Summary:
[Folly] A semaphore type for testing scenarios which need a basic portable semaphore. Supports FIFO and LIFO wake policies.

May be used when testing other, more sophisticated, semaphore types.

Reviewed By: strager

Differential Revision: D15843438

fbshipit-source-id: 9136e8e19ea79fce4191e69795d5fe848a482f03

Summary:
[Folly] Fix a `DistributedMutex` build failure under MSVC, which does not have great support for whatever is happening here, which in this case is a case of variable templates with SFINAE.

Not much information to go on, so this is a best guess:
```
folly/synchronization/DistributedMutex-inl.h(563): fatal error C1001: An internal error has occurred in the compiler.
```

Reviewed By: aary

Differential Revision: D15837884

fbshipit-source-id: 8da993cc27373f86728963d2112812c15a4f34ea

Summary: [Folly] Let `FutureSplitter` hold a `Executor::KeepAlive<>` rather than a raw `Executor*`.

Reviewed By: andriigrynenko

Differential Revision: D15835712

fbshipit-source-id: c0d5b4271212708657f550d5df51d4272e33fc44

Summary:
[Folly] Add `Executor::KeepAlive` copy-assignment operator. Before this change, the copy-assignment operator is implicitly defined as deleted because it is not explicitly defined and `Executor::KeepAlive` has any of a user-declared move constructor or a user-declared move-assignment operator. This is true even though it has converting assignment operators that look like copy-assignment, because the copy-assignment operator is defined as deleted and it is more specific than the converting assignment operators so it is the best candidate overload at overload resolution time.

See: https://en.cppreference.com/w/cpp/language/copy_assignment.

Reviewed By: andriigrynenko

Differential Revision: D15836577

fbshipit-source-id: 4f0887875db2e0233d48d71f2f05d925300d3dc3

Summary: [Folly] Explicitly use correct flags type in `Executor::makeKeepAlive` rather than relying on implicit conversion from `bool` after {D15683241}.

Reviewed By: andriigrynenko

Differential Revision: D15835078

fbshipit-source-id: 49d7895bc909996b646c19c6a2fa0690a58cbe13

Summary: add emplace for folly::sorted_vector_map

Reviewed By: yfeldblum

Differential Revision: D15789529

fbshipit-source-id: 2afccd4553cc53afd0e92729841120722f72b1ae

Summary:
Use `folly::annotate_object_leaked()` in `folly::LeakySingleton`
instead of its own custom suppression. Additionally, this removes
the overhead of the `std::list<>` in opt-mode, but this is minor.

Reviewed By: yfeldblum

Differential Revision: D15755787

fbshipit-source-id: 053b8789c58941176977e6adbc4863d33d6ebed9

Summary:
Add a function `folly::annotate_object_leaked(void const*)`
that suppresses LSAN warnings for the passed pointer. It does so
by keeping a static map of all the pointers passed to the function.
Objects can later be unsuppressed with
`annotate_object_collected(void const*)`.

When ASAN is disabled the function is an inlinable no-op.

This function is useful when you want to intentionally leak
memory, and LSAN isn't smart enough to detect the pointer
stored in memory. For example at the time of writing LSAN
cannot follow the pointer in `folly::atomic_shared_ptr`.

Reviewed By: yfeldblum

Differential Revision: D15755788

fbshipit-source-id: d9be0cfb253f1b89d691892eb085c0b2349c4438

Summary:
[Folly] Fix `DistributedMutex` build failure under MSVC, which fails to understand conversion from `std::integral_constant<T, ...>` to `T` in variable template parameter-list contexts.

Fixes #1164.

Reviewed By: aary

Differential Revision: D15819859

fbshipit-source-id: 1a2647e908fd9ad3362c4bea15d64db75a79f95d

Summary: [Folly] Lift the `accept4` check to an explicit preprocessor symbol set at configure time.

Reviewed By: gkmhub

Differential Revision: D15802038

fbshipit-source-id: e85a258bb6650af42ab149b0bff4854196c3157d

Summary:
- In defining `FOLLY_EXPORT`, we define it differently based on the GCC
  version. In the case of using GCC or Clang 5+, it will rely on
  `[[gnu::visibility("default")]]` which is a C++-specific attribute.
- Since `CPortability.h` is intended to be made to be included for C
  projects, remove `[[gnu::visibility("default")]]` and always define
  `FOLLY_EXPORT` using `__attribute__` syntax which works in C.
Pull Request resolved: https://github.com/facebook/folly/pull/1152

Reviewed By: yfeldblum

Differential Revision: D15618549

Pulled By: Orvid

fbshipit-source-id: fdc72d73f7b38b8a4196cc5677d814544968fb37

Summary:
This diff adds folly/memory/MemoryResource.h, which includes
<experimental/memory_resource> or <memory_resource> if they are available.

