Summary:
On Linux hosts, the fast path to get the current time in
nanoseconds without doing a syscall to the kernel is available via the
VDSO kernel-runtime interface.

In this diff, I:

1. Expose portability wrappers `folly::chrono::clock_gettime()` and
`folly::chrono::clock_gettime_ns()`
2. Implement a VDSO wrapper on Linux hosts to implement those without
a round-trip to the kernel

Depends On D3418054

Reviewed By: bmaurer

Differential Revision: D3418087

fbshipit-source-id: 3fb99f0dd946f19ba29d0d52a1038dad3556bafd

Summary: First cut at autoconf rules for generating a pkg-config file for Folly. The only interesting part is that we want to handle packages that provide their own .pc files as dependencies rather than just stuffing them into the list of libraries required from packages that don't provide .pc.

Reviewed By: simpkins

Differential Revision: D3556611

fbshipit-source-id: d1c5f89416d1d96d2cdf5ccdc5bd7117fb822a82

Summary: It is an error to attempt to get the size of a zero length array, such as `unsigned char[0]`, which is what you get if `MaxInline` has been passed in as 0. We can work around this by simply defining `InlineStorageType` to be `void*` if the size is exactly 0, which will result in the capacity correctly being stored out of line.

Reviewed By: yfeldblum

Differential Revision: D3572898

fbshipit-source-id: c96bb7cc6a890044bb74b0f6d5238c503552ee25

Summary: iters was only being used on one side of the producer/consumer.

Reviewed By: yfeldblum

Differential Revision: D3588593

fbshipit-source-id: 5e9a8a02bb9addbd6f936b8cc411d58cdf82b6e2

Summary: [Folly] Make the `mprotect` variant of `asymmetricHeavyBarrier` work when `mlock` fails.

Reviewed By: djwatson

Differential Revision: D3585948

fbshipit-source-id: c3a46884434b7f9da9caa9cf203573f9e3ce7444

Summary:
FOLLY_X64 is usually defined, so check whehter it is defined
to 0 or 1.  In addition, memory barriers are not necessarily widely
available on the mobile platforms. What leads me to believe this is
that, at least for older ndk's, atomics are not guaranteed to work for
multicore platforms.

Reviewed By: andriigrynenko

Differential Revision: D3586806

fbshipit-source-id: 3ac8c4b74cac09e41bc3cb65c8adc2732b8b2256

Summary:
macOS doesn't have timedwait functionality and this header file was
gating including the boost headers on that check which caused dependent modules
to fail to compile because `boost::mutex` and `boost::recursive_mutex` were not
known to the compiler.

Reviewed By: yfeldblum

Differential Revision: D3585470

fbshipit-source-id: 7f8d9603e95ce01328103c7c6ac0bc75a35ddf4d

Summary: Because, unfortunately, `pthread_exit` is not marked as noreturn in the pthread library primarily used on Windows, we need to return something to avoid errors.

Reviewed By: yfeldblum

Differential Revision: D3571465

fbshipit-source-id: 4713b2364d6584ae255fb83cd21406fdc33ee299

Summary: membarrier guarantees that there's at most one update to thread-local counter, which collecting thread may not see.

Reviewed By: djwatson

Differential Revision: D3532952

fbshipit-source-id: 6106bfe87c70c5f864573a424662778e20423bbb

Summary:
Since OS X 10.6 it is possible to set the name of the current thread.
This diff adjusts our setThreadName routine to do this, partially fixing
the associated test case.  Even though this doesn't completely cover
all cases it is still a valid improvement: most callers are
threads setting their own name.

I've amended the tests so that they can accomodate systems that cannot
set the names of other threads.

Reviewed By: yfeldblum

Differential Revision: D3576281

fbshipit-source-id: 13caf0dca6496aa2da897631e8d7327a6ee452bb

Summary: When installing the mock, we should make sure to remove singleton from the creation_order list.

Differential Revision: D3580725

fbshipit-source-id: dfb489de1be860ab639380644eab0b45a07a1450

Summary:
The check was overly restrictive, the conditional packing was originally used to limit it to GCC only (as it used the `__attribute__` directly), but that restriction is no longer needed as `FOLLY_PACK_*` will be defined appropriately for whatever platform we are currently on.

