* Rendering twice or more could crash layer/pass buttons.
* Compositing would crash while drawing the image.
* Rendering animations could also crash drawing the image.
* Compositing could crash
* Starting to rendering while preview render / compo was
still running could crash.
* Exiting while rendering an animation would not abort the
renderer properly, making Blender seemingly freeze.
* Fixes theoretically possible issue with setting malloc
lock with nested threads.
* Drawing previews inside nodes could crash when those nodes
were being rendered at the same time.
There's more crashes, manipulating the scene data or undo can
still crash, this commit only focuses on making sure the image
buffer and render result access is thread safe.
Implementation:
* Rather than assuming the render result does not get freed
during render, which seems to be quite difficult to do given
that e.g. the compositor is allowed to change the size of
the buffer or output different passes, the render result is
now protected with a read/write mutex.
* The read/write mutex allows multiple readers (and pixel
writers) at the same time, but only allows one writer to
manipulate the data structure.
* Added BKE_image_acquire_ibuf/BKE_image_release_ibuf to access
images being rendered, cases where this is not needed (most
code) can still use BKE_image_get_ibuf.
* The job manager now allows only one rendering job at the same
time, rather than the G.rendering check which was not reliable.
Story time: Once upon a time, in the green valley of fileselect, BLI_end_threads would get called on an empty threadbase, depending on the result of a previous call to readdir(). The function would then gladly decrement thread_level to -1 which would cause all kinds of fun havoc. THE END.
Made sure thread_level is only incremented and decremented when needed. The caller should never have to make sure of that, especially since it already lets you call with a null threadbase.
Please report any further hang (and how to reproduce, if possible).
DONE:
* moved almost all declarations from BLI_blenlib.h into their own proper header files.
* BLI_blenlib.h still includes all the declarations for convenience and to avoid changes in existing code
* split util.c into several files, where it wasn't done already
* DynamicList -> dynamiclist,
* ListBase -> listbase,
* String utility functions -> string.c
* removed a few unused macros and functions, if they're needed back, they're still in svn ;)
TODO:
* btempdir global
* further cleanup in the code of the different modules (especially util.c)
It helps if the fonction to wait on all threads actual does that.
Use user parameter for number of threads (this is really looking like it should be in the userprefs and not render params).
Option to draw object name in 3d window corner, now also displays for
meshes the (pinned) shape key name.
Threads: warning fix, added (void) for function declaration.
- Now baking itself is threaded too (like for render, max 2 cpus. Moving
this to 4 cpus is on todo. Goes twice as fast!
- fix: ESC from bake was broken...
- other fix: toolbox menus didn't treat sublevel string lengths OK,
truncating items like for Group library names.
module itself, replacing the special MEM_mallocT/MEM_freeT functions.
Mutex locking is only enabled when threads are running.
There was no good reason to have these separate, it just led to ugly
hacks when calling functions with non-threadsafe malloc from threads.
- Renderwin still used a thread-unsafe malloc, in the header text print
- Setting clipping flags in vertices for parts required a mutex lock after
all... I thought it would go fine, but noticed on renders with small
amounts of faces that sometimes faces disappear from a render.
(was doing movie credits, so all faces are visible! Otherwise it would
have hardly been noticable...)
For some reason I thought SDL thread handling would be much simpler... but
the migration to posix pthread went very smooth and painless. Less code
even, and I even notice a slight performance increase!
All threading code is still wrapped in blenlib/intern/threads.c
Only real change was making the callback functions to return void pointer,
instead of an int.
The mutex handling is also different... there's no test anymore if a
mutex was initialized, which is a bit confusing. But it appears to run
all fine still. :)
Nathan Letwory has been signalled already to provide the Windows pthread
library and make/scons linking. For MSVC we might need help from someone
else later though.
In Orange we've been fighting the past weeks with memory usage a lot...
at the moment incredible huge scenes are being rendered, with multiple
layers and all compositing, stressing limits of memory a lot.
I had hoped that less frequently used blocks would be swapped away
nicely, so fragmented memory could survive. Unfortunately (in OSX) the
malloc range is limited to 2 GB only (upped half of address space).
Other OS's have a limit too, but typically larger afaik.
