Summary:
In D3241498 addTaskFuture was fixed to work with function returning void. This however changed addTaskFinally API to not allow finally functor which accepts Try<void>.

folly::fibers generally supports Try<void> so there's no reason to force users to use folly::Unit instead of void for addTaskFinally too.

Reviewed By: yfeldblum

Differential Revision: D3243893

fb-gh-sync-id: d1df54738157d2019120103956f59b3971ba25ff
fbshipit-source-id: d1df54738157d2019120103956f59b3971ba25ff

Summary:
There's no Future<void>, you're supposed to use Future<Unit>
instead.  Unit has a "Lift" template to do the conversion.

Reviewed By: andriigrynenko

Differential Revision: D3241498

fb-gh-sync-id: db12d4f343685bc613b701e023c860c2c903ed4c
fbshipit-source-id: db12d4f343685bc613b701e023c860c2c903ed4c

Summary: Clang-format in preparation for other change

Reviewed By: andriigrynenko

Differential Revision: D3241297

fb-gh-sync-id: b7b26812e9e61c291d5c7bdb523df8f28f2d9b4f
fbshipit-source-id: b7b26812e9e61c291d5c7bdb523df8f28f2d9b4f

Summary:
As it might be used during global destruction (for example, to
symbolize unhandled exception happened at that time).

Reviewed By: luciang, ot

Differential Revision: D3238303

fb-gh-sync-id: 39d8a6f99d95e700586349436e961f3624c95718
fbshipit-source-id: 39d8a6f99d95e700586349436e961f3624c95718

use std::forward instead of std::move on objects whose types have been deduced; don't take the sizeof incomplete types

Summary: Pretty sure std::forward is needed here instead of std::move. If you trace the call chain to see where the types of the objects come from, you'll see they can be deduced to be lvalues, so std::forward is the right choice. Also, moved some dicey looking code that appeared to be taking the size of some incomkplete types.

Reviewed By: spacedentist

Differential Revision: D3214199

fb-gh-sync-id: 778190ffb25a648b839760a3dddfad8dc6d41c88
fbshipit-source-id: 778190ffb25a648b839760a3dddfad8dc6d41c88

Summary:
Currently you need to depend on the destructor of `ReadHolder` (using closures as in code block #1 below or empty assignment as in code block #2 below) to ensure that a `ReadHolder` goes out of scope (and unlocks) in order to subsequently acquire a write lock via `WriteHolder` without deadlocking.
This diff introduces a way of unlocking a `ReadHolder` while it's still in scope such that a `WriteHolder` can be acquired. This makes the code more straight forward (reducing the risk of deadlock due to a programmer's misunderstanding of how `SharedMutex` / the holder framework works) => see code block # 3 below
Also add some documentation about why `WriteHolder::WriteHolder(ReadHolder&&)` doesn't exist

Code Block #1 : Use of closures
```
class foo {
 public:
  std::string getMemoizedData() {
    {
      folly::SharedMutex::ReadHolder readHolder(lock_);
      if (!data_.empty()) {
        // important to return by value, otherwise caller might access
        // data_ after we release the read lock
        return data_;
      }
    }
    {
      // try again with a write lock
      folly::SharedMutex::WriteHolder writeHolder(lock_);
      if (data_.empty()) {
        data_ = "my awesome string";
      }
      return data_;
    }
  }

 private:
  folly::SharedMutex lock_;
  std::string data_;
};
```

Code Block #2 : Use of empty assignment
```
class foo {
 public:
  std::string getMemoizedData() {
    folly::SharedMutex::ReadHolder readHolder(lock_);
    if (!data_.empty()) {
      // important to return by value, otherwise caller might access
      // data_ after we release the read lock
      return data_;
    }
    readHolder = {};

    // try again with a write lock
    folly::SharedMutex::WriteHolder writeHolder(lock_);
    if (data_.empty()) {
      data_ = "my awesome string";
    }
    return data_;
  }

 private:
  folly::SharedMutex lock_;
  std::string data_;
};
```

Code Block #3 : Use of unlock()
```
class foo {
 public:
  std::string getMemoizedData() {
    folly::SharedMutex::ReadHolder readHolder(lock_);
    if (!data_.empty()) {
      // important to return by value, otherwise caller might access
      // data_ after we release the read lock
      return data_;
    }
    readHolder->unlock();

    // try again with a write lock
    folly::SharedMutex::WriteHolder writeHolder(lock_);
    if (data_.empty()) {
      data_ = "my awesome string";
    }
    return data_;
  }

 private:
  folly::SharedMutex lock_;
  std::string data_;
};
```

Reviewed By: yfeldblum

Differential Revision: D3176025

fb-gh-sync-id: c7d47ca71df08673c7c1f1fd5ed9e01a663c1797
fbshipit-source-id: c7d47ca71df08673c7c1f1fd5ed9e01a663c1797

Summary: A few code cleanups, no functionality changes.

