Files
blis/frame/thread/bli_pthread.c
Field G. Van Zee 9bb23e6c2a Added support for systemless build (no pthreads).
Details:
- Added a configure option, --[enable|disable]-system, which determines
  whether the modest operating system dependencies in BLIS are included.
  The most notable example of this on Linux and BSD/OSX is the use of
  POSIX threads to ensure thread safety for when application-level
  threads call BLIS. When --disable-system is given, the bli_pthreads
  implementation is dummied out entirely, allowing the calling code
  within BLIS to remain unchanged. Why would anyone want to build BLIS
  like this? The motivating example was submitted via #454 in which a
  user wanted to build BLIS for a simulator such as gem5 where thread
  safety may not be a concern (and where the operating system is largely
  absent anyway). Thanks to Stepan Nassyr for suggesting this feature.
- Another, more minor side effect of the --disable-system option is that
  the implementation of bli_clock() unconditionally returns 0.0 instead
  of the time elapsed since some fixed point in the past. The reasoning
  for this is that if the operating system is truly minimal, the system
  function call upon which bli_clock() would normally be implemented
  (e.g. clock_gettime()) may not be available.
- Refactored preprocess-guarded code in bli_pthread.c and bli_pthread.h
  to remove redundancies.
- Removed old comments and commented #include of "bli_pthread_wrap.h"
  from bli_system.h.
- Documented bli_clock() and bli_clock_min_diff() in BLISObjectAPI.md
  and BLISTypedAPI.md, with a note that both are non-functional when
  BLIS is configured with --disable-system.
2020-11-16 15:55:45 -06:00

587 lines
12 KiB
C

/*
BLIS
An object-based framework for developing high-performance BLAS-like
libraries.
Copyright (C) 2018, Southern Methodist University
Copyright (C) 2018, The University of Texas at Austin
Copyright (C) 2018 - 2019, Advanced Micro Devices, Inc.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are
met:
- Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
- Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
- Neither the name(s) of the copyright holder(s) nor the names of its
contributors may be used to endorse or promote products derived
from this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "blis.h"
#if defined(BLIS_DISABLE_SYSTEM)
// This branch defines a pthread-like API, bli_pthread_*(), and implements it
// in terms of "dummy" code that doesn't depend on POSIX threads or any other
// threading mechanism. See issue #454 to see the use case that prompted this
// feature.
// NOTE: THIS CODE DOES NOT IMPLEMENT THREADING AND IS NOT THREAD-SAFE!
// -- pthread_create(), pthread_join() --
int bli_pthread_create
(
bli_pthread_t* thread,
const bli_pthread_attr_t* attr,
void* (*start_routine)(void*),
void* arg
)
{
//return pthread_create( thread, attr, start_routine, arg );
start_routine( arg );
return 0;
}
int bli_pthread_join
(
bli_pthread_t thread,
void** retval
)
{
//return pthread_join( thread, retval );
return 0;
}
// -- pthread_mutex_*() --
int bli_pthread_mutex_init
(
bli_pthread_mutex_t* mutex,
const bli_pthread_mutexattr_t* attr
)
{
//return pthread_mutex_init( mutex, attr );
return 0;
}
int bli_pthread_mutex_destroy
(
bli_pthread_mutex_t* mutex
)
{
//return pthread_mutex_destroy( mutex );
return 0;
}
int bli_pthread_mutex_lock
(
bli_pthread_mutex_t* mutex
)
{
//return pthread_mutex_lock( mutex );
return 0;
}
int bli_pthread_mutex_trylock
(
bli_pthread_mutex_t* mutex
)
{
//return pthread_mutex_trylock( mutex );
return 0;
}
int bli_pthread_mutex_unlock
(
bli_pthread_mutex_t* mutex
)
{
//return pthread_mutex_unlock( mutex );
return 0;
}
// -- pthread_cond_*() --
int bli_pthread_cond_init
(
bli_pthread_cond_t* cond,
const bli_pthread_condattr_t* attr
)
{
//return pthread_cond_init( cond, attr );
return 0;
}
int bli_pthread_cond_destroy
(
bli_pthread_cond_t* cond
)
{
//return pthread_cond_destroy( cond );
return 0;
}
int bli_pthread_cond_wait
(
bli_pthread_cond_t* cond,
bli_pthread_mutex_t* mutex
)
{
//return pthread_cond_wait( cond, mutex );
return 0;
}
int bli_pthread_cond_broadcast
(
bli_pthread_cond_t* cond
)
{
//return pthread_cond_broadcast( cond );
return 0;
}
// -- pthread_once() --
void bli_pthread_once
(
bli_pthread_once_t* once,
void (*init)(void)
)
{
//pthread_once( once, init );
init();
}
#elif defined(_MSC_VER) // !defined(BLIS_DISABLE_SYSTEM)
#include <errno.h>
// This branch defines a pthread-like API, bli_pthread_*(), and implements it
// in terms of Windows API calls.