This just switches it to unconditionally use the `FOLLY_PACK_*` macros rather than defining it's own `FB_PACK_*` macros.

See https://github.com/facebook/folly/commit/aafd8ff9151615a8de09682d41d1c29966e4c8fe for where the `FB_PACK_*` macros could originally have been removed.

Reviewed By: yfeldblum

Differential Revision: D3373779

fbshipit-source-id: 9e41b0836f8ba12de4f37aba58c51f841be08b41

Summary: The static analysis doesn't quite understand that we are assigning a NUL to, at most, `patternBuf[MAX_PATH + 1]` so increase the buffer size slightly to make it happy.

Reviewed By: yfeldblum

Differential Revision: D3571923

fbshipit-source-id: c027e2b253dc3e56d13e9a15a0e960a6aa3a0e6c

Summary: Because there are situations where we need to do an atomic write to a plain pointer, rather than an atomic value. Unfortunately, there is no support in the standard library for this, so different compilers implement the primitives differently. This specifically implements an `int64_t` overload for `__sync_fetch_and_add` for use in the atomic hash map test.

Reviewed By: yfeldblum

Differential Revision: D3571830

fbshipit-source-id: c27d8d2a5238bbc9aba6a9e48e4b3412a199288f

Summary:
this fixes TimeTest on macOS.

The problem was that `task_info_count` is an in/out parameter and it wasn't correctly initialized due to a typo.  The lack of initialization meant that the `task_info()` call would fail at runtime.

Reviewed By: yfeldblum

Differential Revision: D3576262

fbshipit-source-id: 8388fa3c5020309d64a0fa7e01fd6cea80200219

Summary:
the RNG max and min methods must be marked constexpr in order to
compile.  The macos compiler doesn't know to propagate the constexpr-ness from
numeric_limits::max on its own, so we have to be explicit (this also matches
the annotations in ThreadLocalPRNG in Random.h)

Reviewed By: yfeldblum

Differential Revision: D3576189

fbshipit-source-id: e4eeb3361d1c48f582dad5a52e35cae133f007a1

Summary:
The compiler on macos is pedantic about the size of the 9UL not
matching the size of the type returned by `oneBasedMsbPos`.  Cast it to
the appropriate size.

Reviewed By: meyering

Differential Revision: D3576183

fbshipit-source-id: 41e9afc78eed2994e34238da119774e9bf6b7cea

Summary:
Getting some build errors when doing `buck test folly/...`. This seems to be fixing it.

  folly/test/FBStringTest.cpp:1290:23: error: unknown type name 'basic_fbstring'; did you mean 'basic_fstream'?
    using u16fbstring = basic_fbstring<char16_t>;
                        ^~~~~~~~~~~~~~
                        basic_fstream

Also the test `testHashChar16` was failing because only part of the string is used when computing hash.

Reviewed By: yfeldblum

Differential Revision: D3575858

fbshipit-source-id: cdd5bdb9653d50beaf0ec82b659d31354b345441

Differential Revision: D3572671

fbshipit-source-id: a80390921b41e47ed2794d48d943a9e4060c7135

Summary: In a separate diff, I made changes that switched include order, and suddently this file failed to compile. This fixes it.

Reviewed By: andriigrynenko

Differential Revision: D3574775

fbshipit-source-id: 02422d803708aa8490123d19aab5a16c10fdc36e

Summary: Gtest-1.7's ASSERT macros don't work with types with explicit conversions to bool, so do the cast for it.

Reviewed By: yfeldblum

Differential Revision: D3570782

fbshipit-source-id: 885a1022675e63afca00219c5b9de3791742207f

Summary: Recent changes to SharedMutex.h broke mcrouter's open source build. See https://travis-ci.org/facebook/mcrouter/builds/140608809. It looks like we're getting bitten by https://sourceware.org/bugzilla/show_bug.cgi?id=16773. We're hitting it now because the extern template is forcing the instantiation of the thread-local static member to be located in SharedMutex.o, but the inline members that reference that thread-local are *not* located in SharedMutex.o. binutils seems to be stepping on its own feet trying to fix up the references at link time. We can fix it by making sure the code that references the thread-local is colocated with the thread-local.

