Summary: Fix includes in memory_resource.h

Reviewed By: yfeldblum

Differential Revision: D3935848

fbshipit-source-id: 713ce85ad17072779dfa1c667459e367c5e1d4b7

Summary:
`SharedMutexImpl::lockSharedImpl` has a potentially uninitialized access:

  Assume state = 0
  canAlreadyDefer = (state & kMayDefer) != 0 ==> false
  aboveDeferThreshold = (state & kHasS) >= (kNumSharedToStartDeferring - 1) * kIncrHasS ==> false

  if (canAlreadyDefer || (aboveDeferThreshold && !drainInProgress)) ==> false

  line:1452: gotSlot(slot)->compare_exchange_strong(...) uses slot uninitialized

Reviewed By: Orvid

Differential Revision: D3933638

fbshipit-source-id: 0fbce5c00b8b1f34e50c302cb88def97853c5afe

Summary:
This commit introduces a simple function reference type, similar to
std::reference_wrapper, but the template parameter is the function
signature type rather than the type of the referenced object.

A folly::FunctionRef is cheap to construct as it contains only a
pointer to the referenced callable and a pointer to a function which
invokes the callable.

The user of FunctionRef must be aware of the reference semantics:
storing a copy of a FunctionRef is potentially dangerous and should
be avoided unless the referenced object definitely outlives the
FunctionRef object. Thus any function that accepts a FunctionRef
parameter should only use it to invoke the referenced function and
not store a copy of it. Knowing that FunctionRef itself has reference
semantics, it is generally okay to use it to reference lambdas that
capture by reference.

Reviewed By: ericniebler

Differential Revision: D3277364

fbshipit-source-id: 0a7676919cd240da5b6e1f94cadba4289e0aca28

Summary:
This is a start to wrapping various SSL objects going forward so different
binaries can choose different version of OpenSSL (i.e., BoringSSL, OpenSSL
1.1.0, OpenSSL 1.0.2, etc.). There's no change to the caller - everyone just
uses 'SSLSession', but the implementation details vary

Reviewed By: siyengar

Differential Revision: D3707791

fbshipit-source-id: f895334a768cb7d43b41af40c9bc06be5307cc7f

Summary:
OpenSSL SSL_METHOD->get_cipher_by_char is not present in either OpenSSL
1.1.0 or BoringSSL. In addition, knekritz reports that time's being spent in
binary searching for cipher names.

Since the ciphercodes and names are (fairly) static, we store these in a static
hash map.

Reviewed By: siyengar

Differential Revision: D3275185

fbshipit-source-id: 08b36f3e73239b415b74c6ecc30ed65832d9ebd0

Summary: Makes it easy to split a Future into multiple Futures

Reviewed By: rongrong

Differential Revision: D3885897

fbshipit-source-id: 6ac9fb22444dd828fbdebb44b06bf3d93d0f7583

Summary: See title.

Reviewed By: nbronson

Differential Revision: D3914188

fbshipit-source-id: dd9ccd0c48911632d229ae675cc40d835ea14724

Summary:
In debug mode, CpuId() ends up triggering external linkage from inside this __ifunc__.
However, in PIC, the relocation of external symbols are not ready yet, causing a segfault.

This only reproes in dynamic linking (PIC / so) and dbg mode.

Reviewed By: luciang

Differential Revision: D3895239

fbshipit-source-id: 2b7856c10abb5cfe24736d5bfac28e7e9d0e8272

Summary: Switch from mkstemp to the slightly more portable `folly::test::TemporaryFile`

Reviewed By: jsedgwick

Differential Revision: D3890411

fbshipit-source-id: e98d1e3a5adae92af1bb36f6213b194f633fab0f

Reviewed By: nbronson

Differential Revision: D3905865

fbshipit-source-id: 2743af4ae1b34adb0f8e611e672f9b6068430ec9

Summary:
Sometime we have such unit-test failure

```
folly/futures/test/TimekeeperTest.cpp:134: Failure
Value of: flag
  Actual: false
Expected: true
```

This diff should make it less flaky, though I am not sure what's the best way to fix this flaky unit-test.

