//==========================================================================
//
//        pmutex3.c
//
//        Mutex test 3 - priority inheritance
//
//==========================================================================
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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
    } while ( now < (then + 3) );

#ifdef _POSIX_THREAD_PRIO_INHERIT
    CYG_TEST_INFO( "Checking for mutex priority inheritance" );
    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 for NO mutex priority inheritance" );
    CYG_TEST_CHECK( 0 == t3ran, "Thread 3 DID run" );
    CYG_TEST_CHECK( 0 == got_it, "Thread 1 DID get the mutex" );
#endif

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

    for( i = 0; i < DELAYFACTOR * 20; i++ )    
        nanosleep( &sleeptime, NULL );      // 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.
    sem_post( &hold[0] );

    return 0;    
}

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

static void *t3( void *arg )
{
    int i;
    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 3 running" );

    pthread_mutex_lock( &mutex );

    for( i = 0; i < DELAYFACTOR * 5; i++ )    
        nanosleep( &sleeptime, NULL );      // let thread 3a run

    sem_post( &hold[2] );               // resume thread 2

    while ( 0 == go_flag )
        nanosleep( &sleeptime, NULL );  // 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" );

    pthread_mutex_unlock( &mutex );

    t3ended ++;                         // record that we came back

    CYG_TEST_CHECK( 1 == got_it, "Thread 1 did not get the mutex" );

    CYG_TEST_INFO( "Thread 3 exit" );

    return 0;
}

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

static void *control_thread( void *arg )
{
    int i,z;
    int id = (int)arg;
    //CYG_ADDRWORD data = thread_data[id];
    
    // Emulate resume behaviour
    sem_wait( &hold[id] );
    if( all_exit ) return 0;
    
    // one tick sleep time
    sleeptime.tv_nsec = 10000000;
    sleeptime.tv_sec = 0;
    
    CYG_TEST_INIT();
    CYG_TEST_INFO( "Control Thread running" );

    // Go through the 27 possibilitied 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

#ifdef _POSIX_THREAD_PRIO_INHERIT
        // If the simple scheme plus relay enhancement, or any other
        // *complete* scheme, we can run all three ancillary threads no
        // problem, so no special action here.

#else
        // If no priority inheritance at all, running threads 1a and 2a is
        // OK, but not thread 3a; it blocks the world.
        if ( l )                        // Cannot run thread 3a if no
            break;                      //     priority inheritance at all.
#endif

        // Reinitialize mutex to provide priority inheritance
        {
            pthread_mutexattr_t attr;
            pthread_mutexattr_init( &attr );
            pthread_mutexattr_setprotocol( &attr, PTHREAD_PRIO_INHERIT );
            pthread_mutex_init( &mutex, &attr );
        }

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

        sem_wait( &hold[0] );
        
        kill_threads();
        pthread_mutex_destroy( &mutex );
    }
    CYG_TEST_EXIT( "Control Thread exit" );

    return 0;
}

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

static sem_t main_sem;

externC int
main( int argc, char **argv )
{ 
    new_thread( control_thread, 0, 20, 1 );

    // We have nothing for main to do here, so put it to sleep on
    // its own semaphore. We cannot let it just exit since that
    // will end the whole program.

    sem_init( &main_sem, 0, 0 );
    