Reviewed By: yfeldblum

Differential Revision: D15789182

fbshipit-source-id: ff8410b59354af7124a50ca6000c072372397cda

Summary:
- Simplify `_fs` user defined literal by removing the preprocessor branch.
- Since Folly only supports C++14 now, `#if __cplusplus >= 201402L` will always
  evaluate to true.
Pull Request resolved: https://github.com/facebook/folly/pull/1149

Reviewed By: ericniebler

Differential Revision: D15638288

Pulled By: yfeldblum

fbshipit-source-id: b690e51cbe8ba57baeb8704722e9f126f15e9d4a

Summary: [Folly] Split `kIsSanitizeAddress` and `kIsLibrarySanitizeAddress`, letting them follow the corresponding preprocessor symbols.

Reviewed By: simpkins

Differential Revision: D15773943

fbshipit-source-id: 938ae9d4106a18c3115df5bdbf8560531da3ccbe

Summary: This patch names the thread inside `ObserverManager::NextQueue`, similar to the vector of threads in `ObserverManager::CurrentQueue`.

Reviewed By: yfeldblum

Differential Revision: D15746165

fbshipit-source-id: 02df5616dcc2af27f318088c051a49d14df9a4df

Summary:
Some optimizations and changes to make mutex migrations easier:
- Add exception handling support, this allows using lock_combine pretty much
  anywhere a unique_lock would be used and makes transitioning between lock
  methods easier and more efficient as users aren't required to maintain their
  own unions anywhere (eg. with folly::Try)
- Add support for big return values so people can return anything from the
  critical section.  Without this, users would have to use code of the following
  form, which is prone to false sharing with metadata for the waiting thread
```
auto value = ReturnValue{};
mutex.lock_combine([&]() {
  value = critical_section();
});
```
- Add some optimizations like inlining the combine codepath and an optimistic
  load to elide a branch.  This gets us a ~8% throughput improvement from
  before.  More importantly, This prevents compilers from messing up the
  generated code to dereference the waiter node whenever they feel like.
- Defer time publishing for combinable threads until a preemption.  This gets us
  to the same level of efficiency as std::atomic even on broadwell, takes us to
  7x of the baseline (std::mutex) on the NUMA-less machines and almost perfectly
  parallel in the moderate concurrency levels.  I suspect we can do better with
  NUMA-awareness, but that's for another diff

Reviewed By: yfeldblum

Differential Revision: D15522658

fbshipit-source-id: 420f4202503305d57b6bd59a9a4ecb67d4dd3c2e

Summary:
[Folly] Rename `to_underlying_type` to `to_underlying`, following the pattern of `to_unsigned` and `to_signed`.

(Note: this ignores all push blocking failures!)

Reviewed By: mzlee

Differential Revision: D15776448

fbshipit-source-id: d1f87e917c22a1aa47fb5e37a3ecf7032cec0d48

Summary:
The anticipated (and desired) effect of this change is to make it so that `SKIP` in `SetUp` will actually always skip the test. Right now, test behavior depends on the setting `FOLLY_SKIP_AS_FAILURE` — when this is false, the test will get **executed** despite being "skipped".

I believe it's unlikely that tests rely on the current behavior of doing `SKIP` from `SetUp` and running the test anyway. So, I expect this to be a relatively safe change.

Reviewed By: simpkins

Differential Revision: D15703771

fbshipit-source-id: d32e1d9c4cb8cb99c667882b81946154c6ca906b

Summary:
DeterministicSchedule does not work on mobile because __thread or thread_local
support is not present.  folly::ThreadLocal helps because it uses
pthread_getspecific for mobile and platforms where support for this is not there

This does mean that we can't add DSched tests for folly::ThreadLocal, but that
does not have DSched tests anyway.  When we add DSched tests for that, we can
move to using a lock + map keyed by std::this_thread::get_id

Reviewed By: yfeldblum

Differential Revision: D15770455

fbshipit-source-id: 2a3cc6b3b1c116469cce6295a641d784e5bdfd50

Summary: [Folly] Always define `FOLLY_LIBRARY_SANITIZE_ADDRESS` to either 0 or 1.