int bli_pthread_mutex_init
(
bli_pthread_mutex_t* mutex,
const bli_pthread_mutexattr_t* attr
)
{
if ( attr ) return EINVAL;
InitializeSRWLock( mutex );
return 0;
}
int bli_pthread_mutex_destroy
(
bli_pthread_mutex_t* mutex
)
{
return 0;
}
int bli_pthread_mutex_lock
(
bli_pthread_mutex_t* mutex
)
{
AcquireSRWLockExclusive( mutex );
return 0;
}
int bli_pthread_mutex_trylock
(
bli_pthread_mutex_t* mutex
)
{
return TryAcquireSRWLockExclusive( mutex ) ? 0 : EBUSY;
}
int bli_pthread_mutex_unlock
(
bli_pthread_mutex_t* mutex
)
{
ReleaseSRWLockExclusive( mutex );
return 0;
}
static BOOL bli_init_once_wrapper
(
bli_pthread_once_t* once,
void* param,
void** context
)
{
( void )once;
( void )context;
typedef void (*callback)( void );
((callback)param)();
return TRUE;
}
void bli_pthread_once
(
bli_pthread_once_t* once,
void (*init)(void)
)
{
InitOnceExecuteOnce( once, bli_init_once_wrapper, init, NULL );
}
int bli_pthread_cond_init
(
bli_pthread_cond_t* cond,
const bli_pthread_condattr_t* attr
)
{
if ( attr ) return EINVAL;
InitializeConditionVariable( cond );
return 0;
}
int bli_pthread_cond_destroy
(
bli_pthread_cond_t* cond
)
{
( void )cond;
return 0;
}
int bli_pthread_cond_wait
(
bli_pthread_cond_t* cond,
bli_pthread_mutex_t* mutex
)
{
if ( !SleepConditionVariableSRW( cond, mutex, INFINITE, 0 ) ) return EAGAIN;
return 0;
}
int bli_pthread_cond_broadcast
(
bli_pthread_cond_t* cond
)
{
WakeAllConditionVariable( cond );
return 0;
}
typedef struct
{
void* (*start_routine)( void* );
void* param;
void** retval;
} bli_thread_param;
static DWORD bli_thread_func
(
void* param_
)
{
bli_thread_param* param = param_;
*param->retval = param->start_routine( param->param );
return 0;
}
int bli_pthread_create
(
bli_pthread_t* thread,
const bli_pthread_attr_t* attr,
void* (*start_routine)(void*),
void* arg
)
{
if ( attr ) return EINVAL;
bli_thread_param param = { start_routine, arg, &thread->retval };
thread->handle = CreateThread( NULL, 0, bli_thread_func, &param, 0, NULL );
if ( !thread->handle ) return EAGAIN;
return 0;
}
int bli_pthread_join
(
bli_pthread_t thread,
void** retval
)
{
if ( !WaitForSingleObject( thread.handle, INFINITE ) ) return EAGAIN;
if ( retval ) *retval = thread.retval;
return 0;
}
#else // !defined(BLIS_DISABLE_SYSTEM) && !defined(_MSC_VER)
// This branch defines a pthreads-like API, bli_pthreads_*(), and implements it
// in terms of the corresponding pthreads_*() types, macros, and function calls.
// This branch is compiled for Linux and other non-Windows environments where
// we assume that *some* implementation of pthreads is provided (although it
// may lack barriers--see below).
