New dmnsn_array_size() thread-safe function.

4 files changed, 61 insertions, 27 deletions

diff --git a/libdimension/array.c b/libdimension/array.c
index f0378cf..f8f3c58 100644
--- a/libdimension/array.c
+++ b/libdimension/array.c
@@ -64,15 +64,20 @@ void dmnsn_delete_array(dmnsn_array *array) {
 void
 dmnsn_array_push(dmnsn_array *array, const void *obj)
 {
-  dmnsn_array_set(array, array->length, obj);
+  dmnsn_array_wrlock(array);
+    dmnsn_array_set_impl(array, dmnsn_array_size_unlocked(array), obj);
+  dmnsn_array_unlock(array);
 }
 
 void
 dmnsn_array_pop(dmnsn_array *array, void *obj)
 {
+  size_t size;
+
   dmnsn_array_wrlock(array);
-  dmnsn_array_get_impl(array, array->length - 1, obj);
-  dmnsn_array_resize_unlocked(array, array->length - 1);
+    size = dmnsn_array_size_unlocked(array);
+    dmnsn_array_get_impl(array, size - 1, obj);
+    dmnsn_array_resize_unlocked(array, size - 1);
   dmnsn_array_unlock(array);
 }
 
@@ -80,7 +85,7 @@ void
 dmnsn_array_get(const dmnsn_array *array, size_t i, void *obj)
 {
   dmnsn_array_rdlock(array);
-  dmnsn_array_get_impl(array, i, obj);
+    dmnsn_array_get_impl(array, i, obj);
   dmnsn_array_unlock(array);
 }
 
@@ -88,25 +93,43 @@ void
 dmnsn_array_set(dmnsn_array *array, size_t i, const void *obj)
 {
   dmnsn_array_wrlock(array);
-  dmnsn_array_set_impl(array, i, obj);
+    dmnsn_array_set_impl(array, i, obj);
   dmnsn_array_unlock(array);
 }
 
+size_t
+dmnsn_array_size(const dmnsn_array *array)
+{
+  size_t size;
+
+  dmnsn_array_rdlock(array);
+    size = dmnsn_array_size_unlocked(array);
+  dmnsn_array_unlock(array);
+
+  return size;
+}
+
 void
 dmnsn_array_resize(dmnsn_array *array, size_t length)
 {
   dmnsn_array_wrlock(array);
-  dmnsn_array_resize_unlocked(array, length);
+    dmnsn_array_resize_unlocked(array, length);
   dmnsn_array_unlock(array);
 }
 
 void *
 dmnsn_array_at(dmnsn_array *array, size_t i)
 {
-  if (i >= array->length) {
+  if (i >= dmnsn_array_size_unlocked(array)) {
     dmnsn_error(DMNSN_SEVERITY_HIGH, "Array index out of bounds.");
   }
-  return array->ptr + array->obj_size*i;
+  return (char *)array->ptr + array->obj_size*i;
+}
+
+size_t
+dmnsn_array_size_unlocked(const dmnsn_array *array)
+{
+  return array->length;
 }
 
 void
@@ -158,7 +181,7 @@ dmnsn_array_unlock(const dmnsn_array *array)
 static void
 dmnsn_array_get_impl(const dmnsn_array *array, size_t i, void *obj)
 {
-  if (i >= array->length) {
+  if (i >= dmnsn_array_size_unlocked(array)) {
     dmnsn_error(DMNSN_SEVERITY_HIGH, "Array index out of bounds.");
   }
   memcpy(obj, array->ptr + array->obj_size*i, array->obj_size);
@@ -167,7 +190,7 @@ dmnsn_array_get_impl(const dmnsn_array *array, size_t i, void *obj)
 static void
 dmnsn_array_set_impl(dmnsn_array *array, size_t i, const void *obj)
 {
-  if (i >= array->length) {
+  if (i >= dmnsn_array_size_unlocked(array)) {
     dmnsn_array_resize_unlocked(array, i + 1);
   }
   memcpy(array->ptr + array->obj_size*i, obj, array->obj_size);
diff --git a/libdimension/dimension/array.h b/libdimension/dimension/array.h
index 5abdf48..d0693fc 100644
--- a/libdimension/dimension/array.h
+++ b/libdimension/dimension/array.h
@@ -46,11 +46,13 @@ void dmnsn_array_pop(dmnsn_array *array, void *obj);
 void dmnsn_array_get(const dmnsn_array *array, size_t i, void *obj);
 void dmnsn_array_set(dmnsn_array *array, size_t i, const void *obj);
 
-void dmnsn_array_resize(dmnsn_array *array, size_t length);
+size_t dmnsn_array_size(const dmnsn_array *array);
+void   dmnsn_array_resize(dmnsn_array *array, size_t length);
 
