Summary:
Adds a find_package module for Zstd.
Closes https://github.com/facebook/folly/pull/785

Reviewed By: pixelb

Differential Revision: D7080036

Pulled By: yfeldblum

fbshipit-source-id: 018ff087df725de5344a245dea64ce1b813f6938

Summary: We are going to enable `-Werror=unused-parameter` flag and I need to manually fix some files so we rest of this process can be automated with a tool called clang-tidy.

Reviewed By: yfeldblum

Differential Revision: D7071617

fbshipit-source-id: 0165d9c79834b479ad0f598ea64404a86f47dcc6

Summary:
[Folly] `to_signed` and `to_unsigned`, for casting a value to the signed or unsigned version of the value's type.

And use them in time conversion functions.

Reviewed By: markw65

Differential Revision: D7020215

fbshipit-source-id: 47a6aeeea487cd7d59d23e7ded40cc66dcc57c52

Summary:
[Folly] `throw_exception` to support `-fno-exceptions`, switching all invocations of `std::__throw_....`.

Removes the need to use the non-portable `bits/functexcept.h`.

Reviewed By: mzlee, ot

Differential Revision: D7050335

fbshipit-source-id: 53d15639baa268a51f703816f04f314454d64979

Summary:
This test suite used to wrap equality of two paths by using `EXPECT_TRUE` to
avoid an old bug in GTest 1.6.0. Now that we use GTest 1.8.0, we can
simplify our test.
Closes https://github.com/facebook/folly/pull/780

Differential Revision: D7052503

Pulled By: yfeldblum

fbshipit-source-id: 5459736fca04cc45acf88a3d7dffc855ad7c9376

Summary: format changes, purely generated by clang-format.

Differential Revision: D7035579

fbshipit-source-id: 8452e1613adefe7dcfbbed4a3ef97be681790416

Summary: Packing the structs disregards the alignment of the storage. We should only do this on platforms where we do not need alignment.

Reviewed By: yfeldblum

Differential Revision: D7058593

fbshipit-source-id: 63b0d86bcf8b4f660ca244b1a4696e3ca64ecd6a

Reviewed By: yfeldblum

Differential Revision: D7060959

fbshipit-source-id: 914c517b4c8e93c15771f6acefaddce3138776a4

Summary:
Add a CMake find_package script for LZ4

simpkins
Closes https://github.com/facebook/folly/pull/778

Reviewed By: simpkins

Differential Revision: D7064988

Pulled By: yfeldblum

fbshipit-source-id: 60596ead4b4fd38474dab4c33d4c3fbb0f37549c

Summary:
Clang does not support the warning option "-Wclobbered", so we cannot
do a pragma push and pop for this warning. So, we push and pop this
particular warning for GCC only.

As it stands currently, Clang accepts `#pragma GCC` directives. If this
sort of thing comes up more in the future, it may make sense for Folly
to define a macro for easily disabling warnings for either just GCC or
just Clang.

simpkins yfeldblum
Closes https://github.com/facebook/folly/pull/779

Reviewed By: simpkins

Differential Revision: D7059916

Pulled By: yfeldblum

fbshipit-source-id: a6d420dc6ae435e3be1229b2bb421910bc8794ff

Summary:
Clear hazard pointers in ~hazptr_array() and ~hazptr_local().
Added tests to detect uncleared hazard pointers when using hazptr_array and hazptr_local.

Differential Revision: D6995057

fbshipit-source-id: 5b8fa1d197c3959ed670d0a019959bd57f5df3d0

Reviewed By: igorsugak

fbshipit-source-id: 4a93675cc1931089ddd574cacdb15d228b1e5f37

Summary: Since sysfs doesn't have cache information for the CPU on Android guard this on Android

Reviewed By: yfeldblum

Differential Revision: D7051199

fbshipit-source-id: 20fcfa91aa2f642c6cab33b0fb55f121b609d58f

Reviewed By: everiq, igorsugak

Differential Revision: D7046710

fbshipit-source-id: 8e10b1f1e2aecebbfb229c742e214db887e5a461

Summary:
This allows to create a Channel with AsyncSSLSocket while evb in not looping yet.
Also add ssl channel tests to thrift.

Reviewed By: yfeldblum

Differential Revision: D6991017

fbshipit-source-id: 0852b18e03a6b9d072cb4ec0182f1a41a5960eef

Summary:
[Folly] Fix `folly/experimental/hazptr/` under gcc7, which has a bug in emitting TLS init functions for `extern thread_local` variables.

Fixes:
```
folly/experimental/hazptr/test/HazptrTest.cpp:642: error: undefined reference to 'TLS init function for folly::hazptr::tls_priv_data_'
folly/experimental/hazptr/test/HazptrTest.cpp:642: error: undefined reference to 'TLS init function for folly::hazptr::tls_priv_data_'
```

The trick is to use a template class with `static thread_local` members with member definitions in the same header, and then to use only one instance of that template class.

