diff options
| -rw-r--r-- | src/s6-rc/s6-rc-update.c | 50 |
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 ; } } |