In Figure 12.43, we might be tempted to free the allocated memory block immediately after line 14 in the main thread, instead of freeing it in the peer thread. But this would be a bad idea. Why?

Figure 12.43

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1 #include "csapp.h" 2 #define N 4 3 4 5 67 8 9 10 11 12 13 14 1567 18 19 20 21 22 23 24 25 26 27 28 void *thread (void *vargp); int main() { } pthread_t tid [N]; int i, *ptr; } for (i = 0; i < N; i++) { ptr Malloc(sizeof (int)); *ptr 1; Pthread_create(&tid[i], NULL, thread, ptr); = = } for (i = 0; i < N; i++) Pthread_join(tid[i], NULL); exit(0); /* Thread routine */ void *thread (void *vargp) { int myid*((int *)vargp); Free (vargp); printf("Hello from thread %d\n", myid); return NULL;