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/* ISC license. */
#include <errno.h>
#include <skalibs/avltreen.h>
#include "s6-ps.h"
typedef struct ptreeiter_s ptreeiter_t, *ptreeiter_t_ref ;
struct ptreeiter_s
{
unsigned int *childlist ;
unsigned int const *childindex ;
unsigned int const *ppindex ;
unsigned int *cpos ;
} ;
typedef struct pstuff_s pstuff_t, *pstuff_t_ref ;
struct pstuff_s
{
unsigned int *orderedlist ;
pscan_t *p ;
unsigned int const *childlist ;
unsigned int const *childindex ;
unsigned int const *nchild ;
} ;
static int fillchildlist (unsigned int i, unsigned int h, void *x)
{
ptreeiter_t *pt = x ;
unsigned int j = pt->ppindex[i] ;
pt->childlist[pt->childindex[j] + pt->cpos[j]++] = i ;
(void)h ;
return 1 ;
}
static void fillo_tree_rec (pstuff_t *blah, unsigned int root, signed int h)
{
static unsigned int j = 0 ;
unsigned int i = !blah->p[root].pid ;
if (blah->p[root].pid == 1) h = -1 ;
blah->p[root].height = (h > 0) ? h : 0 ;
blah->orderedlist[j++] = root ;
for (; i < blah->nchild[root] ; i++)
fillo_tree_rec(blah, blah->childlist[blah->childindex[root] + i], h+1) ;
}
/*
Fills up orderedlist with the right indices to print a process tree.
O(n log n) time, O(n) space, all in the stack.
*/
void s6ps_otree (pscan_t *p, unsigned int n, avltreen *pidtree, unsigned int *orderedlist)
{
unsigned int childlist[n] ;
unsigned int childindex[n] ;
unsigned int nchild[n] ;
unsigned int i = 0 ;
for (; i < n ; i++) nchild[i] = 0 ;
/* Compute the ppid tree */
for (i = 0 ; i < n ; i++)
{
unsigned int k ;
if (!avltreen_search(pidtree, &p[i].ppid, &k)) k = n-1 ;
orderedlist[i] = k ; /* using orderedlist as ppindex */
nchild[k]++ ;
}
{
unsigned int j = 0 ;
for (i = 0 ; i < n ; i++)
{
childindex[i] = j ;
j += nchild[i] ;
}
}
/* Fill the childlist by increasing pids so it is sorted */
{
unsigned int cpos[n] ;
ptreeiter_t blah = { .childlist = childlist, .childindex = childindex, .ppindex = orderedlist, .cpos = cpos } ;
for (i = 0 ; i < n ; i++) cpos[i] = 0 ;
avltreen_iter_nocancel(pidtree, avltreen_totalsize(pidtree), &fillchildlist, &blah) ;
}
/* If we have init, make it the last in the orphan list */
if (n > 1 && p[childlist[childindex[n-1]+1]].pid == 1)
{
unsigned int pos1 = childlist[childindex[n-1] + 1] ;
for (i = 2 ; i < nchild[n-1] ; i++)
childlist[childindex[n-1]+i-1] = childlist[childindex[n-1]+i] ;
childlist[childindex[n-1]+nchild[n-1]-1] = pos1 ;
}
/* Finally, fill orderedlist by walking the childindex tree. */
{
pstuff_t blah = { .orderedlist = orderedlist, .p = p, .childlist = childlist, .childindex = childindex, .nchild = nchild } ;
fillo_tree_rec(&blah, n-1, -1) ;
}
}
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