Summary:
Add an ImmediateFileWriter class that implements the LogWriter interface by
immediately writing data it receives to a file descriptor.

This LogWriter implementation can be used by users that want to ensure log
messages are immediately flushed to a file as soon as they are written, at the
expense of possibly having logging I/O block their normal process threads.

Reviewed By: wez

Differential Revision: D5083105

fbshipit-source-id: 15cd071834e1784fe50e1d6d6ce403b9bc907047

Summary:
A few places in the logging code need to report issues when something goes
wrong in the logging code itself.  This adds a new LoggerDB::internalWarning()
method for use in these places.

This provides a default implementation that logs these warnings with
_CrtDbgReport() on Windows, and writes to stderr on non-Windows platforms.
The default implementation can also be overridden for programs that want some
alternative behavior.

Reviewed By: wez

Differential Revision: D5157731

fbshipit-source-id: e27f5587d58b3941fca8d5b38c8c3edbcb75d7f3

Summary:
Add a new RateLimiter API to the logging library, to support rate limiting
messages in the future.  I have included a single IntervalRateLimiter
implementation in this diff.  In the future we can add more implementations if
necessary, to mimic the functionality available with our older logging code, to
make it easier for users to convert to the new framework.

Note that RateLimiter is inside a `folly::logging` namespace, unlike most of
the other code in the logging library that lives directly in the `folly`
namespace.  I intentionally chose this since RateLimiter is a fairly generic
class name, and I wanted to distinguish it from other possible generic class
names in folly.  On the other hand, most of the other class names already start
with `Log`, so there seems to be no need to put them in a `logging` namespace.

Nothing is using this new API yet, but I will use it for some internal logging
APIs in an upcoming diff.  Later on I also plan to use it to implement
per-LogCategory rate limiting, and possibly per-LogHandler rate limiting.

Reviewed By: wez

Differential Revision: D5162805

fbshipit-source-id: 9b81c2f4544006cd392152a768296bce0c5daaa1

Summary:
This simplifies the LogHandler interface to a single generic `handleMessage()`,
and adds a `StandardLogHandler` implementation that defers to separate
`LogFormatter` and `LogWriter` objects.

The `LogFormatter` class is responsible for serializing the `LogMessage` object
into a string, and `LogWriter` is responsible for then doing something with
the serialized string.

This will make it possible in the future to have separate `LogWriter`
implementations that all share the same log formatting code.  For example, this
will allow separate `LogWriter` implementations for performing file I/O
immediately versus performing I/O asynchronously in a separate thread.

Reviewed By: yfeldblum

Differential Revision: D5083103

fbshipit-source-id: e3f5ece25e260c825d49a5eb30e942973d6b68bf

Summary:
This adds new `XLOG()` and `XLOGF()` macros to the logging library.  These are
similar to `FB_LOG()` and `FB_LOGF()`, but do not require a Logger argument.
Instead, the log category is picked automatically based on the current file
name.  The basic algorithm for picking the category name is to replace
directory separators with '.', and to strip off the filename extension.

For instance, all `XLOG()` statements in `src/foo/bar.cpp` will log to the
category `src.foo.bar`.  This also works correctly in header files: `XLOG()`
statements in `src/foo/mylib.h` will log to `src.foo.mylib`

This should generally result in a good log category hierarchy without the user
having to spend additional time picking category names--we simply re-use the
decisions that they already made for their directory layout.

In general I expect the `XLOG()` macros to be convenient enough that users will
use `XLOG()` in almost all cases rather than using `FB_LOG()`.

The log category name used by `XLOG()` statements can be overridden using
`XLOG_SET_CATEGORY()`, but this only works in .cpp files, not in header files.

Reviewed By: wez

Differential Revision: D4920257

fbshipit-source-id: 7ffafd9a4c87e6fb5eb35d86e0eb86ef1ed5be95

Summary:
Added support for thread caching of hazard pointers.
Added thread caching benchmarks.
Removed function call from hazptr_domain constexpr constructor.
Optimizations of memory order and code refactoring.

Reviewed By: davidtgoldblatt

Differential Revision: D5249070

fbshipit-source-id: 487fb23abccde228c3c726de4ac8e9f07bfa9498

Summary: We would always up_ref the ctx before setting it as the initial_ctx.  This causes a leak in 1.1.0 since the initial_ctx isn't set in this version of OpenSSL.  We'll move the up_ref for the initial_ctx into the OpenSSLUtils helper.

Reviewed By: anirudhvr

Differential Revision: D5227823

fbshipit-source-id: b4490b317bd4dc8752a8d7e244fd153100a52aa6

Summary: According to internal linter

Reviewed By: Orvid

Differential Revision: D5051010

fbshipit-source-id: febdeca05ac1cf3ad82617169f90912a445cf173

Summary: Flag caused compilation error on unused param, asserts optimized out in opt-asan/ubsan builds.  Replaced with DCHECK as per meyering's advice.

