dri3: Track current Present swap mode and adjust buffer counts

This automatically adjusts the number of buffers that we want based on
what swapping mode the X server is using and the current swap interval:

        swap mode       interval        buffers
        copy            > 0             1
        copy            0               2
        flip            > 0             2
        flip            0               3

Note that flip with swap interval 0 is currently limited to twice the
underlying refresh rate because of how the kernel manages flipping. Moving
from 3 to 4 buffers would help, but that seems ridiculous.

v2: Just update num_back at the point that the values that change num_back
    change.  This means we'll have the updated value at the point that the
    freeing of old going-to-be-unused backbuffers happens, which might not
    have been the case before (change by anholt, acked by keithp).

Signed-off-by: Keith Packard <keithp@keithp.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Eric Anholt <eric@anholt.net>
This commit is contained in:
Keith Packard
2014-01-26 16:14:29 -08:00
committed by Eric Anholt
parent aea4757eb4
commit 3fbd1b0cb5
2 changed files with 35 additions and 24 deletions

View File

@@ -269,6 +269,16 @@ dri3_create_context(struct glx_screen *base,
static void
dri3_free_render_buffer(struct dri3_drawable *pdraw, struct dri3_buffer *buffer);
static void
dri3_update_num_back(struct dri3_drawable *priv)
{
priv->num_back = 1;
if (priv->flipping)
priv->num_back++;
if (priv->swap_interval == 0)
priv->num_back++;
}
static void
dri3_destroy_drawable(__GLXDRIdrawable *base)
{
@@ -326,6 +336,8 @@ dri3_create_drawable(struct glx_screen *base, XID xDrawable,
break;
}
dri3_update_num_back(pdraw);
(void) __glXInitialize(psc->base.dpy);
/* Create a new drawable */
@@ -373,6 +385,15 @@ dri3_handle_present_event(struct dri3_drawable *priv, xcb_present_generic_event_
priv->recv_sbc = (priv->send_sbc & 0xffffffff00000000LL) | ce->serial;
if (priv->recv_sbc > priv->send_sbc)
priv->recv_sbc -= 0x100000000;
switch (ce->mode) {
case XCB_PRESENT_COMPLETE_MODE_FLIP:
priv->flipping = true;
break;
case XCB_PRESENT_COMPLETE_MODE_COPY:
priv->flipping = false;
break;
}
dri3_update_num_back(priv);
} else {
priv->recv_msc_serial = ce->serial;
}
@@ -389,6 +410,10 @@ dri3_handle_present_event(struct dri3_drawable *priv, xcb_present_generic_event_
if (buf && buf->pixmap == ie->pixmap) {
buf->busy = 0;
if (priv->num_back <= b && b < DRI3_MAX_BACK) {
dri3_free_render_buffer(priv, buf);
priv->buffers[b] = NULL;
}
break;
}
}
@@ -1067,10 +1092,9 @@ dri3_find_back(xcb_connection_t *c, struct dri3_drawable *priv)
xcb_present_generic_event_t *ge;
for (;;) {
for (b = 0; b < DRI3_NUM_BACK; b++) {
int id = DRI3_BACK_ID(b);
struct dri3_buffer *buffer = priv->buffers[id];
for (b = 0; b < priv->num_back; b++) {
int id = DRI3_BACK_ID(b);
struct dri3_buffer *buffer = priv->buffers[id];
if (!buffer)
return b;
@@ -1185,7 +1209,7 @@ dri3_free_buffers(__DRIdrawable *driDrawable,
switch (buffer_type) {
case dri3_buffer_back:
first_id = DRI3_BACK_ID(0);
n_id = DRI3_NUM_BACK;
n_id = DRI3_MAX_BACK;
break;
case dri3_buffer_front:
first_id = DRI3_FRONT_ID;
@@ -1437,6 +1461,7 @@ dri3_set_swap_interval(__GLXDRIdrawable *pdraw, int interval)
}
priv->swap_interval = interval;
dri3_update_num_back(priv);
return 0;
}

View File

@@ -143,25 +143,9 @@ struct dri3_context
__DRIcontext *driContext;
};
#define DRI3_NUM_BACK 2
#define DRI3_MAX_BACK 3
#define DRI3_BACK_ID(i) (i)
#define DRI3_FRONT_ID (DRI3_NUM_BACK)
static inline int
dri3_buf_id_next(int buf_id)
{
if (buf_id == DRI3_NUM_BACK - 1)
return 0;
return buf_id + 1;
}
static inline int
dri3_buf_id_prev(int buf_id)
{
if (buf_id == 0)
return DRI3_NUM_BACK - 1;
return buf_id - 1;
}
#define DRI3_FRONT_ID (DRI3_MAX_BACK)
static inline int
dri3_pixmap_buf_id(enum dri3_buffer_type buffer_type)
@@ -172,7 +156,7 @@ dri3_pixmap_buf_id(enum dri3_buffer_type buffer_type)
return DRI3_FRONT_ID;
}
#define DRI3_NUM_BUFFERS (1 + DRI3_NUM_BACK)
#define DRI3_NUM_BUFFERS (1 + DRI3_MAX_BACK)
struct dri3_drawable {
__GLXDRIdrawable base;
@@ -182,6 +166,7 @@ struct dri3_drawable {
uint8_t have_back;
uint8_t have_fake_front;
uint8_t is_pixmap;
uint8_t flipping;
/* SBC numbers are tracked by using the serial numbers
* in the present request and complete events
@@ -198,6 +183,7 @@ struct dri3_drawable {
struct dri3_buffer *buffers[DRI3_NUM_BUFFERS];
int cur_back;
int num_back;
uint32_t *stamp;