Summary: In C++20, u8 prefixed strings are typed as `char8_t` not `char`, so we need to support that in `StringPiece`.

Reviewed By: yfeldblum

Differential Revision: D19822967

fbshipit-source-id: c3441ba718b40f0781766d4a80c3432b4514a35c

Reviewed By: yfeldblum

Differential Revision: D19768449

fbshipit-source-id: b5a259486403601cf60d4e7066640e1ed4601410

Summary:
Currently the best way to get an eager SemiFuture from an AsyncGenerator is
  folly::coro::co_invoke(
      [&]()
          -> folly::coro::Task<folly::coro::AsyncGenerator<T&&>::NextResult> {
        co_return co_await gen.next();
      })
      .scheduleOn(&ex)
      .start();
which is very verbose. This diff adds helpers to make this a simple function call.

Reviewed By: andriigrynenko

Differential Revision: D19835473

fbshipit-source-id: f6e7e72cad0e0596df375d2662c87d4412536c03

Summary: There are downstream oss builds showing build failure caused by introduction of metadata. We want to make them proceed to build so we won't get errors in CI.

Reviewed By: iahs

Differential Revision: D19900007

fbshipit-source-id: 4201448f7980b53e407fd2bc1c74ed4ffa8e18c1

Summary:
If a key type has a templated constructor that can implicitly
accept const_iterator, then a call to erase or eraseInto with a non-const
iterator results in an ambiguous overload. This diff adds an extra
overload of eraseInto to avoid the ambiguity, as well as adding unit
tests that cover the rare corner case.

Reviewed By: yfeldblum

Differential Revision: D19809069

fbshipit-source-id: 499849da2d6ad64070b13eb0a9ed86a3d49ad9b0

Summary:
It's useful to be able to move the key and value
out of a hash table as that entry is being erased. Since
std::unordered_map's extract API isn't implementable for hash tables
that perform bulk allocation, we expose similar functionality via
F14{Fast,Value,Vector,Node}Map::eraseInto.  eraseInto gives a key_type&&
and mapped_type&& to the specified callback, allowing it to move them
elsewhere before the underlying value_type is destroyed.

The keen observer will note that there is no way to move the key out
of a std::pair<key_type const,mapped_type> without relying on undefined
behavior. We already rely on this form of UB to avoid copying keys during
rehash, and perform it only when we have total control over the lifecycle
of the object and the memory backing the value_type.

eraseInto was previously implemented for F14 sets.

Reviewed By: shixiao

Differential Revision: D19777644

fbshipit-source-id: 9904224af2c6e51abeadae62cc5e66f7bf4b1ae7

Summary: This issue was only showing up in a single test, but include orders meant that stdio.h could end up being included in a way that caused it to not properly define the normal names it's supposed to, as they were getting disabled due to the `_CRT_INTERNAL_NON_STDC_NAMES` changes being made.

Reviewed By: yfeldblum

Differential Revision: D19866950

fbshipit-source-id: 9d6391f5c0e5a2ef44f0f8ba6dad064cfecf0a82

Summary: Newer versions of boost thread re-wrote how this works, so use the new way.

Reviewed By: yfeldblum

Differential Revision: D19824658

fbshipit-source-id: a3d66fd6ef781ac83c92f6313cf47a7920cfebda

Reviewed By: iahs

Differential Revision: D19873296

fbshipit-source-id: f92785feb33be09bdef4c047532b4bd3dd42972e

Summary:
g++ 8.2.1 on some platforms crashes on the gtests defined
in EventBaseTestLib.h that declare inner classes.  This diff
refactors the tests so that they can be successfully compiled.

Reviewed By: yfeldblum

Differential Revision: D19871529

fbshipit-source-id: 3e84c2983e90b7445c014c002bbac504e0366657

Summary: It is possible for blockingWait to crash if just after it leaves it's drive() method in the destructor, from another thread something releases the keep alive. If then the destructor continues it will clean up, but that other thread will then be manipulating freed data.

Reviewed By: andriigrynenko

Differential Revision: D19860616

fbshipit-source-id: 25df16b5e900f283bbc0a264233770b6d3667ba3

Summary:
Take the README.md from
https://github.com/facebookexperimental/mononoke/blob/7ead0e29e41aec0771531a4650b6170bc1ff6566/README.md
and apply it on Eden repo.

Re-add the Cargo.toml file that declares Cargo workspace.

