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| woods2001 (2) |  |
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Hi,I'm Woods！ the function pthread_exit void pthread_exit(void *rval_ptr); will let the controlling thread exit with return value rval_ptr whose type is void *. And then we can get the return value by the function pthread_join int pthread_join(pthread_t thread,void **rval_ptr) So,if we do like this ,it is easy to understand in thread id=tid1 code: int i; i=1; pthread_exit((void *)&i); in main thread code: int *iret; pthread_join(tid1,(void *)&iret); printf("the return value of the thread tid1 is %d\n",(int)*i); but if we do like this in thread: pthread_exit((void *)0); and get the return value in main: void *tret; pthread_join(tid1,&tret); printf("%d",(int)tret); how to understand the pthread_exit((void *)0) expression and the procedure it does somebody help :) | |
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| kbw (3825) | |
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Don't pass the address of a local variable to pthread_exit. The local variable will be gone and the memory possibly reused, the value may have changed by the time you read it. Don't pass zero to pthread_exit as you have done. Your printf attempts to dereference address zero; which, in your case, is an error. Have you tried google for examples? http://publib.boulder.ibm.com/iseries/v5r2/ic2928/index.htm?info/apis/users_18.htm | |
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| woods2001 (2) | |
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thanks,KBW i forgot I used a local variable :int i; i will see the examples. | |
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pthread_exit((void *)0)