Hi,
I would like to create a boot time variable i.e a variable that is set once at
boot time. Variable
does not need to be globally accessible. (actually I am using two variables).
Could any one point me to examples of this already intree please?
I have tried the following but it has a race condition on the zero check and
assignment of randval/oddval.
/* Maps a pointer to a unique identifier. */
static char *ptr_to_id(char *buf, char *end, void *ptr, struct printf_spec spec)
{
long hashval;
static long randval = 0;
static long oddval = 0;
if (oddval == 0 && randval == 0) {
randval = get_random_long();
oddval = get_random_odd_long();
}
hashval = ptr_obfuscate((unsigned long)ptr, randval, oddval);
spec.base = 16;
return number(buf, end, hashval, spec);
}
And the compiler doesn't like
static long randval = get_random_long();
static long oddval = get_random_odd_long();
I thought of wrapping oddval/randval in a struct and protecting it with a lock
but I don't know
how/where to initialize the lock in a race free manner?
Any tips or pointers please?
thanks,
Tobin.
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