update README.md to reference getdeps.py for build and tests

Summary:
Update the README.md to reflect that getdeps.py build and test is the method tested in CI and thus preferred.

Where getdeps.py manifests encode dependencies I've removed the manually specified dependences from the README for consistency (e.g. googletest version in README was outdated, manifest is correct and is tested in CI)

Also referenced main vs master and improved markdown header formatting a little

Reviewed By: meyering

Differential Revision: D33295900

fbshipit-source-id: caec3b3795be0b37bf1efdf12f4dbf23a37a023c

Fix timing-out ConcurrentAdd test

Summary:
This test regularly times out under load.

I made a benchmark diff (prior to this in the stack, but not to be landed) which confirms (a) that the slowness of this test is due to spawning excessively-many threads, and (b) that the performance of ConcurrentSkipList doesn't unduly degrade with excessively-many threads. Conclusion: it is safe to simplify these tests.

To simplify the test, I ratcheted down the number of threads, but also bumped the number of iterations. Much more work is being done (so this test should retain its race-condition-hunting properties), but the time spent is much less, even when the system is under load.

Reviewed By: yfeldblum

Differential Revision: D33269899

fbshipit-source-id: 9f7a0ec5f3c1077c91e5d09c89f3752d552a6320

add missing pragma-once to folly/lang/New.h

Summary: sosorry

Differential Revision: D33218659

fbshipit-source-id: e7c77b503ef6c7144fd8da684b22f793d85b2b96

Remove IOBufQueue::clear()

Summary: All usages in fbsource have been removed.

Reviewed By: yfeldblum, philippv

Differential Revision: D33007671

fbshipit-source-id: 74c5f2dad098c6b7cf7085aa1a2e01a48fa81781

Make ExtendedCoroutineHandle truthy when it holds a truthy basic hand…

…le for a non-extended promise

Reviewed By: simpkins

Differential Revision: D32838375

fbshipit-source-id: d8c350715d3a5fc7ebaa69f723cb6626bdc80031

cut legacy eventfd shims for glibc 2.5

Summary: That is an old glibc. The shims are no longer required.

Reviewed By: Orvid

Differential Revision: D32632173

fbshipit-source-id: d6ce675c6f16b896a950363b411bec66cedca966

Add FOLLY_DISABLE_MEMORY_SANITIZER to FOLLY_DISABLE_SANITIZERS

Summary: Now we'll ignore all the known sanitizers: ASAN, TSAN, MSAN, UBSAN.

Reviewed By: yfeldblum, jdonald

Differential Revision: D32364717

fbshipit-source-id: f71a294dd9ebaa8521f0487ebc65c6f7c1e7bf04

Add support for remove session callbacks in SSLContext; remove from S…

…SLSessionCallbacks

Reviewed By: mingtaoy

Differential Revision: D32218077

fbshipit-source-id: 5a966ced07387340d02ad2a85c095939c9e7f530

Fix CPP20 compile issues

Summary: Fix CPP20 compile issues

Reviewed By: yfeldblum

Differential Revision: D32010566

fbshipit-source-id: 203a272c80a0d54ac7a65809feed146ae0ee70f8

Add ImmutableRequestData

Summary: A simple folly::RequestData implementation.

Reviewed By: praihan

Differential Revision: D31738010

fbshipit-source-id: 3d7c3394fd3daf2dbb2942fe6cdac25207e04e32