c - Second thread doesn't run until first is completed -

i'm trying implement producer/consumer type thing producer thread grabs characters out of string , puts them in circular linked list queue (5 nodes large) , consumer thread reads in characters , prints them screen. both threads stop when reach new line character. problem i'm having consumer thread never starts until producer thread terminates.

int consumer_thread_alive; ...  void * producer(struct node * head) {     while (consumer_thread_alive == 0)     {         printf("waiting on consumer.");     } ... }  void * consumer(struct node * head) {     consumer_thread_alive = 1; ... } ...  int main(int argc, char *argv[]) {     ...     consumer_thread_alive = 0;     pthread_t produce;     pthread_t consume;     printf("creating producer thread.\n");     pthread_create(&produce, null, (void *) producer(&head), null );     printf("creating consumer thread.\n");     pthread_create(&consume, null, (void *) consumer(&head), null );     pthread_join(produce,null);     pthread_join(consume,null);     return 1; } 

i cut out of other parts, thats i'm having trouble (head gets initialized earlier on in main). if run code prints out "creating producer thread." , continually prints out "waiting on consumer." until press ctrl+c , stop it. also, if remove loop in top of producer thread, run through of iterations , consumer thread gets called. whatever reason running serially instead of parallel.

change

pthread_create(&produce, null, (void *) producer(&head), null ); 

to be:

pthread_create(&produce, null, producer, &head); 

(same consumer)

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and: should test outcome of system calls!

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and^2: protect concurrent access consumer_thread_alive using mutex, example!

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and^3: thread function ougth have following form:

void * thread_func(void *); 

so implementation of producer's thread function may start like:

void * producer(void * pvhead) {   struct node * head = pvhead;   ... 

but aware, passing reference the same instance of struct node to both of threads, concurrent access inside thread functions needs protected (see and^2 above).