Summary:
Add SimpleAsyncIO class. This creates an instance of an AsyncIO
and manages a completion thread and a pool of ops, so user does
not have to worry about any of these details.

Differential Revision: D23945993

fbshipit-source-id: 90f9b83ca3447a19e3bc4aaf2a2f196ee4ea614d

Summary: If retries is 0, then `0 < 0` is false, meaning we will skip the `while` loop completely and just try to read retcode, which was never assigned.

Reviewed By: fanzeyi

Differential Revision: D23999523

fbshipit-source-id: fac4a1104eba3585fb52fc8d83163cb1a87b8fee

Summary: This diff adds a utility `withJitter` that creates an observer proxying updates from the input observer, with the difference that each update will be propagated with a random lag.

Reviewed By: andriigrynenko

Differential Revision: D23795834

fbshipit-source-id: cdaee7460c3c346e70f6c8c78f18467fe8cd4e47

Summary: Use separate b_, e_ range members

Reviewed By: yfeldblum

Differential Revision: D23983016

fbshipit-source-id: b17061d7c1022c4776a8a8cb76ad5d0b9da9ace2

Summary: [Folly] A few simplifying tweaks to SFINAE in `Function`.

Reviewed By: aary

Differential Revision: D23798698

fbshipit-source-id: e5a3ecfe755f6eb371c253cfb925a23d4f5d29e4

Summary:
In the sync from fbsource to ovrsource, we found that signal_set macro from libevent
has a conflict with boost::asio::signal_set function in boost_context.

e.g. failure https://www.internalfb.com/intern/sandcastle/job/18014398839678371/

This undef removes the build failures on the ovrsource side.

Reviewed By: yfeldblum

Differential Revision: D23941679

fbshipit-source-id: 25e208bdbc93f289d787ca742623fd6815863705

Summary:
Currently, Hardware.h assumes the `__rdtsc` intrinsic is always available when building with MSVC. However, this is not the case when building for Windows for ARM64.

This blocks successful compilation of https://github.com/facebook/rocksdb on Windows for ARM64, since that library embeds Folly and includes this specific header.

Instead, use a condition similar to the check in `asm_volatile_pause` in Asm.h. This results in successful compilation and a fallback to `steady_clock::now()` on Windows for ARM64 targets.

Pull Request resolved: https://github.com/facebook/folly/pull/1461

Reviewed By: yfeldblum

Differential Revision: D23952622

Pulled By: Orvid

fbshipit-source-id: 1f02d04cbbbde42c80ad56d8d7ccc4dd7fe86847

Summary: It seems after updating zstd to 1.4.5. `Dllexport` for zstd.dll was not being picked up correctly. Instead of having zstd being a runtime dependency let's try statically link it to avoid the DLL issue.

Reviewed By: vitaut

Differential Revision: D23970349

fbshipit-source-id: 3b14dddb64d410cb9546c416f27d73b7604b21ba

Summary:
Fix race condition in hazptr_obj_cohort deactivation

Race condition:
- Thread T1 is doing asynchronous reclamation of objects.
- Thread T2 starts deactivating cohort C.
- T1 reclaims an object that its destructor retires a tagged object A that belongs to cohort C.
- T1 checks that C is active.
- T2 sets C.active_ to false.
- T2 pops and reclaims the objects in C's list.
- T1 pushes A in C's list
- T2 expects to find C's list empty but it is not. Assertion failure.

With the fix.
- Thread T1 is doing asynchronous reclamation of objects.
- Thread T2 starts deactivating cohort C.
- T1 reclaims an object that its destructor retires a tagged object A that belongs to cohort C.
- T1 checks that C is active.
- T2 sets C.active_ to false.
- **T2 waits for T1 to release the lock on the domain tagged list**
- T1 pushes A in C's list
- **T1 releases the lock**
- **T2 cleans up C's objects in the domain tagged list**
- **No subsequent asynchronous reclamation of objects in the domain will involve objects that belong to C**
- T2 pops and reclaims the objects in C's list **including A**
- T2 finds C's list empty as expected.

Reviewed By: yfeldblum

Differential Revision: D23947490

fbshipit-source-id: 943664e61190da7b4ad1bb31ac47609bdea2314d

Summary: Simple typo that I spotted.

Differential Revision: D23963553

fbshipit-source-id: 018e81c4878f4cb27b6676e88278d47d38706ed4

Summary: Store a raw pointer to the managed object outside of the ReadMostlySharedPtrCore to make casting easier.

Reviewed By: yfeldblum

Differential Revision: D23920580

fbshipit-source-id: 4d3d3423f4ef3a78ebbd5efd45bb365ca0f72a18

Summary:
Pull Request resolved: https://github.com/facebookexperimental/rust-shed/pull/12

The OpenSSL version on Mac doesn't work well with EdenSCM and Mononoke integration, just use the one from getdeps/brew.

