Summary:
I think LZ4 was disabled accidentally in our rocksdb getdeps build in
D21319896. Enable it again on macOS and Linux, because otherwise this
breaks people with EdenFS mounts containing LZ4-compressed proxy
hashes.

Reviewed By: xavierd

Differential Revision: D21990356

fbshipit-source-id: b9166c2992ae51f09de3fa9a4f114143aa008f43

Summary:
Adds a helper utility called 'tag_invoke' for defining CPOs that dispatch to a call to an overload of the ADL-name 'tag_invoke()' that takes the CPO as the first argument instead of to a CPO-specific ADL-name.

This makes it possible to build generic adapters, such as type-erasing adapters, that can forward through calls to all CPOs through to an underlying object.

Adds FOLLY_DECLVAL(T) helper macro used in the implementation of some of the traits.

Reviewed By: yfeldblum

Differential Revision: D17867173

fbshipit-source-id: fadae6ec97498008a5238036b7310a1e0ae119a2

Summary:
folly::Hash<Range<T>> uses SpookyHashV2::Hash64 (for integral
T). On 32-bit platforms we need an explicit cast to avoid a narrowing
warning when converting this to size_t.

(Note: this ignores all push blocking failures!)

Reviewed By: shixiao

Differential Revision: D21491467

fbshipit-source-id: 1cbd05553c61b8dccb664ec4478cfb0b049dc5b5

Differential Revision:
D21918702

Original commit changeset: 3213e9536147

fbshipit-source-id: 4e9394b2026f0d6d74e668c7c72b3612a42770ea

Summary: This header is widely included (via `Future.h`) and instantiations of `UnboundedQueue`'s methods are expensive, so outline them (note that the template methods will only be instantiated if used, so that's fine).

Reviewed By: philippv

Differential Revision: D22014083

fbshipit-source-id: b6a71c38c142917e9e0d86fbb64a88462382952a

Summary: This would allow us have better stack trace with inline functions in signal handler output.

Reviewed By: luciang

Differential Revision: D21918702

fbshipit-source-id: 3213e9536147759a4e59f5b6f68d22d941d36c7f

Summary: [Folly] Wrap `_r_debug` per platform, since the way to get it varies by platform.

Reviewed By: ot, luciang

Differential Revision: D22004737

fbshipit-source-id: 6f6a6163c9709da0a5042b807cdd88fcdf2e57eb

Summary: Thread fences are not supported by TSAN

Reviewed By: yfeldblum

Differential Revision: D21989519

fbshipit-source-id: bb657c82a64abe025e8f4c030916c0cacc3c0b81

Summary:
The `collectSemiFuture` method doesn't exist.  Use `collectAllSemiFuture` instead.
Pull Request resolved: https://github.com/facebook/folly/pull/1385

Reviewed By: yfeldblum

Differential Revision: D21991532

Pulled By: DerekTBrown

fbshipit-source-id: 4ba3378fe34b7e6bb910f7045267fdbab87ebb14

Summary:
Original commit changeset: 8eb472ce50bf

This breaks time measurement to include measuring the wait preceding handler/callback invocation.

Reviewed By: w-o-o

Differential Revision: D21986042

fbshipit-source-id: 42701b929878c3f56d736de5ca0417814c64fce1

Summary:
Debug builds can be prone to stack overflows if they are configurated to use the same stack sizes as prod builds.

This diff effectively doubles the stack size for debug builds to provide more buffer against overflows.

Reviewed By: yfeldblum

Differential Revision: D21913754

fbshipit-source-id: bd32cc4dd9c79a50be178e5d6d30804a83e60ee4

Summary: Returns the previous/next power of two that are strictly smaller/greater than the parameter.

Reviewed By: yfeldblum, Gownta

Differential Revision: D21920224

fbshipit-source-id: be919063379e5b231cc69d743128fcaeb0ea9f39

Summary: [Folly] Cut the FOR_EACH_KV macro, which may be replaced by a combination of range-for and structured bindings.

Differential Revision: D21826182

fbshipit-source-id: ce4712afd3d0d7806eb1fca8c97009da117f982e

Reviewed By: yfeldblum

Differential Revision: D21921631

fbshipit-source-id: e905d6d2a96775a8c3b328fb78c8d32897f634f6

Summary: connect will automatically bind the socket if the socket is not bound yet

Reviewed By: yangchi

Differential Revision: D21845740

fbshipit-source-id: 27a5b44476dfc0b2ae5ff2f0a6c1bd4e976eadc9

Summary: [Thrift] Dead Code: `TAsyncSocket`.

