//==========================================================================
//
//        kmutex4.c
//
//        Mutex test 4 - dynamic priority inheritance protocol
//
//==========================================================================
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//==========================================================================
//#####DESCRIPTIONBEGIN####
//
// Author(s):     hmt
// Contributors:  hmt
// Date:          2000-01-06, 2001-08-10, 2001-08-21
// Description:   Tests mutex priority inheritance.  This is an extension of
//                kmutex3.c, to test the new "set the protocol at run-time"
//                extensions.
//####DESCRIPTIONEND####

#include <pkgconf/hal.h>
#include <pkgconf/kernel.h>

#include <cyg/infra/testcase.h>

#include <cyg/hal/hal_arch.h>           // CYGNUM_HAL_STACK_SIZE_TYPICAL

#include <cyg/infra/diag.h>             // diag_printf

#ifdef CYGSEM_HAL_STOP_CONSTRUCTORS_ON_FLAG
externC void
cyg_hal_invoke_constructors();
#endif

// ------------------------------------------------------------------------
//
// 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.

#if defined(CYGVAR_KERNEL_COUNTERS_CLOCK) &&                                    \
    (CYGNUM_KERNEL_SCHED_PRIORITIES > 20) &&                                    \
    defined(CYGFUN_KERNEL_API_C) &&                                             \
    !defined(CYGPKG_KERNEL_SMP_SUPPORT) &&                                      \
    defined(CYGSEM_KERNEL_SYNCH_MUTEX_PRIORITY_INVERSION_PROTOCOL_DYNAMIC)      \

#include <cyg/kernel/kapi.h>

#include <cyg/infra/cyg_ass.h>
#include <cyg/infra/cyg_trac.h>
#include <cyg/infra/diag.h>             // diag_printf

// ------------------------------------------------------------------------

#define nVERBOSE

// ------------------------------------------------------------------------
// We have dynamic protocol choice, so we can set the protocol to whatever
// we want.  We'll do these combinations:
// NONE
// INHERIT
// CEILING = 4 = higher than any thread === INHERIT in behaviour
// CEILING = 11 = mixed in with threads === cannot check anything
// CEILING = 17 = lower than any threads === NONE in behaviour

#define PROTO_NONE            (0)
#define PROTO_INHERIT         (1)
#define PROTO_CEILING_HIGH    (2)
#define PROTO_CEILING_MID     (3)
#define PROTO_CEILING_LOW     (4)

int proto;

static char * protnames[] = {
    "none",
    "inherit",
    "high ceiling",
    "medium ceiling",
    "low ceiling",
};

// ------------------------------------------------------------------------
// Management functions
//
// Stolen from testaux.hxx and copied in here because I want to be able to
// reset the world also.
//
// Translated into KAPI also.

#define NTHREADS 7

#define STACKSIZE CYGNUM_HAL_STACK_SIZE_TYPICAL

static  cyg_handle_t thread[NTHREADS] = { 0 };

typedef cyg_uint64 CYG_ALIGNMENT_TYPE;

static cyg_thread thread_obj[NTHREADS];

static CYG_ALIGNMENT_TYPE stack[NTHREADS] [
   (STACKSIZE+sizeof(CYG_ALIGNMENT_TYPE)-1)
     / sizeof(CYG_ALIGNMENT_TYPE)                     ];

static volatile int nthreads = 0;

#undef NULL
#define NULL (0)

static cyg_handle_t new_thread( cyg_thread_entry_t *entry,
                                cyg_addrword_t data,
                                cyg_addrword_t priority,
                                int do_resume,
                                char *name )
{
    int _nthreads = nthreads++;

