mutex3.c

ecos实时嵌入式操作系统

//==========================================================================
//
//        mutex3.cxx
//
//        Mutex test 3 - priority inheritance
//
//==========================================================================
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// -------------------------------------------
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//==========================================================================
//#####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