Summary:
Move constructors are just like any other constructors. `this` is not in a valid state. You aren't supposed to destroy `this` before move-constructing it.

This was detected by ubsan stress runs.

UBSAN report:

```
[ RUN      ] TemporaryFile.moveCtor
folly/experimental/TestUtil.cpp:91:20: runtime error: load of value 3, which is not a valid value for type 'bool'
 [ failed: 1 ]
 ````

Reviewed By: yfeldblum

Differential Revision: D6501500

fbshipit-source-id: 83bd0525ac2c1f5951f70f5596034bb6cb0ca985

Summary:
[Folly] Rename `Baton::timed_wait` to `try_wait_for` and `try_wait_until`.

For consistency with `std::timed_mutex`'s suite of `lock` member functions, as well as `SaturatingSemaphore` and others.

Reviewed By: davidtgoldblatt

Differential Revision: D6493714

fbshipit-source-id: 566c6d5dc0f6db4a0308cbd1972d53794f898383

Summary: [Folly] Move `folly/Baton.h` to `folly/synchronization/`.

Reviewed By: phoad, Orvid

Differential Revision: D6490282

fbshipit-source-id: 66e2d25ffe3275d576b97b81c1987709000f6649

Summary:
[Folly] Use `boost::filesystem::current_path` in `ChangeToTempDir`.

It will report failures noisily.

Reviewed By: pixelb

Differential Revision: D6493243

fbshipit-source-id: 423dc0e3a46781e9af42fee69060d31085f1a7c6

Reviewed By: yfeldblum

Differential Revision: D6482348

fbshipit-source-id: 5b2d3c984b761a54d5a9eba48953c556ed22cda6

Summary:
Upon debugging for the attached task, it appears to me the problem are in two places:
. After a callback has been run, context_ wasn't reset
. After a callback has been canceled, context_ wasn't reset

In this diff:
. Fix these two places.
. Updating unit tests to cover these two cases.

Reviewed By: yfeldblum

Differential Revision: D6465788

fbshipit-source-id: 85b3b29dc80c9f3971c85f302385d41ded44fa0e

Split get_default() into two for deferred default construction and added forwarding to speed up default element construction with rvalues

Summary:
As it stood currently folly::get_default() would unnecessarily
construct a value into the third parameter, which was unnecessary in the code
path where the element was found in the map.  Also the default value can be
forwarded to the return type in the code path where the element is not found
and an rvalue parameter is passed as the default value

Reviewed By: yfeldblum

Differential Revision: D6390315

fbshipit-source-id: ef692b827d5a36751b4eb1e12042869e8fbba2e5

Summary:
Adds a bitreverse function to Bits.h

AFAIK there is no great way to do this on x86, takes ~4-5ns.
arm has a single instruction we can drop in in the future.

Reviewed By: yfeldblum

Differential Revision: D6459283

fbshipit-source-id: 129db196b2fac95386f601ae57843aa87523b915

Summary:
In the latest stable kernel 4.14.3 as of 2017-12-04, unix domain socket does not support MSG_ERRQUEUE. So recvmsg(MSG_ERRQUEUE) will read application data from unix doamin socket as error message, which breaks the message flow in application. This diff disable setErrMessageCB for Unix Domain Socket.

Both [[ https://github.com/torvalds/linux/blob/master/net/ipv4/tcp.c#L1782 | tcp_recvmsg ]] and [[ https://github.com/torvalds/linux/blob/master/net/ipv4/udp.c#L1571 | udp_recvmsg ]] will check flag MSG_ERRQUEUE and read from error queue.  However, there is nothing about MSG_ERRQUEUE in [[ https://github.com/torvalds/linux/blob/master/net/unix/af_unix.c#L2249 | af_unix ]].

Reviewed By: yfeldblum

Differential Revision: D6479465

fbshipit-source-id: eba2c8650e96466f2b361a42ddf90053d65f19bd

Summary: [Folly] Add missing check against `SemiFuture` in `FutureBase` ctor.

