//==========================================================================
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//==========================================================================
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//
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//
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// kphilo.c
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// kphilo.c
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//
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//
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// A test of the dining philosophers problem
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// A test of the dining philosophers problem
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//
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//
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//==========================================================================
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//==========================================================================
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//####ECOSGPLCOPYRIGHTBEGIN####
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//####ECOSGPLCOPYRIGHTBEGIN####
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// -------------------------------------------
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// -------------------------------------------
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// This file is part of eCos, the Embedded Configurable Operating System.
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// This file is part of eCos, the Embedded Configurable Operating System.
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// Copyright (C) 1998, 1999, 2000, 2001, 2002 Red Hat, Inc.
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// Copyright (C) 1998, 1999, 2000, 2001, 2002 Red Hat, Inc.
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//
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//
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// eCos is free software; you can redistribute it and/or modify it under
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// eCos is free software; you can redistribute it and/or modify it under
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// the terms of the GNU General Public License as published by the Free
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// the terms of the GNU General Public License as published by the Free
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// Software Foundation; either version 2 or (at your option) any later version.
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// Software Foundation; either version 2 or (at your option) any later version.
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//
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//
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// eCos is distributed in the hope that it will be useful, but WITHOUT ANY
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// eCos is distributed in the hope that it will be useful, but WITHOUT ANY
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// WARRANTY; without even the implied warranty of MERCHANTABILITY or
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// WARRANTY; without even the implied warranty of MERCHANTABILITY or
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// FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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// FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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// for more details.
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// for more details.
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//
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//
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// You should have received a copy of the GNU General Public License along
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// You should have received a copy of the GNU General Public License along
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// with eCos; if not, write to the Free Software Foundation, Inc.,
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// with eCos; if not, write to the Free Software Foundation, Inc.,
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// 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
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// 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
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//
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//
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// As a special exception, if other files instantiate templates or use macros
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// As a special exception, if other files instantiate templates or use macros
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// or inline functions from this file, or you compile this file and link it
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// or inline functions from this file, or you compile this file and link it
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// with other works to produce a work based on this file, this file does not
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// with other works to produce a work based on this file, this file does not
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// by itself cause the resulting work to be covered by the GNU General Public
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// by itself cause the resulting work to be covered by the GNU General Public
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// License. However the source code for this file must still be made available
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// License. However the source code for this file must still be made available
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// in accordance with section (3) of the GNU General Public License.
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// in accordance with section (3) of the GNU General Public License.
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//
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//
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// This exception does not invalidate any other reasons why a work based on
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// This exception does not invalidate any other reasons why a work based on
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// this file might be covered by the GNU General Public License.
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// this file might be covered by the GNU General Public License.
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//
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//
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// Alternative licenses for eCos may be arranged by contacting Red Hat, Inc.
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// Alternative licenses for eCos may be arranged by contacting Red Hat, Inc.
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// at http://sources.redhat.com/ecos/ecos-license/
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// at http://sources.redhat.com/ecos/ecos-license/
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// -------------------------------------------
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// -------------------------------------------
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//####ECOSGPLCOPYRIGHTEND####
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//####ECOSGPLCOPYRIGHTEND####
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//==========================================================================
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//==========================================================================
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//#####DESCRIPTIONBEGIN####
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//#####DESCRIPTIONBEGIN####
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//
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//
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// Author(s): dsm
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// Author(s): dsm
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// Contributors: dsm
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// Contributors: dsm
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// Date: 1998-02-24
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// Date: 1998-02-24
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// Description: A test of the dining philosophers problem
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// Description: A test of the dining philosophers problem
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//####DESCRIPTIONEND####
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//####DESCRIPTIONEND####
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//
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//
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#include <cyg/kernel/kapi.h>
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#include <cyg/kernel/kapi.h>
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#include <cyg/infra/cyg_ass.h>
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#include <cyg/infra/cyg_ass.h>
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#include <cyg/kernel/diag.h>
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#include <cyg/kernel/diag.h>
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// -------------------------------------------------------------------------
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// -------------------------------------------------------------------------
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// Data for the philosophers problem
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// Data for the philosophers problem
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#define PHILOSOPHERS 15 // number of philosophers
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#define PHILOSOPHERS 15 // number of philosophers
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#define STACKSIZE (2*1024) // size of thread stack
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#define STACKSIZE (2*1024) // size of thread stack
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// array of stacks for philosopher threads
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// array of stacks for philosopher threads
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char thread_stack[PHILOSOPHERS][STACKSIZE];
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char thread_stack[PHILOSOPHERS][STACKSIZE];
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// array of threads.
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// array of threads.
