The ERROR_TIMEDOUT returned by the Windows API does not
have the same value as ETIMEDOUT. This caused condition_variable
to return timeouts as unknown errors.
llvm-svn: 302297
This reverts SVN r295329. Although `__libcpp_thread_sleep_for` should
be alertable, the implementation causes a large regression in the test
suite. Add a FIXME item there for now to get the test suite in a better
state before attempting to fix that behaviour.
llvm-svn: 295561
On Windows, we were using `Sleep` which is not alertable. This means
that if the thread was used for a user APC or WinProc handling and
thread::sleep was used, we could potentially dead lock. Use `SleepEx`
with an alertable sleep, resuming until the time has expired if we are
awoken early.
llvm-svn: 295329
Different platforms implement the wait/sleep functions in difrerent ways.
It makes sense to externalize this into the threading API.
Differential revision: https://reviews.llvm.org/D29630
Reviewers: EricWF, joerg
llvm-svn: 294573
It is my opinion that libc++ should never use `<cassert>`, including in the `dylib`.
This patch remove all uses of `assert` from within libc++ and replaces most of them with `_LIBCPP_ASSERT` instead.
Additionally this patch turn `LIBCXX_ENABLE_ASSERTIONS` off by default,
because the standard library should not be aborting user programs unless explicitly asked to.
llvm-svn: 294107
Many thread-related libc++ test cases fail on FreeBSD, due to the
following -Werror warnings:
In file included from test/std/thread/thread.threads/thread.thread.this/sleep_until.pass.cpp:17:
In file included from include/thread:97:
In file included from include/__mutex_base:17:
include/__threading_support:222:1: error: mutex '__m' is still held at the end of function [-Werror,-Wthread-safety-analysis]
}
^
include/__threading_support:221:10: note: mutex acquired here
return pthread_mutex_lock(__m);
^
include/__threading_support:231:10: error: releasing mutex '__m' that was not held [-Werror,-Wthread-safety-analysis]
return pthread_mutex_unlock(__m);
^
include/__threading_support:242:1: error: mutex '__m' is still held at the end of function [-Werror,-Wthread-safety-analysis]
}
^
include/__threading_support:241:10: note: mutex acquired here
return pthread_mutex_lock(__m);
^
include/__threading_support:251:10: error: releasing mutex '__m' that was not held [-Werror,-Wthread-safety-analysis]
return pthread_mutex_unlock(__m);
^
include/__threading_support:272:10: error: calling function 'pthread_cond_wait' requires holding mutex '__m' exclusively [-Werror,-Wthread-safety-analysis]
return pthread_cond_wait(__cv, __m);
^
include/__threading_support:278:10: error: calling function 'pthread_cond_timedwait' requires holding mutex '__m' exclusively [-Werror,-Wthread-safety-analysis]
return pthread_cond_timedwait(__cv, __m, __ts);
^
6 errors generated.
This is because on FreeBSD, the pthread functions have lock annotations.
Since the functions in __thread_support are internal to libc++ only, add
no_thread_safety_analysis attributes to suppress these warnings.
Reviewers: mclow.lists, EricWF, delesley, aaron.ballman
Reviewed By: aaron.ballman
Subscribers: ed, aaron.ballman, joerg, emaste, cfe-commits
Differential Revision: https://reviews.llvm.org/D28520
llvm-svn: 293197
This reverts commit r292883. Unfortunately <string_view> uses
_LIBCPP_ASSERT in a way which is not compatible with the C++11 dylib
build. I'll investigate more tomorrow.
llvm-svn: 292923
Summary:
It is my opinion that libc++ should never use `<cassert>`, including in the `dylib`. This patch remove all uses of `assert` from within libc++ and replaces most of them with `_LIBCPP_ASSERT` instead.
Additionally this patch turn `LIBCXX_ENABLE_ASSERTIONS` off by default, because the standard library should not be aborting user programs unless explicitly asked to.
Reviewers: mclow.lists, compnerd, smeenai
Reviewed By: mclow.lists
Subscribers: mgorny, cfe-commits
Differential Revision: https://reviews.llvm.org/D29063
llvm-svn: 292883
We have already refactored the underlying platform thread type into
__libcpp_thread_t, but there are few places in the source where we
still assume it is an integral type.
This patch refactores those points back into the threading API.
Differential revision: https://reviews.llvm.org/D28608
Reviewers: EricWF
llvm-svn: 292107
Although the CriticalSection itself doesnt need to be destroyed, there
may be debug data associated with it. Plug a possible small leak.
llvm-svn: 291536
Add an implementation for the Win32 threading model as a backing API for
the internal c++ threading interfaces. This uses the Fls* family for
the TLS (which has the support for adding termination callbacks),
CRITICAL_SECTIONs for the recursive mutex, and Slim Reader/Writer locks
(SRW locks) for non-recursive mutexes. These APIs should all be
available on Vista or newer.
llvm-svn: 291333
Summary:
This patch attempts to clean up the macro configuration mess in `<__threading_support>`, specifically the mess involving external threading variants. Additionally this patch adds design documentation for `<__threading_support>` and the configuration macros it uses.