Reviewed By: simpkins

Differential Revision: D10414836

fbshipit-source-id: d60ef8380c50971858ed282374f1b5973a27cdf4

Summary:
- Cut `#if __GNUC_PREREQ(5, 0)` preprocessor directive as folly does not
  support any GCC version lower than 5.1.
- Change from `FOLLY_GNU_DISABLE_WARNING` to `FOLLY_GCC_DISABLE_WARNING`
  since Clang does not support `-Wbool-compare` option.
Pull Request resolved: https://github.com/facebook/folly/pull/1151

Reviewed By: Orvid

Differential Revision: D15618528

Pulled By: yfeldblum

fbshipit-source-id: 039e0aad617ccb40392505a6f4585e93d52dc81c

Summary:
Fix https://github.com/facebook/folly/issues/1111 by calling
`assign()` directly. All `ExpectedStorage::assign()` implementations
eventually call `doEmplaceAssign()` which uses SFINAE to assign,
and if that fails emplace. Therefore, they only need `std::is_constructible`.

Reviewed By: yfeldblum

Differential Revision: D15756301

fbshipit-source-id: e7759128c13344ed6e3d58d6ea143fd68af8121b

Summary: [Folly] Rename `FOLLY_ASAN_ENABLED` to `FOLLY_LIBRARY_SANITIZE_ADDRESS`.

Reviewed By: simpkins

Differential Revision: D10414837

fbshipit-source-id: b7ca2a36dd7f91ccab2f8051f78c75909f378d16

Summary:
This is a hack for now to allow fbsource-based watchman getdeps builds to
succeed.  In the long run we need to update Watchman's CMakeLists.txt to
depend on a proper EdenFS build, rather than copying Eden's thrift files into
Watchman's source tree.

Reviewed By: wez

Differential Revision: D15753320

fbshipit-source-id: 2dea483c2053c4ea1cf64021c4bbc3239fce645d

Summary: [Folly] Support various operations on empty `IPAddress` and `SocketAddress`, i.e. default-constructed instances, such as `operator==` and `hash`. V.s. throwing exceptions.

Reviewed By: simpkins

Differential Revision: D15750100

fbshipit-source-id: 89853635f6aab3c295f6fca4e66e6435b0839357

Summary:
The previous diffs in the stack add fbcode_builder manifests for FBOSS
dependencies iproute2 and OpenNSL. The other FBOSS dependencies already have
fbcode_builder support. Thus, add FBOSS manifest.

Additionally, this patch also modifies fboss CMakeLists.txt to get FBOSS to
build using fbcode_builder.

Reviewed By: wez

Differential Revision: D15626298

fbshipit-source-id: 31802ef695ae69b08f526bbeb299c59f3b9d44be

Summary:
D15683387 introduced manifest for libcurl and used cmake instead of autoconf
(rationale: having cmake build curl would make it easy as we want curl to build
on windows and macos).

if libcurl finds ldap.h, then it builds with ldap enabled.
On my devserver, ldap library is not installed, and thus libcurl builds without
it, and links with FBOSS binaries fine.

In sandbox, ldap seems to be installed, thus libcurl builds with ldap. However,
linking fails for FBOSS binaries as those don't link against ldap - FBOSS does
not depend on ldap.

Thus, we need a way to configure libcurl with ldap disabled. [cmake.defines]
CURL_DISABLE_LDAP=OFF, does not quite do it. Thus, am going with autoconf, with
args --disable-ldap for now for Linux and cmake for non-Linux environments.

Reviewed By: wez

Differential Revision: D15730947

fbshipit-source-id: 2ce48976ee785401d550720cbdccb22f9d416675

Summary:
D15588809 introduced manifest and customer builder for iproute2. While the
Iproute2Builder copies include/* from build to install directory, it does not
copy lib/* which contains the libnetlink.a

As a result, the build system looks up libnetlink.a on local machine (which it
may not find).

Fix it by explicitly coping lib/* as well.

Reviewed By: wez

Differential Revision: D15708835

fbshipit-source-id: 3f5906eb48ce982b6e887cca0d3c11314425beab

Summary: This diff allows zmq socket to run on folly::fibers

Reviewed By: saifhhasan

Differential Revision: D15113447

fbshipit-source-id: 8a0e1f91d719a9deda48837d4ff1065408280b72

Summary: Build failures with gcc-7 suggest that gcc-7 is not property short-circuiting SFINAE conditions in the parameter list of function templates. Re-express as cascading tests to avoid the hard error.

