none/tests/linux/mremap6.c

   1 #define _GNU_SOURCE
   2 #include <stdio.h>
   3 #include <stdlib.h>
   4 #include <assert.h>
   5 #include <sys/ipc.h>
   6 #include <sys/shm.h>
   7 #include <sys/stat.h>
   8 #include <sys/mman.h>
   9
  10 static void *mkmap(unsigned sz)
  11 {
  12   int shmid = shmget(IPC_PRIVATE, sz,
  13                      IPC_CREAT | IPC_EXCL | S_IRUSR | S_IWUSR);
  14   assert(shmid != -1);
  15
  16   void *addr = shmat(shmid, NULL, 0);
  17   assert(addr != (void *)-1);
  18
  19   return addr;
  20 }
  21
  22 int main()
  23 {
  24   void *np, *p;
  25
  26   p  = mkmap(1024*1024);
  27   np = mremap(p, 1024*1024, 2048*1024, MREMAP_MAYMOVE); /* grow, maymove */
  28   assert(np != (void *)-1);
  29
  30   return 0;
  31 }