Reviewed By: LeeHowes

Differential Revision: D6469021

fbshipit-source-id: 0ca31461afee4bf64725e065a8cb4d5e933d2013

Summary:
/proc may be unavailable in restricted environments, which can
cause pthread_getattr_np to fail.  This diff adds checking to the return
code from that function.

Reviewed By: yfeldblum

Differential Revision: D6473789

fbshipit-source-id: de016d32f29edf8410808dfb491987692f39e768

Summary:
Currently QueueAppender needs to follow a chain of 4 indirections (QueueAppender->IOBufQueue->IOBuf(head)->IOBuf(tail)->data).
This diff adds a cache of writable tail range in IOBufQueue and allows it to be placed externally.

Before this diff on hot path QueueAppender::write<signed char> was ~167 bytes of code (with majority being actually executed), after this diff it's down to ~30 bytes:
  0x0000000000419d10 <+0>:     mov    (%rdi),%rax
  0x0000000000419d13 <+3>:     cmp    %rax,0x8(%rdi)
  0x0000000000419d17 <+7>:     je     0x419d28 <folly::io::QueueAppender::write<signed char>(signed char)+24>
  0x0000000000419d19 <+9>:     mov    %sil,(%rax)
  0x0000000000419d1c <+12>:    addq   $0x1,(%rdi)
  0x0000000000419d20 <+16>:    retq
  0x0000000000419d21 <+17>:    nopl   0x0(%rax)
  0x0000000000419d28 <+24>:    movsbl %sil,%esi
  0x0000000000419d2c <+28>:    jmpq   0x419ca0 <folly::io::QueueAppender::writeSlow<signed char>(signed char)>

With this diff, Thrift serialization performance is improved up to 2x with production workloads (2x for compact, 3x for binary).

Thrift benchmark output:
Before:
  ============================================================================
  thrift/lib/cpp2/test/ProtocolBench.cpp          relative  time/iter  iters/s
  ============================================================================
  BinaryProtocol_write_Empty                                  58.05ns   17.23M
  BinaryProtocol_write_SmallInt                               75.17ns   13.30M
  BinaryProtocol_write_BigInt                                 74.60ns   13.41M
  BinaryProtocol_write_SmallString                            85.12ns   11.75M
  BinaryProtocol_write_BigString                             802.96ns    1.25M
  BinaryProtocol_write_BigBinary                             174.69ns    5.72M
  BinaryProtocol_write_LargeBinary                           171.81ns    5.82M
  BinaryProtocol_write_Mixed                                 130.97ns    7.64M
  BinaryProtocol_write_SmallListInt                          123.99ns    8.06M
  BinaryProtocol_write_BigListInt                             40.72us   24.56K
  BinaryProtocol_write_BigListMixed                          784.78us    1.27K
  BinaryProtocol_write_LargeListMixed                         98.84ms    10.12
  CompactProtocol_write_Empty                                 64.38ns   15.53M
  CompactProtocol_write_SmallInt                              76.74ns   13.03M
  CompactProtocol_write_BigInt                                83.62ns   11.96M
  CompactProtocol_write_SmallString                           86.05ns   11.62M
  CompactProtocol_write_BigString                            786.18ns    1.27M
  CompactProtocol_write_BigBinary                            184.91ns    5.41M
  CompactProtocol_write_LargeBinary                          182.12ns    5.49M
  CompactProtocol_write_Mixed                                120.89ns    8.27M
  CompactProtocol_write_SmallListInt                         119.74ns    8.35M
  CompactProtocol_write_BigListInt                            43.76us   22.85K
  CompactProtocol_write_BigListMixed                         595.90us    1.68K
  CompactProtocol_write_LargeListMixed                        72.80ms    13.74
  ============================================================================
After:
  ============================================================================
  thrift/lib/cpp2/test/ProtocolBench.cpp          relative  time/iter  iters/s
  ============================================================================
  BinaryProtocol_write_Empty                                  65.97ns   15.16M
  BinaryProtocol_write_SmallInt                               72.31ns   13.83M
  BinaryProtocol_write_BigInt                                 72.67ns   13.76M
  BinaryProtocol_write_SmallString                            77.56ns   12.89M
  BinaryProtocol_write_BigString                             782.07ns    1.28M
  BinaryProtocol_write_BigBinary                             179.69ns    5.57M
  BinaryProtocol_write_LargeBinary                           182.62ns    5.48M
  BinaryProtocol_write_Mixed                                  91.62ns   10.92M
  BinaryProtocol_write_SmallListInt                           96.22ns   10.39M
  BinaryProtocol_write_BigListInt                             19.65us   50.90K
  BinaryProtocol_write_BigListMixed                          245.69us    4.07K
  BinaryProtocol_write_LargeListMixed                         46.56ms    21.48
  CompactProtocol_write_Empty                                 74.44ns   13.43M
  CompactProtocol_write_SmallInt                              80.35ns   12.45M
  CompactProtocol_write_BigInt                                85.30ns   11.72M
  CompactProtocol_write_SmallString                           82.61ns   12.10M
  CompactProtocol_write_BigString                            784.77ns    1.27M
  CompactProtocol_write_BigBinary                            193.20ns    5.18M
  CompactProtocol_write_LargeBinary                          192.53ns    5.19M
  CompactProtocol_write_Mixed                                 99.78ns   10.02M
  CompactProtocol_write_SmallListInt                         104.77ns    9.54M
  CompactProtocol_write_BigListInt                            25.62us   39.03K
  CompactProtocol_write_BigListMixed                         272.42us    3.67K
  CompactProtocol_write_LargeListMixed                        38.32ms    26.09
  ============================================================================