Reviewed By: yfeldblum

Differential Revision: D3889630

fbshipit-source-id: e7486d75fbcb3081d06724d213d4a2cf8942955d

Summary:
Add logs for TFO to AsyncSocket
and wangle

Reviewed By: knekritz

Differential Revision: D3906104

fbshipit-source-id: 9a79b6f91273f8017a5e0d72fe5bdc8eff645ebc

Summary: Fix the build due to a missing gflags header

Reviewed By: yfeldblum

Differential Revision: D3905525

fbshipit-source-id: cc09189196a04741162c2d1561545d3fec417e5e

Summary:
libc++ 3.9 and above define the __throw* functions inside stdexcept, so
defining them ourselves leads to compilation errors when compiling
against libc++ 3.9. Add appropriate preprocessor guards to avoid this.

Reviewed By: meyering

Differential Revision: D3898284

fbshipit-source-id: 435a28c2b3a83ee4d8f5af0df0343c524469011e

Summary:
When we attach and detach from the
event base threads during connections
in the case of SSL it could result in
a crash while using TFO.

When TFO was enabled connectTimeout_
was set, which was not detached.

In the case when we would
fall back from TFO in case TFO did not
succeed, we would try and schedule a
connect timeout again. However because
we are now scheduled in a new evb thread,
this would cause the scheduleTimeout to
assert that it was not in the correct evb
thread.

This fixes the issue by attaching and detaching
connect timeouts as well.

Reviewed By: ngoyal

Differential Revision: D3892490

fbshipit-source-id: 278c0b8029022144cd59366ceb0ce83f0a60a307

Summary:
This diff changes the definition of `folly::Func` from `std::function<void()>`
over to `folly::Function<void()>`. This mostly affects the interface of
`folly::Executor` and derived and related classes. By using
`folly::Function<void()>`, we allow to have lambdas capturing move-only types
passed to executors. This continues an effort to get rid of the potentially
dangerous `folly::MoveWrapper` by allowing to capture move-only types in lambdas
when using `folly::Future`, `folly::EventBase` and now `folly::Executor`.

Reviewed By: yfeldblum

Differential Revision: D3706449

fbshipit-source-id: 11c2cee32cb9f0298c39b7b1695a477777eeb3aa

Summary: Make draft of hazard pointers prototype public

Reviewed By: djwatson

Differential Revision: D3870280

fbshipit-source-id: e029efa336585055f67687059e10ae11766f8d7f

Summary:
`EventBase` has its own methods to wait till it's ready so we can avoid using
barriers and remove boost dependency.

Reviewed By: mzlee

Differential Revision: D3894408

fbshipit-source-id: f050a982c98c4f672cf295845115686c95fc7919

Summary:
Updating fibers code to use https://github.com/llvm-mirror/compiler-rt/commit/b0477747dfa8a9706f2c902e877e616aca51e06f

Patch by andriigrynenko!

Reviewed By: andrewcox

Differential Revision: D3500482

fbshipit-source-id: f51f4bb4ebf0d95a898eb1d4098459aa691acd61

Summary:
Existing logic is broken (unable to correctly handle chained `IOBuf`
in case of both `compress` and `uncompress`) and has unnecessarly strict
`needsUncompressedLength() == true` requirement.

This diff switches `ZSTDCodec` to use streaming to handle chained `IOBuf`,
drops `needsUncompressedLength() == true`.

Reviewed By: luciang

Differential Revision: D3827579

fbshipit-source-id: 0ef6a9ea664ef585d0e181bff6ca17166b28efc2

Summary:
When trying to find an empty deferred reader slot, getting the current CPU can
take quite a few cycles, e.g. >1% CPU on SMC (https://fburl.com/434646643).

Let's track the last slot used by this thread and try that slot first before reading
CPU id and doing the search.

u-benchmark results seem to be improving generally (though a bit noisy and not
sure how much to trust). Results w/ this diff on left side:
P56648675

Reviewed By: nbronson

Differential Revision: D3857793

fbshipit-source-id: 8b1c005362c82e748a663100f889b0b99dc257fe

Summary: Fixing ODR violations...

