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//==========================================================================
//
//      pthread.cxx
//
//      POSIX pthreads implementation
//
//==========================================================================
// ####ECOSGPLCOPYRIGHTBEGIN####                                            
// -------------------------------------------                              
// This file is part of eCos, the Embedded Configurable Operating System.   
// Copyright (C) 1998, 1999, 2000, 2001, 2002 Free Software Foundation, Inc.
//
// eCos is free software; you can redistribute it and/or modify it under    
// the terms of the GNU General Public License as published by the Free     
// Software Foundation; either version 2 or (at your option) any later      
// version.                                                                 
//
// eCos is distributed in the hope that it will be useful, but WITHOUT      
// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or    
// FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License    
// for more details.                                                        
//
// You should have received a copy of the GNU General Public License        
// along with eCos; if not, write to the Free Software Foundation, Inc.,    
// 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.            
//
// As a special exception, if other files instantiate templates or use      
// macros or inline functions from this file, or you compile this file      
// and link it with other works to produce a work based on this file,       
// this file does not by itself cause the resulting work to be covered by   
// the GNU General Public License. However the source code for this file    
// must still be made available in accordance with section (3) of the GNU   
// General Public License v2.                                               
//
// This exception does not invalidate any other reasons why a work based    
// on this file might be covered by the GNU General Public License.         
// -------------------------------------------                              
// ####ECOSGPLCOPYRIGHTEND####                                              
//==========================================================================
//#####DESCRIPTIONBEGIN####
//
// Author(s):           nickg
// Contributors:        nickg, jlarmour, Wade Jensen
// Date:                2000-03-27
// Purpose:             POSIX pthread implementation
// Description:         This file contains the implementation of the POSIX pthread
//                      functions.
//              
//              
//
//####DESCRIPTIONEND####
//
//==========================================================================
 
#include <pkgconf/posix.h>
 
#include <cyg/infra/cyg_trac.h>        // tracing macros
#include <cyg/infra/cyg_ass.h>         // assertion macros
 
#include "pprivate.h"                  // POSIX private header
 
#include <cyg/kernel/thread.hxx>       // thread definitions
#include <cyg/kernel/mutex.hxx>        // mutex definitions
#include <cyg/kernel/clock.hxx>        // clock definitions
#include <cyg/kernel/sched.hxx>        // scheduler primitives
#include <pthread.h>
 
#include <cyg/kernel/thread.inl>       // thread inlines
#include <cyg/kernel/sched.inl>        // scheduler inlines
 
//-----------------------------------------------------------------------------
// new operator to allow us to construct mutex objects
 
inline void *operator new(size_t size,  cyg_uint8 *ptr) { return (void *)ptr; };
 
//=============================================================================
// Mutexes
 
//-----------------------------------------------------------------------------
// Mutex attributes manipulation functions
 
//-----------------------------------------------------------------------------
// Initialize attribute object
 
externC int pthread_mutexattr_init ( pthread_mutexattr_t *attr)
{
    PTHREAD_ENTRY();
 
    PTHREAD_CHECK(attr);
 
    attr->protocol      = PTHREAD_PRIO_NONE;
#ifdef _POSIX_THREAD_PRIO_PROTECT    
    attr->prioceiling   = 0;
#endif
 
    PTHREAD_RETURN(0);
}
 
//-----------------------------------------------------------------------------
// Destroy attribute object
 
externC int pthread_mutexattr_destroy ( pthread_mutexattr_t *attr)
{
    PTHREAD_ENTRY();
 
    PTHREAD_CHECK(attr);
 
    // Nothing to do here...
 
    PTHREAD_RETURN(0);
}
 
//-----------------------------------------------------------------------------
// Optional functions depending on priority inversion protection options.
 