QueueAppender Benchmark output (although not very representative due to a tight loop):
Before:
  ============================================================================
  folly/io/test/QueueAppenderBenchmark.cpp        relative  time/iter  iters/s
  ============================================================================
  write_uint8                                                 10.50us   95.20K
  write_uint16                                                 5.48us  182.49K
  write_uint32                                                 2.73us  366.22K
  push_64b                                                     9.77us  102.36K
  push_1024b                                                 112.87us    8.86K
  append                                                      64.21us   15.57K
  preallocate_postallocate_1b                                 16.34us   61.19K
  preallocate_postallocate_4b                                 15.56us   64.26K
  preallocate_postallocate_32b                                22.17us   45.11K
  preallocate_postallocate_256b                              149.55us    6.69K
  ============================================================================

After:
  ============================================================================
  folly/io/test/QueueAppenderBenchmark.cpp        relative  time/iter  iters/s
  ============================================================================
  write_uint8                                                  8.86us  112.81K
  write_uint16                                                 3.91us  255.68K
  write_uint32                                                 2.08us  481.78K
  push_64b                                                     8.24us  121.39K
  push_1024b                                                 115.50us    8.66K
  append                                                      67.52us   14.81K
  preallocate_postallocate_1b                                 13.86us   72.17K
  preallocate_postallocate_4b                                 11.67us   85.71K
  preallocate_postallocate_32b                                20.35us   49.14K
  preallocate_postallocate_256b                              148.57us    6.73K
  ============================================================================

Reviewed By: yfeldblum

Differential Revision: D6427749

fbshipit-source-id: 8495cc74b6106b15d201e37533ae4c0a1abc9d74

Summary: Adds an AdFork::unregisterHandler command, such that we can register and unregister fork handlers.

