source: src/tests/concurrent/signal/wait.c@ 8eb2018

//---------------------------------------------------------
// Multi wait test
// Ensures that no deadlock from waiting/signalling conditions
//---------------------------------------------------------


#include <fstream>
#include <kernel>
#include <monitor>
#include <stdlib>
#include <thread>

#include <time.h>

#ifdef LONG_TEST
static const unsigned long N = 375_000ul;
#else
static const unsigned long N = 2_500ul;
#endif

#ifndef PREEMPTION_RATE
#define PREEMPTION_RATE 10_000ul
#endif

unsigned int default_preemption() {
        return PREEMPTION_RATE;
}

monitor global_t {};

global_t globalA;
global_t globalB;
global_t globalC;

condition condAB, condAC, condBC, condABC;

thread Signaler {};
thread WaiterAB {};
thread WaiterAC {};
thread WaiterBC {};
thread WaiterABC{};

volatile int waiter_left;

//----------------------------------------------------------------------------------------------------
// Tools
void signal( condition & cond, global_t & mutex a, global_t & mutex b ) {
        signal( cond );
}

void signal( condition & cond, global_t & mutex a, global_t & mutex b, global_t & mutex c ) {
        signal( cond );
}

void wait( condition & cond, global_t & mutex a, global_t & mutex b ) {
        wait( cond );
}

void wait( condition & cond, global_t & mutex a, global_t & mutex b, global_t & mutex c ) {
        wait( cond );
}

//----------------------------------------------------------------------------------------------------
// Signaler
void main( Signaler & this ) {

        while( waiter_left != 0 ) {
                unsigned action = random( 4 );
                switch( action ) {
                        case 0:
                                signal( condABC, globalA, globalB, globalC );
                                break;
                        case 1:
                                signal( condAB , globalA, globalB );
                                break;
                        case 2:
                                signal( condBC , globalB, globalC );
                                break;
                        case 3:
                                signal( condAC , globalA, globalC );
                                break;
                        default:
                                sout | "Something went wrong" | endl;
                                abort();
                }
                yield();
        }
}

//----------------------------------------------------------------------------------------------------
// Waiter ABC
void main( WaiterABC & this ) {
        for( int i = 0; i < N; i++ ) {
                wait( condABC, globalA, globalB, globalC );
        }

        __sync_fetch_and_sub_4( &waiter_left, 1);
}

//----------------------------------------------------------------------------------------------------
// Waiter AB
void main( WaiterAB & this ) {
        for( int i = 0; i < N; i++ ) {
                wait( condAB , globalA, globalB );
        }

        __sync_fetch_and_sub_4( &waiter_left, 1);
}

//----------------------------------------------------------------------------------------------------
// Waiter AC
void main( WaiterAC & this ) {
        for( int i = 0; i < N; i++ ) {
                wait( condAC , globalA, globalC );
        }

        __sync_fetch_and_sub_4( &waiter_left, 1);
}

//----------------------------------------------------------------------------------------------------
// Waiter BC
void main( WaiterBC & this ) {
        for( int i = 0; i < N; i++ ) {
                wait( condBC , globalB, globalC );
        }

        __sync_fetch_and_sub_4( &waiter_left, 1);
}

//----------------------------------------------------------------------------------------------------
// Main
int main(int argc, char* argv[]) {
        srandom( time( NULL ) );
        waiter_left = 4;
        processor p[2];
        sout | "Starting" | endl;
        {
                Signaler  e;
                {
                        WaiterABC a;
                        WaiterAB  b;
                        WaiterBC  c;
                        WaiterAC  d;
                }
        }
        sout | "Done" | endl;
}