On 01.04.2017 11:42, Gregory Hainaut wrote:
Hello,
Please find a new version to handle invalid buffer handles.
Allow to handle this kind of case:
genBuffer(&pbo);
DeleteBuffer(pbo);
BindBuffer(pbo)
TexSubImage2D(user_memory_pointer); // Data transfer will be synchronous
There are various subtely to handle multi threaded shared context. In order to
keep the code sane, I've considered a buffer invalid when it is deleted by a
context even it is still bound to others contexts. It will force a synchronous
transfer which is always safe.
Thanks! I think you're right that tracking pointers is not actually
needed as long as Create/Delete are synchronous. It's less accurate, but
the inaccuracy doesn't necessarily lead to correctness problems.
Still, I believe there is the following bug in the series:
glGenBuffers(1, &pbo);
glBindBuffer(..., pbo);
glDeleteBuffers(1, &pbo);
glTexSubImage2D(...); // will be asynchronous, but refers to user memory
because the pbo was implicitly unbound
Once you fix this bug by updating the current context's bindings in
glDeleteBuffers, you'll have the following multi-context situation,
which is sub-optimal but not a bug -- and applications which do that are
crazy anyway, so let's not worry about them. I'm just mentioning it for
completeness:
Ctx A: glGenBuffers(1, &pbo);
Ctx A: glBindBuffer(PIXEL_UNPACK_BUFFER, pbo);
Ctx B: glDeleteBuffers(1, &pbo);
Ctx A: glGenBuffers(1, &pbo); // assume that this gets the same buffer name
Ctx A: glDeleteBuffers(1, &pbo);
Ctx A: glTexSubImage2D(...); // will be synchronous, even though it
_could_ be asynchronous (because the PBO that was generated first is
still bound!)
Cheers,
Nicolai
Gregory Hainaut (3):
mesa/glthread: track buffer creation/destruction
mesa/glthread: add tracking of PBO binding
mapi/glthread: generate asynchronous code for PBO transfer
src/mapi/glapi/gen/ARB_direct_state_access.xml | 18 +--
src/mapi/glapi/gen/ARB_robustness.xml | 2 +-
src/mapi/glapi/gen/gl_API.dtd | 10 +-
src/mapi/glapi/gen/gl_API.xml | 32 +++---
src/mapi/glapi/gen/gl_marshal.py | 23 +++-
src/mapi/glapi/gen/marshal_XML.py | 19 +++-
src/mesa/main/glthread.h | 10 ++
src/mesa/main/marshal.c | 149 ++++++++++++++++++++++++-
src/mesa/main/marshal.h | 24 ++++
src/mesa/main/mtypes.h | 5 +
src/mesa/main/shared.c | 4 +
11 files changed, 257 insertions(+), 39 deletions(-)
--
Lerne, wie die Welt wirklich ist,
Aber vergiss niemals, wie sie sein sollte.
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