Reviewed By: yfeldblum

Differential Revision: D3498477

fbshipit-source-id: 86ea86812010ff1ef7351e6f8c106bb4291d0234

Summary: Because, if it follows the same pattern as a normal config flag, it simply won't be defined if it isn't available.

Reviewed By: yfeldblum

Differential Revision: D3571862

fbshipit-source-id: 3322ceb0ce349de16b29310b66d1333aa04da516

Summary: Becuase it has bugs that cause the compiler to error :(

Reviewed By: ericniebler

Differential Revision: D3571263

fbshipit-source-id: 9a17fc2c3c7344c3532df33cd4b84517c97d8efc

Summary:
Not all libc's are the same. Some support wchar_t and some
don't do a great job...

Reviewed By: Orvid

Differential Revision: D3565016

fbshipit-source-id: 91da4f1332e30bdb20a93d0a26a0445d5eadd1b7

Summary:
The ASN1_TIME is the typically used within OpenSSL for representing
time. For example, it can be used to represent the NotBefore and NotAfter
properties of a certificate to be verified. This diff introduces a
ASN1TimeUniquePtr type to take care of the ownership of the ASN1_TIME.

Reviewed By: yfeldblum

Differential Revision: D3561274

fbshipit-source-id: ca4d1431b33098cccd727253dd301e209d2561a5

Summary:
The test file in `../portability/test` is named `TimeTest.cpp`. Makefile refers to it as `PortabilityTimeTest.cpp`. Possibly a typo. Or the test file should be renamed to `PortabilityTimeTest.cpp`.
Closes https://github.com/facebook/folly/pull/438

Reviewed By: yfeldblum

Differential Revision: D3558452

Pulled By: Orvid

fbshipit-source-id: 0cee874b63e98e671153c507f42a7a3b9d8084c1

Summary: Closes https://github.com/facebook/folly/pull/407

Reviewed By: ot

Differential Revision: D3428571

Pulled By: Orvid

fbshipit-source-id: 0b82afae2df24803250e8d6005e2e59bbc8348c9

Summary: Closes https://github.com/facebook/folly/pull/430

Reviewed By: yfeldblum

Differential Revision: D3558454

Pulled By: Orvid

fbshipit-source-id: 8a69b4db31b73806b770fbcf15663411140a04f0

Summary:
That currently includes `std::binary_function`, `std::unary_function`, and `std::random_shuffle`.
`std::{unary|binary}_function<T{, T2}, Ret>` changes to `std::function<Ret(T{, T2})>`.
`std::random_shuffle` has no immediate equivalent, but `std::shuffle` while passing a specific RNG achieves the same effect.

Reviewed By: yfeldblum

Differential Revision: D3506405

fbshipit-source-id: cdefc698a841eca762174eddd8ce636e2d8d26ef

Summary:
ManualExecutor::clear removes all waiting functions from the
executor.

Reviewed By: yfeldblum

Differential Revision: D3555434

fbshipit-source-id: 604c352f2299b0dada062e5f8287be98e2a5f72c

Reviewed By: siyengar

Differential Revision: D3550430

fbshipit-source-id: 1489fe502f41e65ce4ce45f26de59db30c9874b8

Summary:
[Folly] Fix Build: `sorted_vector_types.h` on GCC v4.8.

Problem: that compiler does not yet support `auto`-typed lambda parameters.

Solution: specify the types of the lambda parameters.

Reviewed By: mzlee, Orvid

Differential Revision: D3551262

fbshipit-source-id: 160d3245ec422060175ce59ee653d158954477ed

Summary: Because it doesn't in a lot of our open-source builds.

Differential Revision: D3551445

fbshipit-source-id: 599f45f51d1cbecedd02cb2ca3ef611648986039

Summary: Modifies AsyncSocket to check if TFO succeeded. Also added checks to AsyncSocketTest2 to check if TFO succeeded when it should.