Reviewed By: vitaut

Differential Revision: D20851837

fbshipit-source-id: d4279fb1ab712f338d399220df26d56c4ab7076a

Summary:
[Folly] `EventBase::getRecentSteadyTime`, returning a recent `steady_clock::time_point` which is updated each pass through the event loop, but not for each ready event or function.

Assuming everything in the loop is truly asynchronous, this permits callers to get a reasonably accurate approximation of the current time, but for many callers to blend or amortize the cost of getting that current time.

May only be called from the running IO thread.

Differential Revision: D21866783

fbshipit-source-id: 8eb472ce50bf012616e567b29f6724c67ef8d41a

Summary: [Folly] `atomic_ref::compare_exchange_strong` and `atomic_ref::compare_exchange_weak`.

Differential Revision: D21923944

fbshipit-source-id: 55620473ea253782cc1dbb95baef38c96a9fbc70

Summary: This provides a single mechanism to mitigate deadlocks in singleton destructors.

Reviewed By: yfeldblum

Differential Revision: D21827615

fbshipit-source-id: 090bad1a91238310e7814663193711df0f4d622a

Summary: [Folly] Deduction guide for `atomic_ref`.

Reviewed By: markisaa

Differential Revision: D21923854

fbshipit-source-id: 8ad10692b95c653fc65302e6ad0118cbd615a62f

Summary:
All implementations of transports in practice were all AsyncTransportWrappers
(AsyncSocket, AsyncSSLSocket, AsyncFizzBase, etc.).

AsyncTransportWrapper was confusing. The only additional functionality that
it provided was the ability to query underlying transports, a piece of
functionality which makes just as much sense on AsyncTransport.

The simplified model:

"AsyncTransport deals with bidirectional I/O. It is both an AsyncReader, and
an AsyncWriter. It may be nested."

This diff changes AsyncTransportWrapper usages in folly to refer to
AsyncTransport, and aliases AsyncTransportWrapper for compatibility.

Reviewed By: yfeldblum

Differential Revision: D21915048

fbshipit-source-id: 741fad91b8f7c8080f942168f5513b12602cfe9a

Summary:
It was very hard to read without any code highligting.
Pull Request resolved: https://github.com/facebook/folly/pull/1364

Reviewed By: Orvid

Differential Revision: D21921822

Pulled By: yfeldblum

fbshipit-source-id: aa1bc39a5d38b055fe4370ccd4ac0b7d5e0273d4

Summary:
[Folly] Add missing `#include <sys/wait.h>` in `folly/test/RandomTest.cpp`.

Fixes https://github.com/facebook/folly/issues/1371.

Reviewed By: Orvid

Differential Revision: D21910410

fbshipit-source-id: 31a045960b2e67282fa77595dfdf840c338ef661

Summary:
[Folly] Mark `_r_debug` imports as weak imports. `_r_debug` is available in `<link.h>` but is not a portable API, so detect whether it is available at runtime and use it only if it is available.

Fixes: https://github.com/facebook/folly/issues/1373.

Reviewed By: Orvid

Differential Revision: D21911715

fbshipit-source-id: 660c0bc90d405d9a43826e7bdfc3b04480728b66

Summary: [Folly] Cut dead code: `countLoadedElfFiles()`.

Differential Revision: D21910945

fbshipit-source-id: 43ff7d118b4876e2cbd4527713c8552963810537

Summary:
[Folly] Let `ElfCache` be unbounded to permit binaries with many dynamically-linked libraries from continuously missing the cache when symbolizing.

Some applications symbolize stacktraces relatively frequently. When the build is using dynamic linking, such as might be done when developing the application or running the unit-tests, the overhead from re-loading `ElfFile` instances can appear. Address this by making the cache be unboundedly large.

This is unlikely to affect applications built using mostly-static linking, such as might be done for production builds, even when they are large applications built from many libraries, since the capacity parameter is usually much larger than the total number of dynamically loaded libraries.

Currently, no substantial work is done when initializing `ElfFile` instances. If substantial work were to be done, especially in an unoptimized build such as might be used when developing the application or running the unit-tests, and instances do not stay in cache, then that substantial work would be repeated whenever symbolizing stacktraces rather than being amortized.