Reviewed By: yfeldblum

Differential Revision: D6439796

fbshipit-source-id: b710152f8cf98371c330b484cd5fe42de44e74ac

Summary:
UnboundedQueue supports:
- SPSC, MPSC, SCMP, MPMC
- Non-waiting, waiting, and timed consumer operations.
- Producers never wait or fail (unless out-of-memory).
- Memory usage grows and shrinks dynamically

```
/// UnboundedQueue supports a variety of options for unbounded
/// dynamically expanding an shrinking queues, including variations of:
/// - Single vs. multiple producers
/// - Single vs. multiple consumers
/// - Blocking vs. spin-waiting
/// - Non-waiting, timed, and waiting consumer operations.
/// Producer operations never wait or fail (unless out-of-memory).
///
/// Template parameters:
/// - T: element type
/// - SingleProducer: true if there can be only one producer at a
///   time.
/// - SingleConsumer: true if there can be only one consumer at a
///   time.
/// - MayBlock: true if consumers may block, false if they only
///   spins. A performance tuning parameter.
/// - LgSegmentSize (default 8): Log base 2 of number of elements per
///   segment. A performance tuning parameter. See below.
///
/// When to use UnboundedQueue:
/// - If a small bound may lead to deadlock or performance degradation
///   under bursty patterns.
/// - If there is no risk of the queue growing too much.
///
/// When not to use UnboundedQueue:
/// - If there is risk of the queue growing too much and a large bound
///   is acceptable, then use DynamicBoundedQueue.
/// - If the queue must not allocate on enqueue or it must have a
///   small bound, then use fixed-size MPMCQueue or (if non-blocking
///   SPSC) ProducerConsumerQueue.
///
/// Template Aliases:
///   USPSCQueue<T, MayBlock, LgSegmentSize>
///   UMPSCQueue<T, MayBlock, LgSegmentSize>
///   USPMCQueue<T, MayBlock, LgSegmentSize>
///   UMPMCQueue<T, MayBlock, LgSegmentSize>
///
/// Functions:
///   Producer operations never wait or fail (unless OOM)
///     void enqueue(const T&);
///     void enqueue(T&&);
///         Adds an element to the end of the queue.
///
///   Consumer operations:
///     void dequeue(T&);
///         Extracts an element from the front of the queue. Waits
///         until an element is available if needed.
///     bool try_dequeue(T&);
///         Tries to extracts an element from the front of the queue
///         if available. Returns true if successful, false otherwise.
///     bool try_dequeue_until(T&, time_point& deadline);
///         Tries to extracts an element from the front of the queue
///         if available until the specified deadline.  Returns true
///         if successful, false otherwise.
///     bool try_dequeue_for(T&, duration&);
///         Tries to extracts an element from the front of the queue
///         if available for for the specified duration.  Returns true
///         if successful, false otherwise.
///
///   Secondary functions:
///     size_t size();
///         Returns an estimate of the size of the queue.
///     bool empty();
///         Returns true only if the queue was empty during the call.
///     Note: size() and empty() are guaranteed to be accurate only if
```

Reviewed By: djwatson

Differential Revision: D6157613

fbshipit-source-id: db423f86d1d0604d22f6b9c71ea0ed08be32e2a1

Summary:
X509_digest, or the "fingerprint" of the cert, is useful to identify
certificates with the same CN/SANs. This adds an API to get the SHA1 or SHA256
digest of a cert.

Reviewed By: yfeldblum

Differential Revision: D6457917

fbshipit-source-id: 148a5a2270e938b39065e00d7947c2fc57cd7f75

Summary:
AFAICT this is currently the only thing preventing the non-dynamic version of Folly's MPMCQueue from being allocation-free on enqueue and dequeue operations. Allocating this with a constant expression should move the allocation from runtime to link (possibly compile?) time, which will let us use it in allocation sensitive contexts.

Feel free to suggest other reviewers, I couldn't find an existing folly reviewer group.

Reviewed By: yfeldblum, agola11, nbronson

Differential Revision: D6447848

fbshipit-source-id: 86b84b19d62f1e1bcecdb9e757a6dfa90597b084

Summary: As in title, for eg larger stack size

Reviewed By: yfeldblum

Differential Revision: D6466762

fbshipit-source-id: 303e8732c8bfb64fbd8619163779942fe5f8b5a8

Summary:
Add makeSystemError() helper functions that are similar to the existing
throwSystemError() functions but just return the exception rather than throwing
it.  This is helpful for callers using folly::Expected or folly::Future, where
they need to return an exception type rather than throwing it.

This also includes comments about the fact that this code is using the wrong
error category.  The C++ standard indicates that std::generic_category() for
POSIX errno values.  I am not fixing this as part of this diff, since this
change has the potential to break existing users, and would need a fair amount
of testing first.

