Summary:
AsyncServerSocket::bind - call bindSocket with isExistingSocket = false

(Note: this ignores all push blocking failures!)

Reviewed By: danobi

Differential Revision: D18144178

fbshipit-source-id: 0c673bb397fabb737f8595dd0453826bb57c826e

Summary: [Folly] Change an `#ifdef` to a constexpr ternary for `MemoryMapping`.

Reviewed By: meyering

Differential Revision: D18024494

fbshipit-source-id: 7ee040891ecee9bccf46af1dc43e54946e676c70

Summary:
currently, the implementation of `eden prefetch` calls into
a mercurial function that is overly eager in making network connections,
which results in what should be a fast NOP second prefetch call taking
more time than is desirable.

This diff adds a little cache to avoid repeatedly calling prefetch
for the same directory more than once for the life of the getdeps
process.

Given the usage pattern of getdeps it is OK that we don't provide
a way to invalidate this cache.

Reviewed By: fanzeyi

Differential Revision: D18005408

fbshipit-source-id: 0ec3f477da1043a5a715704b512c81fcfaa0acde

Summary:
[Folly] Optimize `Function::operator()` codegen for size and speed.

* Avoid translating between values and references for trivially-copyable values.
* Avoid shifting all arguments to make room for the function object address.

In the optimal case, the codegen for calling a `Function` with many arguments translates into just a `jmp`.

See:
* https://github.com/thecppzoo/zoo/commits/master/inc/zoo/AnyCallable.h
* https://github.com/bloomberg/bde/blob/3.38.0.1/groups/bsl/bslstl/bslstl_function.h
* https://github.com/bloomberg/bde/blob/3.38.0.1/groups/bsl/bslmf/bslmf_forwardingtype.h

Given this example code:

```lang=c++,name=check.cpp
extern "C" void check_0(folly::Function<void()>& f) { f(); }
extern "C" void check_1(int i, folly::Function<void(int)>& f) { f(i); }
extern "C" void check_2(int i, int j, folly::Function<void(int, int)>& f) { f(i, j); }
extern "C" void check_3(int i, int j, int k, folly::Function<void(int, int, int)>& f) { f(i, j, k); }
extern "C" void check_4(int i, int j, int k, int l, folly::Function<void(int, int, int, int)>& f) { f(i, j, k, l); }
```

Before:

```name=check.o
0000000000000000 <check_0>:
   0:   ff 67 30                jmp    QWORD PTR [rdi+0x30]
0000000000000000 <check_1>:
   0:   55                      push   rbp
   1:   48 89 f0                mov    rax,rsi
   4:   48 89 e5                mov    rbp,rsp
   7:   48 83 ec 10             sub    rsp,0x10
   b:   89 7d fc                mov    DWORD PTR [rbp-0x4],edi
   e:   48 8d 75 fc             lea    rsi,[rbp-0x4]
  12:   48 89 c7                mov    rdi,rax
  15:   ff 50 30                call   QWORD PTR [rax+0x30]
  18:   c9                      leave
  19:   c3                      ret
0000000000000000 <check_2>:
   0:   55                      push   rbp
   1:   48 89 d0                mov    rax,rdx
   4:   48 89 e5                mov    rbp,rsp
   7:   48 83 ec 10             sub    rsp,0x10
   b:   89 7d f8                mov    DWORD PTR [rbp-0x8],edi
   e:   89 75 fc                mov    DWORD PTR [rbp-0x4],esi
  11:   48 8d 55 fc             lea    rdx,[rbp-0x4]
  15:   48 8d 75 f8             lea    rsi,[rbp-0x8]
  19:   48 89 c7                mov    rdi,rax
  1c:   ff 50 30                call   QWORD PTR [rax+0x30]
  1f:   c9                      leave
  20:   c3                      ret
0000000000000000 <check_3>:
   0:   55                      push   rbp
   1:   48 89 c8                mov    rax,rcx
   4:   48 89 e5                mov    rbp,rsp
   7:   48 83 ec 10             sub    rsp,0x10
   b:   89 7d f4                mov    DWORD PTR [rbp-0xc],edi
   e:   89 75 f8                mov    DWORD PTR [rbp-0x8],esi
  11:   89 55 fc                mov    DWORD PTR [rbp-0x4],edx
  14:   48 8d 4d fc             lea    rcx,[rbp-0x4]
  18:   48 8d 55 f8             lea    rdx,[rbp-0x8]
  1c:   48 8d 75 f4             lea    rsi,[rbp-0xc]
  20:   48 89 c7                mov    rdi,rax
  23:   ff 50 30                call   QWORD PTR [rax+0x30]
  26:   c9                      leave
  27:   c3                      ret
0000000000000000 <check_4>:
   0:   55                      push   rbp
   1:   4c 89 c0                mov    rax,r8
   4:   48 89 e5                mov    rbp,rsp
   7:   48 83 ec 10             sub    rsp,0x10
   b:   89 7d f0                mov    DWORD PTR [rbp-0x10],edi
   e:   89 75 f4                mov    DWORD PTR [rbp-0xc],esi
  11:   89 55 f8                mov    DWORD PTR [rbp-0x8],edx
  14:   89 4d fc                mov    DWORD PTR [rbp-0x4],ecx
  17:   4c 8d 45 fc             lea    r8,[rbp-0x4]
  1b:   48 8d 4d f8             lea    rcx,[rbp-0x8]
  1f:   48 8d 55 f4             lea    rdx,[rbp-0xc]
  23:   48 8d 75 f0             lea    rsi,[rbp-0x10]
  27:   48 89 c7                mov    rdi,rax
  2a:   ff 50 30                call   QWORD PTR [rax+0x30]
  2d:   c9                      leave
  2e:   c3                      ret
```

