Summary: It's an example, not part of the main Folly library.

Reviewed By: yfeldblum

Differential Revision: D5304985

fbshipit-source-id: 7cfb95da5795af61e9307882f71836ef7fa5a463

Summary: They are intended to be run as separate sets of tests, and the logging tests define multiple mains.

Reviewed By: yfeldblum

Differential Revision: D5307503

fbshipit-source-id: ed38a762177cec3c600791b861584dd47019b5a9

Summary:
Resolve two issues with folly's clock_gettime() shim on Apple platforms (iOS, macOS, etc.):

When detecting whether folly should define clock_gettime() on Apple platforms, don't assume clock_gettime() is declared in Apple's headers just because MAC_OS_X_VERSION_10_12/__IPHONE_10_0 is defined. Someone might use a newer macOS or iOS SDK (which defines MAC_OS_X_VERSION_10_12/__IPHONE_10_0), but not have clock_gettime() (because _DARWIN_FEATURE_CLOCK_GETTIME isn't set).

When defining a shim for clock_gettime(), don't rely on Apple's clock_gettime() declaration. Instead, shadow Apple's declaration with our own. This prevents folly from inheriting Apple's availability and visibility attributes for clock_gettime().

Reviewed By: yfeldblum

Differential Revision: D5312574

fbshipit-source-id: f16634ce92ee6c299613d3db22f0537bd31ac14d

Summary: So that it is available on other transports.

Reviewed By: Orvid

Differential Revision: D5302039

fbshipit-source-id: cbfdadd158061ed9a2b3ed3e0960ce66f0d545fd

Summary: Fix UBSAN failure in atomic_shared_ptr_test by using reinterpret_cast instead of static_cast.

Reviewed By: yfeldblum

Differential Revision: D5314116

fbshipit-source-id: 8479c9c4bdeeb155067a3de75efe4e97c36519e5

Summary: Same as `boost::noncopyable` but it does not disable move constructor/assignment.

Reviewed By: luciang

Differential Revision: D5311043

fbshipit-source-id: 44fe95712169b95a00e474385be43fa857cfd8ec

Summary: `long` is only 32-bits on Windows, which means this call to `std::min` was ambiguous, which caused a compile error.

Reviewed By: simpkins

Differential Revision: D5305964

fbshipit-source-id: 7e4152006e163a0301652be46318f0fc937e5ead

Summary:
exception_wrapper's non-allocating variant was depending
on the exception reference being a reference to a heap object,
which is not the case on Windows. All thrown exceptions are
copied to the stack first.

So, we abuse internals of exception_ptr to get the internally
heap allocated copy of the object. What could possibly go wrong.

Reviewed By: yfeldblum, ericniebler, Orvid

Differential Revision: D5270634

fbshipit-source-id: 2983a6af9a2c3cb66cbee8a382707a76b582c489

Summary: By moving the input shared_ptr instead of copying it, we avoid doing an unnecessary ref count increment + decrement.

Reviewed By: djwatson, yfeldblum

Differential Revision: D5298467

fbshipit-source-id: b9f0b6999278609417bb4dc062030ca2388ba20a

Summary:
It was missing a portability header needed for `setenv`, and was assuming that the `system_clock` was represented as nanoseconds.
On Windows `std::chrono::system_clock` is represented as 100s of nanoseconds, ie. `FILETIME`.

Reviewed By: simpkins

Differential Revision: D5308182

fbshipit-source-id: facb922ebe1587723358b38499dadac683e3517b

Summary: MSVC complains about `<:` being a digraph and that it isn't interpreting it as one (C4628). Make it be quiet by making it not look like a digraph.

Reviewed By: simpkins

Differential Revision: D5305162

fbshipit-source-id: 7385164e8f73226ce18bc04c32894c2f27f8ae25

Summary: These were using `boost::filesystem::path.native()` in contexts where an `std::string` was the expected output. `boost::filesystem::path.native()` returns a `std::wstring` on Windows, so use `.string()` instead.

Reviewed By: simpkins

Differential Revision: D5305649

fbshipit-source-id: 3c7cd53d2f33d2dbb222731655cdab69d1c4a187

Summary: I failed to realize that this helper function also needs to be guarded on `!_WIN32`, because the assertions are false on Windows.

Reviewed By: ot, luciang

Differential Revision: D5304914

fbshipit-source-id: f2564cb2fcbfdc73a2529d4a41df2995748bc3f6

Summary: This enables auto-deps support in more places in Folly. It also fixes a couple of auto-deps declarations that were missing an `s`.

