// safely called from multiple threads at the same time, provided they have
// separate (but sharing) OpenGL contexts.
+#include <GL/glew.h>
+#include <pthread.h>
+#include <stddef.h>
#include <list>
#include <map>
#include <string>
#include <utility>
-#include <GL/glew.h>
-#include <pthread.h>
+
+namespace movit {
class ResourcePool {
public:
// around after they are no longer in use (in case another EffectChain
// wants that exact program later). Shaders are expensive to compile and do not
// need a lot of resources to keep around, so this should be a reasonable number.
- ResourcePool(size_t program_freelist_max_length = 100);
+ //
+ // texture_freelist_max_bytes is how many bytes of unused textures to keep around
+ // after they are no longer in use (in case a new texture of the same dimensions
+ // and format is needed). Note that the size estimate is very coarse; it does not
+ // take into account padding, metadata, and most importantly mipmapping.
+ // This means you should be prepared for actual memory usage of the freelist being
+ // twice this estimate or more.
+ ResourcePool(size_t program_freelist_max_length = 100,
+ size_t texture_freelist_max_bytes = 100 << 20); // 100 MB.
~ResourcePool();
// All remaining functions are intended for calls from EffectChain only.
// Protects all the other elements in the class.
pthread_mutex_t lock;
- size_t program_freelist_max_length;
+ size_t program_freelist_max_length, texture_freelist_max_bytes;
// A mapping from vertex/fragment shader source strings to compiled program number.
std::map<std::pair<std::string, std::string>, GLuint> programs;
std::map<GLuint, std::pair<GLuint, GLuint> > program_shaders;
// A list of programs that are no longer in use, most recently freed first.
- // Once this reaches <program_freelist_max_length>,
+ // Once this reaches <program_freelist_max_length>, the last element
+ // will be deleted.
std::list<GLuint> program_freelist;
+
+ struct Texture2D {
+ GLint internal_format;
+ GLsizei width, height;
+ };
+
+ // A mapping from texture number to format details. This is filled if the
+ // texture is given out to a client or on the freelist, but not if it is
+ // deleted from the freelist.
+ std::map<GLuint, Texture2D> texture_formats;
+
+ // A list of all textures that are release but not freed (most recently freed
+ // first), and an estimate of their current memory usage. Once
+ // <texture_freelist_bytes> goes above <texture_freelist_max_bytes>,
+ // elements are deleted off the end of the list until we are under the limit
+ // again.
+ std::list<GLuint> texture_freelist;
+ size_t texture_freelist_bytes;
+
+ // See the caveats at the constructor.
+ static size_t estimate_texture_size(const Texture2D &texture_format);
};
+} // namespace movit
+
#endif // !defined(_MOVIT_RESOURCE_POOL_H)