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cyg_thread thread[PHILOSOPHERS];
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cyg_thread thread[PHILOSOPHERS];
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cyg_handle_t thread_handle[PHILOSOPHERS];
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cyg_handle_t thread_handle[PHILOSOPHERS];
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// array of chopsticks
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// array of chopsticks
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cyg_sem_t chopstick[PHILOSOPHERS];
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cyg_sem_t chopstick[PHILOSOPHERS];
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cyg_ucount32 data_index;
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cyg_ucount32 data_index;
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// -------------------------------------------------------------------------
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// -------------------------------------------------------------------------
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// State recording and display
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// State recording and display
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static char pstate[PHILOSOPHERS+1]; // state vector showing what each
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static char pstate[PHILOSOPHERS+1]; // state vector showing what each
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// philosopher is doing
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// philosopher is doing
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cyg_mutex_t state_mutex;
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cyg_mutex_t state_mutex;
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#ifdef CYG_HAL_MN10300_MN103002
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#ifdef CYG_HAL_MN10300_MN103002
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static cyg_count8 eaters = 0;
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static cyg_count8 eaters = 0;
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#endif
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#endif
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void change_state(int id, char newstate)
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void change_state(int id, char newstate)
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{
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{
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cyg_mutex_lock(&state_mutex);
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cyg_mutex_lock(&state_mutex);
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#ifdef CYG_HAL_MN10300_MN103002
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#ifdef CYG_HAL_MN10300_MN103002
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if( pstate[id] == 'E' ) eaters--;
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if( pstate[id] == 'E' ) eaters--;
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if( newstate == 'E' ) eaters++;
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if( newstate == 'E' ) eaters++;
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// led(eaters);
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// led(eaters);
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#endif
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#endif
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pstate[id] = newstate;
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pstate[id] = newstate;
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diag_write_string(pstate);
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diag_write_string(pstate);
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#if 0
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#if 0
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diag_write_char(' ');
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diag_write_char(' ');
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diag_write_dec(Cyg_Scheduler::get_thread_switches());
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diag_write_dec(Cyg_Scheduler::get_thread_switches());
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#endif
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#endif
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diag_write_char('\n');
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diag_write_char('\n');
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cyg_mutex_unlock(&state_mutex);
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cyg_mutex_unlock(&state_mutex);
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}
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}
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char get_state( int id)
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char get_state( int id)
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{
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{
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char s;
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char s;
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cyg_mutex_lock(&state_mutex);
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cyg_mutex_lock(&state_mutex);
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s = pstate[id];
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s = pstate[id];
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cyg_mutex_unlock(&state_mutex);
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cyg_mutex_unlock(&state_mutex);
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return s;
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return s;
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}
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}
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// -------------------------------------------------------------------------
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// -------------------------------------------------------------------------
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// Thread to behave like a philosopher
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// Thread to behave like a philosopher
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void Philosopher( cyg_addrword_t vid )
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void Philosopher( cyg_addrword_t vid )
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{
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{
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cyg_uint32 id = (cyg_uint32)vid;
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cyg_uint32 id = (cyg_uint32)vid;
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cyg_sem_t *first_stick = &chopstick[id];
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cyg_sem_t *first_stick = &chopstick[id];
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cyg_sem_t *second_stick = &chopstick[(id+1)%PHILOSOPHERS];
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cyg_sem_t *second_stick = &chopstick[(id+1)%PHILOSOPHERS];
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#ifdef CYGPKG_INFRA_DEBUG
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#ifdef CYGPKG_INFRA_DEBUG
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int left_philo = ((id==0)?PHILOSOPHERS:id)-1;
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int left_philo = ((id==0)?PHILOSOPHERS:id)-1;
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int right_philo = (id==PHILOSOPHERS-1)?0:(id+1);
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int right_philo = (id==PHILOSOPHERS-1)?0:(id+1);
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#endif
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#endif
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CYG_ASSERT( id >= 0 && id < PHILOSOPHERS, "Bad id");
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CYG_ASSERT( id >= 0 && id < PHILOSOPHERS, "Bad id");
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// Deadlock avoidance. The easiest way to make the philosophers
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// Deadlock avoidance. The easiest way to make the philosophers
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// behave is to make each pick up the lowest numbered stick
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// behave is to make each pick up the lowest numbered stick
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// first. This is how it works out anyway for all the philosophers
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// first. This is how it works out anyway for all the philosophers
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// except the last, who must have his sticks swapped.
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// except the last, who must have his sticks swapped.
