cosmopolitan/third_party/libcxx/thread.cc
Justine Tunney ff77f2a6af
Make improvements
- This change fixes a bug that allowed unbuffered printf() output (to
  streams like stderr) to be truncated. This regression was introduced
  some time between now and the last release.

- POSIX specifies all functions as thread safe by default. This change
  works towards cleaning up our use of the @threadsafe / @threadunsafe
  documentation annotations to reflect that. The goal is (1) to use
  @threadunsafe to document functions which POSIX say needn't be thread
  safe, and (2) use @threadsafe to document functions that we chose to
  implement as thread safe even though POSIX didn't mandate it.

- Tidy up the clock_gettime() implementation. We're now trying out a
  cleaner approach to system call support that aims to maintain the
  Linux errno convention as long as possible. This also fixes bugs that
  existed previously, where the vDSO errno wasn't being translated
  properly. The gettimeofday() system call is now a wrapper for
  clock_gettime(), which reduces bloat in apps that use both.

- The recently-introduced improvements to the execute bit on Windows has
  had bugs fixed. access(X_OK) on a directory on Windows now succeeds.
  fstat() will now perform the MZ/#! ReadFile() operation correctly.

- Windows.h is no longer included in libc/isystem/, because it confused
  PCRE's build system into thinking Cosmopolitan is a WIN32 platform.
  Cosmo's Windows.h polyfill was never even really that good, since it
  only defines a subset of the subset of WIN32 APIs that Cosmo defines.

- The setlongerjmp() / longerjmp() APIs are removed. While they're nice
  APIs that are superior to the standardized setjmp / longjmp functions,
  they weren't superior enough to not be dead code in the monorepo. If
  you use these APIs, please file an issue and they'll be restored.

- The .com appending magic has now been removed from APE Loader.
2023-10-03 06:17:16 -07:00

