Summary: We should be able to reset error message callback in AsyncSocket evein if the socket is closed yet. It's common to keep callback installed while the socket is connected. Once the socket is closed, the deinitialization process starts. If the callback callee component gets deallocated before the socket object is deallocated, it should be able to cancel callbacks.

Reviewed By: yfeldblum

Differential Revision: D4897335

fbshipit-source-id: 8eee26f9ebcb78a01d55598be3aff6595a3ed852

Summary:
In a previous diff I added toInverseArpaName methods but I forgot to add the
inverse. This change adds `IPVAddressV(46)::fromInverseArpaName` static methods.
I have also implemented some suggestions that were in D4867502 but I couldn't
incorporate because the diff was landed already.

Reviewed By: yfeldblum

Differential Revision: D4885198

fbshipit-source-id: b95752aa695d6675cb293f8df2daa1787383390f

Summary:
FBString.h doesn't really use any of the facilities defined in <ios>, such as the stream manipulators. No sense dragging it into FBString.h.

This could potentially break downstream users if they are not already including the io facilities they are using. It's unlikely though because the actual stream types (std::ostream, std::istream) and stream objects (std::cout, std::cin) are defined in other headers that #include <ios>.

Reviewed By: yfeldblum, Orvid

Differential Revision: D4886133

fbshipit-source-id: 56adb93280eeeef8b09320b30fb224d4f72707bf

Summary:
What it says on the tin. Add the exception_tracer library to the folly OSS build, enabled with `--enable-exception-tracer`.
Closes https://github.com/facebook/folly/pull/580

Reviewed By: Orvid

Differential Revision: D4895533

Pulled By: yfeldblum

fbshipit-source-id: 4878826c71e7d6af17845b23abc07dc48ea1aa51

Summary:
This is the last piece needed to get Folly working on Windows without PThreads.
Updating Folly's test suite to support compiling without PThreads will come next.

Reviewed By: yfeldblum

Differential Revision: D4894048

fbshipit-source-id: 6076317e1364aef82a5d3cb306bea7c2226b3cdc

Summary: It's unused, and MSVC is warning about that fact.

Reviewed By: anirudhvr

Differential Revision: D4894403

fbshipit-source-id: 767b944eb9fa0376c795555357c09bbf9179e24f

Summary:
Several other warnings that aren't reasonable to disable globally occur in folly headers.

- Wrap the unreachable code warnings in MSVC specific disable blocks to prevent problems for users.
- Use more careful bit twiddling instead of negating unsigned types
- Enable a simpler overload for bool->float conversion than one which attempts float->bool.
- Delete one unneeded undef.

Reviewed By: yfeldblum

Differential Revision: D4891583

fbshipit-source-id: 4d2efda1fe720abcb083bf29b578c065127cda24

Summary: Rather than duplicating logic (and #ifdefs), just call the helper function instead.

Reviewed By: yfeldblum

Differential Revision: D4888362

fbshipit-source-id: f5096f6029cf05526aa74bd40235ac8014824789

Summary: It was previously returning a pointer masquerading as a `uint64_t`.

Reviewed By: yfeldblum

Differential Revision: D4888325

fbshipit-source-id: 6cf6ed09f0e7a39a8a2f93d3fa14b06913c27805

Summary:
Folly is gaining support for compiling without PThread support on Windows, but we need a way to know that at compile-time for certain APIs.
This also includes changes to guard the only API outside of portability/PThread.h that needs to be guarded on the existence of PThread.

Reviewed By: yfeldblum

Differential Revision: D4889526

fbshipit-source-id: 21175ad90f60a47718c7e2775e3b429b2aad62e2

Summary: Because, soon it won't be required.

Reviewed By: yfeldblum

Differential Revision: D4892076

fbshipit-source-id: 6bfbf5bf523262659c0af336f659398ae8545e50

Summary: They aren't actually needed as the primary implementation is supported on all platforms.

Reviewed By: yfeldblum

Differential Revision: D4882687

fbshipit-source-id: 7208c5d3c1f35b29b0cabb6a20fe030fbf10b131

Summary: This reverts commit 9574ea984e1e3daca01101259687f46effcf3a9f

Differential Revision: D4805628

fbshipit-source-id: 3285317a4c3f2012da1f13e9c91b6c623726c9b7

Summary:
Initialize the singleton-vault early in `init()` to avoid ordering problems with other parts of `init()`.

Initialization is done by calling `SingletonVault::singleton()->registrationComplete()`. Do that before (almost) everything, in particular, before parsing args and initializing logging.

Note that this just marks it okay for singletons to be instantiated, but does not by itself instantiate any singletons. However, this is useful if, in some way, parsing args or initializing logging should happen to use singletons.

Reviewed By: andriigrynenko

Differential Revision: D4889777

fbshipit-source-id: 6817db22d38a498cd20e361fc574a146029432ec

Summary:
Several other warnings that aren't reasonable to disable globally occur in folly headers.
- Wrap the unreachable code warnings in MSVC specific disable blocks to prevent problems for users.
- Cast to signed types to perform integral negation before casting back to unsigned for bit operations.
- Enable a simpler overload for bool->float conversion than one which attempts float->bool.
- Delete one unneeded undef.

