Summary:
When future callbacks are to be executed by an executor (via `via`)
and the executor does not actually execute the callback function
(for whatever reason), then waiting for the final future (the one
returned by `via`) block forever. In case the callback function
that got passed to the executor gets destroyed without being executed,
the future should be set to a folly::BrokenPromise exception instead
of remaining unset forever.

This diff modifies the reference counting in folly::detail::Core
to make sure the reference held by the callback function is
properly removed not only after the callback gets executed, but
also when the callback is destroyed without having been executed.

Reviewed By: yfeldblum

Differential Revision: D3455931

fbshipit-source-id: debb6f3563384a658d1e0149a4aadbbcb268938c

Summary: Building/testing with ASAN would elicit a heap use-after-free.

Differential Revision: D3639117

fbshipit-source-id: 30b5fa7d3fe1d804c4fba5bada8197a3a05a8333

Summary: takeOwnershipOfPipes should left zero heap memory allocated in folly:Subprocess class instance.

Reviewed By: snarkmaster

Differential Revision: D3638503

fbshipit-source-id: aac7b10bd7399c44868f32c01164f4123892598f

Summary:
Add an unlock() method to Synchronized LockedPtr objects.  This will make it
easier to replace current users of the UNSYNCHRONIZED macro.

Of the handful of places currently using UNSYNCHRONIZED, many of them want to
simply release the lock before logging a message and returning.  However,
UNSYNCHRONIZED is a poor choice for this, since it will re-acquire the lock on
scope exit.  In these situations where the function returns from inside an
UNSYNCHRONIZED block the code unnecessarily re-acquires the lock just to
immediately release it.  The unlock() method will provide a cleaner mechanism
for these call sites to simply drop the lock early before returning.

Reviewed By: yfeldblum

Differential Revision: D3547652

fbshipit-source-id: 4d28fe9f3aad0d7348e918d1a3d6c705bfec242b

Summary:
MSVC gives warnings if you shift a 32-bit value left but then assign it to a 64-bit variable. This just makes it a 64-bit shift instead.
If we really wanted, this doesn't need to be a size_t to begin with, but it already is, so just leave it alone.

Reviewed By: yfeldblum

Differential Revision: D3622935

fbshipit-source-id: 25931e6df644df8a2160aa80fd5de21cd9c06159

Summary:
MAP_POPULATE is not defined on this system.  Instead we will `madvise` the kernel
that we will need it so that it will populate the mapping.

Reviewed By: yfeldblum

Differential Revision: D3584325

fbshipit-source-id: ece52f3d55c475bcd41367f4e9744d6f41001cd5

Summary:
It was using inline assembly in order to get atomic single-bit operations, so add a variant for MSVC that uses intrinsics.
MSVC is also weird in-that it doesn't have a 16-bit variant of these, so use an atomic OR and AND to achieve the required effect.

Reviewed By: yfeldblum

Differential Revision: D3623220

fbshipit-source-id: b4ff985ef2ed7787115f4d20de6f244123410dc8

Summary: That way the mismatch warning can stay as an error.

Reviewed By: yfeldblum

Differential Revision: D3613761

fbshipit-source-id: 6e0ee42c658d95786f578f6500aba113c00d8f77

Summary: While the previous version did compile, it wouldn't actually work at link time.

Reviewed By: meyering

Differential Revision: D3614424

fbshipit-source-id: 578677b65edca720330319594e1163d214e1400d

Summary: When I initially added the surrounding `#ifdef` I failed at where I put my `#endif`, as I left the shared library test enabled. This disables it for Windows.

Reviewed By: yfeldblum

Differential Revision: D3622769

fbshipit-source-id: f263201239095bbef076300d5f40649ebee1173c

Summary: It didn't like using `decltype(args)`, which wasn't really necessary as we already have it's type.

Reviewed By: yfeldblum

Differential Revision: D3623424

fbshipit-source-id: 994c23cbf486d427c6dd0fe4c6f768e51ea15ad1

Summary: It doesn't exist anywhere else, and `syscall` isn't even defined on Windows, so this completely failed to compile before.