Reviewed By: ericniebler

Differential Revision: D3231369

fb-gh-sync-id: 1a1c8508aab6dce7279e9dfc3f3da6add5496c67
fbshipit-source-id: 1a1c8508aab6dce7279e9dfc3f3da6add5496c67

Summary:
Better enum exception types for SSLException.
These enum types are fairly high level, and more
info can be gleaned from the error.what()

Reviewed By: knekritz

Differential Revision: D3234501

fb-gh-sync-id: 7cd4fbccd7f4367354dc3bd1fe4cd480d58d6173
fbshipit-source-id: 7cd4fbccd7f4367354dc3bd1fe4cd480d58d6173

Summary:
We abuse errno to propagate exceptions from AsyncSSLSocket.
Stop doing this and propagate exceptions correctly.

This also formats the exception messages better.

Reviewed By: anirudhvr

Differential Revision: D3226808

fb-gh-sync-id: 15a5e67b0332136857e5fb85b1765757e548e040
fbshipit-source-id: 15a5e67b0332136857e5fb85b1765757e548e040

Summary: Add X509 param types

Reviewed By: knekritz

Differential Revision: D3230008

fb-gh-sync-id: 660a2f5bdc9355f5b42c2ccfb1d7cab83df34fc2
fbshipit-source-id: 660a2f5bdc9355f5b42c2ccfb1d7cab83df34fc2

Summary:
The array-bounds checker in gcc complains that r could be -1 after leaving CHECK_ERR in ASAN mode. Switch to DCHECK to avoid this possibility. The code was not initially compiling; now it does.

Error from gcc:
  array subscript is below array bounds [-Werror=array-bounds]

Reviewed By: yfeldblum

Differential Revision: D3232694

fb-gh-sync-id: 17f579eb152b661a8e5e4ed29ef91eec405fb90a
fbshipit-source-id: 17f579eb152b661a8e5e4ed29ef91eec405fb90a

Summary: `small_vector.h` had it's own thing being defined inline, and it was breaking the OSX build of HHVM, so have it use the portability header instead.

Reviewed By: yfeldblum

Differential Revision: D3232885

fb-gh-sync-id: 2078a54d1ec9700e81e0a9f4baed8e2d623fa5f3
fbshipit-source-id: 2078a54d1ec9700e81e0a9f4baed8e2d623fa5f3

Summary:
This fixes 2 races in TLRefCount:
1. Thread-local constructor race, exposed by the stress test. It was possible for LocalRefCount to be created (grabbing collectGuard), but not be added to the thread-local list, so that accessAllThreads wasn't collecting it. collectAll() was then blocking waiting on baton to be posted, causing a dead-lock.
2. LocalRefCount::count_ has to be made atomic, because otherwise += operation may be not flushed (nbronson explained the race in D3133443).

Reviewed By: djwatson

Differential Revision: D3166956

fb-gh-sync-id: 17d58a215ebfc572f8316ed46bafaa5e6a9e2368
fbshipit-source-id: 17d58a215ebfc572f8316ed46bafaa5e6a9e2368

Summary:
Use tag dispatching instead of `enable_if`: it is clearer, it
sidesteps the GCC mangling bug, and more importantly the conditional
doesn't leak into the symbol, making stack traces and profiles more
readable.

Testing on a compilation unit with 1000 `Function`s from simple lambdas.
Before:
```
folly::impl::Function<int (), false>::Function<main::{lambda()#1}, {lambda()#1}>(main::{lambda()#1}&&, std::enable_if<std::integral_constant<bool, ((sizeof (std::decay<main::{lambda()#1}>::type))<=(sizeof folly::detail::function::Data::small))&&std::is_nothrow_move_constructible<std::decay<main::{lambda()#1}> >::value>::value, folly::detail::Tag>::type)::Ops::call(folly::detail::function&)
```
After:
```
folly::impl::Function<int (), false>::OpsSmall<main::{lambda()#1}>::call(folly::detail::function::Data&)
```
Note that the function type is repeated 5 times before, and only once after. This makes a large difference with long namespaces.

