Summary:
[Folly] Tweak size handling in `Endian`.

Either multiply by 8 in one place, or divide by 8 in another place. Go with the latter, because `sizeof` in C++ emits byte sizes, not bit sizes.

Reviewed By: simpkins

Differential Revision: D4645020

fbshipit-source-id: cb78600ba4c20bebc66aed506d4b5d6c378fc998

Summary: This reverts commit 21b86944f513da0700039a3e3736937fd72e8887

Differential Revision: D4618623

fbshipit-source-id: 6ab6498a2ce22895d7052e258d1af216d46ca178

Summary:
The current method to supply connect timeouts to AsyncSSLSocket
is to supply only the max connect + ssl connect time.

However in some cases when connect time is known, it is desirable
to supply it so that if connect does not succeed in connect time
we can error out quicker and retry.

This adds a new method for connect time in addition to the total
Connect time.

An alternative to this would be to create a AsyncSocket, connect it
and then pass it's fd to AsyncSSLSocket, however that approach does
not work well when TFO is being used, because TFO State is a part of
the AsyncSocket's state and that is not encapsulated with the fd transfer.

We could move the state around, but that is error prone, and this is much
simpler and isolated to AsyncSSLSocket.

Reviewed By: knekritz

Differential Revision: D4626924

fbshipit-source-id: d802d035efbced68873ab59314d9f0e661e5509b

Summary:
[Folly] Refactor `Endian`.

Define `swap` for all types, instead of only declaring it for all types, but have its implementation call a function that only has a given set of non-template overloads for a given set of supported types.

The effective change is that now `Endian::swap<std::string>` will fail to compile, rather than compile but fail to link.

And support floating-point types.

Reviewed By: nbronson

Differential Revision: D4615706

fbshipit-source-id: 5034e1e4466b8118a258d917ce8f4094460ca01a

Summary: detect_stack_use_after_return enables fake stack logic. Previous implementation was relying on fiber releasing its fake stack before switch, which is not safe, because that fake stack may actually be in use. This diff implements a hacky workaround by building a freeFakeStack function, which can release fake stack outside of the fiber. Ideally this function should be provided by ASAN itself.

Reviewed By: yfeldblum

Differential Revision: D4631962

fbshipit-source-id: 6213e2a6b3cbc35fae3793fcf86b0614dd8ff825

Summary: It doesn't work nicely with fake stacks (which are used with detect_stack_use_after_return).

Reviewed By: yfeldblum

Differential Revision: D4631995

fbshipit-source-id: f139041314f8f64c0cf0a15874d6a4710fb2a5b6

Summary:
Parameterizing Range by the template arg T is potentially
confusing because it violates the typical container pattern of T being
the value type.  This diff uses Range<Iter> consistently in Range.h when
the template arg refers to a fully general iterator.

Reviewed By: yfeldblum

Differential Revision: D4635270

fbshipit-source-id: f70bb2e3e23ab9875fba3dbf7b11492613a037b8

Summary:
C++14 has no direct means of creating a std::weak_ptr, one must always create a (temporary) std::shared_ptr first. C++17 adds weak_from_this() to std::enable_shared_from_this to avoid that overhead.
Alas code that is meant to compile under different language versions cannot rely on std::enable_shared_from_this::weak_from_this().
This new utility class uses SFINAE to call std::enable_shared_from_this<T>::weak_from_this() if available. Falls back to std::enable_shared_from_this<T>::shared_from_this() otherwise.
Use as a drop-in replacement for std::enable_shared_from_this where weak_from_this() is desired.

Reviewed By: yfeldblum

Differential Revision: D4616394

fbshipit-source-id: 73bf6cd8852d4a33478a9280cc69c81e7ea73423

Summary: As title, convenient for debugging. Asked for from D4542856

Reviewed By: nkg-

Differential Revision: D4618623

fbshipit-source-id: 21b86944f513da0700039a3e3736937fd72e8887

Summary:
`make check` was failing because <gmock.h> is included but not supplied. Updating to googletest 1.8.0 includes both googletest & googlemock, so `make check` now runs (and passes).
Closes https://github.com/facebook/folly/pull/547

Reviewed By: igorsugak

Differential Revision: D4593403

Pulled By: Orvid

fbshipit-source-id: 02f80e7b67e17562ff981e9c80a37f985eb685be

Summary: I think this ended up encompassing more than intended.

Reviewed By: yfeldblum, maxgeorg

Differential Revision: D4622645

fbshipit-source-id: 26597098a479b85d6ecc64abef2ecc53637ee759

Summary: Fixes "undefined behavior" in ubsan builds when using an empty ByteRange.

Reviewed By: siyengar

Differential Revision: D4613663

fbshipit-source-id: 4b53ba764609acc986340f10613f84585fa697cf

Summary: They are checks that aren't actually used anywhere to guard anything, so kill them. Many are for things that have long since been standard, or aren't even used.