Reviewed By: yfeldblum

Differential Revision: D3623382

fbshipit-source-id: 302093ddc96d6465e0dcc1883747229a7fb25a84

Summary: So that the `[[noreturn]]` attribute can be applied.

Reviewed By: yfeldblum

Differential Revision: D3614122

fbshipit-source-id: 4b95cb553e85c85c277c00b8165671dcc75afac8

Summary:
Specifically the loosening of the definition of a range where-by the end of an iterator may be represented by a different type than the beginning of the range.
Oh, and it also fixes compilation on MSVC, which didn't like the decltype being used to determine the iterator type.

Reviewed By: yfeldblum

Differential Revision: D3613993

fbshipit-source-id: 2940a15d0f93c5b6310d0b1896f5d12ca9aec639

Summary: Add a declaration to mock out FlagSaver on platforms that don't support gflags.

Reviewed By: ivmaykov, yfeldblum

Differential Revision: D3620421

fbshipit-source-id: c1047f34f384f34276b18f53e966a65cdd5c8075

Summary: This allows having some logic executed before and after FiberManager loop (e.g. grabbing a Python GIL).

Reviewed By: A5he

Differential Revision: D3616752

fbshipit-source-id: 3be35d54ced458328816d583133457a44a863acd

Summary: This crashes unit test with asan, since we never deletes it.

Reviewed By: djwatson

Differential Revision: D3622847

fbshipit-source-id: f7ea7c4f464843353b24a59adefd5d66b95bc169

Summary: cb is an unused variable, and i got error in android. It seems like we don't need to go through the list to increase count.

Differential Revision: D3622772

fbshipit-source-id: fe1f81a1fcad5bacad052e14b7b0b370beb3f3e5

Summary: MSVC needs a bit more glue to expand the varargs.

Reviewed By: yfeldblum

Differential Revision: D3614681

fbshipit-source-id: 901d8c5138b1d2d28434c51bdff31f6d21f26681

Summary: Because it's using `ssize_t`, which MSVC defines weirdly.

Reviewed By: yfeldblum

Differential Revision: D3614050

fbshipit-source-id: 422621ea0dc92b374fa6dfc32a5391c1093d039e

Summary:
Refactor the socket peeker into its
own class so that it can be used in
other places as well, for example
for peeking at plaintext traffic.

Reviewed By: knekritz

Differential Revision: D3521899

fbshipit-source-id: fcd5615dd5d7cd1ddece4c624efbdecfbbc88a09

Summary:
We should go back to 10ms granularity.
Because regressions -
https://www.facebook.com/groups/wfi/permalink/1107102889338325/

Reviewed By: haijunz

Differential Revision: D3616784

fbshipit-source-id: dc1d7ff5195ae836df4a334a9ac5c41164c0627b

Reviewed By: yfeldblum

Differential Revision: D3611881

fbshipit-source-id: 3991c18cc2956e9d0b50a20e6daf913ec58ee501

Reviewed By: dkgi

Differential Revision: D3586189

fbshipit-source-id: ce817233a0293e19400b5689c283531be6302c10

Summary: As more code is using mallctl, it's worth making these helper functions available everywhere.

Reviewed By: yfeldblum

Differential Revision: D3576190

fbshipit-source-id: 968e80e00f2ed93542e117c24861c21745b63f20

Summary:
[Folly] Move `RequestContext` definitions to source files.

Keeping headers lightweight can help with build times.

Reviewed By: djwatson

Differential Revision: D3609809

fbshipit-source-id: 20608e3ff764c86c24355a328da1dcca9a08fce4

Summary: In order to trigger trace points when a new thread begins/finishes executing, I added functionality to call onSet and onUnset methods on all RequestData objects whenever setContext is called. The main question: will this approach cost us too much overhead?

Reviewed By: djwatson

Differential Revision: D3604948

fbshipit-source-id: 3b704ca0f2b713458427aa49be12f776939057f8

Summary: This code very obviously wrote past the end of the buffer when the length was 1. Furthermore, it was just downright broken for all values. The author obviously meant to type * instead of +. I took the time to verify that the algorithm is actually correct, while I was working on this. My proof is in the test plan.

