From ef5dfb7febd8881158e493451a27a2500ced14cb Mon Sep 17 00:00:00 2001
From: Matthias Vogelgesang <matthias.vogelgesang@ipe.fzk.de>
Date: Fri, 18 Mar 2011 11:10:00 +0100
Subject: Initialize all camera fields with NULL to catch errors early on

---
 src/cameras/dummy.c |  6 +-----
 src/cameras/ipe.c   |  5 +----
 src/cameras/pco.c   |  2 +-
 src/cameras/pf.c    |  2 +-
 src/uca-cam.c       | 28 ++++++++++++++++++++++++++++
 src/uca-cam.h       | 11 +++++++++++
 6 files changed, 43 insertions(+), 11 deletions(-)

diff --git a/src/cameras/dummy.c b/src/cameras/dummy.c
index 2ad2ec9..0d6c9d1 100644
--- a/src/cameras/dummy.c
+++ b/src/cameras/dummy.c
@@ -283,7 +283,7 @@ static uint32_t uca_dummy_destroy(struct uca_camera *cam)
 
 uint32_t uca_dummy_init(struct uca_camera **cam, struct uca_grabber *grabber)
 {
-    struct uca_camera *uca = (struct uca_camera *) malloc(sizeof(struct uca_camera));
+    struct uca_camera *uca = uca_cam_new();
 
     uca->destroy = &uca_dummy_destroy;
     uca->set_property = &uca_dummy_set_property;
@@ -296,10 +296,6 @@ uint32_t uca_dummy_init(struct uca_camera **cam, struct uca_grabber *grabber)
     uca->state = UCA_CAM_CONFIGURABLE;
     uca->frame_width = 320;
     uca->frame_height = 240;
-    uca->current_frame = 0;
-    uca->grabber = NULL;
-    uca->callback = NULL;
-    uca->callback_user = NULL;
 
     struct dummy_cam *dummy_cam = (struct dummy_cam *) malloc(sizeof(struct dummy_cam));
     dummy_cam->bitdepth = 8;
diff --git a/src/cameras/ipe.c b/src/cameras/ipe.c
index a9f1ff2..45a619c 100644
--- a/src/cameras/ipe.c
+++ b/src/cameras/ipe.c
@@ -119,7 +119,7 @@ uint32_t uca_ipe_init(struct uca_camera **cam, struct uca_grabber *grabber)
     pcilib_set_error_handler(&uca_ipe_handle_error, &uca_ipe_handle_error);
     model = pcilib_get_model(handle);
 
-    struct uca_camera *uca = (struct uca_camera *) malloc(sizeof(struct uca_camera));
+    struct uca_camera *uca = uca_cam_new();
 
     /* Camera found, set function pointers... */
     uca->destroy = &uca_ipe_destroy;
@@ -130,9 +130,6 @@ uint32_t uca_ipe_init(struct uca_camera **cam, struct uca_grabber *grabber)
     uca->grab = &uca_ipe_grab;
     uca->register_callback = &uca_ipe_register_callback;
 
-    uca->callback = NULL;
-    uca_>callback_user = NULL;
-    uca->state = UCA_CAM_CONFIGURABLE;
     uca->user = handle;
     *cam = uca;
 
diff --git a/src/cameras/pco.c b/src/cameras/pco.c
index 59c689d..3801157 100644
--- a/src/cameras/pco.c
+++ b/src/cameras/pco.c
@@ -250,7 +250,7 @@ uint32_t uca_pco_init(struct uca_camera **cam, struct uca_grabber *grabber)
         return UCA_ERR_CAM_NOT_FOUND;
     }
 
-    struct uca_camera *uca = (struct uca_camera *) malloc(sizeof(struct uca_camera));
+    struct uca_camera *uca = uca_cam_new();
     uca->user = pco;
     uca->grabber = grabber;
     uca->grabber->asynchronous = true;
diff --git a/src/cameras/pf.c b/src/cameras/pf.c
index ab6a490..5ae35ab 100644
--- a/src/cameras/pf.c
+++ b/src/cameras/pf.c
@@ -208,7 +208,7 @@ uint32_t uca_pf_init(struct uca_camera **cam, struct uca_grabber *grabber)
     /* We could check if a higher baud rate is supported, but... forget about
      * it. We don't need high speed configuration. */
 
-    struct uca_camera *uca = (struct uca_camera *) malloc(sizeof(struct uca_camera));
+    struct uca_camera *uca = uca_cam_new();
     uca->grabber = grabber;
     uca->grabber->asynchronous = true;
 
diff --git a/src/uca-cam.c b/src/uca-cam.c
index eb76fad..b26b826 100644
--- a/src/uca-cam.c
+++ b/src/uca-cam.c
@@ -19,3 +19,31 @@ enum uca_cam_state uca_cam_get_state(struct uca_camera *cam)
     return cam->state;
 }
 
+struct uca_camera *uca_cam_new(void)
+{
+    struct uca_camera *cam = (struct uca_camera *) malloc(sizeof(struct uca_camera));
+
+    cam->next = NULL;
+
+    /* Set all function pointers to NULL so we know early on, if something has
+     * not been implemented. */
+    cam->set_property = NULL;
+    cam->get_property = NULL;
+    cam->start_recording = NULL;
+    cam->stop_recording = NULL;
+    cam->grab = NULL;
+    cam->register_callback = NULL;
+    cam->destroy = NULL;
+
+    cam->user = NULL;
+
+    cam->grabber = NULL;
+    cam->state = UCA_CAM_CONFIGURABLE;
+    cam->current_frame = 0;
+
+    /* No callbacks and user data associated yet */
+    cam->callback = NULL;
+    cam->callback_user = NULL;
+
+    return cam;
+}
diff --git a/src/uca-cam.h b/src/uca-cam.h
index ec84c27..d52f390 100644
--- a/src/uca-cam.h
+++ b/src/uca-cam.h
@@ -43,8 +43,10 @@ enum uca_cam_state {
  * 
  * \param[in] n_buffers Number of sub-buffers with size frame_width*frame_height.
  */
+/* FIXME: put this into vtable?! */
 uint32_t uca_cam_alloc(struct uca_camera *cam, uint32_t n_buffers);
 
+
 /**
  * Retrieve current state of the camera.
  *
@@ -55,6 +57,15 @@ uint32_t uca_cam_alloc(struct uca_camera *cam, uint32_t n_buffers);
  */
 enum uca_cam_state uca_cam_get_state(struct uca_camera *cam);
 
+/**
+ * Allocates memory for a new uca_camera structure and initializes all fields to
+ * sane values.
+ *
+ * \return Pointer to block of memory for a uca_camera structure
+ *
+ * \note This is is a utility function used internally by drivers
+ */
+struct uca_camera *uca_cam_new(void);
 
 /*
  * --- virtual methods --------------------------------------------------------
-- 
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