Re-add fbcode_builder/getdeps manifest for Mononoke
Pull Request resolved: https://github.com/facebookexperimental/eden/pull/13

Test Plan:
./build/fbcode_builder/getdeps.py build mononoke
  ./build/fbcode_builder/getdeps.py test mononoke

Reviewed By: ahornby

Differential Revision: D19833059

Pulled By: lukaspiatkowski

fbshipit-source-id: fb37e13306c0b9969a7c4e52b05e1a66a577022f

Summary: When connection is reset by server it's possible for a write to fail before the read callback is called. Make sure we still try to process all the data that was received before closing the socket.

Reviewed By: rhodo

Differential Revision: D19851139

fbshipit-source-id: af50b939ccd7f25384e48bcf29b4892a23c2ef83

Summary: platform_mapping library needs RE2 lib.

Reviewed By: shri-khare

Differential Revision: D19838529

fbshipit-source-id: 71a2c06437ce05a42396a2867ddadb029e36926e

Summary: [Folly] Remove trivial-copyability requirement from `LockFreeRingBuffer` since we can rely on the compiler to optimize copy operations over types which are trivially-copyable without our code having to specify `memcpy`.

Reviewed By: yfeldblum

Differential Revision: D19844612

fbshipit-source-id: 4770e46ac8c63fa68b68598fb5012cb58896f550

Summary: [Folly] Use SingletonThreadLocal for the current fiber manager, which does not depend on whether `__thread` or `thread_local` is available.

Reviewed By: andriigrynenko

Differential Revision: D19229511

fbshipit-source-id: a92016aca89205c2842dc4f71054b1b6306b14b9

Summary: [Folly] Prefer `invoke_result_t` in `DistributedMutex` over the underlying `decltype` and `declval` implementation.

Reviewed By: aary

Differential Revision: D19321643

fbshipit-source-id: 323a0fce49447d2f009ad3bc61e285de3f311ff1

Summary: [Folly] Use invocability helper variables in preference to types.

Reviewed By: aary

Differential Revision: D18748026

fbshipit-source-id: e7a76c1238360c55dd6d41c53f763e9df4069acb

Summary:
1. Add `"-Wshorten-64-to-32"` to `_extra_clang_flags`
2. Fix warnings generated from `buck build --keep-going wangle/...`

Reviewed By: chadaustin

Differential Revision: D19647345

fbshipit-source-id: 417840fe82ed3d5c9c2d989a0acf67e12758c1f9

Summary:
Folly does not compile with Windows SDK 1903. The issues is in folly/portability/Windows.h and surfaces when compiling files including it, e.g.: xplat/folly.portability/Stdlib.cpp
```
xplat\folly/portability/SysStat.h:47:5: error: conflicting types for 'mkdir'
int mkdir(const char* fn, int mode);
    ^
C:\Program Files (x86)\Windows Kits\10\Include\10.0.18362.0\ucrt\direct.h:111:26: note: previous declaration is here
    _ACRTIMP int __cdecl mkdir(
                         ^
xplat\folly\portability\Stdlib.cpp:47:11: error: no matching function for call to 'mkdir'
    ret = mkdir(ptr, 0700);
          ^~~~~
C:\Program Files (x86)\Windows Kits\10\Include\10.0.18362.0\ucrt\direct.h:111:26: note: candidate function not viable:
      requires single argument '_Path', but 2 arguments were provided
    _ACRTIMP int __cdecl mkdir(
                         ^
2 errors generated.
```
Now internal Windows functions collide with folly portability ones defined in https://github.com/facebook/folly/blob/master/folly/portability/Unistd.h#L61-L93

C:\Program Files (x86)\Windows Kits\10\Include\10.0.18362.0\ucrt\direct.h defines a Windows ```mkdir``` function when
```
#if defined(_CRT_INTERNAL_NONSTDC_NAMES) && _CRT_INTERNAL_NONSTDC_NAMES
//...
    _Check_return_ _CRT_NONSTDC_DEPRECATE(_mkdir)
    _ACRTIMP int __cdecl mkdir(
        _In_z_ char const* _Path
        );

    _Check_return_ _CRT_NONSTDC_DEPRECATE(_rmdir)
    _ACRTIMP int __cdecl rmdir(
        _In_z_ char const* _Path
        );

#endif // _CRT_INTERNAL_NONSTDC_NAMES
```