(Note: this ignores all push blocking failures!)

Reviewed By: yfeldblum

Differential Revision: D4805628

fbshipit-source-id: 9574ea984e1e3daca01101259687f46effcf3a9f

Summary:
For getting a thread id for hashing, std::this_thread::get_id()
is just as good and also removes an unneeded pthreads dependency. This enables
using MPMCQueue on Windows without pthreads as well.

Reviewed By: Orvid, yfeldblum

Differential Revision: D4879940

fbshipit-source-id: c4fb5eea165eb450240f94904aa26a10aa394d1b

Summary: As titled. There are some places where scoping prevents trivial conversion, so I've left those places with explicit lock/unlock calls.

Reviewed By: andriigrynenko, yfeldblum

Differential Revision: D4888812

fbshipit-source-id: c124306e0373ee9eb395cb98f88df63c91523d48

Summary: Ignoring the questionability of the approach it's being used in, it's better to not have the direct PThread dependency.

Reviewed By: yfeldblum

Differential Revision: D4889245

fbshipit-source-id: da099c6f938dbe98c1b9eeaf4de0a27a2c4d65f1

Summary:
In Unicode enabled projects, this errors because CreateFile aliases
CreateFileW, which takes wchar_t* not char*.

Reviewed By: Orvid, yfeldblum

Differential Revision: D4878424

fbshipit-source-id: b44b369c0533e74163f68d95c2bf353584033731

Summary: Just use the native Windows API call instead, as it gives the same result.

Reviewed By: yfeldblum

Differential Revision: D4887587

fbshipit-source-id: adbfd288bea425f1aff46d0685083807490f7f09

Summary: `TimedMutex` was already using `folly::SpinLock`, so switch `TimedRWMutex` to do the same.

Reviewed By: andriigrynenko

Differential Revision: D4888005

fbshipit-source-id: 6e782347bc22dc186ed41f2e77c6614b8444bae2

Summary:
As part of the work towards getting Folly compiling without PThread, it needs to be treated as a non-portable include.
This switches the includes not already covered by other diffs.

Reviewed By: yfeldblum

Differential Revision: D4882777

fbshipit-source-id: d9521564c814f9bcff2fcb358cbb89b3777c327d

Summary:
MSVC didn't like referring to members of `exception_wrapper` in the initializer for a `static constexpr` field directly in `exception_wrapper`, so shift the initialization to the actual definition of the fields.
As the fields are only referred to via their address, dropping the `constexpr` loses nothing.

Reviewed By: ericniebler

Differential Revision: D4873939

fbshipit-source-id: 30b690b1ab3f2f7a25b9dc4863b46f64c811797d

Summary:
Add a method where users can determine if a SSL lock is disabled.

This can help when it comes to making decisions about things like whether reusing SSL Contexts is safe in multithreaded programs.

Reviewed By: siyengar

Differential Revision: D4875780

fbshipit-source-id: 91e9259fee25856be1b77823559d16d0679bde5b

Summary: They aren't actually needed, and are in the way of being able to build Folly without PThread.

Reviewed By: yfeldblum

Differential Revision: D4882410

fbshipit-source-id: e4a48600f79c57bb965a35fab94962a29b8e06d4

Summary: This is for use on Windows only, and does not support Linux or OSX in the slightest. There are probably still a few hacks laying around in it, but it works, and that's good enough for now.

Reviewed By: yfeldblum

Differential Revision: D4873498

fbshipit-source-id: 5952a927037dc1d56c51e71d51ba506d2cd17357

Summary:
Adds bzip2 support to `folly/io/Compression.h`.
Adds bzip2 to the default set of supported codecs for the `AutomaticCodec`.

Reviewed By: yfeldblum

Differential Revision: D4873771

fbshipit-source-id: d4f4861aef7e4b9efb67095e8892c265b5ae5557

Summary:
Well, MSVC 2017 anyways.
MSVC 2017 wasn't able to handle the decltype in the type specialization, which was also entirely unnecesary.

Reviewed By: yfeldblum

Differential Revision: D4880272

fbshipit-source-id: b6deed72a12d4b58d6eca200e7287e536f94ca30

Summary:
This is a bit too magical -- it's not clear that the thing produces an Options object. If you do know that you can chain further option setters off this thing, it's nice, but otherwise, the first impression is "what just happened?".

So, let's have one good way for doing things.

Reviewed By: yfeldblum

Differential Revision: D4863947

fbshipit-source-id: 3dfe83cfc077d47f604f47dcb21149fbaa2d2243

Summary:
This operator is WRONG. It has not worked correctly for years, e.g. it lacks support for chdir, and several other options.

The operator is not really useful after C++11. Usually, you should just chain setters, e.g. `Subprocess::Options().pipeStdout().pipeStderr()`. If you must repeatedly mutate options in a fixed way, in the C++11 world you can use a lambda instead.

Reviewed By: yfeldblum

Differential Revision: D4862698

fbshipit-source-id: a2d8ace53424b9232e178cf202cf51beb7b59b12

Summary:
Since IOBuf rounds to a good malloc size, zlib and lzma waste space.
For a 4 MiB `length`, about 1 MiB of the IOBuf is wasted.

