source: doc/papers/concurrency/examples/DatingServiceThread.cfa@ ec21f13

#include <stdlib.hfa>                                                                   // random
#include <fstream.hfa>
#include <kernel.hfa>
#include <thread.hfa>
#include <unistd.h>                                                                             // getpid

enum { CompCodes = 20 };                                                                // number of compatibility codes

thread DatingService {
        condition Girls[CompCodes], Boys[CompCodes];
        unsigned int girlPhoneNo, boyPhoneNo, ccode;
}; // DatingService

unsigned int girl( DatingService & mutex ds, unsigned int phoneno, unsigned int code ) with( ds ) {
        girlPhoneNo = phoneno;  ccode = code;
        wait( Girls[ccode] );                                                           // wait for boy
        girlPhoneNo = phoneno;
        sout | "Girl:" | girlPhoneNo | "is dating Boy at" | boyPhoneNo | "with ccode" | ccode;
        return boyPhoneNo;
} // DatingService girl

unsigned int boy( DatingService & mutex ds, unsigned int phoneno, unsigned int code ) with( ds ) {
        boyPhoneNo = phoneno;  ccode = code;
        wait( Boys[ccode] );                                                            // wait for girl
        boyPhoneNo = phoneno;
        sout | " Boy:" | boyPhoneNo | "is dating Girl" | girlPhoneNo | "with ccode" | ccode;
        return girlPhoneNo;
} // DatingService boy

void main( DatingService & ds ) with( ds ) {                    // thread starts
        for () {
                waitfor( ^?{} : ds ) {
                        break;
                } or waitfor( girl : ds ) {
                        if ( ! is_empty( Boys[ccode] ) ) {                      // no compatible boy ?
                                signal_block( Boys[ccode] );                    // restart boy to set phone number
                                signal_block( Girls[ccode] );                   // restart girl to set phone number
                        } // if
                } or waitfor( boy : ds ) {
                        if ( ! is_empty( Girls[ccode] ) ) {                     // no compatible girl ?
                                signal_block( Girls[ccode] );                   // restart girl to set phone number
                                signal_block( Boys[ccode] );                    // restart boy to set phone number
                        } // if
                }
        }
} // DatingService main

unsigned int girlck[CompCodes];
unsigned int boyck[CompCodes];

thread Girl {
        DatingService & TheExchange;
        unsigned int id, ccode;
}; // Girl

void main( Girl & g ) with( g ) {
        yield( random( 100 ) );                                                         // do not start at the same time
        unsigned int partner = girl( TheExchange, id, ccode );
        girlck[id] = partner;
} // Girl main

void ?{}( Girl & g, DatingService * TheExchange, unsigned int id, unsigned int ccode ) {
        &g.TheExchange = TheExchange;
        g.id = id;
        g.ccode = ccode;
} // Girl ?{}

thread Boy {
        DatingService & TheExchange;
        unsigned int id, ccode;
}; // Boy

void main( Boy & b ) with( b ) {
        yield( random( 100 ) );                                                         // don't all start at the same time
        unsigned int partner = boy( TheExchange, id, ccode );
        boyck[id] = partner;
} // Boy main

void ?{}( Boy & b, DatingService * TheExchange, unsigned int id, unsigned int ccode ) {
        &b.TheExchange = TheExchange;
        b.id = id;
        b.ccode = ccode;
} // Boy ?{}

int main() {
        DatingService TheExchange;
        Girl * girls[CompCodes];
        Boy  * boys[CompCodes];

        srandom( /*getpid()*/ 103 );

        for ( i; (unsigned int)CompCodes ) {
                girls[i] = new( &TheExchange, i, i );                   // TheExchange constructor needs unsigned int
                boys[i]  = new( &TheExchange, i, CompCodes - ( i + 1 ) );
        } // for

        for ( i; CompCodes ) {
                delete( boys[i] );
                delete( girls[i] );
        } // for

        for ( i; CompCodes ) {
                if ( girlck[ boyck[i] ] != boyck[ girlck[i] ] ) abort();
        } // for
} // main

// Local Variables: //
// tab-width: 4 //
// compile-command: "cfa DatingServiceThread.cfa" //
// End: //