Reviewed By: yfeldblum

Differential Revision: D5289542

fbshipit-source-id: 7d34b29bcc172fb31f91f1ba880864e2d5869ffd

Summary:
Add appropriate specializations for detail::Extract() so that you can pass a
plain function pointer to `onError()`.  Previously the code only worked with
member function pointers and functor-style objects.

Reviewed By: yfeldblum, wez

Differential Revision: D5286773

fbshipit-source-id: 67b44d1d7573eb1da501475045fd24ad4ab1c074

Summary:
Update the FB_LOG() and XLOG() macros so that FATAL log messages are correctly
detected as not returning, by both clang and gcc.

We have to ensure that both sides of the log statement check (log message
enabled or disabled) evaluate to `[[noreturn]]` expressions.  I did try
updating the log check itself so that it could be constexpr detected as always
passing, but this was not sufficient.

Reviewed By: wez

Differential Revision: D5290780

fbshipit-source-id: 773a56a8392dfd7c310d5d84fc9311e66edf99cb

Summary:
Currently when calling connect with AsyncSSLSocket in unencrypted
mode it still attempts to perform a SSL handshake. Add check to not
do SSL. Calling sslConnect will always run the SSL handshake

Reviewed By: jrahman

Differential Revision: D5153456

fbshipit-source-id: 4d9164115be72c8ee76e383535561e3083a327e3

Summary:
This test has run into occasional failures on continuous build test runs.
Unfortunately when something goes wrong it crashes in the std::thread
destructor due to this thread still being joinable when it is destroyed, which
hides information about what actually failed in the test.

This updates the test to immediately detach the thread, so that on error we
will be able see the real failure reason.

This also increases the size of the message that we write, which will hopefully
help ensure that this write always blocks.

Reviewed By: wez

Differential Revision: D5295574

fbshipit-source-id: ea8cfa855613398f88f9f982c600ec661018a31c

Summary:
Switch all code in the logging library from using `ERROR` to `ERR`,
and remove the `ERROR` LogLevel entirely, even if it is not already
defined as a macro.

Previously the code kept `ERROR` available as a LogLevel name if it had
not already been defined as a macro (which is done by common Windows header
files).  However, this made for inconsistent behavior, and made it easy to
write code that would not be portable to Windows.

This diff fully drops the `ERROR` name for consistency across platforms.

Reviewed By: wez

Differential Revision: D5288600

fbshipit-source-id: 8d2d52e955959c278345fc9c2086c7cacf9660f9

Summary:
Add some tests for fatal log messages during static initialization and
destruction.  Ideally most programs won't actually do much real work before or
after main, but make sure the logging framework behaves sanely in these
situations.

This also fixes a bug in the `test_none()` test, which previously caused it to
always succeed without testing the desired behavior.

Reviewed By: wez

Differential Revision: D5281718

fbshipit-source-id: ca838c098886e99418264acf9a4d651ea9e7502c

Summary:
- Support empty hazptr_holder, move constructor and assignment operator
- Limit thread caching to the default domain to improve performance of thread caching
- Fix unnecessary calls to stats singleton
- Use the mprotect version of AsymmetricMemoryBarrier for reducing the overhead of bulkReclaim().
- Update read-side benchmark results

Reviewed By: djwatson

Differential Revision: D5292885

fbshipit-source-id: bc5713ac95492a7114e1e467e71d2278e64b165d

Summary:
Remove the "LogLevel::" prefix from the logLevelToString() output.

This makes the output shorter and easier to read, and makes it simpler to write
LogFormatter implementations that want a short human-readable level
description.  Callers can always add a "LogLevel::" prefix on their own if
desired.

Reviewed By: wez

Differential Revision: D5288601

fbshipit-source-id: 046579ebdda76842d5a44c33d68941d73dd81162

Summary: The existing assertion errors do not give a lot of information to track down which thread is incorrectly using the `EventBase`. Print both the current thread name and the name of the thread running the event base loop.

Reviewed By: luciang

Differential Revision: D5289790

fbshipit-source-id: 563c7f68b7f9b7a6e85e22290d7e81afbf89871e

Summary: Make `IndexedMemPool` call `Traits::onRecycle` on the element just before it is marked as deallocated. This mirrors the allocation behavior implemented in D5177462 and simplifies preventing access to recycled elements (the client just needs to check `isAllocated` before accessing the element).