Also remove the now redundant "DEVELOPER_DIR" since the modern XCode version works.

Pull Request resolved: https://github.com/facebookexperimental/eden/pull/63

Reviewed By: StanislavGlebik

Differential Revision: D23927022

Pulled By: lukaspiatkowski

fbshipit-source-id: 6b6b3baa33d49b567b9aa6178cbd20b7ae9edc89

Summary:
Add support for SQ poll groups - this allows sharing of the same SQ kernel poll thread

(Note: this ignores all push blocking failures!)

Reviewed By: kevin-vigor

Differential Revision: D23769744

fbshipit-source-id: c5fd3d22fd1048321896d7445d7bc7e2863ad533

Summary: Skip deadlocking fork tests in TSAN mode

Differential Revision: D23933183

fbshipit-source-id: a5fe2da954676f6ced2f00dea280e10ac88d99cd

Summary: Add support for immediate SQ poll submit

Reviewed By: kevin-vigor

Differential Revision: D23818098

fbshipit-source-id: d8d626c51aef0cf8c0049e081d86313cb731429a

Summary:
The symbolizer takes mapped addresses (address listed in ELF, offset by the binary offset (which is zero for non-PIE)) and symbolizes it into non-mapped addresses. In a couple of places in SymbolizerTest, we took the non-mapped addresses and symbolized them again, which wouldn't work if the binary was compiled with PIE. In another place in SymbolizerTest, the mapped address was used to look up DWARF information, whereas we needed the non-mapped address. This diff addresses these issues.

Additionally, I discovered that r_debug::r_map->l_addr is the "right" way to get the PIE offset, so this diff pulls that common functionality to symbolizer/detail/Debug.h and use it for Symbolizer and the three tests so far that need PIE relocation adjustments.

Reviewed By: yfeldblum

Differential Revision: D23492850

fbshipit-source-id: 62353e576c50b44070b323b5477fea9bb4c0b500

Summary: Similar to D23139413, this is another place where openssl causes TSAN issues widely in fbcode.

Reviewed By: yfeldblum

Differential Revision: D23698225

fbshipit-source-id: e883784500392c2d5be757c37cceb8bf8cc8b2aa

Summary: I don't recall what previous intermediate state justified guarding use of backtrace with __APPLE__ and FOLLY_USE_SYMBOLIZER, but it no longer applies.

Reviewed By: yfeldblum, luciang

Differential Revision: D23881192

fbshipit-source-id: b3ca829f9c738f50f7ab7e038348ec3df65ae4b9

Summary: Original commit changeset: 6362acb7a668 (D23066827 (https://github.com/facebook/folly/commit/0b3d9d21b7d1496e0b592ee6ce7a687c86c0498f))

Reviewed By: yfeldblum

Differential Revision: D23837145

fbshipit-source-id: 642c1401aea0b01c0c5e53c24b100f5daa600512

Summary: [Folly] Fix the Apple LLVM version when disabling is-constexpr-default-constructible test expectations over types with non-trivial destructors for Xcode 12.

Differential Revision: D23917973

fbshipit-source-id: 1238ec5a53ba0ff73afd67f81ad2868f37196eaa

Reviewed By: yfeldblum

Differential Revision: D23847355

fbshipit-source-id: b5fbf5bea515111d34962100af0f44ae11e0845f

Summary:
- Changed namespace from facebook::memory to folly
- Changed include paths
- Left a stub file in common/memory/not_null.h

Differential Revision: D23740776

fbshipit-source-id: 6eff6823017e3a5d20a540fde10b99aa0381d4b0

Summary: [Folly] Internally rename `await` in `folly/fibers/` since some versions of MSVC effectively `#define await co_await` breaking the build - except it's not really a `#define` and there is no reliable way to detect it.

Reviewed By: Orvid

Differential Revision: D23882811

fbshipit-source-id: 836bebcbcfe01ce39c873202b67796efafa1c366

Summary:
folly::Function is non-copyable. This means it can be used with lambdas that capture
a unique_ptr, whereas std::function can not.

See https://www.internalfb.com/intern/wiki/Folly/Function/

Differential Revision: D23883275

fbshipit-source-id: a26cda0d3833e3ea822beef99c6a28a6dd90fa83

Summary:
Fixes a few documentation errors that get surfaced when compiling with the -Wdocumentation flag.
Full explanation of errors with examples here:
https://clang.llvm.org/docs/DiagnosticsReference.html#wdocumentation

Reviewed By: yfeldblum

Differential Revision: D23872718

fbshipit-source-id: 0bb803c6e9412e72985c17415b424be08b51a693

Summary: [Folly] Rename private `find` member in `sorted_vector_set`, `sorted_vector_map` to avoid confusing conflicts with derived-class `using` statements when the derived class privately inherits the base.