    CYG_ASSERT(_nthreads < NTHREADS, 
               "Attempt to create more than NTHREADS threads");

    cyg_thread_create( priority,
                       entry,
                       data, 
                       name,
                       (void *)(stack[_nthreads]),
                       STACKSIZE,
                       &thread[_nthreads],
                       &thread_obj[_nthreads] );

    if ( do_resume )
        cyg_thread_resume( thread[_nthreads] );

    return thread[_nthreads];
}


static void kill_threads( void )
{
    CYG_ASSERT(nthreads <= NTHREADS, 
               "More than NTHREADS threads");
    CYG_ASSERT( cyg_thread_self() == thread[0],
                "kill_threads() not called from thread 0");
    while ( nthreads > 1 ) {
        nthreads--;
        if ( NULL != thread[nthreads] ) {
            do
                cyg_thread_kill( thread[nthreads] );
            while ( ! cyg_thread_delete ( thread[nthreads] ) );
            thread[nthreads] = NULL;
        }
    }
    CYG_ASSERT(nthreads == 1,
               "No threads left");
}

// ------------------------------------------------------------------------

#define DELAYFACTOR 1 // for debugging

// ------------------------------------------------------------------------

static cyg_mutex_t mutex_obj;
static cyg_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( cyg_addrword_t data )
{
    cyg_handle_t self = cyg_thread_self();


#ifdef VERBOSE
#define xXINFO( 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";
#else
#define XINFO( z )  /* nothing */
#endif

    XINFO( running );

    cyg_thread_suspend( self );

    XINFO( resumed );

    cyg_mutex_lock( mutex );

    XINFO( locked );

    cyg_mutex_unlock( mutex );

    XINFO( unlocked );

    extras[ data ] ++;

    XINFO( exiting );

}

// ------------------------------------------------------------------------

static void t1( cyg_addrword_t data )
{
    cyg_handle_t self = cyg_thread_self();
#ifdef VERBOSE
    CYG_TEST_INFO( "Thread 1 running" );
#endif
    cyg_thread_suspend( self );

    cyg_mutex_lock( mutex );

    got_it++;

    CYG_TEST_CHECK( 0 == t3ended, "T3 ended prematurely [T1,1]" );

    cyg_mutex_unlock( mutex );

    CYG_TEST_CHECK( 0 == t3ended, "T3 ended prematurely [T1,2]" );

    // That's all.
#ifdef VERBOSE
    CYG_TEST_INFO( "Thread 1 exit" );
#endif
}

// ------------------------------------------------------------------------

static void t2( cyg_addrword_t data )
{
    cyg_handle_t self = cyg_thread_self();
    int i;
    cyg_tick_count_t then, now;
#ifdef VERBOSE
    CYG_TEST_INFO( "Thread 2 running" );
#endif
    CYG_TEST_CHECK( 0 == (data & ~0x77), "Bad T2 arg: extra bits" );
    CYG_TEST_CHECK( 0 == (data & (data >> 4)), "Bad T2 arg: overlap" );

    cyg_thread_suspend( self );

    // 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
            cyg_thread_resume( thread[i+4] ); // extras are thread[4-6]

    cyg_thread_delay( DELAYFACTOR * 10 ); // let those threads run

    cyg_scheduler_lock();               // do this next lot atomically

    go_flag = 1;                        // unleash thread 3
    cyg_thread_resume( thread[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
            cyg_thread_resume( thread[i] ); // 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
    } while ( now < (then + 3) );

    // Check for whatever result we expect from the protocol selected:
    // This mirrors what is done in configury in kmutex3.c and mutex3.cxx
    if ( PROTO_CEILING_MID == proto ) {
        CYG_TEST_INFO( "Not checking: ceiling mid value" );
    }
    else if ( PROTO_INHERIT == proto ||
              PROTO_CEILING_HIGH == proto ) {
        CYG_TEST_INFO( "Checking priority scheme operating" );
        CYG_TEST_CHECK( 1 == t3ran, "Thread 3 did not run" );
        CYG_TEST_CHECK( 1 == got_it, "Thread 1 did not get the mutex" );
    }
    else {
        CYG_TEST_INFO( "Checking NO priority scheme operating" );
        CYG_TEST_CHECK( 0 == t3ran, "Thread 3 DID run" );
        CYG_TEST_CHECK( 0 == got_it, "Thread 1 DID get the mutex" );
    }

