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-rw-r--r--src/s6-rc/s6-rc-update.c50
1 files changed, 39 insertions, 11 deletions
diff --git a/src/s6-rc/s6-rc-update.c b/src/s6-rc/s6-rc-update.c
index 5f8596e..6704e93 100644
--- a/src/s6-rc/s6-rc-update.c
+++ b/src/s6-rc/s6-rc-update.c
@@ -41,7 +41,8 @@ static unsigned int verbosity = 1 ;
/* Conversions and transitions */
- /* oldstate flags:
+ /*
+ oldstate flags:
1 -> is up
2 -> wanted down
4 -> restart
@@ -50,13 +51,14 @@ static unsigned int verbosity = 1 ;
32 -> wanted down after closure
64 -> appears in convfile
- newstate flags:
+ newstate flags:
1 -> is up (converted from old up)
2 -> wanted up
4 -> is a bijective conversion target
8 -> is a conversion target
16 -> changed names
32 -> is up after closure (i.e. includes new deps)
+ 128 -> depends on a new service, has to be restarted
*/
static inline void parse_line (stralloc *sa, char const *s, unsigned int slen, unsigned int *newnames, unsigned char *oldstate, cdb_t *oldc, s6rc_db_t const *olddb)
@@ -223,10 +225,11 @@ static void compute_transitions (char const *convfile, unsigned char *oldstate,
{
unsigned int oldn = olddb->nshort + olddb->nlong ;
unsigned int newn = newdb->nshort + newdb->nlong ;
+ unsigned int newm = bitarray_div8(newn) ;
unsigned int oldindex[oldn] ;
unsigned int sabase = sa->len ;
- unsigned char conversion_table[oldn * bitarray_div8(newn)] ;
- byte_zero(conversion_table, oldn * bitarray_div8(newn)) ;
+ unsigned char conversion_table[oldn * newm] ;
+ byte_zero(conversion_table, oldn * newm) ;
stuff_with_oldc(oldstate, fdoldc, olddb, convfile, oldindex, sa) ;
stuff_with_newc(fdnewc, newfn, conversion_table, oldstate, newstate, sa->s + sabase, oldindex, invimage, olddb, newdb) ;
sa->len = sabase ;
@@ -234,32 +237,57 @@ static void compute_transitions (char const *convfile, unsigned char *oldstate,
for (;;)
{
int done = 1 ;
- unsigned int i = oldn ;
+ unsigned int i = newn ;
+ while (i--) newstate[i] &= 28 ;
+
+ /*
+ If an old service needs to restart, mark it wanted down, as well
+ as everything that depends on it.
+ */
+
+ i = oldn ;
while (i--)
{
- if (oldstate[i] & 1 && (oldstate[i] & 4 || !(oldstate[i] & 8))) oldstate[i] |= 34 ;
+ if (oldstate[i] & 1 && (oldstate[i] & 4 || !(oldstate[i] & 8)))
+ oldstate[i] |= 34 ;
else oldstate[i] &= 221 ;
}
s6rc_graph_closure(olddb, oldstate, 5, 0) ;
- i = newn ; while (i--) newstate[i] &= 28 ;
+
+
+ /*
+ Convert the old state to the new state: if an old service is up,
+ the new service will be either up or wanted up.
+ This part runs in O(oldn*newn). There are no syscalls in the loop,
+ so it should still be negligible unless you have 10k services.
+ */
+
i = oldn ;
while (i--) if (oldstate[i] & 1)
{
register unsigned int j = newn ;
- while (j--) if (bitarray_peek(conversion_table + i * bitarray_div8(newn), j))
+ while (j--) if (bitarray_peek(conversion_table + i * newm, j))
newstate[j] |= (oldstate[i] & 32) ? 2 : 33 ;
}
+
+
+ /*
+ Check for new dependencies. If a new service is still up but depends on a
+ new service that is not, it has to be restarted. Mark the old service for
+ restart and loop until there are no new dependencies.
+ */
+
s6rc_graph_closure(newdb, newstate, 5, 1) ;
i = newn ;
while (i--) if ((newstate[i] & 33) == 32)
{
done = 0 ;
- newstate[i] |= 4 ;
+ newstate[i] |= 128U ;
}
if (done) break ;
- s6rc_graph_closure(newdb, newstate, 2, 0) ;
+ s6rc_graph_closure(newdb, newstate, 7, 0) ;
i = newn ;
- while (i--) if ((newstate[i] & 5) == 5) oldstate[invimage[i]] |= 4 ;
+ while (i--) if ((newstate[i] & 129U) == 129U) oldstate[invimage[i]] |= 4 ;
}
}