Reviewed By: simpkins, yfeldblum

Differential Revision: D3875667

fbshipit-source-id: 0d8ec0b48e14fffb7e3e60c0e68e2576b2f58d1e

Summary:
Since `shellify` interprets the command as a format string we need to escape
`{` and `}`.

Reviewed By: ldemailly, simpkins

Differential Revision: D3874605

fbshipit-source-id: f47db387c3a44a3ba1c0c1d4726b7212fcb5ef3e

Summary:
Update the stats APIs to correcly distinguish between TimePoint and Duration
types.

This does leave addValue() and update() APIs in place that accept Duration
values, for backwards compatibility.  These should eventually be removed once
all code has been converted to call the new APIs.

Reviewed By: yfeldblum

Differential Revision: D3808805

fbshipit-source-id: 36d6574ba4a09db7eb9f1a35e47addd3e07f8461

Summary: Let the caller do a move, don't force one.

Reviewed By: yfeldblum

Differential Revision: D3873129

fbshipit-source-id: 40c6bf564bcbf794830c99ea1248a9c1bb30e9b0

Summary:
I've found all code paths that contributed to the number of threads in new ScribeClient. Here's a list of flags that reduce the number of thread:
  --default_tls_thread_count=1 # was 32
  --sr2_event_base_pool_size=1
  --has_thrift_dispatcher_reporter=0 # creates a thrift server with a few extra threads
  --observer_manager_pool_size=1 # default is 4

Optimizations in this diff:
- Don't initialize OBCClient object if it is not used
- Added FLAG_observer_manager_pool_size to control size of the pool in ObserverManager

Currently OBC counters are switched off globally in ScribeCliean, it means that new code path that creates SR instances is disabled, but eventually we plan to switch it on. Clients that don't use SR and want to keep their RSS/threads profile low, should pass flags listed above. I'll announce this in ScribeUsers group as well.

Differential Revision: D3870704

fbshipit-source-id: 0efad6b3dc43c072ab11cac7e9461c09532ea11c

Summary: The behavior of inheriting constructors changed in clang 3.9 (see https://llvm.org/bugs/show_bug.cgi?id=30305), and folly::Expected needs to change accordingly. As a drive-by improvement, change all invocations of default constructors to use unified initialization syntax.

Reviewed By: igorsugak

Differential Revision: D3872994

fbshipit-source-id: fdaea8b35980df21b8522e2c3d5a8c3be1d84efa

Summary:
Before this change, an application would fail consistently with a shutdown-time heap use-after-free (i.e., destructor-order-fiasco when one of the following symbols was used after its static-destruction-triggered free):

  DECLARE_CALLBACK(CxaThrow);
  DECLARE_CALLBACK(CxaBeginCatch);
  DECLARE_CALLBACK(CxaRethrow);
  DECLARE_CALLBACK(CxaEndCatch);
  DECLARE_CALLBACK(RethrowException);

Each of those would define a classic meyers singleton.
Since each destructor is trivial, we can fix this by making each a pseudo-leaky (indestructible) meyers singleton instead. Since each static value is never destroyed,
it can never cause a DOF error again.

Differential Revision: D3870740

fbshipit-source-id: 625f5d5268768ca0e4125bed72bc66c53618be29

Summary: This dependency was added but isn't actually needed, so get rid of it.

Reviewed By: mzlee

Differential Revision: D3863923

fbshipit-source-id: 407d2b3db759e30c37d876dde133fc962daeaeae

Summary: Track when session resumption was attempted during connect

Reviewed By: shamdor-fb

Differential Revision: D3861028

fbshipit-source-id: 26ca41084faeeb64666b6833896b9510ef2b4c25

Summary:
Update the timeseries and histogram classes to accept a clock parameter as a
template parameter, instead of a time duration type.

This is a first step towards transitioning the code to correctly distinguishing
between time_point and duration types.  This defines TimePoint and Duration
type aliases, but does not start using them yet.

