📄 mutex3.c
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//==========================================================================
//
// mutex3.cxx
//
// Mutex test 3 - priority inheritance
//
//==========================================================================
//####ECOSGPLCOPYRIGHTBEGIN####
// -------------------------------------------
// This file is part of eCos, the Embedded Configurable Operating System.
// Copyright (C) 1998, 1999, 2000, 2001, 2002 Red Hat, 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
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//
// 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.,
// 59 Temple Place, Suite 330, Boston, MA 02111-1307 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
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//
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// at http://sources.redhat.com/ecos/ecos-license/
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//####ECOSGPLCOPYRIGHTEND####
//==========================================================================
//#####DESCRIPTIONBEGIN####
//
// Author(s): hmt
// Contributors: hmt, nickg, jlarmour
// Date: 2000-01-06
// Description: Tests mutex priority inheritance. This is simply a translation
// of the similarly named kernel test to the POSIX API
//####DESCRIPTIONEND####
// ------------------------------------------------------------------------
#include <cyg/infra/testcase.h>
#include <pkgconf/posix.h>
#include <pkgconf/system.h>
#ifdef CYGPKG_KERNEL
#include <pkgconf/kernel.h>
#endif
#ifdef CYGPKG_ISOINFRA
# include <sys/types.h>
# include <pthread.h>
# include <semaphore.h>
# include <time.h>
# include <unistd.h>
#endif
#if !defined(CYGPKG_POSIX_PTHREAD)
#define NA_MSG "POSIX threads not enabled"
// ------------------------------------------------------------------------
//
// These checks should be enough; any other scheduler which has priorities
// should manifest as having no priority inheritance, but otherwise fine,
// so the test should work correctly.
#elif !defined(_POSIX_THREAD_PRIORITY_SCHEDULING)
#define NA_MSG "No POSIX thread priority scheduling enabled"
#elif !defined(_POSIX_THREAD_PRIO_INHERIT)
#define NA_MSG "No POSIX thread priority inheritance enabled"
#elif !defined(_POSIX_SEMAPHORES)
#define NA_MSG "No POSIX sempaphore support enabled enabled"
#elif !defined(CYGFUN_KERNEL_API_C)
#define NA_MSG "Kernel C API not enabled"
#elif defined(CYGPKG_KERNEL_SMP_SUPPORT)
#define NA_MSG "Test cannot run with SMP support"
#endif
#ifdef NA_MSG
void
cyg_start(void)
{
CYG_TEST_INIT();
CYG_TEST_NA(NA_MSG);
}
#else
#include <cyg/infra/cyg_ass.h>
#include <cyg/infra/cyg_trac.h>
#include <cyg/infra/diag.h> // diag_printf
#include <cyg/kernel/kapi.h> // Some extras
// ------------------------------------------------------------------------
// Management functions
//
// Stolen from testaux.hxx and copied in here because I want to be able to
// reset the world also.
// ... and subsequently POSIXized out of all similarly with its progenitors.
#define NTHREADS 7
#define STACKSIZE (PTHREAD_STACK_MIN*2)
static pthread_t thread[NTHREADS] = { 0 };
typedef CYG_WORD64 CYG_ALIGNMENT_TYPE;
static CYG_ALIGNMENT_TYPE stack[NTHREADS] [
(STACKSIZE+sizeof(CYG_ALIGNMENT_TYPE)-1)
/ sizeof(CYG_ALIGNMENT_TYPE) ];
// Semaphores to halt execution of threads
static sem_t hold[NTHREADS];
// Flag to tell all threads to exit
static int all_exit;
// Application thread data is passed here, the thread
// argument is
static CYG_ADDRWORD thread_data[NTHREADS];
static volatile int nthreads = 0;
// Sleep for 1 tick...