When diffing the current Windows SDK 1903 version: C:\Program Files (x86)\Windows Kits\10\Include\10.0.18362.0\ucrt\corecrt.h
with a previous one, e.g.: 1809 C:\tools\toolchains\vs2017_15.9\WindowsSdk\Include\10.0.17763.0\ucrt\corecrt.h
we see a fundamental change:

## SDK 1903
```
#if ( defined _CRT_DECLARE_NONSTDC_NAMES && _CRT_DECLARE_NONSTDC_NAMES) || \
    (!defined _CRT_DECLARE_NONSTDC_NAMES && !__STDC__                 )
    #define _CRT_INTERNAL_NONSTDC_NAMES 1
#else
    #define _CRT_INTERNAL_NONSTDC_NAMES 0
#endif
```

## SDK 1809
```
#define _CRT_INTERNAL_NONSTDC_NAMES                                            \
    (                                                                          \
        ( defined _CRT_DECLARE_NONSTDC_NAMES && _CRT_DECLARE_NONSTDC_NAMES) || \
        (!defined _CRT_DECLARE_NONSTDC_NAMES && !__STDC__                 )    \
    )
```

Reviewed By: Orvid

Differential Revision: D19804183

fbshipit-source-id: cbbe32c611a3c011175145329c29de4a9597868c

Summary:
[Folly] Adjust allocator ctors.

* Add missing family ctor to `SysAllocator` to bring it into better alignment with generic C++ allocator expectations.
* Make other family ctors implicit.
* Ensure that the actual copy ctors take precedence.
* Hide copy assignment operators.

Reviewed By: marksantaniello

Differential Revision: D19817836

fbshipit-source-id: de90fdd7cae36ac178a89556e63a29f4014532a1

Summary: we've seen people using `apache::thrift::Stream` as a heavyweight way to produce this functionality. As we move to delete that we want to provide an alternative using `AsyncGenerator`.

Reviewed By: andriigrynenko

Differential Revision: D19774841

fbshipit-source-id: 5ebaa0afcb08f04d7fb899b34ac7dc0270186852

Summary: we've seen people using `apache::thrift::Stream` as a heavyweight way to produce this functionality. As we move to delete that we want to provide an alternative using `AsyncGenerator`.

Reviewed By: andriigrynenko

Differential Revision: D19726875

fbshipit-source-id: 047e1db4b429883a69af9819e0c6ad04022ef91f

Summary:
Range lists are contained in a separate object file section called .debug_ranges. A range list is
indicated by a DW_AT_ranges attribute whose value is represented as an offset from the
beginning of the .debug_ranges section to the beginning of the range list.
Each entry in a range list is either:
a range list entry,
a base address selection entry, or
an end of list entry.

Reviewed By: luciang

Differential Revision: D19658819

fbshipit-source-id: ed70915465f0ac6bb8ab6f7efe415a3d8c5b04ee

Summary:
Here is an example for class inline member function declared and defined in the same file:

```
Definition:
0x00004c0a:           DW_TAG_subprogram [55] *
                        DW_AT_linkage_name [DW_FORM_strp] ( .debug_str[0x00177124] = "_ZNK5folly10symbolizer4test24ClassWithInlineFunctions9inlineBarERNS0_10FrameArrayILm100EEE")
                        DW_AT_name [DW_FORM_strp] ( .debug_str[0x00089a73] = "inlineBar")
                        DW_AT_decl_file [DW_FORM_data1] (0x1a)
                        DW_AT_decl_line [DW_FORM_data1] (0xa5)
                        DW_AT_declaration [DW_FORM_flag_present]  (true)
                        DW_AT_external [DW_FORM_flag_present] (true)
                        DW_AT_accessibility [DW_FORM_data1] (0x01)
…

Declaration:   -- no DW_AT_decl_file
0x000164c1:   DW_TAG_subprogram [228] *
                DW_AT_specification [DW_FORM_ref4]  (cu + 0x48ea => {0x00004c0a})
                DW_AT_inline [DW_FORM_data1]  (0x01)
                DW_AT_object_pointer [DW_FORM_ref4] (cu + 0x161ac => {0x000164cc})

…

Inline function call
0x0001657b:     DW_TAG_inlined_subroutine [140] *
                  DW_AT_abstract_origin [DW_FORM_ref4]  (cu + 0x161a1 => {0x000164c1})
                  DW_AT_low_pc [DW_FORM_addr] (0x000000000040fa6e)
                  DW_AT_high_pc [DW_FORM_data4] (0x00000055)
                  DW_AT_call_file [DW_FORM_data1] (0x1a)
                  DW_AT_call_line [DW_FORM_data1] (0xe2)
```