    for(;;) sem_wait( &main_sem );
}

// ------------------------------------------------------------------------
// Documentation: enclosed is the design of this test.
//
// It has been carefully constructed so that it does NOT use other kernel
// facilities (aside from delay-task) to test that priority inheritance is
// working, or not, as intended by the configuration.
//
// These notes describe the flow of control in one run of the test with the
// ancillary tasks optionally interspersed.  The details of how those extra
// tasks are or are not allowed to run are not described.
// 
// 
// 
// The only change in the test that depends on whether there is inheritance or
// not is the check in thread 2 on "3-ran" and "got it" flags marked ****
// 
// 
// volatile &c booleans:
//         "got it"     = FALSE
//         "3-ran"      = FALSE
//         "3-ended"    = FALSE
//         "extras"[3]  = FALSE
// 
// thread 1.  prio 5, self-suspend.
// 
// thread 1a, prio 8, self-suspend.
// 
// thread 2.  prio 10, self-suspend.
// 
// thread 2a, prio 12, self-suspend.
// 
// thread 3.  prio 15, runs, lock mutex, resume(2)
// 
// thread 3a, prio 17, self-suspend.
// 
//        2.  runs,
//        2.  resume(3a) +++OPTIONAL
//        2.  resume(2a) +++OPTIONAL
//        2.  resume(1a) +++OPTIONAL
//        [1a lock-fail]	thread 3->prio := 8
// 
//        [3. runs maybe, does the looping thing]
// 
//        2.  sleep a while...
// 
//        [2a lock-fail]	thread 3->prio := 12
// 
//        [3. runs maybe, does the looping thing]
// 
//        [3a lock-fail]   thread 3->prio unchanged
// 
//        [3. runs maybe, does the looping thing]
// 
//        2.  lock scheduler
//        2.  set "go-flag"
//        2.  resume(1)
//        2.  resume(1a) +++OPTIONAL
//        2.  resume(2a) +++OPTIONAL
//        2.  resume(3a) +++OPTIONAL
//        2.  unlock scheduler
// 
//        1.  runs, lock mutex - thread 3 has it locked
//
//        2.  busy-waits a bit for thread 3 to come out of its delay() loop.
//            This must be a *busy*wait so that 3 can only run via the
//            inherited raised priority.
// 
//        [xa. all do the same: lock mutex,                ]
//        [xa. unlock mutex                                ]
//        [xa. set a flag "extras"[x] to say we are done.  ]
//        [xa. exit                                        ]
// 
// 
// 
// INHERIT
// -------
// 
//                 thread 3->prio := 5
// 
//        3.  runs,
//        3.  set a flag to say "3-ran",
//        3.  loop with a sleep(1) until "go-flag" is set.
//        3.  check "got it" is false,
//        3.  then unlock mutex,
// 
//                 thread 3->prio := 15
// 
//        1.  runs, set a flag to say "got it",
//        1.  check "3-ended" flag is false
//        1.  unlock mutex,
//        1.  check "3-ended" flag is still false
//        1.  exit.
// 
//        [1a locks, unlocks, exits]
// 
//        2.  runs, check "3-ran" and "got it" flags are TRUE ****
//        2.  check "3-ended" flag is false
//        2.  sleeps for a while so that...
// 
//        [2a locks, unlocks, exits]
//            
//        3.  runs, set "3-ended" flag,
//        3.  check "3-ran" and "got it" flags
//        3.  exit
// 
//        [3a locks, unlocks, exits]
// 
//        2.  awakens, checks all flags true,
//        2.  check that all "extra" threads that we started have indeed run
//        2.  end of test.
// 
// 
// 
// 
// NO-INHERIT
// ----------
//                 thread 1 is waiting on the mutex
// 
//        [1a lock-fail]
// 
//        2.  runs, checks that "3-ran" and "got it" flags are FALSE ****
//        2.  check "3-ended" flag is false
//        2.  sleeps for a while so that...
// 
//        [2a. lock-fail]
//            
//        3.  runs, set a flag to say "3-ran",
//        3.  check "got it" is false,
//        3.  then unlock mutex,
// 
//        1.  runs, set a flag to say "got it",
//        1.  check "3-ended" flag is false
//        1.  unlock mutex,
//        1.  check "3-ended" flag is still false
//        1.  exit.
// 
//        [1a locks, unlocks, exits]
//        [2a locks, unlocks, exits]
// 
//        3.  runs, set "3-ended" flag,
//        3.  check "3-ran" and "got it" flags
//        3.  exit
// 
//        [3a locks, unlocks, exits]
//                
//        2.  awakens, checks all flags true, 
//        2.  check that all "extra" threads that we started have indeed run
//        2.  end of test.
// 
// 
// (the end)
// 
// 
// ------------------------------------------------------------------------

#endif

// EOF pmutex3.c
