作业-使用信号量和互斥体排队

Question

...SO I fixed it a bit, but it says now ... Test of acceleration: Program acrossed time limit... Duration: 5 sec !(limit 8 sec)!... Here is my code if anyone had any ideas...

#ifndef __PROGTEST__
#include <stdio.h>
#include <stdlib.h>
#include <pthread.h>
#include <semaphore.h>

#define MAX_TERRORISTS   32

typedef struct TImage
 {
   int              m_W;
   int              m_H;
   unsigned char ** m_Data;
 } TIMAGE;

void  TerroristHunter    ( int        databaseSize,
                           TIMAGE  ** database,
                           int        threads,
                           TIMAGE *(* scanner) ( void ),
                           void    (* officer) ( TIMAGE *, int ) );
#endif /* __PROGTEST__ */


/* Vase implementace / your implementation here */
pthread_mutex_t m1;

typedef struct Par {
TIMAGE *(* scanner) ( void );
TIMAGE ** terrorist;
int number_of_terrorists;
void ( *officer) ( TIMAGE *, int );} PAR;

void * function ( void * arg ) {

PAR * a = ( PAR * ) arg;
TIMAGE * image;
int i1, i2, i3, i4, i5, result = 0;

while ( 1 ) {
pthread_mutex_lock ( & m1 );
if (( image = a->scanner()) == NULL ) {pthread_mutex_unlock ( & m1 );break;}
pthread_mutex_unlock ( & m1 );
for ( i5 = 0; i5 < a->number_of_terrorists; i5 ++ ) {
    for ( i1 = 0; i1 <= ( image->m_H - a->terrorist[i5]->m_H ); i1 ++ ) {
        for ( i2 = 0; i2 <= ( image->m_W - a->terrorist[i5]->m_W ); i2 ++ ) {
            if ( ( a->terrorist[i5]->m_Data[0][0] == image->m_Data[i1][i2] ) || ( a->terrorist[i5]->m_Data[0][0] == 255 ) ) {
            for ( i3 = 0; i3 < a->terrorist[i5]->m_H; i3 ++ ) {
                for ( i4 = 0; i4 < a->terrorist[i5]->m_W; i4 ++ ) 
                    if ( ( a->terrorist[i5]->m_Data[i3][i4]!= image->m_Data[i1 + i3][i2 + i4] ) && ( a->terrorist[i5]->m_Data[i3][i4] != 255 ) )
                        break;
                if ( i4 != a->terrorist[i5]->m_W )
                    break; }
            if ( i3 == a->terrorist[i5]->m_H ) {
                result = result + ( 1 << i5 );
                break; } } }
        if ( i3 == a->terrorist[i5]->m_H )
            break; } }
a->officer ( image, result );
result = 0;}
return NULL;
}

void  TerroristHunter    ( int        databaseSize,
                           TIMAGE  ** database,
                           int        threads,
                           TIMAGE *(* scanner) ( void ),
                           void    (* officer) ( TIMAGE *, int ) ) {
PAR * pom = ( PAR * ) malloc ( sizeof ( * pom ) );
int i;

pthread_t * thr = ( pthread_t * ) malloc ( threads * sizeof( * thr ) );
pthread_attr_t Attr; pthread_attr_init ( & Attr ); pthread_attr_setdetachstate ( & Attr, PTHREAD_CREATE_JOINABLE );
pthread_mutex_init ( & m1, NULL );

pom->terrorist = database;
pom->number_of_terrorists = databaseSize;
pom->officer = officer;
pom->scanner = scanner;

for ( i = 0; i < threads; i ++ )
    pthread_create ( & thr[i], & Attr, function, (void * ) pom );
for ( i = 0; i < threads; i ++ )
    pthread_join (thr[i], NULL);

pthread_attr_destroy ( & Attr); pthread_mutex_destroy ( & m1 );
free ( pom );
return; }
#ifndef __PROGTEST__
unsigned char t0r0[] = { 255, 255, 255, 255, 255, 255, 255, 255 };
unsigned char t0r1[] = { 255,  50,  60,  70, 255, 255, 255, 255 };
unsigned char t0r2[] = { 255,  50,  60,  70, 255, 255, 255, 255 };
unsigned char t0r3[] = { 255, 255,  50,  60,  70,  80, 255, 255 };
unsigned char t0r4[] = { 255, 255,  50,  60,  70,  80, 255, 255 };
unsigned char t0r5[] = { 255, 255, 255, 255, 255, 255, 255, 255 };
unsigned char t0r6[] = { 255, 255, 255, 255, 255, 255, 255, 255 };
unsigned char * t0all[] = { t0r0, t0r1, t0r2, t0r3, t0r4, t0r5, t0r6 };
TIMAGE  t0 = { 8, 7, t0all };  /* one sample */

