69 lines
1.5 KiB
C
69 lines
1.5 KiB
C
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#include <stdio.h>
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#include <stdlib.h>
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#include <sys/ipc.h>
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#include <sys/shm.h>
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#include <unistd.h>
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#include <sys/types.h>
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#include <sys/stat.h>
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int main()
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{
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unsigned long max = 1UL;
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unsigned long temp = 0UL;
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int shmId;
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for (max = 1; max < 10000000000000UL; max *= 2)
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{
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// Getting the shared memory segment.
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if ((shmId = shmget(IPC_PRIVATE, max, IPC_CREAT | S_IRUSR | S_IWUSR)) < 0)
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{
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temp = max;
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break;
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}
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// Flagging shared memory for deletion.
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if (shmctl(shmId, IPC_RMID, 0) < 0)
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{
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perror("can't deallocate\n");
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exit(1);
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}
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}
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for (max = temp / 2; max < temp; max += 67108864)
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{
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// Getting shared memory segment.
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if ((shmId = shmget(IPC_PRIVATE, max, IPC_CREAT | S_IRUSR | S_IWUSR)) < 0)
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{
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temp = max;
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break;
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}
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// Flagging shared memory for deletion.
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if (shmctl(shmId, IPC_RMID, 0) < 0)
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{
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perror("can't deallocate\n");
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exit(1);
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}
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}
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for (max = temp - 67108864; max < temp; max++)
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{
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// Getting the shared memory segment.
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if ((shmId = shmget(IPC_PRIVATE, max, IPC_CREAT | S_IRUSR | S_IWUSR)) < 0)
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{
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printf("Max value: %lu\n", max);
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exit(0);
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}
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// Flagging shared memory for deletion.
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if (shmctl(shmId, IPC_RMID, 0) < 0)
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{
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perror("can't deallocate\n");
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exit(1);
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}
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}
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return 0;
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}
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