// Thread-safety: All functions except the constructor and destructor can be
// safely called from multiple threads at the same time, provided they have
// separate (but sharing) OpenGL contexts.
+//
+// Memory management (only relevant if you use multiple contexts): Some objects,
+// like FBOs, are not shareable across contexts, and can only be deleted from
+// the context they were created in. Thus, you will need to tell the
+// ResourcePool explicitly if you delete a context, or they will leak (and the
+// ResourcePool destructor will assert-fail). See clean_context().
+#include <epoxy/gl.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.
+ size_t fbo_freelist_max_length = 100); // Per context.
~ResourcePool();
// All remaining functions are intended for calls from EffectChain only.
GLuint compile_glsl_program(const std::string& vertex_shader, const std::string& fragment_shader);
void release_glsl_program(GLuint glsl_program_num);
+ // Allocate a 2D texture of the given internal format and dimensions,
+ // or fetch a previous used if possible. Unbinds GL_TEXTURE_2D afterwards.
+ // Keeps ownership of the texture; you must call release_2d_texture() instead
+ // of deleting it when you no longer want it.
+ GLuint create_2d_texture(GLint internal_format, GLsizei width, GLsizei height);
+ void release_2d_texture(GLuint texture_num);
+
+ // Allocate an FBO with the the given texture bound as a framebuffer attachment,
+ // or fetch a previous used if possible. Unbinds GL_FRAMEBUFFER afterwards.
+ // Keeps ownership of the FBO; you must call release_fbo() of deleting
+ // it when you no longer want it.
+ //
+ // NOTE: In principle, the FBO doesn't have a resolution or pixel format;
+ // you can bind almost whatever texture you want to it. However, changing
+ // textures can have an adverse effect on performance due to validation,
+ // in particular on NVidia cards. Also, keep in mind that FBOs are not
+ // shareable across contexts, so you must have the context that's supposed
+ // to own the FBO current when you create or release it.
+ GLuint create_fbo(GLuint texture_num);
+ void release_fbo(GLuint fbo_num);
+
+ // Informs the ResourcePool that the current context is going away soon,
+ // and that any resources held for it in the freelist should be deleted.
+ //
+ // You do not need to do this for the last context; the regular destructor
+ // will take care of that. This means that if you only ever use one
+ // thread/context, you never need to call this function.
+ void clean_context();
+
private:
// Delete the given program and both its shaders.
void delete_program(GLuint program_num);
+ // Deletes all FBOs for the given context that belong to deleted textures.
+ void cleanup_unlinked_fbos(void *context);
+
+ // Remove FBOs off the end of the freelist for <context>, until it
+ // is no more than <max_length> elements long.
+ void shrink_fbo_freelist(void *context, size_t max_length);
+
// 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, fbo_freelist_max_length;
// 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;
+
+ struct FBO {
+ GLuint texture_num; // 0 means associated to a texture that has since been deleted.
+ };
+
+ // For each context, a mapping from FBO number to format details. This is
+ // filled if the FBO is given out to a client or on the freelist, but
+ // not if it is deleted from the freelist.
+ std::map<std::pair<void *, GLuint>, FBO> fbo_formats;
+
+ // For each context, a list of all FBOs that are released but not freed
+ // (most recently freed first). Once this reaches <fbo_freelist_max_length>,
+ // the last element will be deleted.
+ std::map<void *, std::list<GLuint> > fbo_freelist;
+
+ // See the caveats at the constructor.
+ static size_t estimate_texture_size(const Texture2D &texture_format);
};
+} // namespace movit
+
#endif // !defined(_MOVIT_RESOURCE_POOL_H)
projects / movit / blobdiff