263 lines
7.1 KiB
C++

// clang-format off
//===------------------------- thread.cpp----------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "libc/runtime/sysconf.h"
#include "third_party/libcxx/__config"
#ifndef _LIBCPP_HAS_NO_THREADS
#include "third_party/libcxx/thread"
#include "third_party/libcxx/exception"
#include "third_party/libcxx/vector"
#include "third_party/libcxx/future"
#include "third_party/libcxx/limits"
#include "libc/calls/makedev.h"
#include "libc/calls/weirdtypes.h"
#include "libc/intrin/newbie.h"
#include "libc/calls/typedef/u.h"
#include "libc/calls/weirdtypes.h"
#include "libc/sock/select.h"
#include "libc/sysv/consts/endian.h"
#if defined(__unix__) || (defined(__APPLE__) && defined(__MACH__))
#include "libc/intrin/newbie.h"
#include "libc/calls/calls.h"
#include "libc/calls/struct/rlimit.h"
#include "libc/calls/struct/rusage.h"
#include "libc/stdio/sysparam.h"
#include "libc/calls/weirdtypes.h"
#include "libc/limits.h"
#include "libc/sysv/consts/endian.h"
#include "libc/sysv/consts/prio.h"
#include "libc/sysv/consts/rlim.h"
#include "libc/sysv/consts/rlimit.h"
#include "libc/sysv/consts/rusage.h"
# if defined(__FreeBSD__) || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__) || defined(__APPLE__)
// MISSING #include <sys/sysctl.h>
# endif
#endif // defined(__unix__) || (defined(__APPLE__) && defined(__MACH__))
#if defined(__unix__) || (defined(__APPLE__) && defined(__MACH__)) || defined(__CloudABI__) || defined(__Fuchsia__) || defined(__wasi__)
#include "libc/calls/calls.h"
#include "libc/calls/weirdtypes.h"
#include "libc/runtime/sysconf.h"
#include "libc/sysv/consts/fileno.h"
#include "libc/sysv/consts/o.h"
#include "libc/sysv/consts/ok.h"
#endif // defined(__unix__) || (defined(__APPLE__) && defined(__MACH__)) || defined(__CloudABI__) || defined(__Fuchsia__) || defined(__wasi__)
#if defined(_LIBCPP_WIN32API)
#include "libc/nt/accounting.h"
#include "libc/nt/automation.h"
#include "libc/nt/console.h"
#include "libc/nt/debug.h"
#include "libc/nt/dll.h"
#include "libc/nt/enum/keyaccess.h"
#include "libc/nt/enum/regtype.h"
#include "libc/nt/errors.h"
#include "libc/nt/events.h"
#include "libc/nt/files.h"
#include "libc/nt/ipc.h"
#include "libc/nt/memory.h"
#include "libc/nt/paint.h"
#include "libc/nt/process.h"
#include "libc/nt/registry.h"
#include "libc/nt/synchronization.h"
#include "libc/nt/thread.h"
#include "libc/nt/windows.h"
#include "libc/nt/winsock.h"
#endif
#if defined(__unix__) && !defined(__ANDROID__) && defined(__ELF__) && defined(_LIBCPP_HAS_COMMENT_LIB_PRAGMA)
#pragma comment(lib, "pthread")
#endif
_LIBCPP_BEGIN_NAMESPACE_STD
thread::~thread()
{
if (!__libcpp_thread_isnull(&__t_))
terminate();
}
void
thread::join()
{
int ec = EINVAL;
if (!__libcpp_thread_isnull(&__t_))
{
ec = __libcpp_thread_join(&__t_);
if (ec == 0)
__t_ = _LIBCPP_NULL_THREAD;
}
if (ec)
__throw_system_error(ec, "thread::join failed");
}
void
thread::detach()
{
int ec = EINVAL;
if (!__libcpp_thread_isnull(&__t_))
{
ec = __libcpp_thread_detach(&__t_);
if (ec == 0)
__t_ = _LIBCPP_NULL_THREAD;
}
if (ec)
__throw_system_error(ec, "thread::detach failed");
}
unsigned
thread::hardware_concurrency() _NOEXCEPT
{
#if defined(CTL_HW) && defined(HW_NCPU)
unsigned n;
int mib[2] = {CTL_HW, HW_NCPU};
std::size_t s = sizeof(n);
sysctl(mib, 2, &n, &s, 0, 0);
return n;
#elif defined(_SC_NPROCESSORS_ONLN)
long result = sysconf(_SC_NPROCESSORS_ONLN);
// sysconf returns -1 if the name is invalid, the option does not exist or
// does not have a definite limit.
// if sysconf returns some other negative number, we have no idea
// what is going on. Default to something safe.
if (result < 0)
return 0;
return static_cast<unsigned>(result);
#elif defined(_LIBCPP_WIN32API)
SYSTEM_INFO info;
GetSystemInfo(&info);
return info.dwNumberOfProcessors;
#else // defined(CTL_HW) && defined(HW_NCPU)
// TODO: grovel through /proc or check cpuid on x86 and similar
// instructions on other architectures.
# if defined(_LIBCPP_WARNING)
_LIBCPP_WARNING("hardware_concurrency not yet implemented")
# else
# warning hardware_concurrency not yet implemented
# endif
return 0; // Means not computable [thread.thread.static]
#endif // defined(CTL_HW) && defined(HW_NCPU)
}
namespace this_thread
{
void
sleep_for(const chrono::nanoseconds& ns)
{
if (ns > chrono::nanoseconds::zero())
{
__libcpp_thread_sleep_for(ns);
}
}
} // this_thread
__thread_specific_ptr<__thread_struct>&
__thread_local_data()
{
static __thread_specific_ptr<__thread_struct> __p;
return __p;
}
// __thread_struct_imp
template <class T>
class _LIBCPP_HIDDEN __hidden_allocator
{
public:
typedef T value_type;
T* allocate(size_t __n)
{return static_cast<T*>(::operator new(__n * sizeof(T)));}
void deallocate(T* __p, size_t) {::operator delete(static_cast<void*>(__p));}
size_t max_size() const {return size_t(~0) / sizeof(T);}
};
class _LIBCPP_HIDDEN __thread_struct_imp
{
typedef vector<__assoc_sub_state*,
__hidden_allocator<__assoc_sub_state*> > _AsyncStates;
typedef vector<pair<condition_variable*, mutex*>,
__hidden_allocator<pair<condition_variable*, mutex*> > > _Notify;
_AsyncStates async_states_;
_Notify notify_;
__thread_struct_imp(const __thread_struct_imp&);
__thread_struct_imp& operator=(const __thread_struct_imp&);
public:
__thread_struct_imp() {}
~__thread_struct_imp();
void notify_all_at_thread_exit(condition_variable* cv, mutex* m);
void __make_ready_at_thread_exit(__assoc_sub_state* __s);
};
__thread_struct_imp::~__thread_struct_imp()
{
for (_Notify::iterator i = notify_.begin(), e = notify_.end();
i != e; ++i)
{
i->second->unlock();
i->first->notify_all();
}
for (_AsyncStates::iterator i = async_states_.begin(), e = async_states_.end();
i != e; ++i)
{
(*i)->__make_ready();
(*i)->__release_shared();
}
}
void
__thread_struct_imp::notify_all_at_thread_exit(condition_variable* cv, mutex* m)
{
notify_.push_back(pair<condition_variable*, mutex*>(cv, m));
}
void
__thread_struct_imp::__make_ready_at_thread_exit(__assoc_sub_state* __s)
{
async_states_.push_back(__s);
__s->__add_shared();
}
// __thread_struct
__thread_struct::__thread_struct()
: __p_(new __thread_struct_imp)
{
}
__thread_struct::~__thread_struct()
{
delete __p_;
}
void
__thread_struct::notify_all_at_thread_exit(condition_variable* cv, mutex* m)
{
__p_->notify_all_at_thread_exit(cv, m);
}
void
__thread_struct::__make_ready_at_thread_exit(__assoc_sub_state* __s)
{
__p_->__make_ready_at_thread_exit(__s);
}
_LIBCPP_END_NAMESPACE_STD
#endif // !_LIBCPP_HAS_NO_THREADS