Reviewed By: luciang

Differential Revision: D18819555

fbshipit-source-id: 0e75326133e901e7bd49ea3cefe9b318e6d4466f

Summary: It's possible that we still have a recurring pool resizer task scheduled after virtual event base is destroyed. This changes makes sure that we don't try to reschedule it if VirtualEventBase is already destroyed.

Reviewed By: yfeldblum

Differential Revision: D21875241

fbshipit-source-id: c4622c5d103c6291386055c153ab4aeebe7795a2

Summary:
In 0ae204a978c11ddefafd81bd319a078239a44c1c the 'projects_dir' option
became a required constructor argument since it is called within the
constructor. However, it has not been adjusted in the subclasses that
used to set the option after instantiation. This commit fixes the
'shell_builder' and the 'debian_system_builder'.
Pull Request resolved: https://github.com/facebook/openr/pull/50

Test Plan:
1. Go to build directory: `cd build`
2. Run the `shell_builder` & `debian_system_builder`:
    - `python fbcode_builder/shell_builder.py`
    - `python debian_system_builder/debian_system_builder.py`

`shell_builder` output before:
```
Traceback (most recent call last):
  File "fbcode_builder/shell_builder.py", line 102, in <module>
    builder = ShellFBCodeBuilder()
  File "/home/butjar/tu/ma/openr/build/fbcode_builder/fbcode_builder.py", line 93, in __init__
    self._github_dir = self.option('projects_dir')
  File "/home/butjar/tu/ma/openr/build/fbcode_builder/fbcode_builder.py", line 108, in option
    raise RuntimeError('Option {0} is required'.format(name))
RuntimeError: Option projects_dir is required
```

`shell_builder` output after:
```
set -exo pipefail
export CCACHE_DIR='/home/butjar/.fbcode_builder-sZshomesZsbutjarsZstusZsmasZsopenr/.ccache' CC="ccache ${CC:-gcc}" CXX="ccache ${CXX:-g++}"
### Diagnostics ###

# Builder ShellFBCodeBuilder(google/googletest:cmake_defines={u'BUILD_GTEST': u'ON', u'BUILD_SHARED_LIBS': u'OFF'}, google/googletest:git_hash=u'release-1.8.1', facebook/openr:local_repo_dir='/home/butjar/tu/ma/openr', facebook/zstd:git_hash=ShellQuoted(u'$(git describe --abbrev=0 --tags origin/master)'), openr/build:cmake_defines={u'ADD_ROOT_TESTS': u'OFF'}, thom311/libnl:git_hash=u'libnl3_2_25', projects_dir=u'/home/butjar/.fbcode_builder-sZshomesZsbutjarsZstusZsmasZsopenr', fmtlib/fmt:git_hash=u'5.3.0', wangle/wangle/build:cmake_defines={u'BUILD_TESTS': u'OFF'}, prefix=u'/home/butjar/.fbcode_builder-sZshomesZsbutjarsZstusZsmasZsopenr/installed', fizz/fizz/build:cmake_defines={u'BUILD_TESTS': u'ON'}, ccache_dir=u'/home/butjar/.fbcode_builder-sZshomesZsbutjarsZstusZsmasZsopenr/.ccache', zeromq/libzmq:git_hash=u'v4.2.2', make_parallelism=4, jedisct1/libsodium:git_hash=u'stable')
hostname
cat /etc/issue || echo no /etc/issue
g++ --version || echo g++ not installed
cmake --version || echo cmake not installed

### Check out fmtlib/fmt, workdir build ###

mkdir -p '/home/butjar/.fbcode_builder-sZshomesZsbutjarsZstusZsmasZsopenr' && cd '/home/butjar/.fbcode_builder-sZshomesZsbutjarsZstusZsmasZsopenr'
git clone  https://github.com/'fmtlib/fmt'
mkdir -p '/home/butjar/.fbcode_builder-sZshomesZsbutjarsZstusZsmasZsopenr'/'fmt'/'build' && cd '/home/butjar/.fbcode_builder-sZshomesZsbutjarsZstusZsmasZsopenr'/'fmt'/'build'
git checkout '5.3.0'

### Build and install fmtlib/fmt ###

...
```

Reviewed By: steven1327

Differential Revision: D21865881

Pulled By: saifhhasan

fbshipit-source-id: dfd78127d3b2c78721f84a3ecafe0b7198c38f06

Summary:
Typo in python shebang introduced by 0d19e27, probably by accident.