Here is an example for class inline member function declared and defined in different files:

```
Definition:  DW_AT_decl_file: 0x01  --> SymbolizerTestUtils.h
0x00004c3d:           DW_TAG_subprogram [55] *
                        DW_AT_linkage_name [DW_FORM_strp] ( .debug_str[0x0017717f] = "_ZNK5folly10symbolizer4test22InlineFunctionsWrapper9inlineBarERNS0_10FrameArrayILm100EEE")
                        DW_AT_name [DW_FORM_strp] ( .debug_str[0x00089a73] = "inlineBar")
                        DW_AT_decl_file [DW_FORM_data1] (0x01)
                        DW_AT_decl_line [DW_FORM_data1] (0x30)
                        DW_AT_declaration [DW_FORM_flag_present]  (true)
                        DW_AT_external [DW_FORM_flag_present] (true)
                        DW_AT_accessibility [DW_FORM_data1] (0x01)

…

Declaration:   DW_AT_decl_file: 0xbf  --> SymbolizerTestUtils-inl.h
0x00017ee8:   DW_TAG_subprogram [231] *
                DW_AT_decl_file [DW_FORM_data1] (0xbf)
                DW_AT_decl_line [DW_FORM_data1] (0x21)
                DW_AT_specification [DW_FORM_ref4]  (cu + 0x491d => {0x00004c3d})
                DW_AT_inline [DW_FORM_data1]  (0x01)
                DW_AT_object_pointer [DW_FORM_ref4] (cu + 0x17bd5 => {0x00017ef5})

…

Inline function call
0x00017fa5:     DW_TAG_inlined_subroutine [158] *
                  DW_AT_abstract_origin [DW_FORM_ref4]  (cu + 0x17bc8 => {0x00017ee8})
                  DW_AT_low_pc [DW_FORM_addr] (0x00000000004104ee)
                  DW_AT_high_pc [DW_FORM_data4] (0x00000055)
                  DW_AT_call_file [DW_FORM_data1] (0x1a)
                  DW_AT_call_line [DW_FORM_data2] (0x0101)
```

Reviewed By: luciang

Differential Revision: D19658560

fbshipit-source-id: 78c1e42d76c19f09e4632c40e0df18bfb49479f9

Summary: Linkage name (DW_AT_linkage_name) contains more information than the identifier name (DW_AT_name).

Reviewed By: luciang

Differential Revision: D19657767

fbshipit-source-id: 87b2293e6f723ceb8b5202db0f3c569c37c6c7ea

Summary:
Actually class inline functions exist in both .debug_info and .debug_types sections. In this diff, only the information in .debug_info is used.