#if defined(_POSIX_THREAD_PRIO_INHERIT) || defined(_POSIX_THREAD_PRIO_PROTECT)
 
// Set priority inversion protection protocol
externC int pthread_mutexattr_setprotocol ( pthread_mutexattr_t *attr,
                                            int protocol)
{
    PTHREAD_ENTRY();
 
    PTHREAD_CHECK(attr);
 
    switch( protocol )
    {
    case PTHREAD_PRIO_NONE:
#if defined(_POSIX_THREAD_PRIO_INHERIT)        
    case PTHREAD_PRIO_INHERIT:
#endif
#if defined(_POSIX_THREAD_PRIO_PROTECT)
    case PTHREAD_PRIO_PROTECT:
#endif        
        attr->protocol = protocol;
        PTHREAD_RETURN(0);
 
    default:
        PTHREAD_RETURN(EINVAL);
    }
 
    PTHREAD_RETURN(0);
}
 
// Get priority inversion protection protocol
externC int pthread_mutexattr_getprotocol ( pthread_mutexattr_t *attr,
                                            int *protocol)
{
    PTHREAD_ENTRY();
 
    PTHREAD_CHECK(attr);
 
    if( protocol != NULL )
        *protocol = attr->protocol;
 
    PTHREAD_RETURN(0);
}
 
#if defined(_POSIX_THREAD_PRIO_PROTECT)
 
// Set priority for priority ceiling protocol
externC int pthread_mutexattr_setprioceiling ( pthread_mutexattr_t *attr,
                                               int prioceiling)
{
    PTHREAD_ENTRY();
 
    PTHREAD_CHECK(attr);
 
 
    attr->prioceiling = prioceiling;
 
    PTHREAD_RETURN(0);
}
 
// Get priority for priority ceiling protocol
externC int pthread_mutexattr_getprioceiling ( pthread_mutexattr_t *attr,
                                               int *prioceiling)
{
    PTHREAD_ENTRY();
 
    PTHREAD_CHECK(attr);
 
    if( prioceiling != NULL )
        *prioceiling = attr->prioceiling;
 
    PTHREAD_RETURN(0);
}
 
// Set priority ceiling of given mutex, returning old ceiling.
externC int pthread_mutex_setprioceiling( pthread_mutex_t *mutex,
                                          int prioceiling,
                                          int *old_ceiling)
{
    PTHREAD_ENTRY();
 
    PTHREAD_CHECK(mutex);
 
    pthread_mutex_lock( mutex );
 
    Cyg_Mutex *mx = (Cyg_Mutex *)mutex;
 
    if( old_ceiling != NULL )
        *old_ceiling = mx->get_ceiling();
 
    mx->set_ceiling( prioceiling );
 
    pthread_mutex_unlock( mutex );
 
    PTHREAD_RETURN(0);
}
 
// Get priority ceiling of given mutex
externC int pthread_mutex_getprioceiling( pthread_mutex_t *mutex,
                                          int *prioceiling)
{
    PTHREAD_ENTRY();
 
    PTHREAD_CHECK(mutex);
 
    Cyg_Mutex *mx = (Cyg_Mutex *)mutex;
 
    if( prioceiling != NULL )
        *prioceiling = mx->get_ceiling();
 
    PTHREAD_RETURN(0);
}
 
#endif // defined(_POSIX_THREAD_PRIO_PROTECT)
 
#endif // defined(_POSIX_THREAD_PRIO_INHERIT) || defined(_POSIX_THREAD_PRIO_PROTECT)
 
//-----------------------------------------------------------------------------
// Mutex functions
 
//-----------------------------------------------------------------------------
// Initialize mutex. If mutex_attr is NULL, use default attributes.
 
externC int pthread_mutex_init (pthread_mutex_t *mutex,
                                const pthread_mutexattr_t *mutex_attr)
{
    PTHREAD_ENTRY();
 
    PTHREAD_CHECK( mutex );
 
    pthread_mutexattr_t use_attr;
 
    // Set up the attributes we are going to use
    if( mutex_attr == NULL )
        pthread_mutexattr_init( &use_attr );
    else use_attr = *mutex_attr;
 