After:

```name=check.o
0000000000000000 <check_0>:
   0:   ff 67 30                jmp    QWORD PTR [rdi+0x30]
0000000000000000 <check_1>:
   0:   ff 66 30                jmp    QWORD PTR [rsi+0x30]
0000000000000000 <check_2>:
   0:   ff 62 30                jmp    QWORD PTR [rdx+0x30]
0000000000000000 <check_3>:
   0:   ff 61 30                jmp    QWORD PTR [rcx+0x30]
0000000000000000 <check_4>:
   0:   41 ff 60 30             jmp    QWORD PTR [r8+0x30]
```

Reviewed By: luciang

Differential Revision: D17523239

fbshipit-source-id: beed0bae827aad8290e807374e8596f71f98ce99

Summary: This allows the caller to guarantee that the coroutine starts executing on the current thread. This can be necessary for correctness in some situations, where having the coroutine enqueued to the executor, as `.start()` does, and potentially allowing other code to run in the meantime could invalidate some assumptions.

Reviewed By: andriigrynenko

Differential Revision: D18076197

fbshipit-source-id: a6c5c226f2d7189f37e8f9713a30896767e9b8e9

Summary:
MemorySanitizer was failing due to uninitialized memory in the stack.

```
==596112==WARNING: MemorySanitizer: use-of-uninitialized-value
[testserver][INFO]: IOBuff received. Len = 128
    #0 0x9d4b21 in folly::SocketAddress::updateUnixAddressLength(unsigned int) xplat/folly/SocketAddress.cpp:710:7
    #1 0x9d4740 in folly::SocketAddress::setFromSockaddr(sockaddr_un const*, unsigned int) xplat/folly/SocketAddress.cpp:338:3

  Uninitialized value was created by an allocation of 'addrStorage' in the stack frame of function '_ZN5folly17AsyncServerSocket12handler
ReadyEtNS_13NetworkSocketEt'
    #0 0x7de840 in folly::AsyncServerSocket::handlerReady(unsigned short, folly::NetworkSocket, unsigned short) xplat/folly/io/async/Asyn
cServerSocket.cpp:835
```

Differential Revision: D18086738

fbshipit-source-id: f36013b157d7b34d3b29c08d4533f01be1a1a8c9

Summary:
Until [very recently](https://github.com/google/googletest/pull/2517), `googletest` did not print the skip message in any shape or form, so nothing can possibly depend on us customizing the skip message here.

The default is perfectly fine, let's keep it simple.

Reviewed By: yfeldblum

Differential Revision: D18051635

fbshipit-source-id: f7b889b0adf5e34a70c2579a34748bb159809b3c

Summary:
Add `annotate_ignore_thread_sanitizer_guard` class.

(Note: this ignores all push blocking failures!)

Reviewed By: yfeldblum

Differential Revision: D18045913

fbshipit-source-id: 39113e8df3deef3374a3c44246bc55a156bc4d8d

Summary: Allow AsyncServerSocket::bind to be called for multiple addrs (same as for port bind)

Reviewed By: yfeldblum

Differential Revision: D18046496

fbshipit-source-id: efde498fbaa02357d7c66905b8c1e5e839062076

Reviewed By: yfeldblum, lewissbaker

Differential Revision: D18052431

fbshipit-source-id: 9fb1b3faba25093cf67bdf9c6cbe5cc70794deee

Summary:
Generalises the specialisation of collectAllRange() and collectAllWindowed() on a std::vector<Task<T>> to now work for any std::vector<SemiAwaitable>.

This will allow them to work when passed a std::vector<TaskWithExecutor<T>>.

Reviewed By: andriigrynenko

Differential Revision: D18049190

fbshipit-source-id: 658213f93ff3eadda041ac2262cc6bcb759e331c

Summary:
[Folly] Extract `strlcpy` to a new c-string lib in `folly/lang/CString.h`.