Reviewed By: yfeldblum

Differential Revision: D4615947

fbshipit-source-id: 2179caff4ef8583c89efedbff3136ae5fc552424

Summary: This is the only place `inttypes.h` is used in Folly and it's used in a context where `cstdint` would have sufficed.

Reviewed By: yfeldblum

Differential Revision: D4619248

fbshipit-source-id: e67dccb7d8bf1ad5f7539d4b039590253e8d8c79

Summary: These are the only includes of `sched.h` in Folly, and they really are unused:

Reviewed By: yfeldblum

Differential Revision: D4615501

fbshipit-source-id: 6a3a1aad7a91a92a322fd93d18e1284aa3f86b89

Summary:
It currently takes ~32kB of stack trace to run symbolizer, which is
very close to ASan alt stack size (32 kB).

If we exclude `demangle` (which can use unbound stack size in extreme cases),
the heaviest path in symbolizer includes `FrameArray<100>` and three arrays of
`PATH_MAX` (4 kB) size.  This diff removes the former and one of the latters,
reducing this code path from 32 kB to ~10 kB.

Reviewed By: ot, yfeldblum

Differential Revision: D4618467

fbshipit-source-id: e6a53b61b3d5f6e8b892216d2e9b839ed8430d0e

Summary: It was only needed for GCC 4.7 support. GCC 4.8 and above support it.

Reviewed By: yfeldblum

Differential Revision: D4616044

fbshipit-source-id: 177d7b3b7090134f9d8084a3ba7a984446c87d5e

Summary: `last` was already passed in as a variable, so switch this so there isn't a local variable at all.

Reviewed By: mlogan, yfeldblum

Differential Revision: D4615206

fbshipit-source-id: dd8e3157e54dc2abe3dfd97837ce327371f4f7b2

Summary: [Folly] Drop support for gcc 4.7 with byteswap shim

Reviewed By: igorsugak, Orvid

Differential Revision: D4610746

fbshipit-source-id: 092cd432c7bda9ca5507d0230b6fcaa43b96c500

Summary:
`previousValue` makes the incorrect assumption that `outer_`
is a multiple of the word size. This is incorrect because `skipToNext`
can reposition at an arbitrary point.

The bug is very rare because it can only happen if there is a gap
larger than the skip quantum after the first element in the upper
bits.

Reviewed By: philippv

Differential Revision: D4607270

fbshipit-source-id: ff016f09f3f1f87314b68370e3dc137b82694f45

Summary:
antonl noticed that bulk_insert doesn't remove duplicates.
We now run a std::unique() pass after merging.

Reviewed By: yfeldblum

Differential Revision: D4595304

fbshipit-source-id: 538364150aeea64b95488da158c09e07a6597e7c

Summary: `getCommonName` and `getSubjectAltName` are useful shared utility functions.

Reviewed By: anirudhvr

Differential Revision: D4546866

fbshipit-source-id: bcefc1ff3a02df93fbf0cd2d4f24569928bd1753

Summary:
dbg and dbgo builds of hhvm with gcc-5 crash when generating
backtraces using folly::Symbolizer, because the .debug_aranges for
libc-2.23.so are SHF_COMPRESSED, and folly::Symbolizer doesn't
recognize that.

Just pretend that the section doesn't exist if it has SHF_COMPRESSED
set.

We might eventually want to support decompressing such sections under
an option - but folly::Symbolizer's goal is to just mmap and walk the
debug info without allocating memory (so that it can run while
handling signals etc).

Reviewed By: pixelb

Differential Revision: D4586762

fbshipit-source-id: bef61ed670d1a80caa4f7aac1f80fd2a92cc4ba9

Summary:
Added two variants of Baton by adding two Boolean template parameters with defaults that correspond to the original single poster blocking waiter version:
- SinglePoster (single poster vs multiple posters). Default true.
- Blocking (vs spinning). Default true.

The multi-poster baton (SinglePoster = false) can be handed over by multiple concurrent posters, where redundant post()-s are idempotent but if a post() arrives after the baton is reset() then it unblocks the waiter.

The nonblocking Baton (Blocking = false) has faster common case post(), by avoiding CAS in the critical path. It does so by disallowing waiter blocking and timed_wait().

Reviewed By: nbronson

Differential Revision: D4506728

fbshipit-source-id: e5b65ad93e443fbba22164319c985ebc8424554a

Summary:
[Folly] Fix `exception_wrapper::throwException` when called before `main`.

When the `exception_wrapper` is empty, then `throwException` emits a message to `std::cerr` and terminates. If called before `main` begins or after `main` ends, then `std::cerr` might not have been constructed yet or might have already been destructed. Bad. Segfault, etc. So we need to ensure that `std::cerr` is alive by holding an instance of `std::ios_base::Init`.