The primary change in this patch is separating the idea of an "external API" provided by `<__external_threading>` and the idea of having an external threading library. Now `_LIBCPP_HAS_THREAD_API_EXTERNAL` means that libc++ should use `<__external_threading>` and that the header is expected to exist. Additionally the new macro `_LIBCPP_HAS_THREAD_LIBRARY_EXTERNAL` is now used to configure for using an "external library" with the default threading API.
Reviewers: compnerd, rmaprath
Subscribers: smeenai, cfe-commits, mgorny
Differential Revision: https://reviews.llvm.org/D28316
llvm-svn: 291275
Split out the recursive and non-recursive mutex. This split is needed
for platforms which may use differing types for the two mutex (e.g.
Win32 threads).
llvm-svn: 291145
after r290850
Before r290850, building libcxx with -DLIBCXX_HAS_EXTERNAL_THREAD_API=ON had two
uses:
- Allow platform vendors to plug-in an __external_threading header which
should take care of the entire threading infrastructure of libcxx
- Allow testing of an externally-threaded library build; where the thread API
is declared using pthread data structures, and the implementation of this
API is provided as a separate library (test/support/external_threads.cpp)
and linked-in when running the test suite.
r290850 breaks the second use case (pthread data structures are no longer
available). This patch re-stores the ability to build+test an
externally-threaded library variant on a pthread based system.
llvm-svn: 290878
Refactor the header to allow us to implement alternate threading models
with alternate data structures. Take the opportunity to clang-format
the area. This will allow us to avoid re-declaring the interfaces for
Win32 threading. NFC
llvm-svn: 290850
This fixes a small omission where even when __external_threading is provided,
we attempt to declare a pthread based threading API. Instead, we should leave
out everything for the __external_threading header to take care of.
The __threading_support header provides a proof-of-concept externally threaded
libc++ variant when _LIBCPP_HAS_THREAD_API_EXTERNAL is defined. But if the
__external_threading header is present, we should exclude all of that POC stuff.
Reviewers: EricWF
Differential revision: https://reviews.llvm.org/D25468
llvm-svn: 284232
This patch further decouples libc++ from pthread, allowing libc++ to be built
against other threading systems. There are two main use cases:
- Building libc++ against a thread library other than pthreads.
- Building libc++ with an "external" thread API, allowing a separate library to
provide the implementation of that API.
The two use cases are quite similar, the second one being sligtly more
de-coupled than the first. The cmake option LIBCXX_HAS_EXTERNAL_THREAD_API
enables both kinds of builds. One needs to place an <__external_threading>
header file containing an implementation of the "libc++ thread API" declared
in the <__threading_support> header.
For the second use case, the implementation of the libc++ thread API can
delegate to a custom "external" thread API where the implementation of this
external API is provided in a seperate library. This mechanism allows toolchain
vendors to distribute a build of libc++ with a custom thread-porting-layer API
(which is the "external" API above), platform vendors (recipients of the
toolchain/libc++) are then required to provide their implementation of this API
to be linked with (end-user) C++ programs.
Note that the second use case still requires establishing the basic types that
get passed between the external thread library and the libc++ library
(e.g. __libcpp_mutex_t). These cannot be opaque pointer types (libc++ sources
won't compile otherwise). It should also be noted that the second use case can
have a slight performance penalty; as all the thread constructs need to cross a
library boundary through an additional function call.
When the header <__external_threading> is omitted, libc++ is built with the
"libc++ thread API" (declared in <__threading_support>) as the "external" thread
API (basic types are pthread based). An implementation (pthread based) of this
API is provided in test/support/external_threads.cpp, which is built into a
separate DSO and linked in when running the libc++ test suite. A test run
therefore demonstrates the second use case (less the intermediate custom API).
Differential revision: https://reviews.llvm.org/D21968
Reviewers: bcraig, compnerd, EricWF, mclow.lists
llvm-svn: 281179
The existing pthread detection code in __config is pretty good for
common operating systems. It doesn't allow cmake-time choices to be
made for uncommon operating systems though.
This change adds the LIBCXX_HAS_PTHREAD_API cmake flag, which turns
into the _LIBCPP_HAS_THREAD_API_PTHREAD preprocessor define. This is
a name change from the old _LIBCPP_THREAD_API_PTHREAD. The lit tests
want __config_site.in variables to have a _LIBCPP_HAS prefix.
http://reviews.llvm.org/D20573
llvm-svn: 270735
This patch extracts out all the pthread dependencies of libcxx into the
new header __threading_support. The motivation is to make it easy to
re-target libcxx into platforms that do not support pthread.
Original patch from Fulvio Esposito (fulvio.esposito@outlook.com) - D11781
Applied with tweaks - D19412
Change-Id: I301111f0075de93dd8129416e06babc195aa936b
llvm-svn: 268734
Eric Fiselier