On Sun, 20 Aug 2017 06:49:05 +0200, Takashi Sakamoto wrote: > > Hi, > > This patchset is to fix an issue of concurrent access to operate > ELEM_READ/ELEM_WRITE, which I found in my previous patch: > > [PATCH 0/5] ALSA: control: fix issue of concurrent access for TLV operations > http://mailman.alsa-project.org/pipermail/alsa-devel/2017-August/123561.html > > In current implementation of ALSA control core, concurrent accesses with > ELEM_READ/ELEM_WRITE are managed with counting semaphore, however lock > acquisition for both of these operations is a type of 'read'. In this case, > ELEM_READ can be going to be handled for a target element when ELEM_WRITE > is handled for the element. A purpose of the ELEM_WRITE operation is to > change state of the target element. It's better to guarantee that > concurrent accesses to the same element with these two operations are > properly managed. > > For the above aim, this patchset uses the counting semaphore as 'write' > lock for ELEM_WRITE operation. But I can imagine an discussion to add > 'per-element' lock for this issue. In a comment of patch 03, I investigate > it. Please refer to it. > > Takashi Sakamoto (3): > ALSA: control: queue events within locking of controls_rwsem for > ELEM_WRITE operation > ALSA: control: code refactoring for ELEM_READ/ELEM_WRITE operations > ALSA: control: use counting semaphore as write lock for ELEM_WRITE > operation Applied all three patches. Thanks. Takashi _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
