Summary:
Add timeout support to python executor. Executor uses a separate thread running a folly event base.
Whenever a timer operation is called, scheduleTimeout is executed in that event base.

Reviewed By: andriigrynenko

Differential Revision: D18201883

fbshipit-source-id: 337518bea52993461201d6706f438130673ef6ce

Summary: Add iouring folly support, refactor the async IO

Reviewed By: kevin-vigor

Differential Revision: D17834511

fbshipit-source-id: e20c876a32730549f305334fd5eed02cccf23638

Summary: BENCHMARK_COUNTERS tests need to set `using folly::UserCounters` or `using namespace folly`. Add absolute namespace path in the macro to get rid of this requirement.

Reviewed By: Orvid

Differential Revision: D18271700

fbshipit-source-id: 084041142b7c245e3c861943570416ac89ea6c34

Summary: [Folly] Permit multiple primary namespaces for free-invoke traits instead of just 0 or 1 primary namespace.

Reviewed By: vitaut

Differential Revision: D18113151

fbshipit-source-id: 57f7b76a89e6dbd88cc2584d72079fa7fd94fe53

Summary:
Using `shape[0]` as the length of the IOBuf means using the number of _elements_ along the first dimension, rather than the total number of bytes in the memoryview. Thus
- if the element size is not 1 byte, this will get only a fraction of the memory;
- if the memoryview is shapeless, the code will segfault;
- if the memoryview is multidimensional, it will only get a fraction of the memory (and, if the memory is C-contiguous, it will be an odd slice: in a 2x3 memoryview, it will get the entire first row and half of the second).

Perhaps the above was intentional, but I believe that when converting a shaped and typed object to an unshaped and untyped buffer, it's more intuitive to ignore the type and size and just look at the memory backing it.

I also added a check to ensure the view is contiguous. IOBufs can't represent a non-contiguous buffer, except by using a chain, which however in this case could have an arbitrary unbounded length, making it unadvisable. Alternatively we could copy the memory, but this is probably not what the user would expect. Disallowing this seems the safest option.

Reviewed By: yfeldblum

Differential Revision: D18006273

fbshipit-source-id: f21dbb462266eee68f1a5ce0ecea85b1a46e0a8b

Summary: Pull Request resolved: https://github.com/facebook/folly/pull/1248

Reviewed By: yfeldblum

Differential Revision: D18094432

Pulled By: Orvid

fbshipit-source-id: 115afedc62be8881941cfb4d0e02748be349763f

Summary:
create a unorderedReduceSemiFuture method that returns a SemiFuture
instead of just a Future.

Reviewed By: mhlakhani

Differential Revision: D18248163

fbshipit-source-id: ba1f8ede93c95ea0b877ac306056e7e38c4452e6

Summary:
Build folly with -Werror and -Wunused-exception-parameter to prevent
them from sneaking back in.

Reviewed By: yfeldblum

Differential Revision: D18232483

fbshipit-source-id: 7154d3dfec6c672aa3aa46299456bd3c4d757709

Summary: ^

Reviewed By: mjoras

Differential Revision: D18256970

fbshipit-source-id: 4d07b961ab5ab145b620d9e10fa67116236bbf80

Summary:
Only do RAND_poll on older versions of OpenSSL.

RAND_poll is not required on OpenSSL 1.1.0+, as the RNG is implicitly seeded. On OpenSSL 1.1.1., RAND_poll became aliased to RAND_add. With some custom RNG implementations that did not implement RAND_add, (e.g. python-cryptography's osrandom implementation), this would manifest as a failure.

Reviewed By: ngoyal, yfeldblum

Differential Revision: D16786271

fbshipit-source-id: 4fb7876525006517c3e554d70736d7071bd3b4e3

Summary: The functions in QMS are all marked as const already.

Reviewed By: philippv

Differential Revision: D18240371

fbshipit-source-id: 113f5c968207f0a4ff9b780cd43de43cb90f758b

Summary: Floating-point scale conversion doesn't require a cast

Reviewed By: yfeldblum

Differential Revision: D18052505

fbshipit-source-id: 3d87a916da5cec03b23041908066a9862fab6fde

Summary:
Minor improvements to the CompressionContextPool. Although it should be
impossible, this diff checks that we do not retrieve `nullptr`s out of the
stack.

I also threw in a quick refactor to not store a copy of the deleter in the
RTPDeleter.

