Commit Graph

4 Commits

Author SHA1 Message Date
Neil Roberts
534e535a28 Use the Wayland embedded linked list implementation instead of BSD's
This removes cogl-queue.h and adds a copy of Wayland's embedded list
implementation. The advantage of the Wayland model is that it is much
simpler and so it is easier to follow. It also doesn't require
defining a typedef for every list type.

The downside is that there is only one list type which is a
doubly-linked list where the head has a pointer to both the beginning
and the end. The BSD implementation has many more combinations some of
which we were taking advantage of to reduce the size of critical
structs where we didn't need a pointer to the end of the list.

The corresponding changes to uses of cogl-queue.h are:

• COGL_STAILQ_* was used for onscreen the list of events and dirty
  notifications. This makes the size of the CoglContext grow by one
  pointer.

• COGL_TAILQ_* was used for fences.

• COGL_LIST_* for CoglClosures. In this case the list head now has an
  extra pointer which means CoglOnscreen will grow by the size of
  three pointers, but this doesn't seem like a particularly important
  struct to optimise for size anyway.

• COGL_LIST_* was used for the list of foreign GLES2 offscreens.

• COGL_TAILQ_* was used for the list of sub stacks in a
  CoglMemoryStack.

• COGL_LIST_* was used to track the list of layers that haven't had
  code generated yet while generating a fragment shader for a
  pipeline.

• COGL_LIST_* was used to track the pipeline hierarchy in CoglNode.

The last part is a bit more controversial because it increases the
size of CoglPipeline and CoglPipelineLayer by one pointer in order to
have the redundant tail pointer for the list head. Normally we try to
be very careful about the size of the CoglPipeline struct. Because
CoglPipeline is slice-allocated, this effectively ends up adding two
pointers to the size because GSlice rounds up to the size of two
pointers.

Reviewed-by: Robert Bragg <robert@linux.intel.com>

(cherry picked from commit 13abf613b15f571ba1fcf6d2eb831ffc6fa31324)

Conflicts:
	cogl/cogl-context-private.h
	cogl/cogl-context.c
	cogl/driver/gl/cogl-pipeline-fragend-glsl.c
	doc/reference/cogl-2.0-experimental/Makefile.am
2013-06-13 13:45:47 +01:00
Robert Bragg
56382435fa stack: don't deref freed mem in _cogl_memory_stack_free
This fixes _cogl_memory_stack_free to ensure we don't dereference freed
memory as we iterate the sub-stacks to free them.

Reviewed-by: Neil Roberts <neil@linux.intel.com>

(cherry picked from commit 1d27fedef9c599aa9976b809f18e0da1913cec26)
2012-08-06 18:51:32 +01:00
Neil Roberts
85efb7daba Don't typedef CoglMemoryStack twice
CoglMemoryStack was being typedef'd twice, once in the private header
as an incomplete struct and once in the C source with the actual
struct definition. This removes the second typedef so that it just
defines the struct.

This patch was written by Jack River.

https://bugzilla.gnome.org/show_bug.cgi?id=675119

Reviewed-by: Neil Roberts <neil@linux.intel.com>

(cherry picked from commit 75cd425a48e0fc403bf88eace212a6d37b65df11)
2012-08-06 14:27:41 +01:00
Robert Bragg
97d5406aef Adds internal CoglMemoryStack utility API
This adds a very minimal internal allocator api that lets us create a
dynamically growable (grow only) stack.

Underlying the allocator is the idea of "sub stacks" which are simply
malloc()'d chunks of memory kept in a linked list. The stack itself
maintains a pointer to the current sub-stack and a current
sub-stack-offset. 99% of the time allocating from the stack is just a
case of returning a pointer to the current sub-stack + sub-stack-offset
and bumping the offset by the allocation size. If there isn't room in
the current sub-stack then we walk through the list of free sub-stacks
looking for one that's big enough for the allocation and if we reach the
end of the list then we allocate a new sub-stack twice as big as the
last (or twice as big as the requested allocation if that's bigger).

Since it's a stack model there is no api to free allocations, just a
function to rewind the stack to the beginning.

We expect this to be useful in multiple places in Cogl as an extremely
fast allocator in cases when we know we can scrap all the allocations
after we're done figuring something out or as a building block for
other allocators.

For example the tessellator used for CoglPath allocates lots of tiny
structures that can all be freed after tessellation.

Reviewed-by: Neil Roberts <neil@linux.intel.com>

(cherry picked from commit 6ee4a7a1b7f695bdfeb10ffa4112e776beea0a9d)
2012-08-06 14:27:40 +01:00