Binary size is almost unaffected, compile times slightly better:
Before:
GCC opt: 22.3 seconds, 4435232 bytes
Clang dev: 7.7 seconds, 5257344 bytes

After:
GCC opt: 18.6 seconds, 4493920 bytes
Clang dev: 7.2 seconds, 5469136 bytes

Reviewed By: ericniebler

Differential Revision: D3231530

fb-gh-sync-id: 6aa76e7f780a8afdbfed8a378f257ceb86dce704
fbshipit-source-id: 6aa76e7f780a8afdbfed8a378f257ceb86dce704

Summary: there is no need to call `std::function::invoke` for every DestructorGuard.

Reviewed By: yfeldblum

Differential Revision: D3229345

fb-gh-sync-id: c42f8cd05576d56b6a9b2f9d06878d9b01a36e94
fbshipit-source-id: c42f8cd05576d56b6a9b2f9d06878d9b01a36e94

Summary:
Just like the real thing does.
This was causing some issues when trying to link against glog, which expects the flags to be namespaced like this.

Reviewed By: mzlee

Differential Revision: D3230630

fb-gh-sync-id: a73ab3044560d561a39eb91ceee1588c147a46c5
fbshipit-source-id: a73ab3044560d561a39eb91ceee1588c147a46c5

Summary:
folly::Function is causing significant compile time regressions. Reimplement it in a simpler way.

These are the times for a file containing 1000 instantiations of folly::Fuction (old), folly::Function (new), and std::function with **g++ 4.8 -O3** on my CentOS7 server.

|        | Old `folly::Function` | `std::function` | New `folly::Function` |
|--------|-----------------------|-----------------|-----------------------|
| Time   | 10m37s                | 0m16.81s        | 0m14.75s              |

And for the executable size:

|        | Old `folly::Function` | `std::function` | New `folly::Function` |
|--------|-----------------------|-----------------|-----------------------|
| Size   | 10,409,504            | 732,150         | 562,781               |

That's a **43X** improvement in compile times and an **18X** reduction in executable bloat over the old implementation.

The times for **clang (trunk)** are very different:

|       | Old `folly::Function` | `std::function` | New `folly::Function` |
|-------|-----------------------|-----------------|-----------------------|
| Time  | 4m6s                  | 0m45.27s        | 0m11.78s              |

That's a **20X** improvement over the old implementation and almost a **4X** improvement over `std::function`.

For **gcc-5.3.0**, compile times are again different:

|       | Old `folly::Function` | `std::function` | New `folly::Function` |
|-------|-----------------------|-----------------|-----------------------|
| Time  | 2m49s                 | 0m18.99s        | 0m20.70s              |

With gcc-5.3, the new implementation "only" compiles 8x faster than the old one, and is roughly the same as `std::function`.

Reviewed By: spacedentist, ot, luciang

Differential Revision: D3199985

fb-gh-sync-id: b97982a9dc3a63140510babea34988932e89f2d9
fbshipit-source-id: b97982a9dc3a63140510babea34988932e89f2d9

Summary: Without this, malicious inputs can crash anything using folly::parseJson.

Reviewed By: yfeldblum

Differential Revision: D3219036

fb-gh-sync-id: 3604a060170c0201473c420035b21b018383789c
fbshipit-source-id: 3604a060170c0201473c420035b21b018383789c

Summary: Remove dead code in AsyncSSLSocket.

Reviewed By: knekritz

Differential Revision: D3226948

fb-gh-sync-id: e85823f311de2539c6aa2d6bcc3ff3aee07045bf
fbshipit-source-id: e85823f311de2539c6aa2d6bcc3ff3aee07045bf

Summary: This bug causes failure when the test is run under ASAN.

Reviewed By: meyering

Differential Revision: D3229494

fb-gh-sync-id: a43c8332cc45f7892ac86cd0abb799616bca7779
fbshipit-source-id: a43c8332cc45f7892ac86cd0abb799616bca7779

Summary: no need in virtual call from EventHandler.

Reviewed By: yfeldblum

Differential Revision: D3226960

fb-gh-sync-id: eb9c191630e1a1ac022666201100e3778eb7b611
fbshipit-source-id: eb9c191630e1a1ac022666201100e3778eb7b611

Summary:
'get' is the most frequent memcached operation. On a get reply, we should go to heap
as little as possible.  This diff optimizes for this scenario, where replies
have only one IOBuf field.