Reviewed By: pixelb, magedm

Differential Revision: D7047235

fbshipit-source-id: 0551179a40f13796d6c0bb99aa806c73bd9dd471

Summary:
Original commit changeset: bee63b3f597d.

Original revision is breaking integration tests by failing with the SIGSEGV in operator++, please check D6993857 for more details.

Reviewed By: anshulverma

Differential Revision: D7051998

fbshipit-source-id: e5cfbb22aee5f5ec9871a9a34bb27eb5b0036d1b

Summary:
Fixes for hazptr deletion on map destruction.

Several iteration cases don't properly release their hazard pointers.
This isn't disastrous, but means objects may stick around longer than necessary.

This diff adds tests and fixes for iteration to ensure we eagerly reset all hazard pointers.

Reviewed By: magedm

Differential Revision: D6993857

fbshipit-source-id: bee63b3f597d1ed16cae5ed22a971fd4be2e1a77

Summary:
If a pthread_rwlock_t shared mutex is currently write-locked, we can
find its owner. However, if it is not write-locked or read-locked
(possibly by multiple threads), we will be unable to find the owner.

We can extend our deadlock detector to find deadlocks involving write-locked
pthread_rwlock_t mutexes as well.

Example output:

  Type "deadlock" to detect deadlocks.
  (gdb) deadlock
  Found deadlock!
  Thread 2 (LWP ...) is waiting on pthread_mutex_t (0x...) held by Thread 3 (LWP ...)
  Thread 3 (LWP ...) is waiting on pthread_rwlock_t (0x...) held by Thread 2 (LWP ...)

Reviewed By: yfeldblum

Differential Revision: D6974509

fbshipit-source-id: 8e64cb35f93958a9785070184df4c818b086ff0f

Summary:
The install step for folly CMake-based builds installs a folly-config.cmake
file that downstream projects can use to depend on folly in their own
CMakeLists.txt files.

CMakeLists.txt was previously generating the folly-config.cmake file by copying
CMake/folly-deps.cmake.  This seems wrong, as the installed folly-config.cmake
file should not contain `find_package()` statements that depend on CMake
modules only available in the folly source.

This adds a new folly-config.cmake.in template instead.

Reviewed By: yfeldblum

Differential Revision: D7035992

fbshipit-source-id: e6023094a807cf481ac49998c6f21b213be6c288

Summary:
When compiling with optimization enabled, gcc 7.2 complains about the
`childDir` variable potentially being clobbered by the child process after
`vfork()`.  This shouldn't matter since `childDir` is only used in the child
process, and not in the parent after the `vfork()`.

Reviewed By: yfeldblum

Differential Revision: D7035993

fbshipit-source-id: c80a4e18ad4f629a3d08e310cfd4500ebaf70994

Summary:
gcc does not complain about unknown `-Wno-*` flags by default, and older
versions of gcc do not support `-Werror=unknown-warning-option`.  Therefore
these checks for `-Wno-noexcept-type` and `-Wno-nullability-completeness` could
incorrectly indicate that the compiler supports these flags.

This changes the checks to check against the positive version of the warning
flag.

Reviewed By: yfeldblum

Differential Revision: D7035995

fbshipit-source-id: b1511d31721aeb779859848e20820c8a7fea4faa

Summary:
This brings us closer to being able to compile the open
source version of Folly with Clang. There are a few other
open pull requests that need to be addressed to allow us to
compile on Clang without any warnings that aren't already
explicitly disabled. See pull requests #745 and #756.

Closes https://github.com/facebook/folly/pull/772

Reviewed By: simpkins

Differential Revision: D7021595

Pulled By: yfeldblum

fbshipit-source-id: 350b972c74502ca2bc147f21428c622b19805b89

Summary:
[Folly] Avoid assuming that `FOLLY_HAVE_VLA` is defined.

Treat undefined as meaning `0` rather than requiring it be defined to either `0` or `1`.

Closes #773.

Reviewed By: andrewjcg

Differential Revision: D7028174

fbshipit-source-id: 90c52a3c5b640776f728c70b69f0500749d7ab7f

Summary: [Folly] Split definition of `kMscVer` from `kIsWindows` and use in `hazptr`.

Reviewed By: mzlee

Differential Revision: D7027159

fbshipit-source-id: 1dd2bad821919a2d579aa615ecb2921e5a3ce4d8

Summary:
During move construction and assignment `size_` and `max_size_` aren't set.
Added a test case that attempted to allocate 4096 GB before the patch, and passes after.

Reviewed By: yfeldblum

Differential Revision: D7005041

fbshipit-source-id: b42a0a408ce49ddded4ba805fc064cd11df2457e

Summary: Log bytes before/after (de)compression, and timing to the logging backend with probability 1/50.