Reviewed By: Orvid

Differential Revision: D4576190

fbshipit-source-id: dd84b5e82eb6bd817d405baf530714e0f4c314c5

Summary: [Folly] Drop support for Clang < 3.9.

Reviewed By: igorsugak

Differential Revision: D4567233

fbshipit-source-id: cd94c711f0390d249b6736ab292721a477022b02

Summary: MSVC 2015 has issues with templated `using` declarations using `decltype`, so adjust the definition to use constexpr evaluation to fill a template parameter of a base type instead.

Reviewed By: yfeldblum

Differential Revision: D4510155

fbshipit-source-id: cc2e33625b515085dff4e682971299810905fef0

Summary: This includes both unused parameters (W4100) and conditional expression is constant (W4127).

Reviewed By: yfeldblum

Differential Revision: D4525057

fbshipit-source-id: 7c057dbe239d02fa2e3ce96373d53814591994ec

Summary: They do the same thing, and the first is portable.

Reviewed By: yfeldblum

Differential Revision: D4569649

fbshipit-source-id: db0434766f674a7789d6e59335e122b4d2131e06

Summary: Fixed a data race between an atomic store by the waker and a nonatomic memcpy by the waiter.

Reviewed By: nbronson

Differential Revision: D4572410

fbshipit-source-id: 3982ca433e0f628636916516e35aeb7738ae030f

Summary: In D4558451 I want to pull elements off an atomic list onto a thread-local (single-consumer) vector and pop to get elements in insertion order.  A sweep that provides elements in LIFO order will avoid a redundant pair of list reversals.

Reviewed By: nbronson

Differential Revision: D4564816

fbshipit-source-id: 38cf50418e6afe0be3eec96ce85d571c65f06d7e

Summary:
`defaultNumLowerBits` is heavily used during PL encoding with
optimally-partitioned EF. This diff improves its performance by 3.5x by
avoiding expensive 64-bit division.

Reviewed By: ot, luciang

Differential Revision: D4564615

fbshipit-source-id: 4521d3c05f19573cd2c84f702fcfeaace5f98e77

Summary:
The previous mechanism in SharedPromise doesn't work if the lifetime of the
SharedPromise object ends before the Future which it was splitting is
completed.

This variation on the same theme doesn't have that problem.

Reviewed By: spacedentist

Differential Revision: D4339670

fbshipit-source-id: f619762bff1390481715575b3e638ec26b5c4edd

Summary: memcpy's src cannot be nullptr even if the size is 0.

Reviewed By: djwatson

Differential Revision: D4560100

fbshipit-source-id: 37cd3ed73f902a136f711a5c1a918258f94d1063

Summary: Intended to be used for case-insensitive prefix/suffix matching.

Reviewed By: yfeldblum

Differential Revision: D4552336

fbshipit-source-id: 0030b883426dd67bea27c3f878279359d51e1d33

Summary: Adding an interface to folly::AsyncSocket allowing to receive timestamp notifications collected using recvmsg(fd, MSG_ERRQUEUE, ...).

Reviewed By: djwatson

Differential Revision: D4329066

fbshipit-source-id: 154f5c0d04e5c0e410081d48c937af4069479fc2

Summary:
Add explicit constructors to create Range objects referring to the contents of
a std::array.

D4165608 previously added a folly::range() factory function to create Ranges
around const arrays.  However, it did not support non-const arrays.  However,
providing this as a constructor seems better.  This new constructor does not
appear ambiguous with any existing constructors, and a constructor allows for
more natural support of non-const arrays: the caller can explicitly indicate
if they want to construct a Range to const or non-const data in this case.

Reviewed By: yfeldblum

Differential Revision: D4523515

fbshipit-source-id: c1a262f9e8f76907d87d80b03f252576506e70ab

Reviewed By: lbrandy

Differential Revision: D4544705

fbshipit-source-id: d60f2026d31c94e020df51f8c887b995986ddcd7

Summary: folly/docs/Synchronized.md now reflects the fact that SharedMutex is default mutex for Synchronized

Reviewed By: yfeldblum

Differential Revision: D4529851

fbshipit-source-id: b3b8eafe908ba92e3629392fbc4b856b5a99b658

Summary:
D4499520 added typedefs to `dynamic` which made it start matching
tests for ranges/containers. However, the typedefs are unconditional on the
actual contents of the `dynamic`. This made toDynamic(dynamic) select the
range-based conversion operator, always, which immediately asserts when
trying to do range-based iteration over an Object or a primitive. Add tests
to the converters that enable/disable depending on whether the object is
already a `dynamic` and early-out in that case.

Reviewed By: mzlee

Differential Revision: D4538617

fbshipit-source-id: f3a5aafab07946a221dcead782fc27de51afa0a6