This patch does three main things:
(1) It re-writes the cxa guard implementation to make it testable.
(2) Adds support for recursive init detection on non-apple platforms.
(3) It adds a futex based implementation.
The futex based implementation locks and notifies on a per-object basis, unlike the
current implementation which uses a global lock for all objects. Once this patch settles
I'll turn it on by default when supported.
llvm-svn: 359060
Summary:
The goal is to use a descriptive name for this feature, instead of just
using __arm__.
Reviewers: EricWF
Subscribers: javed.absar, kristof.beyls, christof, jkorous, dexonsmith, libcxx-commits
Tags: #libc
Differential Revision: https://reviews.llvm.org/D60520
llvm-svn: 358106
This reverts commit r357944 and r357949.
These changes failed to account for the fact that
the guard object is under aligned for atomic operations
on 32 bit platforms (It's aligned to 4 bytes but we require 8).
llvm-svn: 357958
The read of the guard variable by the caller is atomic,
and doesn't happen under a mutex.
Our internal reads and writes were non-atomic, because they happened
under a mutex.
The writes should always be atomic since they can be observed outside
of the lock.
Making the reads atomic is not strictly necessary under the current
global mutex approach, but will be under implementations that use a
futex (which I plan to land shortly). However, they should add little
additional cost.
llvm-svn: 357944
This patch is a part of a series of patches to cleanup
our implementation of __cxa_acquire et al. No functionality
change was intended.
This patch does two primary things.
It introduces the GuardObject class to abstract the reading
and writing to the guard object. In future, it will be used
to ensure atomic accesses are used when needed.
It also introduces the GuardValue class used to represent
values of the guard object. It is an abstraction to access
and write to the various different bits of a guard.
llvm-svn: 357804
This patch is a part of a series of cleanups to cxa_guard.cpp.
It should introduce no functionality change.
This patch refactors the use of the global mutex and condvar into
a RAII lock guard class. This improves correctness (since unlocks can't
be forgotten). It also allows the unification of the non-threading and
threading implementations.
llvm-svn: 357669
to reflect the new license. These used slightly different spellings that
defeated my regular expressions.
We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.
Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.
llvm-svn: 351648
Summary: It's now completely empty, so we can remove it entirely.
Reviewers: mclow.lists, EricWF
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D31502
llvm-svn: 299129
r281179 Introduced an externally threaded variant of the libc++ library. This
patch adds support for a similar library variant for libc++abi.
Differential revision: https://reviews.llvm.org/D27575
Reviewers: EricWF
llvm-svn: 290888
This patch refactors all pthread uses of libc++abi into a separate API. This
is the first step towards supporting an externlly-threaded libc++abi library.
I've followed the conventions already used in the libc++ library for the same
purpose.
Patch from: Saleem Abdulrasool and Asiri Rathnayake
Reviewed by: compnerd, EricWF
Differential revisions:
https://reviews.llvm.org/D18482 (original)
https://reviews.llvm.org/D24864 (final)
llvm-svn: 284128
is_initialized is only used in the no threads case or if on non ARM Apple
targets. Use the preprocessor to remove the function otherwise. NFC.
llvm-svn: 280286
Mark functions and types with the appropriate visibility. This is particularly
useful for environments which explicitly indicate origin of functions (Windows).
This aids in generating libc++abi as a DSO which exposes only the public
interfaces.
llvm-svn: 254691
The problem that caused the need for http://reviews.llvm.org/D7419 was
caused by testing the value of something that was undefined. This
should prevent that in the future.
llvm-svn: 228257
Also remove the audotedection part so that if you're crazy enough to want a
single-threaded abi library, you'll say so explicitly in the build.
llvm-svn: 217262
