hw1.rar_memory

#include <stdio.h> #include <sys/shm.h> #include <sys/stat.h> #include <unistd.h> #include <sys/types.h> #define MAX_SEQUENCE 10 long fib(long n); typedef struct{ long fib_seq[MAX_SEQUENCE]; int seq_size; }shared_data; int main(int argc,char *argv[] ) { shared_data sd; sd.seq_size=atoi(argv[1]); if (argv==NULL) { printf("enter fib.sequence length(0...10)"); exit(0); } if (sd.seq_size>10||sd.seq_size<0) //if(sd.seq_size>=0&&sd.seq_size<=10) printf("%%"); //else { printf("entered number must be between 0-10\n"); fflush(stdin); exit(0); } int segment_id; long* shared_memory;//pointer to the shared mem.seg. const int size=sizeof(sd);//printf("%d bytes size\n",size);//size of shared mem.seg. segment_id=shmget(IPC_PRIVATE,size,S_IRUSR|S_IWUSR);//allocate a shared mem.seg. shared_memory=(long*) shmat(segment_id,NULL,0);//attach shared mem.seg. //sprintf(shared_memory,""); //sprintf(shared_memory,itoa(ss)); printf("%s\n",shared_memory);//print string from shared memory printf("shared mem.(fib.seq.)\n"); printf("====================\n"); pid_t child=fork(); if (child==0) { int i; for(i=0;i<=sd.seq_size;i++) { if (i==0||i==1) sd.fib_seq[i]=i; else sd.fib_seq[i]=sd.fib_seq[i-1]+sd.fib_seq[i-2]; *(shared_memory)=sd.fib_seq[i]; printf("%d\n",*(shared_memory)); shared_memory++; } printf("======================\n"); shmdt(shared_memory);//detach shared mem.segment. printf("child %d terminated\n",getpid()); }else if(child>0) { wait(); shmdt(shared_memory);//detach shared mem.seg. shmctl(segment_id,IPC_RMID,NULL);//remove the shared mem.seg. printf("father %d terminated\n",getpid()); }else { printf("error"); exit(0); } return 0; }