This can be used in a generic way as common interface by all platforms
that, in one way or another, pass around physical memory addresses.
This is used by the gl lib and seems useful enough, so might just as
well move it next to the other allocators.
https://bugzilla.gnome.org/show_bug.cgi?id=779067
For example mmap can fail with EACCES if the the fd has been open
with read only mode. And mapping the memory might be the only way
to check that. So no need to print out an error.
Ex: ioctl(dev, DRM_IOCTL_PRIME_HANDLE_TO_FD, flags & ~DRM_RDWR)
https://bugzilla.gnome.org/show_bug.cgi?id=765600
This class was made subclassable, though for future growth of the code,
it's better if we have some room for add class members. Using the small
padding since this is unlikely.
Adds "memory:DMABuf" caps feature. Since 1.11 tag.
Useful when the the dma-buf buffer cannot be mapped to CPU for r/w requests.
Example: protected content or platform constraints.
https://bugzilla.gnome.org/show_bug.cgi?id=759358
https://github.com/mesonbuild/meson
With contributions from:
Tim-Philipp Müller <tim@centricular.com>
Jussi Pakkanen <jpakkane@gmail.com> (original port)
Highlights of the features provided are:
* Faster builds on Linux (~40-50% faster)
* The ability to build with MSVC on Windows
* Generate Visual Studio project files
* Generate XCode project files
* Much faster builds on Windows (on-par with Linux)
* Seriously fast configure and building on embedded
... and many more. For more details see:
http://blog.nirbheek.in/2016/05/gstreamer-and-meson-new-hope.htmlhttp://blog.nirbheek.in/2016/07/building-and-developing-gstreamer-using.html
Building with Meson should work on both Linux and Windows, but may
need a few more tweaks on other operating systems.
Add GST_FD_MEMORY_FLAG_DONT_CLOSE to avoid closing the fd when the
memory is freed. When you can guarantee the lifetime of the fd is
longer than the memory, this can save a dup() call.
All those where super straight forward from the warnings gtkdoc prints. It kind
of makes sense to apply them before the list of warnings is >100 and people
complain that gtkdoc is noisy.
Make a base class that can help with allocating fd-backed memory.
Make dmabuf extend from the base class.
We can now make methods to check if memory has an fd and get the fd for
all the different types of fd-backed memory.
Make a separate file for the code to handle the fd backed memory.
This would make it possible later to add other allocators also using
fd backed memory.
Fixes regression introduced by:
commit b60888fd4b
Author: Michael Olbrich <m.olbrich@pengutronix.de>
Date: Tue May 20 11:18:56 2014 +0200
dmabuf: share the mapping with shared copies of the memory
https://bugzilla.gnome.org/show_bug.cgi?id=730441
A simple '&' is not sufficiant. With mmapping_flags == PROT_READ and
prot == PROT_READ|PROT_WRITE the check produces the wrong result.
Change the check to make sure that prot is a subset of mmapping_flags.
https://bugzilla.gnome.org/show_bug.cgi?id=730559
With lots of shared memory instances (e.g. created by a RTP payloader) the
overhead of duplicating the file descriptor and creating extra mappings is
significant. To avoid this, the parent memory maps the whole region and the
shared copies just reuse the same mapping.
https://bugzilla.gnome.org/show_bug.cgi?id=730441
Makes it easier to track how many users there are
Also make it possible to create a dmabuf struct on systems without mmap,
it just won't be possible to map it.
https://bugzilla.gnome.org/show_bug.cgi?id=707793
A successful gst_dmabuf_mem_map must always increment the mmap count.
Otherwise the first gst_dmabuf_mem_unmap will unmap the memory and all
other user will access unmapped memory.
https://bugzilla.gnome.org/show_bug.cgi?id=706680
In decide_allocation function some element may when to test the proposed allocator.
For example like this:
if (gst_query_get_n_allocation_params (query) > 0) {
GstAllocator * allocator;
GstAllocationParams params;
gst_query_parse_nth_allocation_param (query, 0, &allocator, ¶ms);
if (g_strcmp0(allocator->mem_type, GST_ALLOCATOR_DMABUF) == 0)
GST_DEBUG("got dmabuf allocator");
else
GST_DEBUG("got an other allocator");
}
https://bugzilla.gnome.org/show_bug.cgi?id=703659