    CYG_TEST_CHECK( 0 == t3ended, "Thread 3 ended prematurely [T2,1]" );

    cyg_thread_delay( DELAYFACTOR * 20 ); // let those threads run

    CYG_TEST_CHECK( 1 == t3ran, "Thread 3 did not run" );
    CYG_TEST_CHECK( 1 == got_it, "Thread 1 did not get the mutex" );
    CYG_TEST_CHECK( 1 == t3ended, "Thread 3 has not ended" );

    for ( i = 0; i < 3; i++ )
        if ( (1 << i) & (data | data >> 4) ) // bits 0-2 and 4-6 control
            CYG_TEST_CHECK( 1 == extras[i+1], "Extra thread did not run" );
        else
            CYG_TEST_CHECK( 0 == extras[i+1], "Extra thread ran" );

    CYG_TEST_PASS( "Thread 2 exiting, AOK" );
    // That's all: restart the control thread.
    cyg_thread_resume( thread[0] );
}

// ------------------------------------------------------------------------

static void t3( cyg_addrword_t data )
{
#ifdef VERBOSE
    CYG_TEST_INFO( "Thread 3 running" );
#endif
    cyg_mutex_lock( mutex );

    cyg_thread_delay( DELAYFACTOR * 5 ); // let thread 3a run

    cyg_thread_resume( thread[2] );     // resume thread 2

    while ( 0 == go_flag )
        cyg_thread_delay(1);            // wait until we are told to go

    t3ran ++;                           // record the fact

    CYG_TEST_CHECK( 0 == got_it, "Thread 1 claims to have got my mutex" );
    
    cyg_mutex_unlock( mutex );
    
    t3ended ++;                         // record that we came back

    CYG_TEST_CHECK( 1 == got_it, "Thread 1 did not get the mutex" );
#ifdef VERBOSE
    CYG_TEST_INFO( "Thread 3 exit" );
#endif
}

// ------------------------------------------------------------------------

static void control_thread( cyg_addrword_t data )
{
    cyg_handle_t self = cyg_thread_self();
    int i, z;

    CYG_TEST_INIT();
    CYG_TEST_INFO( "Control Thread running" );

    // Go through the 27 possibilities of resuming the extra threads
    //     0: not at all
    //     1: early in the process
    //     2: later on
    // which are represented by bits 0-3 and 4-6 resp in the argument to
    // thread 2 (none set means no resume at all).
    for ( i = 0; i < 27; i++ ) {
        static int xx[] = { 0, 1, 16 };
        int j = i % 3;
        int k = (i / 3) % 3;
        int l = (i / 9) % 3;

        int d = xx[j] | (xx[k]<<1) | (xx[l]<<2) ;

        if ( cyg_test_is_simulator && (0 != i && 13 != i && 26 != i) )
            continue;    // 13 is 111 base 3, 26 is 222 base 3

        // Go through all these priority inversion prevention protocols:
        // (if supported in this configuration)
	// PROTO_NONE            (0)
	// PROTO_INHERIT         (1)
	// PROTO_CEILING_HIGH    (2)
	// PROTO_CEILING_MID     (3)
	// PROTO_CEILING_LOW     (4)
        for ( proto = PROTO_NONE; proto <= PROTO_CEILING_LOW; proto++ ) {

            // If no priority inheritance at all, running threads 1a and 2a is
            // OK, but not thread 3a; it blocks the world.
            if ( PROTO_NONE == proto ||
                 PROTO_CEILING_MID == proto ||
                 PROTO_CEILING_LOW == proto )
                if ( l )                // Cannot run thread 3a if no
                    continue;           // priority inheritance at all.