Reviewed By: meyering

Differential Revision: D5246089

fbshipit-source-id: dc0abda91f900dd98af31410f4667c52404997f5

Summary: `ZSTD_decompress()` doesn't verify the uncompressed length in the frame as I thought, so throw an exception instead of `DCHECK()`.

Reviewed By: meyering

Differential Revision: D5234576

fbshipit-source-id: f72cf085a7267de32ce13553ce7ebbfe3b8a3f05

Summary:
The removed comment cites a gcc compiler bug as a reason to spell
out the return type of the three operator() methods. While that
compiler bug can lead to compiler errors in some situations,
it is not the only reason why we need the return type arrow
notation.

If the compiler tries to instantiate operator() with a set of
parameters that the embedded function does not accept, then the
substitution failure is inside decltype, which is not a compiler
error (SFINAE) but just means that the Partial class doesn't define
operator() for that parameter signature. Without decltype, the body
of operator() is ill-formed and that is a compiler error.

Reviewed By: meyering

Differential Revision: D5236537

fbshipit-source-id: 7daa0fbcf128a2c7c5c36532a5402deba394e1b8

Summary: A common use case for `IPAddress::toFullyQualified()` is to print a `<ip>:<port>` string. It is faster to reserve enough space for both beforehand than create 2 strings.

Reviewed By: yfeldblum

Differential Revision: D5224454

fbshipit-source-id: 4536f89a9d51d39dd9fd970c753ecb8ecced5d22

Summary: During decompression, when the data is truncated, `StreamCodec::doUncompress()` loops forever, since it doesn't check forward progress. `Bzip2Codec` does the same.

Reviewed By: chipturner

Differential Revision: D5233052

fbshipit-source-id: 8797a7f06d9afa494eea292a8a5dc980c7571bd0

Summary:
If the folly::sformat() call fails in an FB_LOGF() statement, make a
best-effort attempt to log the format arguments as well, in addition to the
format string.  For each argument, folly::to<std::string>() is use if it is
supported for this argument.

This will help ensure that the arguments that were being logged aren't lost
even if the format string was incorrect.

Reviewed By: WillerZ

Differential Revision: D5082978

fbshipit-source-id: 0d56030e639cd7e8f2242bb43646ab4248c6a877

Summary:
Update the logging library so that FB_LOG() and FB_LOGF() also accept
streaming style arguments:

  FB_LOG(logger) << "logs can be written like this now: " << 1234;
  FB_LOG(logger, "both styles can be used") << " together";
  FB_LOGF(logger, "test: {}, {}", 1234, 5678) << " and with FB_LOGF() too";

Streaming support does make the upcoming XLOG() macros more complicated to
implement, since the macro has to expand to a single ternary `?` expression.
However I was able to come up with a solution that works and has minimal
overhead.

Reviewed By: wez

Differential Revision: D5082979

fbshipit-source-id: 11734e39c02ad28aceb44bbfbd137d781caa30cf

Summary:
This begins adding a new logging library for efficient, hierarchical logging.

This includes the basic library framework, plus a README file with a brief
overview and the motivation for creating a new logging library.

Reviewed By: wez

Differential Revision: D4911867

fbshipit-source-id: 359623e11feeaa547f3ac2c369bf806ee6996554

Summary: Closes https://github.com/facebook/folly/pull/609

Differential Revision: D5228342

Pulled By: Orvid

fbshipit-source-id: edb81284a0401a4ea267310e1ca01c390bcdfb32

Summary: 2_ms seems too short. I am not sure whether it's feasible to check whether thread is waiting for an address. We could wait for longer to reduce false alarm.

Reviewed By: nbronson

Differential Revision: D5220819

fbshipit-source-id: 42f31206e9cb7f9addaa049d0e7cd995f6735f6c

Summary:
[Folly] Let `SubprocessError` inherit `std::runtime_error`.

As an added bonus, this gives it `std::runtime_error`'s refcounted string for cheap copies.

Reviewed By: ericniebler

Differential Revision: D5216758

fbshipit-source-id: 43298e06f02cfd88abf2d73f7aa16117a6cb052b

Summary: The source and tests for the stats directory was spread across folly/detail and folly/test, move them into folly/stats directly instead.

Reviewed By: yfeldblum

Differential Revision: D5216810

fbshipit-source-id: 00a8bb95a4f7830d0bc46b3f914f256a37833b78

Summary: Use clang-tidy to mechanically add missing `override` and remove redundant `virtual`.

Reviewed By: igorsugak

Differential Revision: D5211868

fbshipit-source-id: 6a85f7c4a543a4c9345ec5b0681a8853707343dc

Summary: Use clang-tidy to mechanically add missing `override` and remove redundant `virtual`.

Reviewed By: igorsugak

Differential Revision: D5211868

fbshipit-source-id: 4118c4c72f8ec3485507f69679f7e852b3eaeb73

Summary:
[Folly] Saner test exception in `ExceptionWrapperTest.cpp`.

Make construction do the work and make `what()` free.