Reviewed By: yfeldblum

Differential Revision: D6456771

fbshipit-source-id: 4724b51b8d4a7f513ae70ea1b0c4f0516cfc205f

Summary:
Add an explicit `std::move()` around the return value of
`logConfigToDynamic()`.  This explicit move is required pre-C++14,
but is not required after DR 1579:
http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_defects.html#1579

Newer versions of g++ and clang no longer require the move.  However gcc
versions earlier than 5.0 do require it.

Reviewed By: yfeldblum

Differential Revision: D6466447

fbshipit-source-id: 1b15934490d4966e9b3e5612e0e2ecbb43c979ca

Summary:
Replace the initLoggingGlogStyle() function with a more generic initLogging()
function that accepts a log config string to be parsed with parseLogConfig().

Reviewed By: bolinfest, yfeldblum

Differential Revision: D6342086

fbshipit-source-id: fb1bffd11f190b70e03e2ccbf2b30be08d655242

Reviewed By: yfeldblum

Differential Revision: D6453972

fbshipit-source-id: fa083c0b782188f5f45a2a354045aee03e528829

Summary:
Implement conversions between std::chrono::duration and POSIX-style time
structures even when neither the numerator nor the denominator of the duration
ratio are 1.

Both of these are done by first converting to an intermediate type where the
numerator is 1, and then using the conversion routines for that case.

Reviewed By: yfeldblum

Differential Revision: D6366647

fbshipit-source-id: 8f9495fb4101cac6d8b4cf0353a679107007b298

Summary: As title

Reviewed By: yfeldblum

Differential Revision: D6440723

fbshipit-source-id: 3168d7bb616ae0ff3fe42f7584c5a255c4953875

Summary:
Fix bug in non-jemalloc build.

(Note: this ignores all push blocking failures!)

Reviewed By: igorsugak

Differential Revision: D6451342

fbshipit-source-id: 44725d4e0c685a59325fa3d08877d0f62120c5c2

Summary:
[Folly] Let `SaturatingSemaphore::try_wait` be non-`const` and add `ready`.

For internal API consistency.

Reviewed By: magedm

Differential Revision: D6450089

fbshipit-source-id: 65b9b723672521710a69719b192eb2922a27b778

Summary: Add preprocessor checks to guard jemalloc headers if any sanitizer is enabled.

Reviewed By: yfeldblum

Differential Revision: D6441578

fbshipit-source-id: 85364fca5af33c95cd05f232d1e3f9cbac9a4120

Summary:
[Folly] Some fixes for custom conversions of enums.

Of note, `to` was defined for enum -> all conversions, including enum -> string conversions, but we actually want enum -> string conversions to be done via ADL-discovered toAppend.

Reviewed By: ot

Differential Revision: D6411250

fbshipit-source-id: 852b64309e6adf1c68e5153635cb29632e2d86d4

Summary:
SaturatingSemaphore is a flag that allows:
- multiple concurrent posters
- multiple concurrent waiters
- idempotent posting
- non-destructive waiting
- blocking and spinning
- pre-block spin time control

```
/// SaturatingSemaphore is a flag that allows concurrent posting by
/// multiple posters and concurrent non-destructive waiting by
/// multiple waiters.
///
/// A SaturatingSemaphore allows one or more waiter threads to check,
/// spin, or block, indefinitely or with timeout, for a flag to be set
/// by one or more poster threads. By setting the flag, posters
/// announce to waiters (that may be already waiting or will check
/// the flag in the future) that some condition is true. Posts to an
/// already set flag are idempotent.
```

Reviewed By: djwatson

Differential Revision: D6379704

fbshipit-source-id: 59aed76caa2d159639e75425a778a9c63f18f375

Summary: Most of the time we want to guard some code when any of the sanitizers are enabled not just one.

Reviewed By: yfeldblum

Differential Revision: D6429720

fbshipit-source-id: 7157a0a13f2b2acabd36a19c61b9fdbf38ba96b8

Summary:
Add a method for merging the settings from two LogConfig objects.
This allows LogConfig objects to be merged before applying them to the
LoggerDB.  The effects are the same as two sequential LoggerDB::updateConfig()
calls, but without having to apply the intermediate state to the LoggerDB.