In upcoming diffs I will start converting more APIs to correctly use TimePoint
instead of just Duration.

For now the default clock type is folly::LegacyStatsClock, which still uses
std::chrono::seconds as the default duration.  At the moment the stats code is
optimized for second granularity--the addValue() code has a fast path when
called in the same second as the last update.  When using finer granularity
durations this fast path can't be used as often.  I will also send out
subsequent diffs to make the code optimized for updates within the same bucket,
rather than just updates with the exact same time value.

Reviewed By: yfeldblum

Differential Revision: D3807715

fbshipit-source-id: 77696c4f44a8d85e4d6ff84d7656fe7a9709797c

Summary:
Why `$SHELL` is a bad idea:

- getenv() is not thread safe. (In practice it should work if other threads aren't calling setenv(), but still seems undesirable if we can avoid it.)
- It seems confusing for the program to have different behavior for different developers.
- Other shells besides /bin/sh may have different quoting behaviors. For instance, I don't think csh allows unescaped newlines inside single quotes.
- SHELL might be set to other non-shell-like programs in some cases. (Say, if this gets run from inside a git or mercurial hook it might end up being set to the restricted git or hg shell that only lets you run specific commands.)
Anyway, this isn't related to your diff, so nothing needs to be done for now,
but I would vote for changing this to always use /bin/sh in a future diff.

Both the C system() call and python's subprocess module appear to
always use /bin/sh and ignore $SHELL.

Reviewed By: simpkins

Differential Revision: D3867047

fbshipit-source-id: dab0e6afbe1c20ff13d9a52f212df95af425dd77

Summary:
Adding formatting support with automatic escaping of parameters. Will
subsequentyl try and make it harder for people to use non-statically determined
format strings for this.

Reviewed By: simpkins

Differential Revision: D3866174

fbshipit-source-id: 80bb5886386692643876116fbf338ca0d6986e6a

Summary:
introducing `Subprocess::shellify` to get around this. Still thinking
about how to make sure people escape arguments passing into that function. I'd
like to have something along the lines of Phabricator's `csprintf` here.

Reviewed By: yfeldblum

Differential Revision: D3857827

fbshipit-source-id: 8afbc9f1c62c62e0fc91782e11b808145b370933

Summary:
If you split out debug info into a separate file, folly::Symbolizer
didn't find it, and failed to include file and line number info in
backtraces.

This adds a new open mode which follows the .gnu_debuginfo link, and
uses it from ElfCache and SignalSafeElfCache.

Reviewed By: meyering, luciang

Differential Revision: D3852311

fbshipit-source-id: fec9e57378ae59fa1b82d41a163bb9cfcf9ca23c

Summary: Because it's needed with the way the portability layer works.

Reviewed By: yfeldblum

Differential Revision: D3863954

fbshipit-source-id: 3b682dcc2d2799f17c61fe16a4391fc9f0c2b127

Summary: Validates that we create a distinct singleton for each thread and that each such singleton is destroyed at its owning-thread's exit.

Reviewed By: yfeldblum

Differential Revision: D3849146

fbshipit-source-id: af878b32ecfc6c82b866d7a805e1385d74a8a5f5

Summary: It would seem the folly/Benchmark.h dependency was to pull in glog/logging.h. Include what you use.

Reviewed By: yfeldblum

Differential Revision: D3857112

fbshipit-source-id: 8d5bd105e10eee8f5b6e5d377d58ae84d908ed57

Summary:
Removing string::reserve() which causes O(n^2) penalty.

Fixes #477
Closes https://github.com/facebook/folly/pull/478

Reviewed By: yfeldblum

Differential Revision: D3850509

Pulled By: Orvid

fbshipit-source-id: ecf44c35b2aedadc5385d23c325cacab1abfd02d

Summary:
It appears that a feature of recording exact stack usage on fibers is broken for a long time.
This diff brings it back.

Reviewed By: andriigrynenko

Differential Revision: D3847035

fbshipit-source-id: d9cf532774204b6ac2f40e1b39fd98ea06c08f55