Reviewed By: yfeldblum, meyering

Differential Revision: D3603255

fbshipit-source-id: 5f2a0011ff5401a70ba03993eab6e53e29d87c1c

Summary: Because Windows already defines a funtion named `GetTickCount` with a different signature.

Reviewed By: yfeldblum

Differential Revision: D3601877

fbshipit-source-id: fa0fb422156a3dc71e149e02a000ccdf3479eea5

Summary: There was an MSVC section, but it's much simpler to just use the glue to solve the issue instead.

Reviewed By: yfeldblum

Differential Revision: D3601184

fbshipit-source-id: f95bd3dfc4b244e1bce21997f44de2970575ad7f

Summary: A `long` on MSVC is only 4 bytes, so the `static_assert` will fail. Remove the static assert and use the `long long` version instead. Do the same for the unsigned version.

Reviewed By: yfeldblum

Differential Revision: D3601064

fbshipit-source-id: 70c5f4bca597ba05c3729f5d15feeea3cc8fde57

Summary: Because we need it for MSVC.

Reviewed By: yfeldblum

Differential Revision: D3601138

fbshipit-source-id: 4d2ba3f9c972717745289686b025d2763f9ef30d

Summary: As the comment in the file says, this has to be included in a weird order due to issues on Windows.

Reviewed By: yfeldblum

Differential Revision: D3601008

fbshipit-source-id: fca4b6d906eb0d1f001c28197987165cd075752d

Summary: As the `sizeof()` is being evaluated in a static context, MSVC doesn't let you reference non-static locals. Solve the issue by getting the type of the local via `decltype` instead.

Reviewed By: yfeldblum

Differential Revision: D3600845

fbshipit-source-id: 825d93ced8f09d9f4bf0dcf02142f47a0ec32605

Summary:
This was causing MSVC to complain due to `DSched` already being declared in `BatonTestHelpers.h` as `::folly::DSched`, but it's then typedef'd again in `BatonTest.cpp`, this time as `::DSched`. MSVC complains about the duplicate definitions even though they resolve to the same type, so kill the one in the source file and keep the one in the header.
The same is the case with `GroupVarint32Decoder` and `GroupVarint64Decoder`, which are both declared in `GroupVarint.h` and then again, this time in an anon namespace, in `GroupVarintTest.cpp`.

Reviewed By: yfeldblum

Differential Revision: D3600948

fbshipit-source-id: 401790aa918289fe4a34dd5af683f8c6ca50d847

Summary:
uniform_int_distribution is implemented differently on this system and
always returns the generated number from our constant random number generator.

Reviewed By: yfeldblum

Differential Revision: D3585418

fbshipit-source-id: 754076599ba77b49c17f03bb0c92264a3bed4ab0

Summary:
Because it doesn't exist in the C++ standard.

This switches them to the explicitly expanded form, which is in the spec.
It also removes a few that were doing absolutely nothing. (MSVC still complained about the division by zero)

Reviewed By: yfeldblum

Differential Revision: D3479260

fbshipit-source-id: 5386e27057beeb4b228f5d6be4e1cf9941cf3176

Summary:
Sure, it's big, but it compiles.

There are a few different changes to make this happen, the first is to deal with quite a few places where MSVC was complaining about the implicit coersion of template and noexcept parameters to bool.
Next, the gating that disabled this for 4.7 is now gone.
MSVC's runtime expected `difference_type` to be defined on our custom allocator, so it now is.
`ReadTSC()` was changed to use MSVC's intrinsic for this.
And finally, the named variadic parameters to macros were switched to normal variadic macro params, as MSVC doesn't support named ones.

Reviewed By: yfeldblum

Differential Revision: D3479761

fbshipit-source-id: 703a5ef942ffc9b63381d13fc3960ac6f2780aa0

Summary: Because they aren't captured, and thus aren't accessible, in the callback used further on in the function.

Reviewed By: yfeldblum

Differential Revision: D3600874

fbshipit-source-id: 699b3d4caa0a310b1ccc7810d670671850f4366b

Summary: We don't have `fork()` to begin with, so disable the test and the includes it required if we're compiling on Windows.

Reviewed By: yfeldblum

Differential Revision: D3600600

fbshipit-source-id: 5399705753b456139105f4ac757190e1ba1765f2