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POC pthread and struct questions
 

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  1. POC pthread and struct questions
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    <p>Basic function of this code is to get number of counter and thread, creates the counters then create the threads then get numbers of instructions in each thread (format of instruction [counter] [work-function] [repetition] )</p> <pre><code>/* ============================================================================ * File-global variables * ========================================================================== */ static int ncounters = 0; static struct counter *counters = NULL; static int nthreads = 0; static int *ninstructions = NULL; static struct instruction **instructions = NULL; struct counter { long long counter; /* to store counter */ }; /* counter value */ struct instruction { struct counter *counter; /* pointer to counter */ int repetitions; /* number of repetitions */ void (*work_fn)(long long *); /* function pointer to work function */ }; /* ============================================================================ * Thread function * ========================================================================== */ static void * worker_thread(void *arg) { (void)arg; int Tcounter; int Trepetition; char Tfuntion; scanf(" %d %c %d", &amp;Tcounter, &amp;Tfuntion, &amp;Trepetition); </code></pre> <p>How do I actually store this three variable using struct instruction **instructions???</p> <pre><code> return NULL; } /* ============================================================================ * Main function * ========================================================================== */ int main(void) { scanf(" %d", &amp;ncounters); int i; if(counters = malloc(sizeof(struct counter)*ncounters)){ for( i=0; i &lt; ncounters ;i++){ counters[i].counter = 0; } for( i=0; i &lt; ncounters ;i++){ printf("%lld\n", counters[i].counter); } } scanf(" %d", &amp;nthreads); pthread_t threads[nthreads]; int ninst; for( i=0; i &lt; nthreads ;i++){ scanf(" %d", &amp;ninst); ninstructions = ninst; for( i=0; i &lt; ninstructions ;i++){ pthread_create(&amp;threads[i], NULL, worker_thread, NULL); } } free(counters); return 0; } </code></pre> <p>Is the pthread_create function correct?</p> <pre><code>int main(void) { scanf(" %d", &amp;ncounters); int i; if(counters = malloc(sizeof(struct counter)*ncounters)){ for( i=0; i &lt; ncounters ;i++){ counters[i].counter = 0; } } scanf(" %d", &amp;nthreads); pthread_t threads[nthreads]; if(ninstructions = (int*)malloc(nthreads*sizeof(int)){ for( i=0; i &lt; nthreads ;i++){ scanf(" %d", &amp;ninstructions[i]); int j; for(j=0; i &lt; ninstructions[i] ;j++){ pthread_create(&amp;threads[j], NULL, worker_thread, NULL); } } } free(ninstructions); free(counters); return 0; } </code></pre> <p>I also tried to change the ninstruction into array, if its correct...</p>
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    1. COwhere do you want to store what? you have to pass the correct struct to the thread somehow (and then take care of synchromization)
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    2. COI want to store the instruction into struct instruction by using struct instruction **instruction format. say input is 1 D 10, I want a instruction structure stored as counter = 1 , work_fn = Increment , reptitions = 10.
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    3. COwell, to access a struct instruction** ppData would be (*ppData)->repetitions .
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      1. USMario The Spoon
 

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