Summary:
This diff causes Baton to reduce a thread's memory footprint when it
blocks for an extended period (by default 5 to 7.5 seconds).  Reductions
are achieved by flushing the thread-local jemalloc caches (if jemalloc
is in use) and by calling madvise(MADV_DONTNEED) on the portion of the
thread's stack that isn't active.  Once the thread resumes execution
both of these resources will be reallocated.  Configuration is via
system-wide default.

Test Plan:
1. new unit tests
2. manual execution of existing unit tests with very low idleTimeout
3. peek and poke with gdb to observe madvise discarding the page

Reviewed By: davejwatson@fb.com

FB internal diff: D1146966

Summary:
FB_LOG_EVERY_MS was using clock() as its source of time, which
measures the elapsed CPU time of the process.  The name and the docs
suggest that wall time was intended, so that's what this diff does.

Test Plan: new unit test

Reviewed By: andrei.alexandrescu@fb.com

FB internal diff: D1157926

Summary:
Change the way forward / skip pointers are encoded, so we can
expect that `uint32_t` will be enough to address ~4B elements instead
of ~2B as it is now.

Test Plan:
Ran benchmarks for both versions, saw no significant
difference.

Added tests.

Reviewed By: lucian@fb.com

FB internal diff: D1156950

Summary:
- Use the BOOST_STD_EXTENSION_NAMESPACE macro to pick the namespace to
use for hash specializations

Test Plan:
- fbconfig -r unicorn/utils/ && fbmake opt
- fbconfig -r folly && fbmake runtests
- Build in fbobjc with libc++
@override-unit-failures

Reviewed By: rajatr@fb.com

FB internal diff: D1153422

Blame Revision: D1152140

Summary:
Add wrapper functions for directly appending to a string, similar to the
existing format() and vformat() wrappers.

Test Plan:
Converted some existing code using these format() and vformat() wrappers
to use formatChecked() and vformatChecked().

Reviewed By: jon.coens@fb.com

FB internal diff: D1151496

@override-unit-failures

Summary:
- The fbobjc builds complain about use of deprecated <ext/hash_set> and
friends, and then fail because of -Werror. Just use the C++ standard
collections.

Test Plan:
- fbconfig -r folly && fbmake runtests
- Build for iOS and Android
@override-unit-failures

Reviewed By: andrei.alexandrescu@fb.com

FB internal diff: D1152140

Summary: - Update the pre-computed folly-config.h file for Apple builds

Test Plan:
- fbconfig -r folly && fbmake runtests
- Build in fbobjc

Reviewed By: delong.j@fb.com

FB internal diff: D1150188

Summary: ...and stop lint complaining at everyone.

@override-unit-failures

Test Plan: Inspection. Build folly.

Reviewed By: delong.j@fb.com

FB internal diff: D1151216

Summary:
- In libstdc++, existing code uses the internal std::__ostream_insert()
method to write a formatted string that can include '\0' characters.
This internal method doesn't exist in libc++. Instead, use the
relevant internal bits.

Test Plan:
- fbconfig -r folly && fbmake runtests
- ./configure && make check on Mac OS X

Reviewed By: njormrod@fb.com

FB internal diff: D1108540

Summary:
- The fbobjc codebase defines this macro as well, and to the same thing.
However, Clang complains on macro redefinitions if paramater names are
different, even if the macros expand to the same thing. Normalize the
Folly version to 'x', which is what fbobjc uses.

Test Plan:
- fbconfig -r folly && fbmake runtests
- Builds in fbobjc

Reviewed By: andrei.alexandrescu@fb.com

FB internal diff: D1149985

Summary: this is a simple method that allows a folly::Range `[b, e)` to be split on a character at position `i` (where b <= i < e) in an incremental manner.
@override-unit-failures

Test Plan: unit tests added

Reviewed By: andrei.alexandrescu@fb.com

FB internal diff: D1145631

Summary:
- On iOS, off_t is an int64_t, and as such std::min() doesn't compile
since the types don't match. Normalize to size_t and fail with an
error if this conversion can't be made

Test Plan:
- fbconfig -r folly && fbmake runtests
- Built on iOS

Reviewed By: tudorb@fb.com

FB internal diff: D1142795

Summary: explicit ctor

Test Plan: contbuild

Reviewed By: andrei.alexandrescu@fb.com

FB internal diff: D1134033

Blame Revision: D1133938

Summary:
This restore's format()'s behavior of crashing on invalid format
strings, and adds an alternative formatChecked() function to throw
instead of crashing.

Format strings are commonly programmer defined, and fixed at compile
time.  Bad format strings are usually programmer errors, and crashing is
desirable to help catch these bugs early.

However, it is also useful to support dynamic format strings which are
not guaranteed to be well formed at compile time.  formatChecked() makes
it safe to use dynamic format strings, as a bad format strings will not
crash the program.

This does change the throwing/crashing behavior slightly: the old
format() code also used to crash if the format string referred to a
non-existent key in one of the argument containers.  I removed this,
since it seems like the argument containers are likely to be dynamic.

