// 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 <set>
+#include <stack>
#include <string>
#include <utility>
+#include <vector>
namespace movit {
// 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);
+ size_t fbo_freelist_max_length = 100, // Per context.
+ size_t vao_freelist_max_length = 100); // Per context.
~ResourcePool();
// All remaining functions are intended for calls from EffectChain only.
// compiled program from the cache if possible. Keeps ownership of the
// program; you must call release_glsl_program() instead of deleting it
// when you no longer want it.
- GLuint compile_glsl_program(const std::string& vertex_shader, const std::string& fragment_shader);
+ //
+ // If <fragment_shader_outputs> contains more than one value, the given
+ // outputs will be bound to fragment shader output colors in the order
+ // they appear in the vector. Otherwise, output order is undefined and
+ // determined by the OpenGL driver.
+ GLuint compile_glsl_program(const std::string& vertex_shader,
+ const std::string& fragment_shader,
+ const std::vector<std::string>& frag_shader_outputs);
void release_glsl_program(GLuint glsl_program_num);
+ // Same as the previous, but for compile shaders instead. There is currently
+ // no support for binding multiple outputs.
+ GLuint compile_glsl_compute_program(const std::string& compile_shader);
+ void release_glsl_compute_program(GLuint glsl_program_num);
+
+ // Since uniforms belong to the program and not to the context,
+ // a given GLSL program number can't be used by more than one thread
+ // at a time. Thus, if two threads want to use the same program
+ // (usually because two EffectChains share them via caching),
+ // we will need to make a clone. use_glsl_program() makes such
+ // a clone if needed, calls glUseProgram(), and returns the real
+ // program number that was used; this must be given to
+ // unuse_glsl_program() to release it. unuse_glsl_program() does not
+ // actually change any OpenGL state, though.
+ GLuint use_glsl_program(GLuint glsl_program_num);
+ void unuse_glsl_program(GLuint instance_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
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,
+ // Allocate an FBO with the the given texture(s) bound as framebuffer attachment(s),
// 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. You can get an appropriate context
- // pointer from get_gl_context_identifier().
+ // 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.
- GLuint create_fbo(void *context, GLuint texture_num);
+ // 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 texture0_num,
+ GLuint texture1_num = 0,
+ GLuint texture2_num = 0,
+ GLuint texture3_num = 0);
void release_fbo(GLuint fbo_num);
+ // Create a VAO of a very specific form: All the given attribute indices
+ // are bound to start of the given VBO and contain two-component floats.
+ // Keeps ownership of the VAO; you must call release_vec2_vao() of deleting
+ // it when you no longer want it. VAOs are not sharable across contexts.
+ //
+ // These are not cached primarily for performance, but rather to work
+ // around an NVIDIA driver bug where glVertexAttribPointer() is thread-hostile
+ // (ie., simultaneous GL work in unrelated contexts can cause the driver
+ // to free() memory that was never malloc()-ed).
+ GLuint create_vec2_vao(const std::set<GLint> &attribute_indices,
+ GLuint vbo_num);
+ void release_vec2_vao(const GLuint vao_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);
+
+ // Same, for VAOs.
+ void shrink_vao_freelist(void *context, size_t max_length);
+
+ // Increment the refcount, or take it off the freelist if it's zero.
+ void increment_program_refcount(GLuint program_num);
+
+ // If debugging is on, output shader to a temporary file, for easier debugging.
+ void output_debug_shader(const std::string &shader_src, const std::string &suffix);
+
+ // For a new program that's not a clone of anything, insert it into the right
+ // structures: Give it a refcount, and set up the program_masters / program_instances lists.
+ void add_master_program(GLuint program_num);
+
+ // Link the given vertex and fragment shaders into a full GLSL program.
+ // See compile_glsl_program() for explanation of <fragment_shader_outputs>.
+ static GLuint link_program(GLuint vs_obj,
+ GLuint fs_obj,
+ const std::vector<std::string>& fragment_shader_outputs);
+
+ static GLuint link_compute_program(GLuint cs_obj);
+
// Protects all the other elements in the class.
pthread_mutex_t lock;
- size_t program_freelist_max_length, texture_freelist_max_bytes, fbo_freelist_max_length;
+ size_t program_freelist_max_length, texture_freelist_max_bytes, fbo_freelist_max_length, vao_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;
+ // A mapping from compute shader source string to compiled program number.
+ std::map<std::string, GLuint> compute_programs;
+
// A mapping from compiled program number to number of current users.
// Once this reaches zero, the program is taken out of this map and instead
// put on the freelist (after which it may be deleted).
std::map<GLuint, int> program_refcount;
// A mapping from program number to vertex and fragment shaders.
- std::map<GLuint, std::pair<GLuint, GLuint> > program_shaders;
+ // Contains everything needed to re-link the program.
+ struct ShaderSpec {
+ GLuint vs_obj, fs_obj;
+ std::vector<std::string> fragment_shader_outputs;
+ };
+ std::map<GLuint, ShaderSpec> program_shaders;
+
+ struct ComputeShaderSpec {
+ GLuint cs_obj;
+ };
+ std::map<GLuint, ComputeShaderSpec> compute_program_shaders;
+
+ // For each program, a list of other programs that are exactly like it.
+ // By default, will only contain the program itself, but due to cloning
+ // (see use_glsl_program()), may grow. Programs are taken off this list
+ // while they are in use (by use_glsl_program()).
+ std::map<GLuint, std::stack<GLuint>> program_instances;
+
+ // For each program, the master program that created it
+ // (inverse of program_instances).
+ std::map<GLuint, GLuint> program_masters;
// A list of programs that are no longer in use, most recently freed first.
// Once this reaches <program_freelist_max_length>, the last element
std::list<GLuint> texture_freelist;
size_t texture_freelist_bytes;
+ static const unsigned num_fbo_attachments = 4;
struct FBO {
- void *context;
- GLuint texture_num;
+ GLuint fbo_num;
+ // GL_INVALID_INDEX means associated to a texture that has since been deleted.
+ // 0 means the output isn't bound.
+ GLuint texture_num[num_fbo_attachments];
};
- // 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<GLuint, FBO> fbo_formats;
+ // 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;
+ typedef std::map<std::pair<void *, GLuint>, FBO>::iterator FBOFormatIterator;
- // A list of all FBOs that are release but not freed (most recently freed
- // first). Once this reaches <fbo_freelist_max_length>, the last element
- // will be deleted.
- std::list<GLuint> fbo_freelist;
+ // 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.
+ //
+ // We store iterators directly into <fbo_format> for efficiency.
+ std::map<void *, std::list<FBOFormatIterator>> fbo_freelist;
+
+ // Very similar, for VAOs.
+ struct VAO {
+ GLuint vao_num;
+ std::set<GLint> attribute_indices;
+ GLuint vbo_num;
+ };
+ std::map<std::pair<void *, GLuint>, VAO> vao_formats;
+ typedef std::map<std::pair<void *, GLuint>, VAO>::iterator VAOFormatIterator;
+ std::map<void *, std::list<VAOFormatIterator>> vao_freelist;
// See the caveats at the constructor.
static size_t estimate_texture_size(const Texture2D &texture_format);