Step 1. Find the DW_TAG_inlined_subroutine debug info entry (DIE) based on the given address.
Step 2. Find the DW_TAG_subprogram DIE based on the DW_AT_abstract_origin attr in inlined_subroutine, but this DIE is just a declaration.
Step 3. Find the actual definition DW_TAG_subprogram DIE based on the DW_AT_specification attr.

```
.debug_info

0x00003657:           DW_TAG_subprogram [56] *   ---- step 3
                        DW_AT_linkage_name [DW_FORM_strp] ( .debug_str[0x0002932d] = "_ZN5folly10symbolizer4test24ClassWithInlineFunctions9inlineBarERNS0_10FrameArrayILm100EEE")
                        DW_AT_name [DW_FORM_strp] ( .debug_str[0x00014064] = "inlineBar")
                        DW_AT_decl_file [DW_FORM_data1] (0x18)
                        DW_AT_decl_line [DW_FORM_data1] (0xa1)
                        DW_AT_declaration [DW_FORM_flag_present]  (true)
                        DW_AT_external [DW_FORM_flag_present] (true)
                        DW_AT_accessibility [DW_FORM_data1] (0x01)

…

0x0000cd74:   DW_TAG_subprogram [203] * .   ---- step 2
                DW_AT_specification [DW_FORM_ref4]  (cu + 0x358f => {0x00003657})
                DW_AT_inline [DW_FORM_data1]  (0x01)
                DW_AT_object_pointer [DW_FORM_ref4] (cu + 0xccb7 => {0x0000cd7f})

…
0x0000cda0:   DW_TAG_subprogram [181] *
                DW_AT_low_pc [DW_FORM_addr] (0x00000000002a4980)
                DW_AT_high_pc [DW_FORM_data4] (0x00001e22)
                DW_AT_frame_base [DW_FORM_exprloc]  (<0x1> 56 )
                DW_AT_object_pointer [DW_FORM_ref4] (cu + 0xccf0 => {0x0000cdb8})
                DW_AT_specification [DW_FORM_ref4]  (cu + 0x312f => {0x000031f7})

…

0x0000ce02:     DW_TAG_inlined_subroutine [157] *               ---- step 1
                  DW_AT_abstract_origin [DW_FORM_ref4]  (cu + 0xccac => {0x0000cd74})
                  DW_AT_low_pc [DW_FORM_addr] (0x00000000002a4f66)
                  DW_AT_high_pc [DW_FORM_data4] (0x000000c0)
                  DW_AT_call_file [DW_FORM_data1] (0x18)
                  DW_AT_call_line [DW_FORM_data1] (0xe6)

.debug_types

0x00020fdf:         DW_TAG_class_type [33] *
                      DW_AT_calling_convention [DW_FORM_data1]  (0x05)
                      DW_AT_name [DW_FORM_strp] ( .debug_str[0x00067094] = "ClassWithInlineFunctions")
                      DW_AT_byte_size [DW_FORM_data1] (0x08)
                      DW_AT_decl_file [DW_FORM_data1] (0x18)
                      DW_AT_decl_line [DW_FORM_data1] (0x9f)

…

0x00020ff5:           DW_TAG_subprogram [56] *
                        DW_AT_linkage_name [DW_FORM_strp] ( .debug_str[0x0002932d] = "_ZN5folly10symbolizer4test24ClassWithInlineFunctions9inlineBarERNS0_10FrameArrayILm100EEE")
                        DW_AT_name [DW_FORM_strp] ( .debug_str[0x00014064] = "inlineBar")
                        DW_AT_decl_file [DW_FORM_data1] (0x18)
                        DW_AT_decl_line [DW_FORM_data1] (0xa1)
                        DW_AT_declaration [DW_FORM_flag_present]  (true)
                        DW_AT_external [DW_FORM_flag_present] (true)
                        DW_AT_accessibility [DW_FORM_data1] (0x01)

```

Reviewed By: luciang

Differential Revision: D19644033

fbshipit-source-id: fa5d6dc46dbb1a417b40c1d06d9eaf9178661d21

Summary:
[Folly] Revise `SignalSafeElfCache` to use `mmap` for dynamic allocation and not to require static preallocation.

While, technically, `mmap` is not documented to be async-signal-safe, in practice it is so at least on Linux. Take advantage.

Prior to this change, the `SignalSafeElfCache` with all of its storage would have to be preallocated before setting the signal handler and must not be destroyed ever. Prior to this change, the preallocation would require at least `sizeof(Path) * capacity`, which defaults to ~2MB.

It is now possible to use stack-allocated SignalSafeElfCache in signal handlers.

This change adds a multi-thread-safe and async-signal-safe `mmap`-based allocator. Details as follows:
* All allocations are rounded up to the nearest power of two in size and alignment.
* Page or larger allocations are handled directly by `mmap` and free by `munmap` and are not tracked.
* Smaller allocations are handled by an `mmap`-backed refcounted arena. Arena sections are 16 pages in size; they are allocated on demand; and they are linked together to allow for `munmap` when the allocator refcounted arena is destroyed.

Reviewed By: davidtgoldblatt

Differential Revision: D18760282

fbshipit-source-id: 56a34abfe39a7108f790537afeda832fd39714d7

Summary: [Folly] Put the current fiber manager behind an accessor function v.s. having it as a static class member.

Reviewed By: andriigrynenko

Differential Revision: D19229507

fbshipit-source-id: 7cf4eab00ee281bc6104f994a71f5e48d9553852

Summary: MSVC informed me that these classes had noexcept move constructors but the move assignment operators were not marked as noexecpt.

Reviewed By: yfeldblum

Differential Revision: D19796949

fbshipit-source-id: d2bdc8ebb6d77709e367a4137fb0817c8006084f

Summary: This logic makes it impossible to reason about order between io events, internal and external events. The comment also seems outdated.