Reviewed By: nbronson

Differential Revision: D5275283

fbshipit-source-id: 58365b5b7b32b07fa56529c476078f241fc20811

Summary: Tests and benchmarks don't belong in the same directory as source code.

Reviewed By: yfeldblum

Differential Revision: D5288080

fbshipit-source-id: 865c6dfbeff751bda49870e5284e168d33aff256

Summary:
Original sys_membarrier call supported an EXPEDITED flag, that was much faster than the current version, at some extra CPU cost.

The basic idea was a normal one would be used in a background thread, while EXPEDITED would be useful inline in foreground threads.

Add the flag here, and use the mprotect hack until sys_membarrier supports both.

Reviewed By: magedm

Differential Revision: D5292680

fbshipit-source-id: 30edf27514976991bbaa8e776a7138eb815ade36

Summary: as title, similar to TTLS

Reviewed By: djwatson

Differential Revision: D5284200

fbshipit-source-id: 7eb95668740b239349c6e73f3b152e6506671072

Summary: Absence of "uint32" type in gFlagAdders map breaks all apps that use gflags of this type (i.e. define a flag with "DEFINE_uint32").

Reviewed By: WillerZ

Differential Revision: D5286720

fbshipit-source-id: c02bd959cb9ea9a47fba1e01429181ba09edf5dd

Summary: Complete the `ThreadName.h` API.

Reviewed By: luciang, Orvid

Differential Revision: D5289160

fbshipit-source-id: a48e61093008039da50b1c568364fa5b8744b401

Summary:
This refactors the logging code with the aim of reducing the amount of assembly
code emitted for each log statement, particularly for `XLOG()` statements.
Ideally it should be possible to put debug `XLOG()` statements throughout your
code without having to worry about the performance overhead.  Therefore we
should attempt to make sure that `XLOG()` statements do not generate a lot of
assembly and hurt icache performance.

This diff does not have any code behavior changes--it just moves code around a
bit.  The high-level summary is:

- Move as much code as possible into the LogStreamProcessor constructors and
  destructor.  Make sure these methods are defined in LogStreamProcessor.cpp to
  avoid having them be emitted inline at each log statement.
- Move some of the XLOG level checking logic into separate non-inline functions
  defined in xlog.cpp
- Pass xlog category information around as a pair of (categoryName,
  isOverridden) parameters.  If isOverridden is true then the categoryName
  parameter should be used as the category name directly.  If isOverridden is
  false, then categoryName is a filename that needs to go through filename to
  category name string processing.  This allows the category name processing to
  be done in non-inlined code.

Reviewed By: wez

Differential Revision: D5269976

fbshipit-source-id: 7a7877ddfed66cd27ed82f052330b6aa2be4b37b

Summary:
Add new `FB_LOGC()` and `XLOGC()` macros that accept C-style printf format
strings.  (The `FB_LOGF()` and `XLOGF()` macro names are already used for
`folly::format()` style formatting.)

This will make it easier for users to update existing printf-style code to use
this new logging library.

These are in a separate `printf.h` header file that must be explicitly included
to have access to these macros.  The intent is to encourage users to use one of
the other APIs (streaming, append-style, or `folly::format()`) instead of these
printf-like APIs in new code.

Reviewed By: omry

Differential Revision: D5269974

fbshipit-source-id: 56e55f9642bb00806d9b4c762fb6a91778ef6ad3

Summary:
The `XLOG_GET_CATEGORY()` macro was previously written assuming it was only
used inside `XLOG()` statement.  When used inside the main translation unit
being compiled (e.g., a .cpp file and not a header file), the code assumed that
the file-scope category had already been initialized, since a level check had
presumably already been performed.

However, it is useful in some places for external users (outside of the logging
library itself) to call `XLOG_GET_CATEGORY()`.  In these cases a log level
check may not have been performed yet, so the file-scope category may not be
initialized yet.

This diff renames the existing `XLOG_GET_CATEGORY()` macro to
`XLOG_GET_CATEGORY_INTERNAL()` and adds a new `XLOG_GET_CATEGORY()` macro that
is slower (it always looks up the category by name) but always safe to use.

This also adds a new `XLOG_GET_CATEGORY_NAME()` macro, and renames the existing
`XLOG_SET_CATEGORY()` macro to `XLOG_SET_CATEGORY_NAME()` for API consistency.

Reviewed By: wez

Differential Revision: D5269975

fbshipit-source-id: 373805255823855282fa7a8d4a4d232ba06367f6

Summary:
This improves the test that exercises the AsyncFileWriter message discarding
logic.

