diff options
author | yokota <yokota@FreeBSD.org> | 1999-07-07 13:48:50 +0000 |
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committer | yokota <yokota@FreeBSD.org> | 1999-07-07 13:48:50 +0000 |
commit | dde3bd678dd648c47f2136b10cbf07f754e3be4c (patch) | |
tree | b2eb9e67839a34f3c1138f9f2f6dce5ffb8f8e4d /sys/dev/syscons/schistory.c | |
parent | de9b240dd7c3c1a682e04673eb1c25d2ef8c4cc5 (diff) | |
download | FreeBSD-src-dde3bd678dd648c47f2136b10cbf07f754e3be4c.zip FreeBSD-src-dde3bd678dd648c47f2136b10cbf07f754e3be4c.tar.gz |
- Fixed memory leak in sc_alloc_history_buffer().
- Correctly observe the variable `extra_history_size' when changing
the size of history (scroll back) buffer.
- Added sc_free_history_buffer().
Pointed out by: des
Diffstat (limited to 'sys/dev/syscons/schistory.c')
-rw-r--r-- | sys/dev/syscons/schistory.c | 82 |
1 files changed, 66 insertions, 16 deletions
diff --git a/sys/dev/syscons/schistory.c b/sys/dev/syscons/schistory.c index 765733c..433182d 100644 --- a/sys/dev/syscons/schistory.c +++ b/sys/dev/syscons/schistory.c @@ -26,7 +26,7 @@ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. * - * $Id:$ + * $Id: schistory.c,v 1.1 1999/06/22 14:13:26 yokota Exp $ */ #include "sc.h" @@ -68,7 +68,7 @@ static void history_to_screen(scr_stat *scp); /* allocate a history buffer */ int -sc_alloc_history_buffer(scr_stat *scp, int lines, int wait) +sc_alloc_history_buffer(scr_stat *scp, int lines, int prev_ysize, int wait) { /* * syscons unconditionally allocates buffers upto @@ -77,38 +77,82 @@ sc_alloc_history_buffer(scr_stat *scp, int lines, int wait) * subject to extra_history_size. */ sc_vtb_t *history; + sc_vtb_t *prev_history; int cur_lines; /* current buffer size */ int min_lines; /* guaranteed buffer size */ + int delta; /* lines to put back */ if (lines <= 0) lines = SC_HISTORY_SIZE; /* use the default value */ + + /* make it at least as large as the screen size */ lines = imax(lines, scp->ysize); - min_lines = imax(SC_HISTORY_SIZE, scp->ysize); - history = scp->history; + /* remove the history buffer while we update it */ + history = prev_history = scp->history; scp->history = NULL; - if (history == NULL) { - cur_lines = 0; - } else { + + /* calculate the amount of lines to put back to extra_history_size */ + delta = 0; + if (prev_history) { cur_lines = sc_vtb_rows(history); + min_lines = imax(SC_HISTORY_SIZE, prev_ysize); if (cur_lines > min_lines) - extra_history_size += cur_lines - min_lines; - sc_vtb_destroy(history); + delta = cur_lines - min_lines; } - if (lines > min_lines) - extra_history_size -= lines - min_lines; - history = (sc_vtb_t *)malloc(sizeof(*history), - M_DEVBUF, (wait) ? M_WAITOK : M_NOWAIT); - if (history != NULL) + /* lines upto min_lines are always allowed. */ + min_lines = imax(SC_HISTORY_SIZE, scp->ysize); + if (lines > min_lines) { + if (lines - min_lines > extra_history_size + delta) { + /* too many lines are requested */ + scp->history = prev_history; + return EINVAL; + } + } + + /* destroy the previous buffer and allocate a new one */ + if (prev_history == NULL) { + history = (sc_vtb_t *)malloc(sizeof(*history), + M_DEVBUF, + (wait) ? M_WAITOK : M_NOWAIT); + } else { + extra_history_size += delta; + sc_vtb_destroy(prev_history); + } + if (history != NULL) { + if (lines > min_lines) + extra_history_size -= lines - min_lines; sc_vtb_init(history, VTB_RINGBUFFER, scp->xsize, lines, NULL, wait); + } + scp->history_pos = 0; scp->history = history; return 0; } +void +sc_free_history_buffer(scr_stat *scp, int prev_ysize) +{ + sc_vtb_t *history; + int cur_lines; /* current buffer size */ + int min_lines; /* guaranteed buffer size */ + + history = scp->history; + scp->history = NULL; + if (history == NULL) + return; + + cur_lines = sc_vtb_rows(history); + min_lines = imax(SC_HISTORY_SIZE, prev_ysize); + extra_history_size += (cur_lines > min_lines) ? cur_lines - min_lines : 0; + + sc_vtb_destroy(history); + free(history, M_DEVBUF); +} + /* copy entire screen into the top of the history buffer */ void sc_hist_save(scr_stat *scp) @@ -200,6 +244,7 @@ sc_hist_ioctl(struct tty *tp, u_long cmd, caddr_t data, int flag, struct proc *p) { scr_stat *scp; + int error; switch (cmd) { @@ -209,9 +254,14 @@ sc_hist_ioctl(struct tty *tp, u_long cmd, caddr_t data, int flag, return EINVAL; if (scp->status & BUFFER_SAVED) return EBUSY; - return sc_alloc_history_buffer(scp, + DPRINTF(5, ("lines:%d, ysize:%d, pool:%d\n", + *(int *)data, scp->ysize, extra_history_size)); + error = sc_alloc_history_buffer(scp, imax(*(int *)data, scp->ysize), - TRUE); + scp->ysize, TRUE); + DPRINTF(5, ("error:%d, rows:%d, pool:%d\n", error, + sc_vtb_rows(scp->history), extra_history_size)); + return error; } return ENOIOCTL; |