Reviewed By: siyengar

Differential Revision: D3540330

fbshipit-source-id: 8a4b64fdb040dea73ba264b8e3dfff4d717fd96f

Summary:
Folly currently contains wrappers to emulate
`clock_gettime()` on platforms which don't support it.

The OS X and Windows wrappers are missing a bit of functionality we
need. In this diff, I:

1. Bring the OS X and Windows wrappers closer to Linux's functionality
2. Add unit tests

Reviewed By: bmaurer, mzlee

Differential Revision: D3418054

fbshipit-source-id: 47eba871e844b4c3dccd7ab201ec82e1f6edf729

Summary:
Add withLock() and related methods for invoking a lambda function while the
lock is held.  This is sometimes more convenient than opening a new scope and
using lock().

withLock() also retains some of the benefits of the SYNCHRONIZED macro in that
it forces users to put their critical section code in a new scope, making the
critical section more visibly distinct in the code.  This also encourages users
to only put necessary work inside the critical section, and do to other work
once the lock is released.

This also adds a LockedGuardPtr class, which is a slightly cheaper version of
LockedPtr.  The relationship between LockedGuardPtr and LockedPtr is very much
like that between std::lock_guard and std::unique_lock.  It saves a branch in
the destructor, and in the case of std::mutex it also saves a small amount of
storage space (since LockedPtr is specialized for std::mutex to also store a
std::unique_lock).

Reviewed By: yfeldblum, djwatson

Differential Revision: D3530368

fbshipit-source-id: 72a4f457b3f18e8e8f4cc6713218f6882bb89818

Summary:
This refactors the Synchronized::LockedPtr class, and adds new
lock()/wlock()/rlock() APIs to Synchronized.

The LockedPtr changes include:

- Consolidate code so a single template class can be used for both const
  and non-const operation, rather than requiring separate class definitions.
  A LockPolicy template parameter controls if the lock should be acquired in
  exclusive or shared mode, and a SynchronizedType parameter controls whether
  or not the internal data is const or not.

- Specialize LockedPtr for std::mutex, so it uses std::unique_lock<std::mutex>
  internally.  This requires slightly more storage space internally, but it
  allows Synchronized<T, std::mutex> to be used with std::condition_variable.

- Implement operator*() to dereference the pointer and retrieve a reference to
  the locked data.

- Implement operator!() and provide an isValid() method to check the validity
  of the LockedPtr.  These are needed to tell if a timed acquire operation
  succeeded or timed out.

- Drop the LockedPtr copy constructor.  Previously the copy constructor
  acquired the lock a second time.  If anyone needs the ability to hold a
  shared lock a second time solely via a LockedPtr (and not via the original
  Synchronized object), I think we should add back a much more explicit API to
  do this.

Furthermore, this adds lock(), wlock(), and rlock() methods to Synchronized to
explicitly obtain a LockedPtr.  These APIs behave similar to operator->(), but
are more explicit, and require the caller to make a concious choice about
whether or not an exclusive or shared lock should be acquired.  The lock()
method is present only on Synchronized instantiations using an exclusive mutex,
and the wlock() and rlock() methods are present only on Synchronized
instantiations that use a shared mutex.

I plan to deprecate the existing Synchronized::operator->() method and the
various SYNCHRONIZED macros in upcoming diffs.  For now this adds comments
directing users to the new methods, but does not start any of the technical
deprecation changes yet.

Reviewed By: yfeldblum

Differential Revision: D3526489

fbshipit-source-id: 8a96a09b68656ff9215dcdfdf32ecd2bfbb1727f

Summary:
[Folly] Inline the `lower_bound` and `upper_bound` callbacks in `sorted_vector_map`.

Avoids unnecessary use of legacy `boost::bind`, and allows the compiler to avoid the indirection it introduces. This way, we use templates instead of vtables.

Reviewed By: Orvid

Differential Revision: D3545939

fbshipit-source-id: 277e9e4862beb71e99b94a62308783771071d2bc

Summary:
[Folly] Move `IPAddress` definitions to source files.

And to internal header files. Keeping headers lightweight can help with build times.

Reviewed By: simpkins

Differential Revision: D3514455

fbshipit-source-id: de78f4ef9e70e7ddd7fb666348ed705c5228531c