| Message ID | 20211228215951.32396-5-laurent.pinchart@ideasonboard.com |
|---|---|
| State | Accepted |
| Delegated to: | Laurent Pinchart |
| Headers | show |
| Series |
|
| Related | show |
Quoting Laurent Pinchart (2021-12-28 21:59:50) > The mmaps_ map stores a pointer to the V4L2CameraProxy to avoid > increasing the reference count on the V4L2CameraFile shared pointer > needlessly. While this provides a small optimization, it prevents > accessing the V4L2CameraFile from the munmap() function which doesn't > take an fd as argument. > > To prepare for improved debugging that will require access to > V4L2CameraFile in munmap(), store the V4L2CameraFile pointer in mmaps_. > > Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com> > --- > src/v4l2/v4l2_compat_manager.cpp | 10 +++------- > src/v4l2/v4l2_compat_manager.h | 2 +- > 2 files changed, 4 insertions(+), 8 deletions(-) > > diff --git a/src/v4l2/v4l2_compat_manager.cpp b/src/v4l2/v4l2_compat_manager.cpp > index 585046e97e4b..ded568beb60e 100644 > --- a/src/v4l2/v4l2_compat_manager.cpp > +++ b/src/v4l2/v4l2_compat_manager.cpp > @@ -198,11 +198,7 @@ void *V4L2CompatManager::mmap(void *addr, size_t length, int prot, int flags, > if (map == MAP_FAILED) > return map; > > - /* > - * Map to V4L2CameraProxy directly to prevent adding more references > - * to V4L2CameraFile. > - */ > - mmaps_[map] = file->proxy(); > + mmaps_[map] = file; > return map; > } > > @@ -212,9 +208,9 @@ int V4L2CompatManager::munmap(void *addr, size_t length) > if (device == mmaps_.end()) > return fops_.munmap(addr, length); > > - V4L2CameraProxy *proxy = device->second; > + V4L2CameraFile *file = device->second.get(); > > - int ret = proxy->munmap(addr, length); > + int ret = file->proxy()->munmap(addr, length); > if (ret < 0) > return ret; > > diff --git a/src/v4l2/v4l2_compat_manager.h b/src/v4l2/v4l2_compat_manager.h > index f52069f7b62d..64af9a8c008f 100644 > --- a/src/v4l2/v4l2_compat_manager.h > +++ b/src/v4l2/v4l2_compat_manager.h > @@ -65,5 +65,5 @@ private: > > std::vector<std::unique_ptr<V4L2CameraProxy>> proxies_; > std::map<int, std::shared_ptr<V4L2CameraFile>> files_; > - std::map<void *, V4L2CameraProxy *> mmaps_; > + std::map<void *, std::shared_ptr<V4L2CameraFile>> mmaps_; > }; > -- > Regards, > > Laurent Pinchart >
Hi Laurent, On Tue, Dec 28, 2021 at 11:59:50PM +0200, Laurent Pinchart wrote: > The mmaps_ map stores a pointer to the V4L2CameraProxy to avoid > increasing the reference count on the V4L2CameraFile shared pointer > needlessly. While this provides a small optimization, it prevents > accessing the V4L2CameraFile from the munmap() function which doesn't > take an fd as argument. > > To prepare for improved debugging that will require access to > V4L2CameraFile in munmap(), store the V4L2CameraFile pointer in mmaps_. > > Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Paul Elder <paul.elder@ideasonboard.com> > --- > src/v4l2/v4l2_compat_manager.cpp | 10 +++------- > src/v4l2/v4l2_compat_manager.h | 2 +- > 2 files changed, 4 insertions(+), 8 deletions(-) > > diff --git a/src/v4l2/v4l2_compat_manager.cpp b/src/v4l2/v4l2_compat_manager.cpp > index 585046e97e4b..ded568beb60e 100644 > --- a/src/v4l2/v4l2_compat_manager.cpp > +++ b/src/v4l2/v4l2_compat_manager.cpp > @@ -198,11 +198,7 @@ void *V4L2CompatManager::mmap(void *addr, size_t length, int prot, int flags, > if (map == MAP_FAILED) > return map; > > - /* > - * Map to V4L2CameraProxy directly to prevent adding more references > - * to V4L2CameraFile. > - */ > - mmaps_[map] = file->proxy(); > + mmaps_[map] = file; > return map; > } > > @@ -212,9 +208,9 @@ int V4L2CompatManager::munmap(void *addr, size_t length) > if (device == mmaps_.end()) > return fops_.munmap(addr, length); > > - V4L2CameraProxy *proxy = device->second; > + V4L2CameraFile *file = device->second.get(); > > - int ret = proxy->munmap(addr, length); > + int ret = file->proxy()->munmap(addr, length); > if (ret < 0) > return ret; > > diff --git a/src/v4l2/v4l2_compat_manager.h b/src/v4l2/v4l2_compat_manager.h > index f52069f7b62d..64af9a8c008f 100644 > --- a/src/v4l2/v4l2_compat_manager.h > +++ b/src/v4l2/v4l2_compat_manager.h > @@ -65,5 +65,5 @@ private: > > std::vector<std::unique_ptr<V4L2CameraProxy>> proxies_; > std::map<int, std::shared_ptr<V4L2CameraFile>> files_; > - std::map<void *, V4L2CameraProxy *> mmaps_; > + std::map<void *, std::shared_ptr<V4L2CameraFile>> mmaps_; > }; > -- > Regards, > > Laurent Pinchart >
diff --git a/src/v4l2/v4l2_compat_manager.cpp b/src/v4l2/v4l2_compat_manager.cpp index 585046e97e4b..ded568beb60e 100644 --- a/src/v4l2/v4l2_compat_manager.cpp +++ b/src/v4l2/v4l2_compat_manager.cpp @@ -198,11 +198,7 @@ void *V4L2CompatManager::mmap(void *addr, size_t length, int prot, int flags, if (map == MAP_FAILED) return map; - /* - * Map to V4L2CameraProxy directly to prevent adding more references - * to V4L2CameraFile. - */ - mmaps_[map] = file->proxy(); + mmaps_[map] = file; return map; } @@ -212,9 +208,9 @@ int V4L2CompatManager::munmap(void *addr, size_t length) if (device == mmaps_.end()) return fops_.munmap(addr, length); - V4L2CameraProxy *proxy = device->second; + V4L2CameraFile *file = device->second.get(); - int ret = proxy->munmap(addr, length); + int ret = file->proxy()->munmap(addr, length); if (ret < 0) return ret; diff --git a/src/v4l2/v4l2_compat_manager.h b/src/v4l2/v4l2_compat_manager.h index f52069f7b62d..64af9a8c008f 100644 --- a/src/v4l2/v4l2_compat_manager.h +++ b/src/v4l2/v4l2_compat_manager.h @@ -65,5 +65,5 @@ private: std::vector<std::unique_ptr<V4L2CameraProxy>> proxies_; std::map<int, std::shared_ptr<V4L2CameraFile>> files_; - std::map<void *, V4L2CameraProxy *> mmaps_; + std::map<void *, std::shared_ptr<V4L2CameraFile>> mmaps_; };
The mmaps_ map stores a pointer to the V4L2CameraProxy to avoid increasing the reference count on the V4L2CameraFile shared pointer needlessly. While this provides a small optimization, it prevents accessing the V4L2CameraFile from the munmap() function which doesn't take an fd as argument. To prepare for improved debugging that will require access to V4L2CameraFile in munmap(), store the V4L2CameraFile pointer in mmaps_. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> --- src/v4l2/v4l2_compat_manager.cpp | 10 +++------- src/v4l2/v4l2_compat_manager.h | 2 +- 2 files changed, 4 insertions(+), 8 deletions(-)