Reviewed By: pavlo-fb

Differential Revision: D3226592

fb-gh-sync-id: 92e1a1fac5735bd268691cf11990a96ae6fa8309
fbshipit-source-id: 92e1a1fac5735bd268691cf11990a96ae6fa8309

Summary:
Currently UTF8Range has a constructor that allows you construct an object of type UTF8Range using only an object of type folly::Range. Adding a constructor so that we can construct an UTF8Range object using a std::string.

Currently,
  void sampleMethod(UTF8StringPiece sp) {...}
  /*
  ...
  */
  std::string str = "example";
  folly::UTF8Range utf8Range(str);
  folly::StringPiece sp(str);
  sampleMethod(utf8Range); // works
  sampleMethod(sp); // works
  sampleMethod(str); // doesn't work

This diff hopes to fix this issue.

Reviewed By: ddrcoder

Differential Revision: D3221144

fb-gh-sync-id: dd6ec4d7790d4602dccb3b63a4861d358aed3608
fbshipit-source-id: dd6ec4d7790d4602dccb3b63a4861d358aed3608

Summary: same as D3156698, without changes in Cpp2Connection (which was the only real change in the diff)

Reviewed By: haijunz

Differential Revision: D3222792

fb-gh-sync-id: 245c7add837c0fc6d0bc84aa7d80b929ba2ce386
fbshipit-source-id: 245c7add837c0fc6d0bc84aa7d80b929ba2ce386

Summary: If we don't, then anywhere we include `glog/logging.h` after the portability header will get the `DECLARE_*` and `DEFINE_*` macros undefined -_-....

Reviewed By: mzlee

Differential Revision: D3220797

fb-gh-sync-id: 52907ddcd6b222fb1c6423034ea999eac5ce09ab
fbshipit-source-id: 52907ddcd6b222fb1c6423034ea999eac5ce09ab

Summary: This dependency is in the wrong order.

Reviewed By: knekritz

Differential Revision: D3224312

fb-gh-sync-id: 98d2c58b75cf5f16892d462ae1b877d06bce3faa
fbshipit-source-id: 98d2c58b75cf5f16892d462ae1b877d06bce3faa

Summary: Why not kill fbstring entirely? There are some legitimate use cases. For example, `folly::IOBuf` supports `moveToFbstring()` method which is impossible to implement with `std::string`.

Reviewed By: joeg, snarkmaster

Differential Revision: D3189410

fb-gh-sync-id: 9bb9090ca6012ac32ba9fb79041b26ec4888781f
fbshipit-source-id: 9bb9090ca6012ac32ba9fb79041b26ec4888781f

Summary:
Retire `BOOST_STATIC_ASSERT` in favor of `static_assert`.

`static_assert` is part of C++ now, so we don't need workarounds like `BOOST_STATIC_ASSERT` anymore.

Partially automated:

    hg grep -lw BOOST_STATIC_ASSERT | xargs perl -pi -e 's~\bBOOST_STATIC_ASSERT\(([^;]*)\);~static_assert(\1, "");~g'
    hg grep -lw 'boost/static_assert.hpp' | xargs perl -pi -e 's,^#include <boost/static_assert\.hpp>\n,,gm'

Caught most instances. Formatting and remaining instances addressed manually.

Reviewed By: meyering

Differential Revision: D3215944

fb-gh-sync-id: f4552d5d9bfc416ce283923abe880437a4d0cba5
fbshipit-source-id: f4552d5d9bfc416ce283923abe880437a4d0cba5

Summary: This assignment is unnecessary, because in `for` loop we **always** call `cloneOneInto` that would assign another IOBuf to that IOBuf.

Reviewed By: alikhtarov

Differential Revision: D3215861

fb-gh-sync-id: ad87b99848aaae79f0870d49e0474f1abf0f28e5
fbshipit-source-id: ad87b99848aaae79f0870d49e0474f1abf0f28e5

Summary:
Had this in another diff, but it caused too much test noise. So I've separated
it out on it's own.