 /* Manual locking */
 
 void *dmnsn_array_at(dmnsn_array *array, size_t i);
+size_t dmnsn_array_size_unlocked(const dmnsn_array *array);
 void dmnsn_array_resize_unlocked(dmnsn_array *array, size_t length);
 
 void dmnsn_array_rdlock(const dmnsn_array *array);
diff --git a/libdimension/progress.c b/libdimension/progress.c
index aa6891c..dc0339c 100644
--- a/libdimension/progress.c
+++ b/libdimension/progress.c
@@ -22,6 +22,7 @@
 #include <pthread.h>
 #include <stdlib.h> /* For malloc */
 
+/* Allocate a new dmnsn_progress*, returning NULL on failure */
 dmnsn_progress *
 dmnsn_new_progress()
 {
@@ -42,6 +43,8 @@ dmnsn_new_progress()
   return progress;
 }
 
+/* Delete a dmnsn_progress*, which has not yet been associated with a thread;
+   mostly for failed returns from *_async() functions. */
 void
 dmnsn_delete_progress(dmnsn_progress *progress)
 {
@@ -58,6 +61,7 @@ dmnsn_delete_progress(dmnsn_progress *progress)
   }
 }
 
+/* Join the worker thread and delete `progress'. */
 int dmnsn_finish_progress(dmnsn_progress *progress)
 {
   void *ptr;
@@ -82,25 +86,27 @@ int dmnsn_finish_progress(dmnsn_progress *progress)
   return retval;
 }
 
+/* Get the current progress of the worker thread, in [0.0, 1.0] */
 double
 dmnsn_get_progress(const dmnsn_progress *progress)
 {
   dmnsn_progress_element *element;
   double prog = 0.0;
-  unsigned int i;
+  unsigned int i, size;
 
   dmnsn_array_rdlock(progress->elements);
-  for (i = 0; i < progress->elements->length; ++i) {
-    element = dmnsn_array_at(progress->elements,
-                             progress->elements->length - i - 1);
-    prog += element->progress;
-    prog /= element->total;
-  }
+    size = dmnsn_array_size_unlocked(progress->elements);
+    for (i = 0; i < size; ++i) {
+      element = dmnsn_array_at(progress->elements, size - i - 1);
+      prog += element->progress;
+      prog /= element->total;
+    }
   dmnsn_array_unlock(progress->elements);
 
   return prog;
 }
 
+/* A new level of algorithmic nesting */
 void
 dmnsn_new_progress_element(dmnsn_progress *progress, unsigned int total)
 {
@@ -108,20 +114,23 @@ dmnsn_new_progress_element(dmnsn_progress *progress, unsigned int total)
   dmnsn_array_push(progress->elements, &element);
 }
 
+/* Only the innermost loop needs to call this function - it handles the rest
+   upon loop completion (progress == total) */
 void
 dmnsn_increment_progress(dmnsn_progress *progress)
 {
   dmnsn_progress_element *element;
+  size_t size;
 
   dmnsn_array_wrlock(progress->elements);
-    element = dmnsn_array_at(progress->elements, progress->elements->length - 1);
+    size = dmnsn_array_size_unlocked(progress->elements);
+    element = dmnsn_array_at(progress->elements, size - 1);
     ++element->progress;
 
-    while (element->progress >= element->total
-          && progress->elements->length > 1) {
-      dmnsn_array_resize_unlocked(progress->elements,
-                                  progress->elements->length - 1);
-      element = dmnsn_array_at(progress->elements, progress->elements->length - 1);
+    while (element->progress >= element->total && size > 1) {
+      --size;
+      dmnsn_array_resize_unlocked(progress->elements, size);
+      element = dmnsn_array_at(progress->elements, size - 1);
       ++element->progress;
     }
 
@@ -139,7 +148,7 @@ dmnsn_progress_done(dmnsn_progress *progress)
 
   dmnsn_array_wrlock(progress->elements);
     dmnsn_array_resize_unlocked(progress->elements, 1);
-    element = dmnsn_array_at(progress->elements, progress->elements->length - 1);
+    element = dmnsn_array_at(progress->elements, 0);
     element->progress = element->total;
 
     if (pthread_cond_broadcast(&progress->cond) != 0) {
diff --git a/libdimension/raytrace.c b/libdimension/raytrace.c
index e91dbb2..8a01f23 100644
--- a/libdimension/raytrace.c
+++ b/libdimension/raytrace.c
@@ -88,7 +88,7 @@ dmnsn_raytrace_scene_thread(void *arg)
         /* Get the ray corresponding to the (i,j)th pixel */
         ray = (*scene->camera->ray_fn)(scene->camera, scene->canvas, i, j);
 
-        for (k = 0; k < scene->objects->length; ++k) {
+        for (k = 0; k < dmnsn_array_size(scene->objects); ++k) {
           dmnsn_array_get(scene->objects, k, &object);
 
           /* Transform the ray according to the object */
@@ -96,7 +96,7 @@ dmnsn_raytrace_scene_thread(void *arg)
 
           /* Test for intersections with objects */
           intersections = (*object->intersections_fn)(object, ray_trans);
-          for (l = 0; l < intersections->length; ++l) {
+          for (l = 0; l < dmnsn_array_size(intersections); ++l) {
             dmnsn_array_get(intersections, l, &t_temp);
             if (t_temp < t || t == 0.0) t = t_temp;
           }