This new lib would be for routines that should but don't appear in `<cstring>`.

Reviewed By: marcinpe

Differential Revision: D18032925

fbshipit-source-id: 746851f68e86a5ec2bea5cc659c19c4fe2f0f02a

Summary: [Folly] Guard the forward declaration of `fibers::Baton` by the same condition which determines whether `fibers::Baton` is ever used in futures.

Reviewed By: lewissbaker

Differential Revision: D17962552

fbshipit-source-id: 2494026999cd170c36adec91108732254212abf1

Summary: [Folly] Prefer a C++ symbol over back-defining `MAP_POPULATE`.

Reviewed By: nbronson

Differential Revision: D18024313

fbshipit-source-id: 7f3b754a7911d6947e5a6f34860f9f0d3833aa51

Summary: [Folly] Add missing `inline` to `co_current_executor`.

Reviewed By: ericniebler

Differential Revision: D18034078

fbshipit-source-id: 8c212ef6278112cc8e90075494a3038d9111bb64

Summary:
The PAUSE instruction's latency varies widely across x64
architectures, resulting in too much spinning on Skylake in some
scenarios.  This diff switches to using cycle counts to limit spinning
on x64, so that the minimum and maximum spin durations are independent
of asm_volatile_pause's latency.

Reviewed By: yfeldblum

Differential Revision: D17961663

fbshipit-source-id: 6170bfa48d007ca21b73b1a5c7e68da0043cda2c

Summary:
This avoids invalidating the entire build in response
to just running `hg amend`, which is frustrating and slow.

Reviewed By: chadaustin

Differential Revision: D18005409

fbshipit-source-id: ef93313859919298be78204046eb08bcadc5398e

Summary: [Folly] Backport invocability variable templates: `is_invocable_v`, `is_invocable_r_v`, `is_nothrow_invocable_v`, `is_nothrow_invocable_r_v`. And for the member-invoke and free-invoke traits.

Reviewed By: ericniebler

Differential Revision: D17950331

fbshipit-source-id: 5409d7a72116b0976573e1f64760c5ef9274966f

Summary:
If CH parsing is enabled, also parse out the ServerName extension. OpenSSL 1.1.1
changes the behavior of `SSL_get_servername`: an SNI value is stored in
the underlying SESSION if and only if both parties negotiated that SNI.

There are some situations where one would wish to retrieve the original
ServerName that the client sent.

Reviewed By: knekritz

Differential Revision: D17893443

fbshipit-source-id: b29ee42e90629c869dd5e68c93c7cb2abc19745f

Summary:
No longer allow a child task's modifications to the RequestContext made before it's first suspension point to bleed into the next child task's context.

Now always restore the parent task's RequestContext before starting subsequent tasks.

Reviewed By: andriigrynenko

Differential Revision: D17846070

fbshipit-source-id: 44e206d4c833759fc36c7d1bd0f3545ca6bb9ab1

Summary: Relax DFATAL message

Reviewed By: yfeldblum

Differential Revision: D18001089

fbshipit-source-id: 2027d0257e1cba6905dc4eb1863b70a8fe6a7366

Summary: trim, ltrim and rtrim are similar to ltrimWhitespace, rtrimWhitespace and trimWhitespace but you can specify what you want to remove

Reviewed By: yfeldblum

Differential Revision: D17946658

fbshipit-source-id: 9bdc5e6eb810e628a8c16b5142c17a3313f884f2

Summary:
ThreadPoolExecutor::getPoolStats depends on derived classes implementation.
Calling `getPoolStats` is specially useful from `ThreadPoolExecutor::withAll`.

This change moves registration of thread pool executor instances to derived classes
to avoid `ThreadPoolExecutor::withAll` racing with thread pool destruction while calling `getPoolStats`.

Reviewed By: yfeldblum

Differential Revision: D17965135

fbshipit-source-id: 637de55ed78b085dc86fffa0e0f4a66cd4cfcede

Summary: keepAliveRelease code reorg

Reviewed By: kevin-vigor

Differential Revision: D17835172

fbshipit-source-id: 48c60b04324f0d9bd1ac628e2625d3d4d2654c99

Summary: Add missing switch case

Reviewed By: yfeldblum

Differential Revision: D17945170

fbshipit-source-id: 8128c40e1c86b2a5ff8d1bad3c0e9fe197adc174

Summary:
this should help avoid this particular error:

```
IOError: [Errno socket error] [Errno 11001] getaddrinfo failed
```

Reviewed By: chadaustin

Differential Revision: D17886598

fbshipit-source-id: bd9f5b84ebd7ca5c339be3afec3a975fa907d052

Summary:
This diff allows passing a watchman version number override
via the environment as well as via the cmake `WATCHMAN_VERSION_OVERRIDE`
option.