Reviewed By: yfeldblum

Differential Revision: D15730238

fbshipit-source-id: 793e12630d609d4e135b4a55714be0cb0496f6f7

Summary: Original commit changeset: 5e101fc38417

Reviewed By: snarkmaster

Differential Revision: D15726457

fbshipit-source-id: 001ee9ebaee81ebc60996e5fb95c1870121b2dec

Summary:
[Folly] Fixed constexpr append in `FixedString` tests after {D15618465}.

```
folly/test/FixedStringTest.cpp: In member function 'virtual void FixedStringAssignTest_ConstexprAppendLiteral_Test::TestBody()':
folly/test/FixedStringTest.cpp:360:3: error: non-constant condition for static assertion
   static_assert(constexpr_append_literal_test() == "hello world!", "");
   ^~~~~~~~~~~~~
In file included from folly/Range.h:25:0,
                 from folly/FixedString.h:33,
                 from folly/test/FixedStringTest.cpp:20:
folly/test/FixedStringTest.cpp:360:47:   in constexpr expansion of 'constexpr_append_literal_test()'
folly/test/FixedStringTest.cpp:355:18:   in constexpr expansion of '#'result_decl' not supported by dump_expr#<expression error>.folly::BasicFixedString<char, 20>::append((& s[7]))'
folly/FixedString.h:1277:48:   in constexpr expansion of 'folly::constexpr_strlen<char>(that)'
folly/portability/Constexpr.h:68:21: error: 'strlen((& s[7]))' is not a constant expression
   return std::strlen(s);
          ~~~~~~~~~~~^~~
```

Reviewed By: simpkins

Differential Revision: D15643402

fbshipit-source-id: c7e26a0c37c956300364c566f211c866985d9dc2

Summary:
It's common for people reading the F14 code to
see the fallback implementation without noticing the #if
!FOLLY_F14_VECTOR_INTRINSICS_AVAILABLE at the top, which leads them to
incorrect conclusions about the code. This diff flips the order in the
file to reduce confusion.

Reviewed By: shixiao

Differential Revision: D15571969

fbshipit-source-id: 10d2aa29da3f1b8dd48af490a53f1f845f103fa8

Summary: [Folly] Merge `folly/futures/helpers.h` into `folly/futures/Future.h` to avoid the cyclic include trap.

Differential Revision: D15600550

fbshipit-source-id: a0d14c0092bb433f7af797201d9fafebab370502

Summary: pthread_getname_np() tries to dereference 0 when called with it, let's turn it into an error instead

Reviewed By: yfeldblum

Differential Revision: D15708351

fbshipit-source-id: aa2dd92e12e33174c8998daed056de50d4111774

Summary:
This diff adds an option "level" to standard log handler configuration so handlers can have individual logging level set.

This allows us to have multiple handler that handles messages with different level settings.

For example,

> eden=DBG3:default:other; default=stream; other=stream:level=WARN;

This configuration creates two log handlers "default" and "other". Both of the handlers will be receiving log messages level "DBG3" from "eden" log category. In this example, "other" handler will only be receiving log messages that is >= "WARN" while the "default" handler still receives all messages >= "DBG3".

However, one catch of this diff is that, when the log category is set to a higher logging level and the log handler has a lower logging level. The log handler will NOT receive any log messages that is lower than the log category logging level. The test `LogLevelReverseTest` illustrate this situation.

Reviewed By: simpkins

Differential Revision: D15541101

fbshipit-source-id: 741aa97d2d5e93c40324bf6a3dd1d9e38f4dc6a5

Change SharedInfoObserverEntryBase::beforeFreeExtBuffer to SharedInfoObserverEntryBase::afterFreeExtBuffer

Summary: Change SharedInfoObserverEntryBase::beforeFreeExtBuffer to SharedInfoObserverEntryBase::afterFreeExtBuffer

Reviewed By: yfeldblum

Differential Revision: D15687084

fbshipit-source-id: 8f77a123f1bdc0e0ee7391dee7da47d9b9addc6d

Summary:
This is towards getting open source FBOSS to build using fbcode_builder.
libnl is one of the dependencies for FBOSS. This patch adds a manifest
file to build libnl.

Reviewed By: wez

Differential Revision: D15686853

fbshipit-source-id: f7549df6dc1005630193b024be6e1ea330cc6646

Summary:
This is towards getting open source FBOSS to build using fbcode_builder.
libcurl is one of the dependencies for FBOSS. This patch adds a manifest
file to build libcurl.

Reviewed By: wez

Differential Revision: D15683387

fbshipit-source-id: 8df5c413e7dff06d1a19e0ce3b1706bff2f1ab54

Summary:
This is towards getting open source FBOSS to build using fbcode_builder.
libusb is one of the dependencies for FBOSS. This patch adds a manifest
file to build libusb. FBOSS does not need libudev, so we avoid unncessary
dependency by passing right argument to ./configure.

Reviewed By: wez

Differential Revision: D15683386

fbshipit-source-id: 1d35caecf4012ddc0df24a7305019d522b4763fa