    // Now translate the POSIX protocol identifier into the eCos one.
    Cyg_Mutex::cyg_protcol protocol;
 
    switch( use_attr.protocol )
    {
#if defined(_POSIX_THREAD_PRIO_PROTECT)
    case PTHREAD_PRIO_PROTECT:
        protocol = Cyg_Mutex::CEILING;
        break;
#endif
#if defined(_POSIX_THREAD_PRIO_INHERIT)
    case PTHREAD_PRIO_INHERIT:
        protocol = Cyg_Mutex::INHERIT;
        break;
#endif        
    case PTHREAD_PRIO_NONE:
        protocol = Cyg_Mutex::NONE;
        break;
 
    default:
        PTHREAD_RETURN(EINVAL);
    }
 
    Cyg_Mutex *mx = new((cyg_uint8 *)mutex) Cyg_Mutex(  protocol );
 
    mx = mx; // silence compiler warning
#if defined(_POSIX_THREAD_PRIO_PROTECT)
    if ( protocol == Cyg_Mutex::CEILING )
        mx->set_ceiling( use_attr.prioceiling );
#endif
 
    PTHREAD_RETURN(0);
}
 
//-----------------------------------------------------------------------------
// Destroy mutex.
 
externC int pthread_mutex_destroy (pthread_mutex_t *mutex)
{
    PTHREAD_ENTRY();
 
    int err = ENOERR;
 
    PTHREAD_CHECK( mutex );
 
    Cyg_Mutex *mx = (Cyg_Mutex *)mutex;
 
    if( mx->get_owner() != NULL )
        err = EBUSY;
    else mx->~Cyg_Mutex();
 
    PTHREAD_RETURN(err);
}
 
//-----------------------------------------------------------------------------
// Lock mutex, waiting for it if necessary.
 
externC int pthread_mutex_lock (pthread_mutex_t *mutex)
{
    PTHREAD_ENTRY();
 
    PTHREAD_CHECK( mutex );
 
    Cyg_Mutex *mx = (Cyg_Mutex *)mutex;
 
    if( mx->get_owner() == Cyg_Thread::self() )
        PTHREAD_RETURN(EDEADLK);
 
    // Loop here until we acquire the mutex. Even if we are kicked out
    // of the wait by a signal or release we must retry.
    while( !mx->lock() )
        continue;
 
    PTHREAD_RETURN(0);
}
 
//-----------------------------------------------------------------------------
// Try to lock mutex.
 
externC int pthread_mutex_trylock (pthread_mutex_t *mutex)
{
    PTHREAD_ENTRY();
 
    PTHREAD_CHECK( mutex );
 
    Cyg_Mutex *mx = (Cyg_Mutex *)mutex;
 
    if( mx->get_owner() == Cyg_Thread::self() )
        PTHREAD_RETURN(EDEADLK);
 
    if( mx->trylock() )
        PTHREAD_RETURN(0);
 
    PTHREAD_RETURN(EBUSY);
}
 
 
//-----------------------------------------------------------------------------
// Unlock mutex.
 
externC int pthread_mutex_unlock (pthread_mutex_t *mutex)
{
    PTHREAD_ENTRY();
 
    PTHREAD_CHECK( mutex );
 
    Cyg_Mutex *mx = (Cyg_Mutex *)mutex;
 
    mx->unlock();
 
    PTHREAD_RETURN(0);
}
 
 
//=============================================================================
// Condition Variables
 
//-----------------------------------------------------------------------------
// Attribute manipulation functions
// We do not actually support any attributes at present, so these do nothing.
 
//-----------------------------------------------------------------------------
// Initialize condition variable attributes
 
externC int pthread_condattr_init (pthread_condattr_t *attr)
{
    PTHREAD_ENTRY();
 
    PTHREAD_CHECK(attr);
 
    // There are no condition variable attributes at present
 
    PTHREAD_RETURN(0);
}
 
//-----------------------------------------------------------------------------
// Destroy condition variable attributes
 
externC int pthread_condattr_destroy (pthread_condattr_t *attr)
{
    PTHREAD_ENTRY();
 
    PTHREAD_CHECK(attr);
 
    // nothing to do here...
 