Reviewed By: terrelln

Differential Revision: D18131791

fbshipit-source-id: eda1856720fdb86a69ee0a2a867b25bb20ebc319

Summary:
This change adds basic support for server auth through AsyncSSLSocket and fills in the implementation under SSLContext::authenticate() to support peer name verification.

virtual void SSLContext::authenticate(
      bool checkPeerCert,
      bool checkPeerName,
      const std::string& peerName = std::string());

SSLContext::authenticate signature has parameters intended for server-auth scenarios, but it doesn't have an implementation underneath it and silently ignores the checkPeerName and peerName parameters. This change implements the intended behavior through OPENSS's SSL_set1_host. The intended behavior is as follows:
* When checkPeerName is false, the behavior is unchanged and this should cover all existing use cases.
* When checkPeerName is true, either the peerName or the servername (suppled through the AsyncSSLSocket constructor) in this given order is expected to be present in the SAN or CN of the peer's certificate as described in [the OPENSSL documentation](https://www.openssl.org/docs/man1.1.0/man3/SSL_add1_host.html). Socket will error our if neither name is supplied. Wildcard matching when checking the name is intentionally disabled for now since there is no known need for it at the moment.

Unit tests are added to cover both positive and negative scenarios around SSL server name auth.

Reviewed By: mingtaoy

Differential Revision: D18162775

fbshipit-source-id: d275f5e2e9e760895c27ba9d73cf8b6a2d0ff599

Summary: [Folly] Use simpler `cacheline_aligned` v.s. `CachelinePadded` in `LifoSem`, per comments atop `CachelinePadded`.

Reviewed By: aary

Differential Revision: D18166262

fbshipit-source-id: 807c668666fbbc9c16d5f449fa20234e56b29042

Summary: Fixes CVE-2019-11934

Reviewed By: mingtaoy

Differential Revision: D18020613

fbshipit-source-id: db82bb250e53f0d225f1280bd67bc74abd417836

Summary: `EliasFanoCoding` is used with 64-bits values in some logic, but we have no tests for that. Also, we weren't testing the larges admissible value. Finally, clarify in the comments what the various size types are for.

Reviewed By: philippv

Differential Revision: D18146549

fbshipit-source-id: e97ec9e1344db6e56a591a9b4c77c5929e10b22b

Reviewed By: Orvid

Differential Revision: D18169787

fbshipit-source-id: 1580df251c9ae87e9c268f1599d8c61232b48a4d

Summary: [Folly] Use attribute-based suppression in free-invoke traits v.s. pragma-based suppression for suppressing warnings about unused functions.

Reviewed By: vitaut

Differential Revision: D18112966

fbshipit-source-id: 2519f94d4ff4609c8418d4fd009a24acefe23ab2

Summary: [Folly] Remove `classname` from free-invoke traits inner names - it's already present for disambiguation in the outer private namespace name. Also adjust some of the names better to fit a singular pattern.

Reviewed By: vitaut

Differential Revision: D18112947

fbshipit-source-id: 0a3e76a72a16fff7d4c127c2994a8c38639083e2

Summary: [Folly] `is_constexpr_default_constructible`, for deciding whether a type is constexpr default-constructible.

Reviewed By: vitaut

Differential Revision: D18092652

fbshipit-source-id: a4642726a9495135abca1506c5dbb3d57c0e0558

Summary: [Folly] Cut `folly/futures/exercises/`, which was never finished.

Reviewed By: fugalh

Differential Revision: D18149557

fbshipit-source-id: ec5654c2d37996c42a3673523422bafe2a64c89e

Summary: The computation of the upper bits size is incorrect when both `kUpperFirst` and `kChecked` are true. In addition, when `kUpperFirst` is true, we might actually need 8 additional bytes in the buffer, for when `numLowerBits = 0`, so clarify the comment.

Reviewed By: philippv

Differential Revision: D18145144

fbshipit-source-id: 1372d39023e2d5d1c5ccbfb8e6c7af9a5a930f1d

Summary: In most cases lists are not iterated from the beginning, so reading the first word wastes a memory access.

Reviewed By: philippv

Differential Revision: D18140137

fbshipit-source-id: d5cd07a8b9ed67febcc89cef0314a538e5ca8423

Summary:
Our CI environment cannot directly connect to the internet,
and even if it could, doing so is undesirable to fetch javascript deps.
We maintain an offline mirror of packages used by the build(s) so that
we don't have to go out to the internet.

When running in fbsource, configure the environment to use that offline
mirror.

Reviewed By: chadaustin

Differential Revision: D18061773

fbshipit-source-id: 1a5e112f23c1baaedfb3dff0c4c2a1641f6bb9a1

Summary: Ask testpilot to include more output in test failures.

Reviewed By: fanzeyi

Differential Revision: D18061772

fbshipit-source-id: 0c14092557c21396c877d3b1776c5707437a117c

Reviewed By: davidtgoldblatt

Differential Revision: D16530636

fbshipit-source-id: 0ea2b9b628f3c41f87a3d31e0b4c1dc71101f639

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