// -- pthread_create(), pthread_join() --
int bli_pthread_create
(
bli_pthread_t* thread,
const bli_pthread_attr_t* attr,
void* (*start_routine)(void*),
void* arg
)
{
return pthread_create( thread, attr, start_routine, arg );
}
int bli_pthread_join
(
bli_pthread_t thread,
void** retval
)
{
return pthread_join( thread, retval );
}
// -- pthread_mutex_*() --
int bli_pthread_mutex_init
(
bli_pthread_mutex_t* mutex,
const bli_pthread_mutexattr_t* attr
)
{
return pthread_mutex_init( mutex, attr );
}
int bli_pthread_mutex_destroy
(
bli_pthread_mutex_t* mutex
)
{
return pthread_mutex_destroy( mutex );
}
int bli_pthread_mutex_lock
(
bli_pthread_mutex_t* mutex
)
{
return pthread_mutex_lock( mutex );
}
int bli_pthread_mutex_trylock
(
bli_pthread_mutex_t* mutex
)
{
return pthread_mutex_trylock( mutex );
}
int bli_pthread_mutex_unlock
(
bli_pthread_mutex_t* mutex
)
{
return pthread_mutex_unlock( mutex );
}
// -- pthread_cond_*() --
int bli_pthread_cond_init
(
bli_pthread_cond_t* cond,
const bli_pthread_condattr_t* attr
)
{
return pthread_cond_init( cond, attr );
}
int bli_pthread_cond_destroy
(
bli_pthread_cond_t* cond
)
{
return pthread_cond_destroy( cond );
}
int bli_pthread_cond_wait
(
bli_pthread_cond_t* cond,
bli_pthread_mutex_t* mutex
)
{
return pthread_cond_wait( cond, mutex );
}
int bli_pthread_cond_broadcast
(
bli_pthread_cond_t* cond
)
{
return pthread_cond_broadcast( cond );
}
// -- pthread_once() --
void bli_pthread_once
(
bli_pthread_once_t* once,
void (*init)(void)
)
{
pthread_once( once, init );
}
#endif // _MSC_VER
// -- pthread_barrier_*() --
#if defined(BLIS_DISABLE_SYSTEM)
int bli_pthread_barrier_init
(
bli_pthread_barrier_t* barrier,
const bli_pthread_barrierattr_t* attr,
unsigned int count
)
{
//return pthread_barrier_init( barrier, attr, count );
return 0;
}
int bli_pthread_barrier_destroy
(
bli_pthread_barrier_t* barrier
)
{
//return pthread_barrier_destroy( barrier );
return 0;
}
int bli_pthread_barrier_wait
(
bli_pthread_barrier_t* barrier
)
{
//return pthread_barrier_wait( barrier );
return 0;
}
#elif defined(__APPLE__) || defined(_MSC_VER) // !defined(BLIS_DISABLE_SYSTEM)
#include <errno.h>
// For OS X and Windows, we define barriers ourselves in terms of the rest
// of the API, though for slightly different reasons: For Windows, we must
// define barriers because we are defining *everything* from scratch. For
// OS X, we must define barriers because Apple chose to omit barriers from
// their implementation of POSIX threads (since barriers are actually
// optional to the POSIX standard).
int bli_pthread_barrier_init
(
bli_pthread_barrier_t* barrier,
const bli_pthread_barrierattr_t* attr,
unsigned int count )
{
if ( attr ) return EINVAL;
if ( count == 0 ) return EINVAL;
int err;
if ( (err = bli_pthread_mutex_init( &barrier->mutex, 0 )) != 0 ) return err;
if ( (err = bli_pthread_cond_init( &barrier->cond, 0 )) != 0 )
{
bli_pthread_mutex_destroy( &barrier->mutex );
return err;
}
barrier->tripCount = count;
barrier->count = 0;
return 0;
}
int bli_pthread_barrier_destroy
(
bli_pthread_barrier_t *barrier
)
{
bli_pthread_cond_destroy( &barrier->cond );
bli_pthread_mutex_destroy( &barrier->mutex );
return 0;
}
int bli_pthread_barrier_wait
(
bli_pthread_barrier_t *barrier
)
{
bli_pthread_mutex_lock( &barrier->mutex );
++(barrier->count);
if ( barrier->count >= barrier->tripCount )
{
barrier->count = 0;
bli_pthread_cond_broadcast( &barrier->cond );
bli_pthread_mutex_unlock( &barrier->mutex );
return 1;
}
else
{
bli_pthread_cond_wait( &barrier->cond, &(barrier->mutex) );
bli_pthread_mutex_unlock( &barrier->mutex );
return 0;
}
}
#else // !defined(BLIS_DISABLE_SYSTEM) && !defined(__APPLE__) && !defined(_MSC_VER)
// Linux environments implement the pthread_barrier* sub-API. So, if we're
// on Linux, we can simply call those functions, just as we did before for
// the other functions.
int bli_pthread_barrier_init
(
bli_pthread_barrier_t* barrier,
const bli_pthread_barrierattr_t* attr,
unsigned int count
)
{
return pthread_barrier_init( barrier, attr, count );
}
int bli_pthread_barrier_destroy
(
bli_pthread_barrier_t* barrier
)
{
return pthread_barrier_destroy( barrier );
}
int bli_pthread_barrier_wait
(
bli_pthread_barrier_t* barrier
)
{
return pthread_barrier_wait( barrier );
}
#endif