Previously each writer thread wrote a fixed number of small messages.  This was
fairly slow, and wasn't always guaranteed to reliably produce discards.
Now each writer thread writes larger messages, which produce discards faster.
The test also automatically stops after 10 separate discard events, so that it
finishes faster (typically a few hundred milliseconds, rather than 5+ seconds).

This also updates the test to use XLOG() internally rather than using fprintf()
to print to stderr, now that the XLOG() diffs have landed.

Reviewed By: wez

Differential Revision: D5261059

fbshipit-source-id: 120224706fee36948ef76efbeb579ccc56400c51

Summary:
Add new `FATAL` and `DFATAL` log levels.

Any log message with a level of `FATAL` always crashes the program.  Log
messages with a level of `DFATAL` crash the program in debug build modes.

Before crashing, the code makes sure to flush all LogHandlers, so that the
fatal message is not lost if some of the LogHandlers process messages
asynchronously.  If no LogHandlers were configured, the message is printed to
stderr.

Reviewed By: wez

Differential Revision: D5189497

fbshipit-source-id: c45dbd582fb1c3a962d00effb2967737ef97cc8b

Summary:
Updated to the interface to be in synch with the latest standard proposal in P0233R4 as follows:
- Renamed hazptr_owner as hazptr_holder.
- Combined hazptr_holder member functions set() and clear() as reset().
- Replaced the template parameter A for hazptr_holder member function templates try_protect() and get_protected with atomic<T*>.
- Moved the template parameter T from the class hazptr_holder to its member functions try_protect(), get_protected(), and reset().
- Added a non-template overload of hazptr_holder::reset() with an optional nullptr_t parameter.
- Removed the template parameter T from the free function swap() as hazptr_holder is no longer a template.

Reviewed By: davidtgoldblatt

Differential Revision: D5283863

fbshipit-source-id: 2bc1a09f4f844aa72d9b7dff9c450540bbe09972

Summary:
When
- only one function is scheduled in FunctionScheduler; and
- the function is running while cancelFunctionAndWait() is being called;
FunctionScheduler.cancelFunctionAndWait() will hang forever.  The root cause is that the condition in cancelFunctionAndWait() is incorrect:

```
runningCondvar_.wait(l, [currentFunction, this]() {
  return currentFunction != currentFunction_;
});
```

because currentFunction will not be changed if only one function is in the scheduler.

The fix here is to
- clear currentFunction as nullptr.  This also makes the internal behaviors of cancelFunction() and cancelFunctionAndWait() consistent.
- introduces additional variable to indicate the state of cancelling current function.  After running the function, the background thread will detect cancellation of current function and clear the variable.
- cancelFunctionAndWait() condition variable will wait for the variable to be cleared.

Similarly, cancelAllFunctionsAndWait() also suffers from the same issue.

Unit tests are added to reproduce the issue.

Reviewed By: yfeldblum

Differential Revision: D5271664

fbshipit-source-id: acb223304d3eab23129907ce9ff5e57e55f1e909

Summary:
Add a method to flush all LogHandler objects.

This will be necessary to implement FB_LOG(FATAL), as we will want to flush all
outstanding messages before crashing.

Reviewed By: wez

Differential Revision: D5189501

fbshipit-source-id: faf260b8e71e5dfed4a3b1c1aee32f072bd7b764

Summary:
Add a flush() call to the LogHandler interface.  This is needed to implement
`FB_LOG(FATAL)` so that we can flush all LogHandlers before aborting the
program.

Reviewed By: wez

Differential Revision: D5189499

fbshipit-source-id: 75fa4d7e75ea26de5b7383bf7e8d073fb37e9309

Summary:
Add a flag to the LogWriter so we can ensure that particular messages are never
discarded, even when the LogWriter is throttling messages.

This functionality will be necessary to implement `FB_LOG(FATAL)` to that we
can avoid discarding the reason for crashing.

Reviewed By: wez

Differential Revision: D5189498

fbshipit-source-id: dc4322ea5ba449a341cdbdc32afb0ed466019801

Summary:
This adds a small example program which demonstrates using the logging library.

This gives a very basic example of how the library is intended to be used, and
can also be used to play around with controlling the log levels from the
command line argument.

Reviewed By: wez

Differential Revision: D5083104

fbshipit-source-id: ab09c6c88db33065f6e39f35b28014f2a6153cef