Reviewed By: ha1dfo

Differential Revision: D23863338

fbshipit-source-id: 43e67da9683fb4c0af3fa1c86ade7735935e5e0c

Summary:
[Folly] Suppress is-constexpr-default-constructible test for types with non-trivial user-provided (until C++20) or non-constexpr (since C++20) destructors under Clang 10.

Responsible llvm commit: https://github.com/llvm/llvm-project/commit/457226e02a6e.

Related llvm bug report: https://bugs.llvm.org/show_bug.cgi?id=47620. This bug report documents a crash in the compiler, but fails to document deviation from the language spec.

Reviewed By: Mizuchi

Differential Revision: D23862920

fbshipit-source-id: 855db4773ffc062ad9d361feac3709922db7b42d

Summary: This shows up when compiling with mode/win.

Reviewed By: yfeldblum

Differential Revision: D23871729

fbshipit-source-id: 1d52f41f425cd542bae1ac2c3bfe9893fffefdf4

Summary:
Change WARNING to INFO because there are cases where not using a dedicated thread pool is the right choice. INFO still provides the debugging benefit if the lack of dedicated thread pool indeed leads to deadlock.

Clarify that the likely cause for the message about the reclamation executor is that the program did not call folly::enable_hazptr_thread_pool_executor which is called by folly::init.

Reviewed By: yfeldblum, joshkehn

Differential Revision: D23826463

fbshipit-source-id: a5906ee974b5fe87c2d38dcff9a0f2717afb2a5c

Summary: Fix document typo for `folly::IsOneOf` (see diff)

Reviewed By: yfeldblum

Differential Revision: D23863254

fbshipit-source-id: 02f64a72decab028be832f71e1132dfce7fe5fa9

Summary:
Now that symbolizer has precise feature flags, enable
FOLLY_USE_SYMBOLIZER on any platform that has backtrace(3), which is
all that's needed to get a useful stack trace printed in the signal
handler.

Reviewed By: yfeldblum, luciang

Differential Revision: D23361609

fbshipit-source-id: b124f7fd01e94f90d8f8586555a64bd6e412040c

Summary: Allow changing the Sleeper sleep interval

Reviewed By: yfeldblum

Differential Revision: D23591682

fbshipit-source-id: 81b55fa699362d62e436c599c38046d15fecee37

Summary:
To have parity with C++20 `std::erase_if`: https://en.cppreference.com/w/cpp/container/unordered_set/erase_if

Added a return value for `folly::erase_if` for the number of the removed elements.

(Note: this ignores all push blocking failures!)

Reviewed By: yfeldblum

Differential Revision: D23779631

fbshipit-source-id: cea42b90557dd570db8e010d68c2b9ecf0bcc515

Summary: Fix 1-byte buffer overrun when parsing the string "\t".

Reviewed By: mhlakhani

Differential Revision: D22931605

fbshipit-source-id: a90d0a64b882ed8fef96285d47e11fa082178449

Summary:
Move ContextPrimaryPtr definition outside of the function.
Rename MasterPtr to PrimaryPtr.

Reviewed By: Orvid

Differential Revision: D23836006

fbshipit-source-id: d2ad229809fb260c485a7349eca7378e22dc66c4

Differential Revision: D23829791

fbshipit-source-id: 4a13cd70f20de487ece11a1eada94467e1700b6e

Summary:
To be able to override this feature, we should check that
`FOLLY_USE_JEMALLOC` is set to 1 rather than just set.

Reviewed By: yfeldblum

Differential Revision: D22681072

fbshipit-source-id: 18b35910217fd1869cc23107a50241c4ed2ed1b7

Summary: FOLLY_USE_SYMBOLIZER is too coarse of a flag to determine whether ExceptionTracer is available. Instead, use FOLLY_HAVE_ELF and FOLLY_HAVE_DWARF.

Reviewed By: yfeldblum, luciang

Differential Revision: D23361407

fbshipit-source-id: 2326f185c98f58e7afb007befc9121a365c22e77

Summary: [Folly] Revise SFINAE in `Padded`.

Reviewed By: iahs

Differential Revision: D23799751

fbshipit-source-id: 1bf08c5f61f14e95c33077dd690a550fb49fe776

Summary:
Pull Request resolved: https://github.com/facebook/folly/pull/1447

The operation is performed with StringPiece, and avoids temporary strings.

Reviewed By: yfeldblum

Differential Revision: D23479603

fbshipit-source-id: 4718fa062b1eb1910b96f3b0c3ae40af8c05f2e3