Reviewed By: bolinfest

Differential Revision: D6342085

fbshipit-source-id: 0f8a1b7d8d195a80bc74342444dd3152d331fcb6

Summary:
Add a static_assert() to check that the FLAG_INHERIT bit does not conflict with
valid LogLevel values.

Reviewed By: bolinfest

Differential Revision: D6341242

fbshipit-source-id: cec284623c8a612a3c54f1b593d169310790616e

Summary:
The logging code used to support a LogLevel::ERROR value on non-Windows
platforms.  I removed it in D5288600 to make all platforms consistent, but I
forgot to remove this comment describing it.

Reviewed By: bolinfest

Differential Revision: D6341244

fbshipit-source-id: 054427d342066f354c859b12611b907dc2d4fa35

Summary: Add methods for applying config changes from a LogConfig object to the LoggerDB.

Reviewed By: bolinfest

Differential Revision: D6200564

fbshipit-source-id: a25eb99e84b2885bf6853e2222db0d7432a6c37b

Summary: Add a method to get the current LogConfig state from the LoggerDB.

Reviewed By: bolinfest

Differential Revision: D6200596

fbshipit-source-id: 3bc57d498a5d25d19099d861376d71ea9f7e4039

Summary:
Remove the logic that clamps the log level to DFATAL in debug builds.

This behavior logically makes some sense, but results in subtle and potentially
confusing behavior changes.  It seems confusing that after calling
`setLevel(LogLevel::MAX_LEVEL)` on a log category, calling `getLevel()` on that
object would return `DFATAL` rather than `MAX_LEVEL`.  We also weren't clamping
the level to DFATAL consistently: `setLevel()` would clamp the value, but on
construction the initial level was still set to MAX_LEVEL rather than DFATAL.
This resulted in some issues when implementing `LoggerDB::getConfig()` since we
could not consistently detect if a log category was using the default level
settings.  Rather than fix this inconsistency it seems better to simply remove
this clamping behavior.

This means that it is possible for users to disable DFATAL log messages even in
debug builds if they really want to.  Previously this was only allowed in
release builds.  This protection doesn't really seem all that
valuable--presumably most developers won't really want to do this, and if they
really do request this configuration it doesn't seem all that bad to honor it.

Reviewed By: bolinfest, yfeldblum

Differential Revision: D6200569

fbshipit-source-id: 83ef8e2e4d3b61bc5b105038cbe3132979e9ac67

Summary:
Add a method to LogHandler to return its current configuration.  This will
make it possible to query the LoggerDB for its current configuration state.

Reviewed By: bolinfest

Differential Revision: D6200563

fbshipit-source-id: 2b8b9752bbeb26c8aac28d1a73b7e2312fd198c8

Summary:
Update the LoggerDB to track a list of LogHandlers by name, and
LogHandlerFactories by handler type.

This will be needed to support updating the LoggerDB configuration from a
LogConfig object.

Reviewed By: bolinfest

Differential Revision: D6200562

fbshipit-source-id: e365b4e0df65aa5aaa34e118eb3cee9c9c45cb05

Summary:
[Folly] Synchronize coupled caches in `folly::threadlocal_detail::StaticMeta`.

The caches should be set together, and only together, because they are coupled. This prevents bugs where one function that sets one cache but not the other cache is inlined into the caller in one module, and another function that reads both caches is inlined into the caller in another module.

Reviewed By: djwatson

Differential Revision: D6435175

fbshipit-source-id: 846c4972b40e525f2c04da6e6609c2ad54f674c0

Summary:
Add a new LogHandlerFactory interface for creating LogHandler objects from a
LogHandlerConfig.

Also add an initial FileHandlerFactory implementation capable of creating
LogHandler objects that write to a file descriptor.

Reviewed By: bolinfest

Differential Revision: D6200567

fbshipit-source-id: 14b86fc14ad475223aa4b57d45c40638b48c7594

Summary:
Just testing that ElfFile returns expected error code and message for
non-ELF files.

Depends on D6410210

Reviewed By: yfeldblum

Differential Revision: D6418365

fbshipit-source-id: aaab3b9f3ca1a12d384ae98a1772b7f640115192