Reviewed By: andrewjcg

Differential Revision: D5216707

fbshipit-source-id: bfb4c2473a61ff7da7a3a01adc85facae30d6586

Summary: Add a few more compatibility wrappers for pre-1.1.0 APIs

Reviewed By: yfeldblum

Differential Revision: D5194164

fbshipit-source-id: ae8db08c31370eca729df2927798b6f4d99ee70c

Summary: [Folly] Apply `clang-format` to `folly/gen/` (template decls).

Reviewed By: Orvid

Differential Revision: D5216229

fbshipit-source-id: 1659f1944ccde4de39bccd189bb6490395cf29c2

Summary: This is entirely the wrong way to include these headers, and is being included within an anon namespace so just wrong.

Reviewed By: yfeldblum

Differential Revision: D5215065

fbshipit-source-id: 499df58c0202f7a1d4482eaa6a0e8b2e1535c763

Summary:
[Folly] Apply `clang-format` to `folly/experimental/exception_tracer/` (headers).

With some manual rearrangement in the places where `clang-format` does awkward things, with the result that `clang-format` over the listed directory becomes a no-op.

Reviewed By: Orvid

Differential Revision: D5215212

fbshipit-source-id: 5570f02c238b1874adbc2ff4150f465c947ad0e6

Summary:
[Folly] Apply `clang-format` to `folly/fibers/`

With some manual rearrangement in the places where `clang-format` does awkward things, with the result that `clang-format` over `folly/fibers/` becomes a no-op.

Reviewed By: igorsugak

Differential Revision: D5178118

fbshipit-source-id: ae65ff1902666ba9106e18f916bb1d10e6406bf4

Summary: Otherwise downstream Windows users have to explicitly disable MSVC's warnings about unknown pragmas.

Reviewed By: yfeldblum

Differential Revision: D5211415

fbshipit-source-id: 42871e03895010818c7e1cb6e57c1885970e98c2

Summary:
Folly is a C++ library not a C library, and (almost) universally uses `nullptr` everywhere, so refer to `nullptr` rather than `NULL`.
This also fixes the 1 place in our actual code where we were using `NULL` rather than `nullptr`.

Reviewed By: yfeldblum

Differential Revision: D5204766

fbshipit-source-id: 2a5d5011a28d7d5dd48789f60643a656f51b9732

Summary: FixedString.h has a workaround for a gcc bug regarding erroneous -Werror=array-bounds errors. This commit extends the workaround to the gcc-5 series, which sadly is still broken. Life gets better with gcc-6.

Reviewed By: luciang

Differential Revision: D5210633

fbshipit-source-id: 4fcf080d18ddc573636a3e58b61a97167a8c06ce

Summary:
Make extent hooks static and avoid calling arena_destroy, in case there are
alive allocations not freed yet.

Reviewed By: yfeldblum

Differential Revision: D5208102

fbshipit-source-id: 612c772347cd90227fa303fd0b059edbaeb7d4e2

Summary:
I thought I had already implemented this, but apparently I had only implemented the ll variable. Whoops.
This implements the 32-bit version which fixes the build on Windows.

Reviewed By: yfeldblum

Differential Revision: D5203680

fbshipit-source-id: 02b133db59e232cac586944b0ffc0e8bbf5f533a

Summary: The directory contains benchmarks and multiple `main`'s so shouldn't be included as part of the main folly library.

Reviewed By: yfeldblum

Differential Revision: D5204132

fbshipit-source-id: 7289cb9c2ec292c13df39c9e7b48eca4166ca951

Summary:
[Folly] Pass `Try` by rvalue ref in `onError` implementation.

As is done in other overloads and in `thenImplementation`. For consistency.

Reviewed By: spacedentist

Differential Revision: D5199302

fbshipit-source-id: c78db0c36fc7a0b846ca5e44fc237422c9203a24

Summary: Update tuple generated for hash/equal_to for `folly::Uri` to also use std::string

Reviewed By: Orvid

Differential Revision: D5199266

fbshipit-source-id: bcd619dae01ffbf82fbb5c8987b0e87103572452

Reviewed By: anirudhvr

Differential Revision: D5193205

fbshipit-source-id: 5b427ee4f31008518078f5e54e85c0f0f2201da5

Summary:
[Folly] Shrink the implementations of `then` and `onError`.

Just a small refactor.

Reviewed By: spacedentist

Differential Revision: D5180784

fbshipit-source-id: a399d18500a2b4c5d8f24dee54891cca802b4461

Summary:
[Folly] `Try::tryGetExceptionObject`.

If the `Try` has a `std::exception` for the non-template overload or a `From` where `is_convertible<From*, Ex*>` for the template overload parameterized by `typename Ex`, returns a pointer to it. Otherwise returns `nullptr`.

Reviewed By: spacedentist

Differential Revision: D5180848

fbshipit-source-id: b7593b7459259f9a1e1e78b36d548e55d086e722

Summary:
[Folly] Remove `exception_wrapper::throwException`.

It has been renamed to `throw_exception`.

Reviewed By: Orvid

Differential Revision: D5181005

fbshipit-source-id: 442b3fd9bdaa8170db504a81651cbb085ea50624