I also changed the code to crash on std::range_errors as well.  Various
problems in format string arguments are caught in the Conv.h code, which
throws range_errors.  The old crashing code did not crash on these
errors, but it seems useful to do so.  The only minor concern here is
that this may also crash unintentionally if the Output callback throws a
range_error.  This seems low-risk, but we can remove this behavior if
needed.

Test Plan:
Updated the BogusFormatString test to check both format() and
formatChecked().

Reviewed By: tudorb@fb.com

FB internal diff: D1144301

Summary:
This reverts 61e20daa, which changed the format code to abort on error.

I do plan to restore the crashing behavior, but I plan to make it
optional.  I will add a formatSafe() function that throws on error,
while format() catches these exceptions and crashes.

This diff is an intermediate diff to make it easier to review the
changes.  This is close to a straight revert of 61e20daa and 61a41c9b.
However, I did leave the new test case, as well as the
FormatArg::errorStr() method added by those diffs.

Test Plan:
Verified that the existing format tests pass.

Also added a handful of new tests for bad format strings.  This did
catch one bug in the code where it wasn't correctly checking for a null
return value from memchr().

Reviewed By: delong.j@fb.com

FB internal diff: D1144298

Summary:
rallocm sets the value of the second argument even if it has failed to allocate the requested size:
https://github.com/jemalloc/jemalloc/blob/898960247a8b2e6534738b7a3a244855f379faf9/src/jemalloc.c#L1903-L1906

As a result newAllocatedCapacity was being set to a value less than the original value and the logic was broken.

Test Plan: unit tests pass and my code which was crashing before now works!

Reviewed By: soren@fb.com

FB internal diff: D1144314

Test Plan: fbconfig -r folly/experimental/test && fbmake runtests_opt

Reviewed By: chaoyc@fb.com

FB internal diff: D1141124

Summary:
* Added benchmark functions to the checksum unit tests
* While in the code, fixed the order of the arguments to
the EXPECT_EQ statements so the tests will report the
actual and expected values properly upon error

Test Plan:
fbconfig -r folly && fbmake opt
_build/opt/folly/test/checksum_test --benchmark

Reviewed By: rajat@fb.com

FB internal diff: D1134930

Summary:
Removed duplicate #includes.

Facebook: The removals were examined by hand: several duplicate includes
were not removed because they were/seemed to
be in different preprocessor branches of the source.

@override-unit-failures

Test Plan: arc unit

Reviewed By: robbert@fb.com

FB internal diff: D1136491

Summary:
Adjusted the ifdefs to allow the use of the hardware CRC instructions
when compiling with gcc-4.7.x

Test Plan:
Built with gcc-4.7.1, ran the unit tests, verified that they ran the
hardware-accelerated code path

Reviewed By: saramg@fb.com

FB internal diff: D1134567

Summary:
Many callers of byLine method use it by providing arguments for File
explicit constructors. Added function breaks byLine(file desciptor)
use case. Commenting it out until File constructors are made exlicit to
fix failing tests.

Test Plan: unittest

Reviewed By: lucian@fb.com

FB internal diff: D1133938

Blame Revision: D1129497

Summary:
Previously, all IOBuf APIs required that IOBufs always be allocated on
the heap.  The only methods provided to create IOBufs returned
unique_ptr<IOBuf>.

This adds new methods to support creating IOBufs on the stack.  This is
useful in cases where the IOBuf will be short-lived, and the overhead of
the heap allocation is undesirable.  (One use case is to wrap an
existing buffer in a short-lived IOBuf so that it can be used with the
Cursor API.)

I have currently made IOBufs movable but not copyable.  (Move operations
clearly should move only a single IOBuf, but it is not clear if the copy
operators should copy only a single IOBuf or the entire chain.)

Test Plan:
Updated the unit tests to test the new CREATE, WRAP_BUFFER,
TAKE_OWNERSHIP, and COPY_BUFFER constructors, as well as the move
constructor and assignment operator.

Reviewed By: davejwatson@fb.com

FB internal diff: D1067341

Summary:
A Baton allows a thread to block once and be awoken: it captures
a single handoff.  During its lifecycle (from construction/reset to
destruction/reset) a baton must either be post()ed and wait()ed exactly
once each, or not at all.  Batons may be reused after a call to
recycle().

Baton includes no internal padding, and is only 4 bytes in size.
Any alignment or padding to avoid false sharing is up to the user.

This is basically a stripped-down semaphore that supports only a single
call to sem_post.  The current posix semaphore sem_t isn't too bad, but
this provides more a bit more speed, checking, inlining, smaller size,
a guarantee that the implementation won't change, and compatibility
with DeterministicSchedule.  Baton is directly implemented on top of
futex, and takes care to avoid system calls.

Test Plan:
1. new unit tests
2. this code has already been in production use in TAO for many months

Reviewed By: davejwatson@fb.com

FB internal diff: D1130407

Summary: -1LL<<63 was passed to folly::to() without '-' so it overflowed. Fixed that

Test Plan:
tried this:

int main() {
stringstream s;
s << "{\"int\":" << -1LL<<63 << "}";
string str = s.str();
cout << "string to parse: " << endl << str << endl;

int64_t sample = folly::parseJson(str.c_str())["int"].asInt();
LOG(INFO) << "test result = " << sample;

return 0;
}

it returns right value.