static struct timespec sleeptime;
static pthread_t new_thread( void *(*entry)(void *),
CYG_ADDRWORD data,
int priority,
int do_resume)
{
pthread_attr_t attr;
int _nthreads = nthreads++;
struct sched_param schedparam;
schedparam.sched_priority = priority;
pthread_attr_init( &attr );
pthread_attr_setstackaddr( &attr, (void *)((char *)(&stack[_nthreads])+STACKSIZE) );
pthread_attr_setstacksize( &attr, STACKSIZE );
pthread_attr_setinheritsched( &attr, PTHREAD_EXPLICIT_SCHED );
pthread_attr_setschedpolicy( &attr, SCHED_RR );
pthread_attr_setschedparam( &attr, &schedparam );
CYG_ASSERT(_nthreads < NTHREADS,
"Attempt to create more than NTHREADS threads");
thread_data[_nthreads] = data;
sem_init( &hold[_nthreads], 0, do_resume ? 1 : 0 );
all_exit = 0;
pthread_create( &thread[_nthreads],
&attr,
entry,
(void *)_nthreads);
return thread[_nthreads];
}
static void kill_threads( void )
{
CYG_ASSERT(nthreads <= NTHREADS,
"More than NTHREADS threads");
CYG_ASSERT( pthread_equal(pthread_self(),thread[0]),
"kill_threads() not called from thread 0");
all_exit = 1;
while ( nthreads > 1 ) {
nthreads--;
if ( 0 != thread[nthreads] ) {
sem_post( &hold[nthreads] );
pthread_cancel( thread[nthreads] );
pthread_join( thread[nthreads], NULL );
thread[nthreads] = 0;
sem_destroy( &hold[nthreads] );
}
}
CYG_ASSERT(nthreads == 1,
"No threads left");
}
// ------------------------------------------------------------------------
#define DELAYFACTOR 1 // for debugging
// ------------------------------------------------------------------------
pthread_mutex_t mutex;
// These are for reporting back to the master thread
volatile int got_it = 0;
volatile int t3ran = 0;
volatile int t3ended = 0;
volatile int extras[4] = {0,0,0,0};
volatile int go_flag = 0; // but this one controls thread 3 from thread 2
// ------------------------------------------------------------------------
// 0 to 3 of these run generally to interfere with the other processing,
// to cause multiple prio inheritances, and clashes in any orders.
static void *extra_thread( void *arg )
{
#define XINFO( z ) \ do { z[13] = '0' + data; CYG_TEST_INFO( z ); } while ( 0 )
static char running[] = "Extra thread Xa running";
static char exiting[] = "Extra thread Xa exiting";
static char resumed[] = "Extra thread Xa resumed";
static char locked[] = "Extra thread Xa locked";
static char unlocked[] = "Extra thread Xa unlocked";
int id = (int)arg;
CYG_ADDRWORD data = thread_data[id];
CYG_ASSERT( (id >= 4 && id <= 6), "extra_thread invalid id" );
// Emulate resume behaviour
sem_wait( &hold[id] );
if( all_exit ) return 0;
XINFO( running );
sem_wait( &hold[id] );
XINFO( resumed );
pthread_mutex_lock( &mutex );
XINFO( locked );
pthread_mutex_unlock( &mutex );
XINFO( unlocked );
extras[ data ] ++;
XINFO( exiting );
return NULL;
}
// ------------------------------------------------------------------------
static void *t1( void *arg )
{
int id = (int)arg;
//CYG_ADDRWORD data = thread_data[id];
// Emulate resume behaviour
sem_wait( &hold[id] );
if( all_exit ) return 0;
CYG_TEST_INFO( "Thread 1 running" );
sem_wait( &hold[id] );
pthread_mutex_lock( &mutex );
got_it++;
CYG_TEST_CHECK( 0 == t3ended, "T3 ended prematurely [T1,1]" );
pthread_mutex_unlock( &mutex );
CYG_TEST_CHECK( 0 == t3ended, "T3 ended prematurely [T1,2]" );
// That's all.
CYG_TEST_INFO( "Thread 1 exit" );
return 0;
}
// ------------------------------------------------------------------------
static void *t2( void *arg )
{
int i;
int id = (int)arg;
CYG_ADDRWORD data = thread_data[id];
cyg_tick_count_t now, then;
// Emulate resume behaviour
sem_wait( &hold[id] );
if( all_exit ) return 0;
CYG_TEST_INFO( "Thread 2 running" );
CYG_TEST_CHECK( 0 == (data & ~0x77), "Bad T2 arg: extra bits" );
CYG_TEST_CHECK( 0 == (data & (data >> 4)), "Bad T2 arg: overlap" );
sem_wait( &hold[id] );
// depending on our config argument, optionally restart some of the
// extra threads to throw noise into the scheduler:
for ( i = 0; i < 3; i++ )
if ( (1 << i) & data ) // bits 0-2 control
sem_post( &hold[i+4] ); // made sure extras are thread[4-6]
// let those threads run
for( i = 0; i < DELAYFACTOR * 10; i++ )
nanosleep( &sleeptime, NULL );
cyg_scheduler_lock(); // do this next lot atomically
go_flag = 1; // unleash thread 3
sem_post( &hold[1] ); // resume thread 1
// depending on our config argument, optionally restart some of the
// extra threads to throw noise into the scheduler at this later point:
for ( i = 4; i < 7; i++ )
if ( (1 << i) & data ) // bits 4-6 control
sem_post( &hold[i] ); // made sure extras are thread[4-6]
cyg_scheduler_unlock(); // let scheduling proceed
// Need a delay (but not a CPU yield) to allow t3 to awaken and act on
// the go_flag, otherwise we check these details below too soon.
// Actually, waiting for the clock to tick a couple of times would be
// better, so that is what we will do. Must be a busy-wait.
then = cyg_current_time();
do {
now = cyg_current_time();
// Wait longer than the delay in t3 waiting on go_flag
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