diff options
| -rw-r--r-- | lib/qpselect.c | 40 | ||||
| -rw-r--r-- | lib/qpselect.h | 2 |
2 files changed, 28 insertions, 14 deletions
diff --git a/lib/qpselect.c b/lib/qpselect.c index a281a61d..7df59752 100644 --- a/lib/qpselect.c +++ b/lib/qpselect.c @@ -132,7 +132,6 @@ qps_selection_init_new(qps_selection qps) * * files -- empty vector * - * fd_last -- unset * enabled_count -- no fd's enabled in any mode * enabled -- empty bit vectors * @@ -147,8 +146,9 @@ qps_selection_init_new(qps_selection qps) * signum -- no signal to be enabled * sigmask -- unset * - * So nothing else to do -- see also qps_selection_re_init(), below. + * So nothing much else to do -- see also qps_selection_re_init(), below. */ + qps->fd_last = -1 ; /* not an fd in sight. */ return qps ; } ; @@ -159,6 +159,8 @@ static void qps_selection_re_init(qps_selection qps) { memset(qps, 0, sizeof(struct qps_selection)) ; + + qps->fd_last = -1 ; /* not an fd in sight. */ } ; /* Add given file to the selection, setting its fd and pointer to further @@ -309,16 +311,21 @@ qps_pselect(qps_selection qps, qtime_mono_t timeout) /* Prepare the argument/result bitmaps */ /* Capture pend_mnum and tried_count[] */ - n = fd_byte_count[qps->fd_last] ; /* copy up to last sig. byte */ + n = (qps->fd_last >= 0) + ? fd_byte_count[qps->fd_last] /* copy up to last sig. byte */ + : 0 ; qps->pend_mnum = qps_mnum_count ; for (mnum = 0 ; mnum < qps_mnum_count ; ++mnum) if ((qps->tried_count[mnum] = qps->enabled_count[mnum]) != 0) { + dassert(n != 0) ; /* n == 0 => no fds ! */ + memcpy(&(qps->results[mnum].bytes), &(qps->enabled[mnum].bytes), n) ; p_fds[mnum] = &(qps->results[mnum].fdset) ; + if (mnum < qps->pend_mnum) - qps->pend_mnum = mnum ; + qps->pend_mnum = mnum ; /* collect first active mode */ } else p_fds[mnum] = NULL ; @@ -347,11 +354,12 @@ qps_pselect(qps_selection qps, qtime_mono_t timeout) return qps->pend_count = n ; /* set and return pending count */ } ; + /* Nothing pending at all */ + qps->pend_count = 0 ; /* qps_dispatch_next() does nothing */ + /* Flush the results vectors -- not apparently done if n <= 0) */ qps_super_set_zero(qps->results, qps_mnum_count) ; - qps->pend_count = 0 ; /* nothing pending */ - /* Return appropriately, if we can */ if ((n == 0) || (errno == EINTR)) return n ; @@ -372,6 +380,10 @@ qps_pselect(qps_selection qps, qtime_mono_t timeout) * removes it from the selection. * * Returns the number of files left to process (after the one just processed). + * + * NB: clears result bits as it finds them -- so at end of process, the + * result bit vectors should be zeroised again. Also, this allows the + * search to proceed from the last known fd -- won't find it again ! */ int qps_dispatch_next(qps_selection qps) @@ -386,12 +398,13 @@ qps_dispatch_next(qps_selection qps) if (qps->pend_count == 0) return 0 ; /* quit immediately of nothing to do. */ - fd = qps->pend_fd ; - mnum = qps->pend_mnum ; + fd = qps->pend_fd ; /* look for fd >= this */ + mnum = qps->pend_mnum ; /* starting with this mode */ dassert( (mnum >= 0) && (mnum < qps_mnum_count) && (qps->tried_count[mnum] != 0) - && (qps->pend_count > 0) ) ; + && (qps->pend_count > 0) + && (qps->tried_fd_last >= 0)) ; while (1) { @@ -733,10 +746,9 @@ qps_file_remove(qps_selection qps, qps_file qf) dassert(qps->fd_count > 0) ; --qps->fd_count ; - dassert( ((qps->fd_count != 0) && (fd_last >= 0)) || - ((qps->fd_count == 0) && (fd_last < 0)) ) ; + dassert(fd_last >= (qps->fd_count - 1)) ; - qps->fd_last = (fd_last >= 0) ? fd_last : 0 ; + qps->fd_last = fd_last ; /* Also, remove the from all vectors. */ qps_disable_modes(qf, qps_all_mbits) ; @@ -850,6 +862,8 @@ qps_next_fd_pending(fd_super_set* pending, int fd, int fd_last) { uint8_t b ; + dassert((fd >= 0) && (fd <= fd_last)) ; + while (pending->words[fd_word_map[fd]] == 0) /* step past zero words */ { fd = (fd & ~ (FD_WORD_BITS - 1)) + FD_WORD_BITS ; @@ -1247,7 +1261,7 @@ qps_selection_validate(qps_selection qps) zabort("Number of files in the selection does not tally") ; /* 6) check the last fd */ - if ( ((n == 0) && (qps->fd_last !=0)) || (fd_last != qps->fd_last) ) + if ( (qps->fd_last < (n - 1)) || (fd_last != qps->fd_last) ) zabort("The last fd does not tally") ; /* 7) check that the enabled counts tally. */ diff --git a/lib/qpselect.h b/lib/qpselect.h index aec56c38..538ebf68 100644 --- a/lib/qpselect.h +++ b/lib/qpselect.h @@ -131,7 +131,7 @@ struct qps_selection struct vector files ; /* mapping fd to qps_file */ - int fd_last ; /* highest numbered fd we are looking after */ + int fd_last ; /* highest numbered fd; -1 => none at all */ int enabled_count[qps_mnum_count] ; /* no. enabled fds in each mode */ fd_full_set enabled ; /* bit vectors for pselect enabled stuff */ |