the old code worked fine for a long time and was not affected by
the bug the new code fixes and the new is not widely tested yet.
This can be reverted once the code received more testing in
master
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
(cherry picked from commit f783259fdb37e288643fe54ac162d723b1bec548)
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
* commit 'c790e31ae46d4304af893d04806ec9e3bff5ae28':
lavu: fix memory leaks by using a mutex instead of atomics
Conflicts:
libavutil/buffer.c
The atomics code is left in place as a fallback for synchronization in the
absence of p/w32 threads. Our ABI did not requires applications to
only use threads (and matching ones) to what libavutil was build with
Our code also was not affected by the leak this change fixes, though
no question the atomics based implementation is not pretty at all.
First and foremost the code must work, being pretty comes after that.
If this causes problems, for example when libavutil is used by multiple
applications each using a different kind of threading system then the
default possibly has to be changed to the uglier atomics.
See: cea3a63ba3d89d8403eef008f7a7c54d645cff70
Merged-by: Michael Niedermayer <michaelni@gmx.at>
The buffer pool has to atomically add and remove entries from the linked
list of available buffers. This was done by removing the entire list
with a CAS operation, working on it, and then setting it back again
(using a retry-loop in case another thread was doing the same thing).
This could effectively cause memory leaks: while a thread was working on
the buffer list, other threads would allocate new buffers, increasing
the pool's total size. There was no real leak, but since these extra
buffers were not needed, but not free'd either (except when the buffer
pool was destroyed), this had the same effects as a real leak. For some
reason, growth was exponential, and could easily kill the process due
to OOM in real-world uses.
Fix this by using a mutex to protect the list operations. The fancy
way atomics remove the whole list to work on it is not needed anymore,
which also avoids the situation which was causing the leak.
Signed-off-by: Anton Khirnov <anton@khirnov.net>
(cherry picked from commit fbd6c97f9ca858140df16dd07200ea0d4bdc1a83)
Signed-off-by: Anton Khirnov <anton@khirnov.net>
(cherry picked from commit 517ce1d09b5e6b72afc2ef9490b5f8ca42fa6a65)
Signed-off-by: Anton Khirnov <anton@khirnov.net>
This reverts commit 3144440004941aa22ffea9933f5e5dfe826df654.
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
(cherry picked from commit bba7b6fc41057d4aec6b1f0e12240db56fe6e9b6)
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
new function allows to unref buffer and obtain its data.
Signed-off-by: Lukasz Marek <lukasz.m.luki@gmail.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
This race will always happen sooner or later in a multi-threaded
environment and it will over time lead to OOM.
This fix works by spinning, there are other ways by which this
can be fixed, like simply detecting the issue after it happened
and freeing the over-allocated memory or simply using a mutex.
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
* commit '8e401dbe90cc77b1f3067a917d9fa48cefa3fcdb':
lavu: add a new API for reference-counted data buffers.
Conflicts:
libavutil/Makefile
Merged-by: Michael Niedermayer <michaelni@gmx.at>