Also tried it with "-Infinity" and double type for sample. In works fine as well.

Reviewed By: andrei.alexandrescu@fb.com

FB internal diff: D1130155

Test Plan: unittest

Reviewed By: lucian@fb.com

FB internal diff: D1129497

Summary:
It is useful when writing additional specializations of of
toAppend() and related functions to use IsSomeString, the same way the
ones in Conv.h do.  Move IsSomeString out of detail, so outside code
doesn't access a detail namespace inappropriately.

Test Plan: fbmake runtests; arc lint

Reviewed By: tudorb@fb.com

FB internal diff: D1130910

Summary: Our script wasn't picking up removed files.

Summary: A function was getting inlined in opt mode but not in debug mode.

Test Plan: ran test

Reviewed By: philipp@fb.com

FB internal diff: D1130949

@override-unit-failures
test fix only

Summary: Include guard had FOLLY_DETAIL_.. even though code is in folly

Test Plan: unit tests

Reviewed By: davejwatson@fb.com

FB internal diff: D1130269

@override-unit-failures

Summary:
Instances of IndexedMemPool dynamically allocate and then pool
their element type (T), returning 4-byte integer indices that can be
passed to the pool's operator[] method to access or obtain pointers to
the actual elements.  Once they are constructed, elements are never
destroyed.  These two features are useful for lock-free algorithms.
The indexing behavior makes it easy to build tagged pointer-like-things,
since a large number of elements can be managed using fewer bits than a
full pointer.  The pooling behavior makes it safe to read from T-s even
after they have been recycled

Test Plan:
1. unit tests
2. unit tests using DeterministicSchedule
3. this code is moved from tao/queues where it is in production use

Reviewed By: davejwatson@fb.com

FB internal diff: D1089053

Summary:
Detailed output is a bit hard to parse visually. Add some colors for
clarity (clownyness?). Enabled only when printing stack traces from a
signal-handler to TTY.

Also:
- terse output printed empty lines if it could not find a symbol for an address; fixed by printing "(unknown)".
- added a dummy ##Crash## program to test colorization easily

Test Plan: n/a

Reviewed By: tudorb@fb.com

FB internal diff: D1128303

Summary: AHM::find checks that the returned SimpleRetT index is >= numMapsAllocated_ but that value may have changed and find pick the first element in the next sub map. Use success instead.

@override-unit-failures

Test Plan: unit tests

Reviewed By: delong.j@fb.com

FB internal diff: D1126684

Test Plan: eyeballed it

@override-unit-failures

Reviewed By: soren@fb.com

FB internal diff: D1125180

Summary:
The __builtin_ia32_crc[qd]i() functions are GCC >= 4.8 specific
folly-config.h includes must be wrapped in a FOLLY_NO_CONFIG guard
FOLLY_HAVE_WEAK_SYMBOLS needs to apply to the cpp file as well as the header

Closes #44
Closes #42

Test Plan: HHVM builds with recent folly

Reviewed By: seanc@fb.com

FB internal diff: D1117181

Summary:
The invariant after Cursor::insert is that the cursor points to the buffer
after the insert. That invariant was not followed in the branch where the
new buffer was just prepended. This change fixes the bug.

Test Plan:
Unit test modified, all tests run with
fbconfig -r folly && fbmake runtests_opt

Reviewed By: davejwatson@fb.com

FB internal diff: D1114749

Summary:
timed_mutex::try_lock_for is broken in gcc 4.8 (see
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54562), so this diff adds
a workaround using try_lock_until.  The internal implementation of
try_lock_for converts to try_lock_until, but it uses the steady_clock
instead of the system_clock as its time base.  In some gcc versions
these are the same clock so it works okay, but not in all.

Test Plan: unit tests

Reviewed By: delong.j@fb.com

FB internal diff: D1108584

Summary:
- Remove FOLLY_NORETURN from function definitions, which was causing
compilation errors on some platforms.

Test Plan: - Compile on Mac OS X with Clang

Reviewed By: tudorb@fb.com

FB internal diff: D1111416

Summary:
* Added a new crc32c() function, with a portable implementation
and an optimized version for x86 with SSE4.2

Test Plan: New unit test included

Reviewed By: tudorb@fb.com

FB internal diff: D1111515

Summary:
* folly/test/PackedSyncPtrTest.cpp: Avoid an operator new [] vs
operator delete mismatch.

Test Plan:
fbconfig --platform-all=gcc-4.8.1-glibc-2.17 --sanitize=address \
folly/test:packed_sync_ptr_test && fbmake runtests

Reviewed By: tudorb@fb.com

FB internal diff: D1111227

Summary:
- Add autoconf check for cplus_demangle_v3_callback() in libiberty and
avoid is usage when not available. Clang/libc++ on Mac OS X doesn't
support this.

Test Plan:
- fbconfig -r folly && fbmake runtests
- ./configure && make check on Mac OS X

Reviewed By: tudorb@fb.com

FB internal diff: D1108543