unsigned char t1r0[] = {  10,  20,  30 };
unsigned char t1r1[] = {  20,  50, 255 };
unsigned char t1r2[] = {  80,  50, 255 };
unsigned char * t1all[] = { t1r0, t1r1, t1r2 };
TIMAGE  t1 = { 3, 3, t1all };  /* another sample */

TIMAGE * terrorists[2] = { &t0, &t1};

unsigned char i0r0[] = {   1,   2,   3,   4,   5,   6,   7,   8 };
unsigned char i0r1[] = {   2,  50,  60,  70,   6,   7,   8,   1 };
unsigned char i0r2[] = {   3,  50,  60,  70,   7,  10,  20,  30 };
unsigned char i0r3[] = {   4,  50,  60,  70,   8,  20,  50,   3 };
unsigned char i0r4[] = {   5,   6,  50,  60,  70,  80,  50,   4 };
unsigned char i0r5[] = {   6,   7,  50,  60,  70,  80,   4,   5 };
unsigned char i0r6[] = {   7,   8,   1,   2,   3,   4,   5,   6 };
unsigned char i0r7[] = {   8,   1,   2,   3,   4,   5,   6,   7 };
unsigned char * i0all[] = { i0r0, i0r1, i0r2, i0r3, i0r4, i0r5, i0r6, i0r7 };
TIMAGE i0 = { 8, 8, i0all }; /* t0 and t1 here */

unsigned char i1r0[] = {   1,   2,   3,   4,   5,   6,   7,   8 };
unsigned char i1r1[] = {   2,   3,   4,   5,   6,   7,   8,   1 };
unsigned char i1r2[] = {   3,   4,   5,   6,   7,   8,   1,   2 };
unsigned char i1r3[] = {  10,  20,  30,   7,   8,   1,   2,   3 };
unsigned char i1r4[] = {  20,  50,   7,   8,   1,   2,   3,   4 };
unsigned char i1r5[] = {  80,  50,   8,   1,   2,   3,   4,   5 };
unsigned char i1r6[] = {   7,   8,   1,   2,   3,   4,   5,   6 };
unsigned char * i1all[] = { i1r0, i1r1, i1r2, i1r3, i1r4, i1r5, i1r6 };
TIMAGE i1 = { 8, 7, i1all }; /* t1 here */

unsigned char i2r0[] = {   1,  50,  60,  70,   5,   6 };
unsigned char i2r1[] = {   2,  50,  60,  70,   6,   7 };
unsigned char i2r2[] = {   3,   4,  50,  60,  70,  80 };
unsigned char i2r3[] = {  10,  20,  50,  50,  70,  81 };
unsigned char i2r4[] = {  20,  50,   7,   8,   1,   2 };
unsigned char * i2all[] = { i2r0, i2r1, i2r2, i2r3, i2r4 };
TIMAGE i2 = { 6, 5, i2all }; /* no terrorists here */

TIMAGE * scans[3] = { &i0, &i1, &i2 };

TIMAGE   * dummyScanner ( void )
 {
   static int idx = 0;

   if ( idx < 3 ) return ( scans[idx ++] );
   return ( NULL );
 }

void       dummyOfficer  ( TIMAGE * img, int found )
 {
   int i;

   printf ( "Image: %d x %d  ", img -> m_W, img -> m_H );
   if ( found )
    {
      printf ( "TERRORISTS:" );
      for ( i = 0; i < (int)sizeof ( found ) * 8; i ++ )
       if ( found & ( 1 << i ) )
        printf ( " %d", i );
      printf ( "\n" );
    }
   else
    printf ( "no terrorists found\n" );
 }

int main ( int argc, char * argv[] )
 {
   TerroristHunter ( 2, terrorists, 20, dummyScanner, dummyOfficer );
   return ( 0 );
 }
#endif /* __PROGTEST__ */

Answer 1

Starvation is not an issue because when scanner() returns NULL, the thread will end.

Therefore it seems to me the problem is when PROGTEST is defined. In other words, there is something wrong elsewhere in your program not listed here; possibly with the scanner() and/or officer() functions.