            mutex = &mutex_obj;
            
            switch ( proto ) {
#ifdef CYGSEM_KERNEL_SYNCH_MUTEX_PRIORITY_INVERSION_PROTOCOL_NONE
            case PROTO_NONE:
                cyg_mutex_init( mutex );
                cyg_mutex_set_protocol( mutex, CYG_MUTEX_NONE );
                break;
#endif
#ifdef CYGSEM_KERNEL_SYNCH_MUTEX_PRIORITY_INVERSION_PROTOCOL_INHERIT
            case PROTO_INHERIT:
                cyg_mutex_init( mutex );
                cyg_mutex_set_protocol( mutex, CYG_MUTEX_INHERIT );
                break;
#endif
#ifdef CYGSEM_KERNEL_SYNCH_MUTEX_PRIORITY_INVERSION_PROTOCOL_CEILING
            case PROTO_CEILING_HIGH:
                cyg_mutex_init( mutex );
                cyg_mutex_set_protocol( mutex, CYG_MUTEX_CEILING );
                cyg_mutex_set_ceiling( mutex, (cyg_priority_t)  4 );
                break;
            case PROTO_CEILING_MID:
                cyg_mutex_init( mutex );
                cyg_mutex_set_protocol( mutex, CYG_MUTEX_CEILING );
                cyg_mutex_set_ceiling( mutex, (cyg_priority_t) 11 );
                break;
            case PROTO_CEILING_LOW:
                cyg_mutex_init( mutex );
                cyg_mutex_set_protocol( mutex, CYG_MUTEX_CEILING );
                cyg_mutex_set_ceiling( mutex, (cyg_priority_t) 17 );
                break;
#endif
            default:
                continue; // Break out of the prio for loop - do nothing
            }

            got_it  = 0;
            t3ran   = 0;
            t3ended = 0;
            for ( z = 0; z < 4; z++ ) extras[z] = 0;
            go_flag = 0;
        
            new_thread( t1, 0,  5, 1, "test 1" ); // Slot 1
            new_thread( t2, d, 10, 1, "test 2" ); // Slot 2
            new_thread( t3, 0, 15, 1, "test 3" ); // Slot 3
        
            new_thread( extra_thread, 1,  8, j, "extra 1" ); // Slot 4
            new_thread( extra_thread, 2, 12, k, "extra 2" ); // Slot 5
            new_thread( extra_thread, 3, 17, l, "extra 3" ); // Slot 6
        
            {
                static char *a[] = { "inactive", "run early", "run late" };
                diag_printf( "\n----- %s [%2d] New Cycle: 0x%02x, Threads 1a %s, 2a %s, 3a %s -----\n",
                             protnames[proto], i, d,  a[j], a[k], a[l] );
            }

            cyg_thread_suspend( self );
        
            kill_threads();
            cyg_mutex_destroy( mutex );
        }
    }
    CYG_TEST_EXIT( "Control Thread exit" );
}

// ------------------------------------------------------------------------

externC void
cyg_user_start( void )
{ 
#ifdef CYGSEM_HAL_STOP_CONSTRUCTORS_ON_FLAG
    cyg_hal_invoke_constructors();
#endif
    new_thread( control_thread, 0, 2, 1, "control thread" );
}

#else // CYGVAR_KERNEL_COUNTERS_CLOCK &c

externC void
cyg_start( void )
{
    CYG_TEST_INIT();
    CYG_TEST_INFO("KMutex4 test requires:\n"
                         "CYGFUN_KERNEL_API_C &&\n"
                         "CYGVAR_KERNEL_COUNTERS_CLOCK &&\n"
                         "(CYGNUM_KERNEL_SCHED_PRIORITIES > 20) &&\n"
                         "!defined(CYGPKG_KERNEL_SMP_SUPPORT) &&\n"
    "defined(CYGSEM_KERNEL_SYNCH_MUTEX_PRIORITY_INVERSION_PROTOCOL_DYNAMIC)\n"
        );
    CYG_TEST_NA("KMutex4 test requirements");
}
#endif // CYGVAR_KERNEL_COUNTERS_CLOCK &c


// ------------------------------------------------------------------------
// Documentation: enclosed is the design of this test.
//
// See mutex3.cxx or kmutex3.c

// ------------------------------------------------------------------------
// EOF mutex4.c