Now here's mmap to the rescue! It has a very nice feature to map to
a virtual (non existing) file, allowing to allocate disk-mapped memory
on the fly. For as long there's real memory it works nearly as fast as
a regular malloc, and when you go to the swap boundary, it knows nicely
what to swap first.
The upcoming commit will use mmap for all large memory blocks, like
the composit stack, render layers, lamp buffers and images. Tested here
on my 1 GB system, and compositing huge images with a total of 2.5 gig
still works acceptable here. :)
http://www.blender.org/bf/memory.jpg
This is a silly composit test, using 64 MB images with a load of nodes.
Check the header print... the (2323.33M) is the mmap disk-cache in use.
BTW: note that is still limited to the virtual address space of 4 GB.
The new call is:
MEM_mapalloc()
Per definition, mmap() returns zero'ed memory, so a calloc isn't required.
For Windows there's no mmap() available, but I'm pretty sure there's an
equivalent. Windows gurus here are invited to insert that here in code! At
the moment it's nicely ifdeffed, so for Windows the mmap defaults to a
regular alloc.
I noticed still several cases where the Imbuf library was called within a
thread... and that whilst the Imbuf itself isn't threadsafe. Also the
thread lock I added in rendering for loading images actually didn't
work, because then it was still possible both threads were accessing the
MEM_malloc function at same time.
This commit nearly fully replaces ImBuf calls in compositor (giving another
nice speedup btw, the way preview images in Nodes were calculated used
clumsy imbuf scaling code).
I've also centralized the 'mutex' locking for threading, which now only
resides in BLI_threads.h. This is used to secure the last ImBuf calls
I cannot replace, which is loading images and creating mipmaps.
Really hope we get something more stable now!
- Enabled Groups to execute in Compositor. They were ignored still.
Note; inside of groups nothing is cached, so a change of a group input
will recalculate it fully. This is needed because groups are linked
data (instances use same internal nodes).
- Made Composit node "Viewer" display correctly input for images with
1/2/3/4 channels.
- Added pass rendering, tested now with only regular Materials. For
Material nodes this is quite more complex... since they cannot be
easily separated in passes (each Material does a full shade)
In this commit all pass render is disabled though, will continue work on
that later.
Sneak preview: http://www.blender.org/bf/rt.jpg (temporal image)
- What did remain is the 'Normal' pass output. Normal works very nice for
relighting effects. Use the "Normal Node" to define where more or less
light should be. (Use "Value Map" node to tweak influence of the
Normal node 'dot' output.)
- EVIL bug fix: I've spend almost a day finding it... when combining AO and
mirror render, the event queue was totally screwing up... two things not
related at all!
Found out error was in ray-mirror code, which was using partially
uninitialized 'ShadeInput' data to pass on to render code.
- Another fix; made sure that while thread render, the threads don't get
events, only the main program will do. Might fix issues reported by
people on linux/windows.
for compositing code.
Officially malloc/calloc/free is threadsafe, but our secure malloc system
requires all memory blocks to be stored in a single list, so when two
threads write in this list you get conflicts.
- Compositor now is threaded
Enable it with the Scene buttons "Threads". This will handle over nodes to
individual threads to be calculated. However, if nodes depend on others
they have to wait. The current system only threads per entire node, not for
calculating results in parts.
I've reshuffled the node execution code to evaluate 'changed' events, and
prepare the entire tree to become simply parsed for open jobs with a call
to node = getExecutableNode()
By default, even without 'thread' option active, all node execution is
done within a separate thread.
Also fixed issues in yesterdays commit for 'event based' calculations, it
didn't do animated images, or execute (on rendering) the correct nodes
when you don't have Render-Result nodes included.
- Added generic Thread support in blenlib/ module
The renderer and the node system now both use same code for controlling the
threads. This has been moved to a new C file in blenlib/intern/threads.c.
Check this c file for an extensive doc and example how to use it.
The current implementation for Compositing allows unlimited amount of
threads. For rendering it is still tied to two threads, although it is
pretty easy to extend to 4 already. People with giant amounts of cpus can
poke me once for tests. :)
- Bugfix in creating group nodes
Group node definitions demand a clear separation of 'internal sockets' and
'external sockets'. The first are sockets being linked internally, the latter
are sockets exposed as sockets for the group itself.
When sockets were linked both internal and external, Blender crashed. It is
solved now by removing the external link(s).