    PTHREAD_RETURN(0);
}
 
//-----------------------------------------------------------------------------
// Condition variable functions
 
//-----------------------------------------------------------------------------
// Initialize condition variable.
 
externC int pthread_cond_init (pthread_cond_t *cond,
                               const pthread_condattr_t *attr)
{
    PTHREAD_ENTRY();
 
    PTHREAD_CHECK( cond );
 
    Cyg_Condition_Variable *cv =
        new((cyg_uint8 *)cond) Cyg_Condition_Variable();
 
    cv = cv;
 
    PTHREAD_RETURN(0);
}
 
//-----------------------------------------------------------------------------
// Destroy condition variable.
 
externC int pthread_cond_destroy (pthread_cond_t *cond)
{
    PTHREAD_ENTRY();
 
    PTHREAD_CHECK( cond );
 
    ((Cyg_Condition_Variable *)cond)->~Cyg_Condition_Variable();
 
    PTHREAD_RETURN(0);
}
 
//-----------------------------------------------------------------------------
// Wake up one thread waiting for condition variable
 
externC int pthread_cond_signal (pthread_cond_t *cond)
{
    PTHREAD_ENTRY();
 
    PTHREAD_CHECK( cond );
 
    ((Cyg_Condition_Variable *)cond)->signal();
 
    PTHREAD_RETURN(0);
}
 
//-----------------------------------------------------------------------------
// Wake up all threads waiting for condition variable
 
externC int pthread_cond_broadcast (pthread_cond_t *cond)
{
    PTHREAD_ENTRY();
 
    PTHREAD_CHECK( cond );
 
    ((Cyg_Condition_Variable *)cond)->broadcast();
 
    PTHREAD_RETURN(0);
}
 
//-----------------------------------------------------------------------------
// Block on condition variable until signalled. The mutex is
// assumed to be locked before this call, will be unlocked
// during the wait, and will be re-locked on wakeup.
 
externC int pthread_cond_wait (pthread_cond_t *cond,
                               pthread_mutex_t *mutex)
{
    PTHREAD_ENTRY();
 
    // check for cancellation first.
    PTHREAD_TESTCANCEL();
 
    PTHREAD_CHECK( cond );
    PTHREAD_CHECK( mutex );    
 
    ((Cyg_Condition_Variable *)cond)->wait( *(Cyg_Mutex *)mutex );
 
    // check if we were woken because we were being cancelled
    PTHREAD_TESTCANCEL();
 
    PTHREAD_RETURN(0);
}
 
//-----------------------------------------------------------------------------
// Block on condition variable until signalled, or the timeout expires.
 
externC int pthread_cond_timedwait (pthread_cond_t *cond,
                                    pthread_mutex_t *mutex,
                                    const struct timespec *abstime)
{
    PTHREAD_ENTRY();
 
    // check for cancellation first.
    PTHREAD_TESTCANCEL();
 
    PTHREAD_CHECK( cond );
    PTHREAD_CHECK( mutex );    
    PTHREAD_CHECK( abstime );    
 
    // Only initialize the converters once or they will consume a huge
    // amount or runtime.
 
    static struct Cyg_Clock::converter ns_converter;
    static struct Cyg_Clock::converter sec_converter;
    static volatile cyg_atomic conv_init;
    if (!conv_init)
    {
 
        // Try to avoid unnecessarily locking the scheduler when we are not
        // initializing the converters.  Check the conv_init flag again to
        // avoid race conditions.
 
        struct Cyg_Clock::converter temp_ns_converter, temp_sec_converter;
 
        Cyg_Clock::real_time_clock
            ->get_other_to_clock_converter( 1, &temp_ns_converter );
        Cyg_Clock::real_time_clock
            ->get_other_to_clock_converter( 1000000000, &temp_sec_converter );
 
        Cyg_Scheduler::lock();
        if (!conv_init)
        {
            ns_converter = temp_ns_converter;
            sec_converter = temp_sec_converter;
            conv_init=1;
        }
        Cyg_Scheduler::unlock();
    }
 
    cyg_tick_count ticks;
    ticks = Cyg_Clock::convert( abstime->tv_sec, &sec_converter );
    ticks += Cyg_Clock::convert( abstime->tv_nsec, &ns_converter );
 
    ((Cyg_Condition_Variable *)cond)->wait( *(Cyg_Mutex *)mutex, ticks );
 
    // check if we were woken because we were being cancelled
    PTHREAD_TESTCANCEL();
 
    if ( Cyg_Thread::self()->get_wake_reason() == Cyg_Thread::TIMEOUT )
        PTHREAD_RETURN(ETIMEDOUT);
    else
        PTHREAD_RETURN(0);
}
 
// -------------------------------------------------------------------------
// EOF mutex.cxx