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if( id == PHILOSOPHERS-1 )
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if( id == PHILOSOPHERS-1 )
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{
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{
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cyg_sem_t *t = first_stick;
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cyg_sem_t *t = first_stick;
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first_stick = second_stick;
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first_stick = second_stick;
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second_stick = t;
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second_stick = t;
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}
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}
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for(;;)
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for(;;)
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{
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{
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cyg_ucount32 val;
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cyg_ucount32 val;
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// The following variable is shared by all philosophers.
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// The following variable is shared by all philosophers.
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// It is incremented unprotected, but this does not matter
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// It is incremented unprotected, but this does not matter
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// since it is only present to introduce a little variability
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// since it is only present to introduce a little variability
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// into the think and eat times.
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// into the think and eat times.
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static volatile int cycle = 0;
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static volatile int cycle = 0;
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// Think for a bit
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// Think for a bit
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cyg_thread_delay((id+cycle++)%12); // Cogito ergo sum...
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cyg_thread_delay((id+cycle++)%12); // Cogito ergo sum...
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// I am now hungry, try to get the chopsticks
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// I am now hungry, try to get the chopsticks
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change_state(id,'H');
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change_state(id,'H');
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// Get the first stick
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// Get the first stick
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cyg_semaphore_wait(first_stick);
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cyg_semaphore_wait(first_stick);
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// Get the second stick
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// Get the second stick
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cyg_semaphore_wait(second_stick);
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cyg_semaphore_wait(second_stick);
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// Got them, now eat
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// Got them, now eat
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change_state(id,'E');
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change_state(id,'E');
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// Check that the world is as I think it is...
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// Check that the world is as I think it is...
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cyg_semaphore_peek( first_stick, &val);
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cyg_semaphore_peek( first_stick, &val);
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CYG_ASSERT( val == 0, "Not got first stick");
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CYG_ASSERT( val == 0, "Not got first stick");
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cyg_semaphore_peek( second_stick, &val);
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cyg_semaphore_peek( second_stick, &val);
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CYG_ASSERT( val == 0, "Not got second stick");
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CYG_ASSERT( val == 0, "Not got second stick");
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CYG_ASSERT( get_state(left_philo) != 'E', "Left neighbour also eating!!");
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CYG_ASSERT( get_state(left_philo) != 'E', "Left neighbour also eating!!");
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CYG_ASSERT( get_state(right_philo) != 'E', "Right neighbour also eating!!");
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CYG_ASSERT( get_state(right_philo) != 'E', "Right neighbour also eating!!");
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cyg_thread_delay((id+cycle++)%6); // munch munch
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cyg_thread_delay((id+cycle++)%6); // munch munch
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// Finished eating, put down sticks.
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// Finished eating, put down sticks.
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change_state(id,'T');
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change_state(id,'T');
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cyg_semaphore_post( first_stick );
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cyg_semaphore_post( first_stick );
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cyg_semaphore_post( second_stick );
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cyg_semaphore_post( second_stick );
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}
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}
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}
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}
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// -------------------------------------------------------------------------
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// -------------------------------------------------------------------------
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externC void
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externC void
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cyg_start( void )
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cyg_start( void )
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{
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{
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int i;
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int i;
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diag_init();
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diag_init();
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diag_write_string("Philosophers\n");
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diag_write_string("Philosophers\n");
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diag_write_string("Started\n");
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diag_write_string("Started\n");
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// Zero last element in state so it acts like
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// Zero last element in state so it acts like
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// a string.
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// a string.
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pstate[PHILOSOPHERS] = 0;
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pstate[PHILOSOPHERS] = 0;
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#if 1
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#if 1
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for( i = 0; i < PHILOSOPHERS; i++ )
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for( i = 0; i < PHILOSOPHERS; i++ )
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{
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{
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change_state(i,'T'); // starting state
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change_state(i,'T'); // starting state
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cyg_thread_create(4, Philosopher, (cyg_addrword_t)i, "philosopher",
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cyg_thread_create(4, Philosopher, (cyg_addrword_t)i, "philosopher",
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(void *)(&thread_stack[i]), STACKSIZE,
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(void *)(&thread_stack[i]), STACKSIZE,
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&thread_handle[i], &thread[i]);
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&thread_handle[i], &thread[i]);
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// resume it
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// resume it
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cyg_thread_resume(thread_handle[i]);
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cyg_thread_resume(thread_handle[i]);
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// and make the matching chopstick present
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// and make the matching chopstick present
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cyg_semaphore_init( &chopstick[i], 1);
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cyg_semaphore_init( &chopstick[i], 1);
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}
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}
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#endif
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#endif
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// Get the world going
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// Get the world going
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cyg_scheduler_start();
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cyg_scheduler_start();
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}
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}
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// -------------------------------------------------------------------------
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// -------------------------------------------------------------------------
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// EOF kphilo.c
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// EOF kphilo.c
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