From b0bf6b0aa90e2ce94ec77e389eea0e5849f2eaec Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?N=C3=ADcolas=20F=2E=20R=2E=20A=2E=20Prado?= Date: Fri, 2 Jul 2021 09:21:10 -0300 Subject: libcamera: camera: Make stop() idempotent MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Make Camera::stop() idempotent so that it can be called in any state and consecutive times. When called in any state other than CameraRunning, it is a no-op. This simplifies the cleanup path for applications. Signed-off-by: Nícolas F. R. A. Prado Reviewed-by: Laurent Pinchart Reviewed-by: Jacopo Mondi Signed-off-by: Jacopo Mondi --- src/libcamera/camera.cpp | 20 +++++++++++++++++--- 1 file changed, 17 insertions(+), 3 deletions(-) (limited to 'src') diff --git a/src/libcamera/camera.cpp b/src/libcamera/camera.cpp index de0123ae..29f2d91d 100644 --- a/src/libcamera/camera.cpp +++ b/src/libcamera/camera.cpp @@ -348,6 +348,7 @@ public: const std::set &streams); ~Private(); + bool isRunning() const; int isAccessAllowed(State state, bool allowDisconnected = false, const char *from = __builtin_FUNCTION()) const; int isAccessAllowed(State low, State high, @@ -389,6 +390,11 @@ static const char *const camera_state_names[] = { "Running", }; +bool Camera::Private::isRunning() const +{ + return state_.load(std::memory_order_acquire) == CameraRunning; +} + int Camera::Private::isAccessAllowed(State state, bool allowDisconnected, const char *from) const { @@ -1062,9 +1068,10 @@ int Camera::start(const ControlList *controls) * This method stops capturing and processing requests immediately. All pending * requests are cancelled and complete synchronously in an error state. * - * \context This function may only be called when the camera is in the Running - * state as defined in \ref camera_operation, and shall be synchronized by the - * caller with other functions that affect the camera state. + * \context This function may be called in any camera state as defined in \ref + * camera_operation, and shall be synchronized by the caller with other + * functions that affect the camera state. If called when the camera isn't + * running, it is a no-op. * * \return 0 on success or a negative error code otherwise * \retval -ENODEV The camera has been disconnected from the system @@ -1074,6 +1081,13 @@ int Camera::stop() { Private *const d = LIBCAMERA_D_PTR(); + /* + * \todo Make calling stop() when not in 'Running' part of the state + * machine rather than take this shortcut + */ + if (!d->isRunning()) + return 0; + int ret = d->isAccessAllowed(Private::CameraRunning); if (ret < 0) return ret; -- cgit v1.2.1