Reviewed By: yfeldblum

Differential Revision: D6817204

fbshipit-source-id: 7fde5284b8c97355ec445376a7c481e9ffd2cfce

Summary: s/lock_unshared/unlock_shared/

Reviewed By: yfeldblum

Differential Revision: D7017355

fbshipit-source-id: 7f9d12b4c80cc796086a74890c58aceea931d93c

Summary:
[Folly] Less `goto` in `ltrimWhitespace` and `rtrimWhitespace`.

The generated machine code remains unchanged for `g++ -O3` builds.

Generally, prefer to use `goto` in cases which cannot, or which can only arduously, be accomplished without it. In other words, reserve `goto` to cases where `goto` is necessary, rather than to cases where it saves one line.

Closes #732.

Reviewed By: andrewjcg

Differential Revision: D7027269

fbshipit-source-id: 91a4c5dba0e4c13dc727393799edc9b596cdb8b9

Summary: It's not available in VS2015u3.

Reviewed By: yfeldblum

Differential Revision: D7005874

fbshipit-source-id: 5477018e444d9bf118089bbbcfabbbf4e16a3198

Summary: Closes https://github.com/facebook/folly/pull/770

Reviewed By: nbronson

Differential Revision: D6991705

Pulled By: yfeldblum

fbshipit-source-id: 9f6ae0e09b436993ee998fe6c5d347121c229489

Summary:
std::atomic is no longer trivial, and VS2015 and VS2017 both
fail this static assert, as will future versions of conforming compilers.
Updates to folly mean that the hazptr header is transitively included in
more places which makes it easier to trip this even when not using hazptr.
Disabling this assert to visual studio at least saves users a headache.

Reviewed By: yfeldblum, magedm

Differential Revision: D7006587

fbshipit-source-id: 8481e1d5668aee8cab703a04b2a390550c210a2c

Summary:
UndefinedBehaviorSanitizer: null-pointer-use buck-out/dev-asan-ubsan/gen/folly/concurrency/concurrent_hash_map#header-mode-symlink-tree-with-header-map,headers/folly/concurrency/ConcurrentHashMap.h:440:30 in
Finished test run: https://our.intern.facebook.com/intern/testinfra/testrun/882372015
Summary (total time 1.49s):
  PASS: 0
  FAIL: 0
  SKIP: 0
  FATAL: 1
    folly/concurrency/test:concurrent_hash_map_test - ConcurrentHashMap.CopyIterator
  TIMEOUT: 0
  OMIT: 0
```

Reviewed By: djwatson

Differential Revision: D7003359

fbshipit-source-id: d6764caf2dfb1f19cf5b38a9e89d7c0583c75412

Summary: [Folly] Cut outdated comment referencing `TFramedAsyncChannel`.

Reviewed By: knekritz

Differential Revision: D7002980

fbshipit-source-id: 206ac77abf8882e26a5b98ad4229c7a645912947

Summary: This makes it easier to integrate folly::Observer with callback-based code.

Reviewed By: spalamarchuk

Differential Revision: D6888234

fbshipit-source-id: ccf9b57c07ee323ee11496d14f8c90e3331cc7bb

Reviewed By: yfeldblum

Differential Revision: D6957008

fbshipit-source-id: 848932827efaf8529513026b45446da2c1697253

Summary: The template that this template wraps requires only forward iterators, so it doesn't make sense for the wrapper to be stricter than that.

Reviewed By: yfeldblum

Differential Revision: D6988987

fbshipit-source-id: 575dcacf7b1873ea0d7112acf84670842ee82fa7

Summary: Add hazptr_cleanup to ConcurrentHashMap destructor & add a test to ensure deletion is working.

Reviewed By: djwatson

Differential Revision: D6951359

fbshipit-source-id: 277c304a0e5073605010b14764d05a27e6e10b2d

Summary:
Added missing steps for registering and deregistering per-thread hazptr_priv structures with the default domain.
Updated tests to detect the error

Reviewed By: djwatson, davidtgoldblatt

Differential Revision: D6965459

fbshipit-source-id: 6eb6a5981c1d22518f318ace7387a3941a013352

Summary:
It's common to use UBSAN with ASAN at the same time, and we'll merge them eventually too. As a result we can check for ASAN defined macros to conditionally compile code for UBSAN.

We still have a few build modes that use standalone UBSAN, and unlike other sanitizers, UBSAN doesn't define a magic macro that we could use. In the past we added UNDEFINED_SANITIZER to our compiler flags, but I'd like to go away from it towards a more standard solution (eg check for ASAN).

Reviewed By: yfeldblum, luciang

Differential Revision: D6931054

fbshipit-source-id: 4b298d1cd72cecd693bf99eda309568ef019c544