Reviewed By: yfeldblum

Differential Revision: D19785249

fbshipit-source-id: 62eee5427a3c47cccba6cb33c2ca88af82767bed

Summary:
The `Future(T2&&)` constructor is currently constrained to disallow other `Future` and `SemiFuture` types, but it allows types which will cause a hard error when instantiating the body of the constructor. The constructor argument is later used to initialize a `Try<T>`, so the function should properly be constrained with `std::is_constructible<Try<T>, T2>::value`.

Also, add the same constraint to the `SemiFuture(T2&&)` constructor, and to the `FutureBase(T2&&)` constructor for good measure.

Reviewed By: yfeldblum

Differential Revision: D19782313

fbshipit-source-id: 5e1ef5425b0c7ab9cc76c998425e90d0ba0b148f

Summary:
The current implementation does not guarantee atomicity on power
failure or OS crash.  For instance, if a crash happens after writing
the directory to storage but before writing the file data to storage,
then a zero-byte file can result.

Provide an optional parameter to sync and provide atomicity in these
situations.

Adjust comments to reflect the actual guarantees provided.

Differential Revision: D19754974

fbshipit-source-id: 5ddb2f3a1b9e72b523ee13937f648e0913c94c2f

Summary:
[Folly] Use atomic operations on maybe-TLS `SharedMutex` static data  via `atomic_ref`. The fields are thread-local on platforms which support thread-local fields, but global otherwise.

When thread-local is supported, relaxed loads and stores should ordinarily have the same overhead as non-atomic loads and stores on most platforms. When thread-local is not supported and these fields are global, the concurrent atomic loads and stores will change to become defined behavior.

Differential Revision: D19688867

fbshipit-source-id: 51873e12924ecff9d971316658fe71e2de18bdec

Summary:
Instead of fetching a tarball for the vendored Rust crates, let's just use
what's present in third-party/rust.

Reviewed By: wez, fanzeyi

Differential Revision: D19770580

fbshipit-source-id: ca6615a5f5c672d9a5527ad47feab6bdd33a39db

Summary: [Folly] Cut `StaticMetaBase` `[[noreturn]]` dtor, since MSVC C4722 flags it.

Reviewed By: filipecalasans

Differential Revision: D19738476

fbshipit-source-id: d697aad1194b76e7c371aa9a34ea50cb793b5c32

Summary: Mononoke is becoming part of Eden repository, remove it's getdeps manifest until we finalize the move.

Reviewed By: krallin

Differential Revision: D19769090

fbshipit-source-id: 9b471686728e9ff28317f9157f5f8a1834c5f5e4

Summary:
D19417574 added support for snapshotting stack traces for threads our requests are running on. The problem with this approach was that we are racing - stack trace may be recorded AFTER requests has already left the thread. Hence we might be presenting incorrect and confusing picture to the users.

Here we make sure that request root id and stack trace are recorded together, and there is no race.

Because we are using interrupts to get on the thread, sometimes we might not be able to record the information using this approach. We then fallback to the previous way of associating threads and requests (by walking TLS entries).

(Note: this ignores all push blocking failures!)

Reviewed By: andriigrynenko

Differential Revision: D19445100

fbshipit-source-id: 4311f4e521a48852bf99aede03814de0941c7814

Summary:
[Folly] Fix gcc-specific problem in `reentrant_allocator` test.

```
folly/memory/test/ReentrantAllocatorTest.cpp: In member function ‘virtual void ReentrantAllocatorTest_large_Test::TestBody()’:
folly/folly/memory/test/ReentrantAllocatorTest.cpp:68:22: error: no matching function for call to ‘std::vector<ReentrantAllocatorTest_large_Test::TestBody()::type, folly::reentrant_allocator<ReentrantAllocatorTest_large_Test::TestBody()::type> >::push_back(<brace-enclosed initializer list>)’
     vec.push_back(type{i});
                      ^
```

Differential Revision: D19738608

fbshipit-source-id: bbffd1f47749be1aa88bb45bddc401ffca48c4ca

Summary: Pull Request resolved: https://github.com/facebook/folly/pull/1298

Reviewed By: igorsugak

Differential Revision: D19281240

Pulled By: yfeldblum

fbshipit-source-id: 3bf437d49aa85b40923ff1ad93ba62fa97b726af