Tracking the full 64-bit SBC values makes it clearer how those values are being used, and simplifies the wait_msc code. The only trick is in re-constructing the full 64-bit value from Present's 32-bit serial number that we use to pass the SBC value from request to event.
Signed-off-by: Keith Packard keithp@keithp.com --- src/glx/dri3_glx.c | 34 +++++++++++++++++++++------------- src/glx/dri3_priv.h | 16 +++++++++------- 2 files changed, 30 insertions(+), 20 deletions(-)
diff --git a/src/glx/dri3_glx.c b/src/glx/dri3_glx.c index 4c0dc29..b9a786f 100644 --- a/src/glx/dri3_glx.c +++ b/src/glx/dri3_glx.c @@ -364,10 +364,17 @@ dri3_handle_present_event(struct dri3_drawable *priv, xcb_present_generic_event_ case XCB_PRESENT_COMPLETE_NOTIFY: { xcb_present_complete_notify_event_t *ce = (void *) ge;
- if (ce->kind == XCB_PRESENT_COMPLETE_KIND_PIXMAP) - priv->present_event_serial = ce->serial; - else - priv->present_msc_event_serial = ce->serial; + /* Compute the processed SBC number from the received 32-bit serial number merged + * with the upper 32-bits of the sent 64-bit serial number while checking for + * wrap + */ + if (ce->kind == XCB_PRESENT_COMPLETE_KIND_PIXMAP) { + priv->recv_sbc = (priv->send_sbc & 0xffffffff00000000LL) | ce->serial; + if (priv->recv_sbc > priv->send_sbc) + priv->recv_sbc -= 0x100000000; + } else { + priv->recv_msc_serial = ce->serial; + } priv->ust = ce->ust; priv->msc = ce->msc; break; @@ -398,12 +405,13 @@ dri3_wait_for_msc(__GLXDRIdrawable *pdraw, int64_t target_msc, int64_t divisor, struct dri3_drawable *priv = (struct dri3_drawable *) pdraw; xcb_generic_event_t *ev; xcb_present_generic_event_t *ge; + uint32_t msc_serial;
/* Ask for the an event for the target MSC */ - ++priv->present_msc_request_serial; + msc_serial = ++priv->send_msc_serial; xcb_present_notify_msc(c, priv->base.xDrawable, - priv->present_msc_request_serial, + msc_serial, target_msc, divisor, remainder); @@ -412,7 +420,7 @@ dri3_wait_for_msc(__GLXDRIdrawable *pdraw, int64_t target_msc, int64_t divisor,
/* Wait for the event */ if (priv->special_event) { - while (priv->present_msc_request_serial != priv->present_msc_event_serial) { + while ((int32_t) (msc_serial - priv->recv_msc_serial) > 0) { ev = xcb_wait_for_special_event(c, priv->special_event); if (!ev) break; @@ -423,7 +431,7 @@ dri3_wait_for_msc(__GLXDRIdrawable *pdraw, int64_t target_msc, int64_t divisor,
*ust = priv->ust; *msc = priv->msc; - *sbc = priv->sbc; + *sbc = priv->recv_sbc;
return 1; } @@ -450,7 +458,7 @@ dri3_wait_for_sbc(__GLXDRIdrawable *pdraw, int64_t target_sbc, int64_t *ust, { struct dri3_drawable *priv = (struct dri3_drawable *) pdraw;
- while (priv->sbc < target_sbc) { + while (priv->send_sbc < target_sbc) { sleep(1); } return dri3_wait_for_msc(pdraw, 0, 0, 0, ust, msc, sbc); @@ -1281,15 +1289,15 @@ dri3_swap_buffers(__GLXDRIdrawable *pdraw, int64_t target_msc, int64_t divisor, /* Compute when we want the frame shown by taking the last known successful * MSC and adding in a swap interval for each outstanding swap request */ - ++priv->present_request_serial; + ++priv->send_sbc; if (target_msc == 0) - target_msc = priv->msc + priv->swap_interval * (priv->present_request_serial - priv->present_event_serial); + target_msc = priv->msc + priv->swap_interval * (priv->send_sbc - priv->recv_sbc);
priv->buffers[buf_id]->busy = 1; xcb_present_pixmap(c, priv->base.xDrawable, priv->buffers[buf_id]->pixmap, - priv->present_request_serial, + (uint32_t) priv->send_sbc, 0, /* valid */ 0, /* update */ 0, /* x_off */ @@ -1301,7 +1309,7 @@ dri3_swap_buffers(__GLXDRIdrawable *pdraw, int64_t target_msc, int64_t divisor, target_msc, divisor, remainder, 0, NULL); - ret = ++priv->sbc; + ret = (int64_t) priv->send_sbc;
/* If there's a fake front, then copy the source back buffer * to the fake front to keep it up to date. This needs diff --git a/src/glx/dri3_priv.h b/src/glx/dri3_priv.h index 4adef50..4c5579e 100644 --- a/src/glx/dri3_priv.h +++ b/src/glx/dri3_priv.h @@ -183,16 +183,18 @@ struct dri3_drawable { uint8_t have_fake_front; uint8_t is_pixmap;
- uint32_t present_request_serial; - uint32_t present_event_serial; - - uint64_t sbc; + /* SBC numbers are tracked by using the serial numbers + * in the present request and complete events + */ + uint64_t send_sbc; + uint64_t recv_sbc;
+ /* Last received UST/MSC values */ uint64_t ust, msc;
- /* For WaitMSC */ - uint32_t present_msc_request_serial; - uint32_t present_msc_event_serial; + /* Serial numbers for tracking wait_for_msc events */ + uint32_t send_msc_serial; + uint32_t recv_msc_serial;
struct dri3_buffer *buffers[DRI3_NUM_BUFFERS]; int cur_back;