Test Plan: run tests

Reviewed By: andrei.alexandrescu@fb.com

FB internal diff: D878032

Summary:
For handling exceptions from downstream operations.

Now with cleaner build.

Test Plan: Unit tests, including those outside `folly`.

Reviewed By: marcelo.juchem@fb.com

FB internal diff: D877795

Blame Revision: https://phabricator.fb.com/D872581

Summary:
Looks like D880140 left off this part when it was committed.

This fixes the build.

Test Plan: runtests

Reviewed By: vini@fb.com

FB internal diff: D881445

Summary:
This should fix the build breakage in hphp caused by the latest fbstring changes (after being ported to engshare). Note that I'm flying blind here; I couldn't test with the hphp build because I don't have write access to engshare. @agallagher could you please make sure that this works after the fix?

fbconfig -r hphp && fbmake dbg

Test Plan: tested on folly

Reviewed By: tudorb@fb.com

FB internal diff: D880140

Summary: Adds the eponymous C++11 capability to fbstring.

Test Plan: fbstring runtests

Reviewed By: tudorb@fb.com

FB internal diff: D867995

Summary:
Introduced a new serialization option, `allow_trailing_comma`, which allows trailing commas to be included in strings when they are parsed. This isn't strictly allowed by RFC 4627, but we're allowing more than that anyway.

I've run into this dozens of times, especially while using SMC.

Test Plan: Unit tests

Reviewed By: delong.j@fb.com

FB internal diff: D872581

Summary:
Clean revert.  Please be more careful; phabricator warned you
these would break the build.

Test Plan: build something that wasn't working

Reviewed By: myang@fb.com

FB internal diff: D877526

Summary: For handling exceptions from downstream operations.

Test Plan: Unit tests

Reviewed By: marcelo.juchem@fb.com

FB internal diff: D874344

Summary:
* added move assignment operators,
* fixed `operator=(const Synchronized& rhs)` (it had a typo),
* fixed deadlock on self-assignment,
* changed `swap` to call `swap(lhs.datum_, rhs.datum_)` instead of `lhs.datum_.swap(rhs.datum_)`.

Test Plan: fbconfig -r folly/test && fbmake opt -j32 && fbmake runtests_opt

Reviewed By: delong.j@fb.com

FB internal diff: D875977

Summary:
- conditionally compile rfind overrides
- conditionally add support for timed_mutex/recursive_timed_mutex

Test Plan:
- compiled on OSX
- unit tests

Reviewed By: andrei.alexandrescu@fb.com

FB internal diff: D872272

Summary:
- Noticed this due to an -fpermissive compiler warning while compiling
HHVM for OSX (complaint of trying to cast int to char*)

Test Plan:
- Compiled
- Confirmed the build warning is fixed by this on the Mac OS X build

Reviewed By: tudorb@fb.com

FB internal diff: D865169

Summary: It only makes sense to be able to go the other direction, too.

Test Plan: Unit tests

Reviewed By: delong.j@fb.com

FB internal diff: D785282

Test Plan: Unit tests

Reviewed By: andrei.alexandrescu@fb.com

FB internal diff: D865951

Summary:
MPMCQueue<T> is a high-performance bounded concurrent queue that
supports multiple producers, multiple consumers, and optional blocking.
The queue has a fixed capacity, for which all memory will be allocated
up front.  The bulk of the work of enqueuing and dequeuing can be
performed in parallel.

To make an MPMCQueue<T>, T must satisfy either of two conditions:
- it has been tagged FOLLY_ASSUME_FBVECTOR_COMPATIBLE; or
- both the constructor used during enqueue and the move operator are
marked noexcept.

This diff extracts the generic component from tao/queues/ConcurrentQueue
and renames identifiers to match those of existing folly queues.
It also includes an extraction of Futex, which wraps the futex syscall,
and DeterministicScheduler, which allows for deterministic exploration
of thread interleavings for components built from std::atomic and Futex.

Test Plan: new unit tests

Reviewed By: tudorb@fb.com

FB internal diff: D866566

Test Plan: Use it

Reviewed By: tudorb@fb.com

FB internal diff: D865211

Summary:
We have an off-by-one in our enable_if/sfinae logic here. We do not want to actually do the comparison in `less_than` when the rhs is exactly the minimum possible lhs. This results in a tautological comparison.

I added a unit test for these traits that test all the various sfinae cases.

Test Plan: See the clang tautological warnings go away. Under gcc, rerun all tests. All pass.

Reviewed By: marcelo.juchem@fb.com

FB internal diff: D856869

Summary:
Don't use two atomic variables when only one will suffice (otherwise, the
increments in doNotify() and prepareWait() would require memory_model_seq_cst,
because they need to globally order a store before a load, and no weaker
model allows you to do that)

Of course, this makes this 64-bit only, but I don't care.

Test Plan: eventcount_test, tests outside of folly

Reviewed By: delong.j@fb.com

FB internal diff: D858963

Summary:
8-bit StringPiece comparisons are broken.
The reason is char_traits is magic for 'char', but not 'const char'.

Test Plan: test added

Reviewed By: chip@fb.com

FB internal diff: D861521

Test Plan: used it

Reviewed By: soren@fb.com

FB internal diff: D859244

Test Plan: exception_tracer_test

Reviewed By: bmaurer@fb.com

FB internal diff: D858195

Summary:
Add MultiLevelTimeSeries class which represents a timeseries which keeps several
levels of data granularity (similar in principle to the loads reported by the
UNIX 'uptime' command).  It uses several instances (one per level) of
BucketedTimeSeries as the underlying storage.

This can easily be used to track sums (and thus rates or averages) over several
predetermined time periods, as well as all-time sums.  For example, you would
use to it to track query rate or response speed over the last 5, 15, 30, and 60
minutes.

Test Plan: unittest included.

Reviewed By: simpkins@fb.com

FB internal diff: D851444

Summary: This template is only used in folly::Conv (to avoid tautological comparisons) and as best as I can tell, the rhs/lhs names are not correct as it's currently used (and not consistent with `less_than`). Just swap rhs/lhs variable names.

Test Plan:
Test Results Summary:
Passed: 471
100% successful

Reviewed By: marcelo.juchem@fb.com

FB internal diff: D856785

Summary:
Without this change, any folly-using project that attempts to enable
gcc's -Wshadow option will be overwhelmed by warnings about violations
in folly's class definitions.  Violations are often due to local
variable or parameter names shadowed by a member function.

Bracket offending content with directives like this:

#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wshadow"
...
#pragma GCC diagnostic pop

This set of modified files is the minimal set to allow tao
to use -Wshadow with no folly-related warning.

Test Plan:
fbmake folly/test && fbmake opt

Reviewed By: simpkins@fb.com

FB internal diff: D848455

Summary:
This eliminates the CommunicateFlags argument to communicate().  It now
always reads from both stdout and stderr if they were set up a pipes.
If a non-empty input buffer was supplied, it always writes that to
stdin.

This mimics the communicate() behavior of python's subprocess.py module.
This also makes it impossible to have buffering deadlocks by forgetting
to call communicate() with readStderr().

Test Plan:
Ran the existing subprocess tests, and also added a more complicated
duplex test that requires communication on stdin, stdout, and stderr all
at the same time.

Also grepped for all existing users of Subprocess::communicate(), and
made sure they will work correctly with the new behavior.

Reviewed By: tudorb@fb.com

FB internal diff: D814405