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       random_r,  srandom_r, initstate_r, setstate_r - reentrant random number


       #include <stdlib.h>

       int random_r(struct random_data *buf, int32_t *result);

       int srandom_r(unsigned int seed, struct random_data *buf);

       int initstate_r(unsigned int seed, char *statebuf,
                       size_t statelen, struct random_data *buf);
       int setstate_r(char *statebuf, struct random_data *buf);

   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

       random_r(), srandom_r(), initstate_r(), setstate_r(): _SVID_SOURCE ||


       These   functions  are  the  reentrant  equivalents  of  the  functions
       described in random(3).  They are suitable  for  use  in  multithreaded
       programs where each thread needs to obtain an independent, reproducible
       sequence of random numbers.

       The random_r() function is like random(3), except that instead of using
       state  information  maintained  in a global variable, it uses the state
       information in the argument pointed to by buf.   The  generated  random
       number is returned in the argument result.

       The srandom_r() function is like srandom(3), except that it initializes
       the seed for the random number generator whose state is  maintained  in
       the  object  pointed to by buf, instead of the seed associated with the
       global state variable.

       The  initstate_r()  function  is  like  initstate(3)  except  that   it
       initializes  the  state  in  the  object pointed to by buf, rather than
       initializing the global state variable.

       The setstate_r() function is like setstate(3) except that  it  modifies
       the  state  in  the object pointer to by buf, rather than modifying the
       global state variable.


       All of these functions return 0 on success, or -1 on error.


       EINVAL A  state  array  of  less  than  8  bytes   was   specified   to

       EINVAL The statebuf or buf argument to setstate_r() was NULL.

       EINVAL The buf or result argument to random_r() was NULL.


       These functions are nonstandard glibc extensions.


       drand48(3), rand(3), random(3)


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