Reviewed By: yfeldblum

Differential Revision: D4872830

fbshipit-source-id: 42fc83277b2dae22b75403e0e71c43e8f2b19f21

Reviewed By: anirudhvr

Differential Revision: D4830205

fbshipit-source-id: 55f34c3bddead8a73174c403f76572248c541a10

Summary:
Template pack expansion plays much nicer when being expanded into the template parameters of a base class than it does as the template parameters to a templated `using` when under MSVC.
This fixes the other half of `folly::exception_wrapper`.

Reviewed By: yfeldblum

Differential Revision: D4874047

fbshipit-source-id: 6593d10f8737b940bd550353e54f43bc96402a48

Summary: opensource changes for t16702532

Reviewed By: yfeldblum

Differential Revision: D4846899

fbshipit-source-id: 67a610ff399e95c7cf1c9c8a5950f79bfc3aabb9

Summary: This is a follow up commit for the thread https://github.com/facebook/folly/pull/378

Reviewed By: nbronson

Differential Revision: D4860356

fbshipit-source-id: f10a0d12a593c18b1abf94da5b477c524c04f4be

Summary:
This diffs adds supports on folly::Subprocess to be able to take clone flags and
use them to call clone(2) instead of the default vfork()

I checked that all tests pass when I replace vfork with fork on trunk. So there
isn't anything built assuming the parent is paused for an execve. Correct me if
I am wrong here.

(Note: this ignores all push blocking failures!)

Reviewed By: snarkmaster

Differential Revision: D4853169

fbshipit-source-id: 7e5851df3a49996a4a5dc1945457686dd042e1f4

Summary: As per the title, this adds methods to convert IPv(46) to their inverse representation, this is useful for applications that needs to calculate the inverse arpa representation, typically used when making PTR DNS requests.

Reviewed By: Orvid

Differential Revision: D4867502

fbshipit-source-id: 190e5c309b17a633e1c97b077f212ab38725860f

Summary:
The purpose of this reimplementation of `exception_wrapper` is threefold:

- Make `exception_wrapper` smaller. It goes from 48 bytes to 24.
- Give it `noexcept` ~~copy and~~ move
- Store small exception objects in an internal buffer; i.e., with zero allocations.

The ultimate goal is to change `folly::Try<T>` to a thin wrapper over `folly::Expected<T, exception_wrapper>`. (Currently, it stores the `exception_wrapper` on the heap.)

As part of this redesign, I:

- Remove `exception_wrapper::getCopied`. The user shouldn't care how the `exception_wrapper` stores the exception.
- Remove `exception_wrapper::operator==`. It was only used in 2 places in test code. The existing semantics (return true IFF two `exception_wrapper`s point to the //same// exception object) prevented the small-object optimization.
- Add new `handle()` API that behaves like cascading `catch` clauses. For instance:
```lang=c++
exception_wrapper ew = ...;
ew.handle(
    [&](const SomeException& e) { /*...*/ },
    [&](const AnotherException& e) { /*...*/ },
    [&](...) { /* catch all*/ }, // yes, lambda with ellipses works!
```
- Add a `type()` member for accessing the `typeid` of the wrapped exception, if it's known or can be determined with a `catch(std::exception&)`.

This table shows the percent improvement for the exception_wrapper_benchmark test:

| Test  | Percent improvement (gcc-5)  | Percent improvement (gcc-4)
| -----  | -----  | -----
| exception_wrapper_create_and_test  | 14.33%    | -6.50%
| exception_wrapper_create_and_test_concurrent | 11.91% | 20.15%
| exception_wrapper_create_and_throw | -0.82% | -0.25%
| exception_wrapper_create_and_cast | 15.02% | 14.31%
| exception_wrapper_create_and_throw_concurrent | 18.37% | 8.03%
| exception_wrapper_create_and_cast_concurrent | 28.18% | -10.77%

The percent win for gcc-5 is 15% on average. The non-throwing tests show a greater win since the cost of actually throwing an exception drowns out the other improvements. (One of the reasons to use `exception_wrapper` is to not need to throw in the first place.) On gcc-4, there is roughly no change since the gcc-4 standard exceptions (`std::runtime_error`, std::logic_error`) are non-conforming since they have throwing copy operations.

Reviewed By: yfeldblum

Differential Revision: D4385822

fbshipit-source-id: 63a8316c2923b29a79f8fa446126a8c37aa32989

Summary: On Windows, the OpenSSL headers have to be included in a specific order relative to WinSock. Fixing the issues ad-hock is not a viable way to continue, so treat it as completely non-portable and require all includes of it in Folly to go through the portability header.

Reviewed By: yfeldblum

Differential Revision: D4856858

fbshipit-source-id: 56aca1fb0fe095f41a8af12488c6c2080344603d

Summary:
It doesn't exist on OSX or Windows, so implement it.

Closes https://github.com/facebook/folly/issues/567

Reviewed By: yfeldblum

Differential Revision: D4783463

fbshipit-source-id: 0a2586aced7123b797a8e55a3e86124b449634e4