Reviewed By: yfeldblum

Differential Revision: D3213605

fb-gh-sync-id: 9ebfcf8430da7c66a31868032a0cef1e616ffc58
fbshipit-source-id: 9ebfcf8430da7c66a31868032a0cef1e616ffc58

Summary:When dealing with universal references, std::move will move from
objects that are passed as lvalue references. Instead std::forward
should be used, which only moves from an object if it's passed
as rvalue reference.

Reviewed By: yfeldblum

Differential Revision: D3200402

fb-gh-sync-id: 14be071e8498dd64cb8b2583c0cc2dd383bfebb8
fbshipit-source-id: 14be071e8498dd64cb8b2583c0cc2dd383bfebb8

Summary:It's been awhile.

Still has intern URLs (#10943549) but I'll fix that separately.

Reviewed By: jsedgwick

Differential Revision: D3213245

fb-gh-sync-id: ff60193ff368deaac8ca233d4289f30d8f6bb223
fbshipit-source-id: ff60193ff368deaac8ca233d4289f30d8f6bb223

Summary:Instead of std::function<bool(int, int)>, use folly::Function to
pass callbacks to Subprocess::communicate. This makes it possible
to pass non-copyable callables, which is especially interesting
because Subprocess::readLinesCallback returns a non-copyable
object.

This diff also fixes the forwarding of the callback passed to
readLinesCallback in case you pass an lvalue reference.

Reviewed By: snarkmaster

Differential Revision: D3169956

fb-gh-sync-id: 7a906f9a3ab50502fc04e0d83a23ca5e0201bb3e
fbshipit-source-id: 7a906f9a3ab50502fc04e0d83a23ca5e0201bb3e

Summary:[Folly] `get_default` and `get_ref_default` variants taking functions.

Useful if the default value is computationally expensive to construct or requires IO.

Reviewed By: andriigrynenko, spacedentist

Differential Revision: D3189247

fb-gh-sync-id: 51c64293f8712d7590348d53cbfd892a5efd9e82
fbshipit-source-id: 51c64293f8712d7590348d53cbfd892a5efd9e82

Summary: The signals were represented using bytes in a pipe or using a count on an event fd (when available). This count was ever growing and caused the pipe to overflow, and in both cases you would get signals on empty queues. This diff only writes to the fd if it there are no bytes to read. Due to races there can still be multiple bytes in the pipe, but overflowing should not be possible. Instead of blindly signaling when there could be messages in the queue, the signals are now synchronized with the state of the queue so that the signals are drained when the queue is empty. This also made it possible to skip the semaphore behavior of the event fd which should improve perf.

Reviewed By: dcolascione

Differential Revision: D3198252

fb-gh-sync-id: 39e620b10c254ffcacabc4c5ac36950a215d4803
fbshipit-source-id: 39e620b10c254ffcacabc4c5ac36950a215d4803

Summary: as titled. When I tried re-adding all functions after cancelAllFunctions, it throws error. This is because it doesn't reset currentFunction to null.

Reviewed By: jjs0

Differential Revision: D3209237

fb-gh-sync-id: 5b6e2d967fc3c0986320d23b8d61eb1bfbff8940
fbshipit-source-id: 5b6e2d967fc3c0986320d23b8d61eb1bfbff8940

Summary: Closes https://github.com/facebook/folly/pull/401

Reviewed By: yfeldblum

Differential Revision: D3207682

Pulled By: snarkmaster

fb-gh-sync-id: 617aeec0e6fe1f46d2464df4b72a3e91c953dc12
fbshipit-source-id: 617aeec0e6fe1f46d2464df4b72a3e91c953dc12

Summary: Add more compatibility for missing gflags

Reviewed By: yfeldblum

Differential Revision: D3202560

fb-gh-sync-id: d25e4abfe8ceee9fb329c9ba12d259d1d03d4974
fbshipit-source-id: d25e4abfe8ceee9fb329c9ba12d259d1d03d4974

Summary: these macros are generally useful for other higher-order macros

Reviewed By: yfeldblum

Differential Revision: D3194777

fb-gh-sync-id: 667fc51c681786ad422309ee463881dc22c972f7
fbshipit-source-id: 667fc51c681786ad422309ee463881dc22c972f7

Summary:Clean up a deprecation warning for JSONSchema's use of
Singleton. This is in experimental, so the interface change should be
reasonable..

Reviewed By: agoder

Differential Revision: D3203348

fb-gh-sync-id: 3283c7d9c507a545f3217eb5afc3734eb047b833
fbshipit-source-id: 3283c7d9c507a545f3217eb5afc3734eb047b833