Found while skimming the code.
Pull Request resolved: https://github.com/facebook/openr/pull/51

Reviewed By: steven1327

Differential Revision: D21865922

Pulled By: saifhhasan

fbshipit-source-id: 5f2c2c2fac82078070920915812139f5fef1c7fe

Summary: [Folly] Move `AlignedSysAllocator` computation of max value over input alignment values from two places to a single place.

Differential Revision: D19229096

fbshipit-source-id: 4e95c7b7e0afe99c37116150184eb180683c7d13

Reviewed By: StanislavGlebik

Differential Revision: D21549859

fbshipit-source-id: 0e143354a60578732ae1eed8c3c71b9f859e3958

Summary: Currently output from build command is decoded with "surrogateescape" error handler, but when writing to log files/stdout we don't specify error handlers to be also "surrogateescape" according to https://docs.python.org/3/library/codecs.html#error-handlers, which could cause exception when there's surrogate characters logged in message.

Reviewed By: yfeldblum

Differential Revision: D21850411

fbshipit-source-id: 21c51d1ab2132171ae29f2d1fbe42655ebee94c5

Summary:
When a session is newly negotiated, pass it to the SSLSession belonging to the corresponding AsyncSSLSocket through SSLSessionManager. That SSLSession then becomes resumable.

This allows SSLSessions obtained from an AsyncSSLSocket to later become resumable once the session is negotiated (asynchronously in TLS 1.3).

Reviewed By: yfeldblum

Differential Revision: D21035731

fbshipit-source-id: acbaa258798e7774e742c5765ef33e24573f1c78

Summary: Refactor AsyncSSLSocket session code into a new class called SSLSessionManager, which is a member of AsyncSSLSocket. Will allow for SSLContext to interact with SSLSession through SSLSessionManager, without depending on AsyncSSLSocket.

Reviewed By: yfeldblum, mingtaoy

Differential Revision: D21164020

fbshipit-source-id: e6b38336127fb000587bfe6948c2274afe8d85e0

Summary: codecleanupraccoon

Reviewed By: mjoras

Differential Revision: D21845742

fbshipit-source-id: 5adf159ed4ec7a48c76cffdb02d039888ab1686d

Summary:
Update fmt version to 6.2.1 for better compatibility with the version used in fbcode. Among other things this fixes fbthrift build failure on Travis:

```
/home/fbthrift/thrift/lib/cpp2/async/RocketClientChannel.cpp:70:67:   required from here
/home/install/include/fmt/core.h:492:3: error: static assertion failed: don't know how to format the type, include fmt/ostream.h if it provides an operator<< that should be used
```
which is caused by trying to format an enum class without a formatter - only supported as of 6.0.

Reviewed By: stevegury, avalonalex

Differential Revision: D21860076

fbshipit-source-id: 1857ab65822956b005980b8dfff7a967508f507c

Summary: [Folly] Cut the `FOR_EACH_ENUMERATE` macro, which may be replaced by a combination of range-for, `ranges::view::enumerate`, and structured bindings.

Reviewed By: markisaa

Differential Revision: D21813019

fbshipit-source-id: fc9ac09a4e2f72f1433d0a518f03d5cd69a59c55

Summary: Expose async read/write functionality

Reviewed By: yfeldblum, kevin-vigor

Differential Revision: D21731597

fbshipit-source-id: 95a0af53c7b85e1bf1a2619586091b6633bc7b8a

Summary: Pull Request resolved: https://github.com/facebook/folly/pull/1110

Reviewed By: Orvid

Differential Revision: D21110331

Pulled By: yfeldblum

fbshipit-source-id: 57522232efb7268bc290e4f22057f531a380fb81

Summary:
SemiFuture::within creates two valid SemiFutures and promptly overwrites them, both discarding valid SemiFutures and wasting the core allocation. It later drops the updated versions without directly consuming them, instead stealing the deferred executors.

This update initializes the two SemiFutures as empty, and safely terminates the chain with trivial callbacks so the SemiFutures can be treated as consumed.

Reviewed By: yfeldblum

Differential Revision: D21769500

fbshipit-source-id: eab13a78b17ecfc937b42c8d5e01e1292158d9ed