To help invalidate the build I've added a new section to the manifest
files that allows listing out additional env vars that the project
hashes should be sensitive to.  The effect of this is that we'll
re-run the cmake configure step if the listed env vars are changed.

Reviewed By: Ben0mega

Differential Revision: D17865896

fbshipit-source-id: 8ea5572b0b9b7af95ec5c310e494cb17a139ced4

Summary: testpilot's defaults assume a bigger machine than some of our laptops

Reviewed By: fanzeyi

Differential Revision: D17878120

fbshipit-source-id: e01f1f9c77a4f5f011051c9c642dbe934c66bc0b

Summary: During shutdown there's a race condition in IOThreadPoolExecutor::getEventBase where a thread is created in ensureActiveThreads, and then destroyed before pickThread() is called. This adds the same guard that exists in add().

Reviewed By: yfeldblum

Differential Revision: D17955227

fbshipit-source-id: 042cb5c42056a9da4578571fb10936bbc477c4ff

Summary: Add a portability macro for testing whether the compiler supports C++17's inline variables.

Reviewed By: yfeldblum

Differential Revision: D17957184

fbshipit-source-id: bff7d2bc15867e32f787860b4f8e5a0176ac1017

Summary: [Folly] Fix wrong definition of `FOLLY_HAVE_GROUP_VARINT` when group varint is unsupported.

Reviewed By: Orvid

Differential Revision: D17961015

fbshipit-source-id: 3c82aaaf4b257180ab0956e4b181bfd619d7adda

Summary:
/home/folly/folly/experimental/test/QuotientMultiSetTest.cpp:60:29: error:
missing template arguments before 'reader'
     folly::QuotientMultiSet reader(data);

Reviewed By: vitaut

Differential Revision: D17959566

fbshipit-source-id: 02fec44b3d644eea0213895aa4df70349ef7d062

Differential Revision:
D17908896

Original commit changeset: 85847fc17f4a

fbshipit-source-id: 9b2bd8c11881cad18cffea0e14349e25d743b150

Summary:
Calling `folly::ThreadPoolExecutor::withAll` is powerfull when combined with `folly::ThreadPoolExecutor::getPoolStats`.
However getPendingTaskCountImpl being pure virtual can trigger `__cxa_pure_virtual ... std::terminate()` while object is partially destructed.

This change signals implementors of derived clases to write a body for getPendingTaskCountImpl while allowing calling getPoolStats -> getPendingTaskCountImpl within a try/catch block.

Reviewed By: yfeldblum

Differential Revision: D17915523

fbshipit-source-id: 2ffad7076313407969d88c75c7e457fa4e7e2d6d

Summary:
- There is not an easy way to check if a given type is an instantiation
  of a class template.
- The common solution is to write a custom trait each time and
  specialize it for the given instantiation so that the trait returns
  `std:true_type`.
- Add `is_instantiation_of` to help with DRY in custom traits for
  checking if a type is an instance of a given class template. Note that
  this does not work when the class template has a mix of type and
  non-type template parameters. It only works with types.
Pull Request resolved: https://github.com/facebook/folly/pull/1184

Reviewed By: vitaut

Differential Revision: D16161679

Pulled By: yfeldblum

fbshipit-source-id: c933fd3db7c56f61b6784fdcd199ff7963d61d8f

Summary:
The deadlock repro is described https://github.com/facebook/folly/issues/1211.
Fix is to check the working epoch before retire() starts the sync work.

Reviewed By: yfeldblum

Differential Revision: D17908896

fbshipit-source-id: 85847fc17f4a75058d4a72c43dba0c570a2593d6

Summary: As title.

Reviewed By: yfeldblum

Differential Revision: D17937014

fbshipit-source-id: a0ff5f5f9cbbb182794dc564610d7adb9c7c8d08

Summary: [Folly] Fix `Json.SortKeys` test when `F14NodeMap` may randomize table iteration order.

Reviewed By: shixiao

Differential Revision: D17903465

fbshipit-source-id: 00f1a8c441af3e11815a4312f6dc810ec9455a5e

Summary:
Unconditionally sleeping for 100ms in the wait polling loop has high average latency. If a process exits just after the initial wait() call, it's better to poll again sooner.

Start with a 2ms sleep and double it every sleep, capping out at 100ms.

Reviewed By: yfeldblum, mzhaom

Differential Revision: D17769851

fbshipit-source-id: efec8fdb8c2199b8db29b46b8c43fdaac56f69a8

Summary: `waitOrTerminateOrKill` fills the gap between `wait()` and `terminateOrKill`. It allows giving the subprocess a chance to shut down cleanly (after closing its stdin pipe, for example), but avoids waiting forever or leaking a child process.

Reviewed By: yfeldblum, mzhaom

Differential Revision: D17769090

fbshipit-source-id: 8940fd63f7eb9c09ef293c89a5e97f69805735ff