Add a shared ResourcePool to share resources between EffectChains.

[movit] / resource_pool.cpp

diff --git a/resource_pool.cpp b/resource_pool.cpp
new file mode 100644 (file)
index 0000000..e65d0a9
--- /dev/null
+++ b/resource_pool.cpp
@@ -0,0 +1,129 @@
+#include "resource_pool.h"
+
+#include <stdio.h>
+#include <pthread.h>
+
+#include <algorithm>
+#include <map>
+#include <string>
+#include <utility>
+
+#include "init.h"
+#include "util.h"
+
+using namespace std;
+
+ResourcePool::ResourcePool(size_t program_freelist_max_length)
+       : program_freelist_max_length(program_freelist_max_length) {
+       pthread_mutex_init(&lock, NULL);
+}
+
+ResourcePool::~ResourcePool()
+{
+       assert(program_refcount.empty());
+
+       for (list<GLuint>::const_iterator freelist_it = program_freelist.begin();
+            freelist_it != program_freelist.end();
+            ++freelist_it) {
+               delete_program(*freelist_it);
+       }
+       assert(programs.empty());
+       assert(program_shaders.empty());
+}
+
+void ResourcePool::delete_program(GLuint glsl_program_num)
+{
+       bool found_program = false;
+       for (std::map<std::pair<std::string, std::string>, GLuint>::iterator program_it = programs.begin();
+            program_it != programs.end();
+            ++program_it) {
+               if (program_it->second == glsl_program_num) {
+                       programs.erase(program_it);
+                       found_program = true;
+                       break;
+               }
+       }
+       assert(found_program);
+       glDeleteProgram(glsl_program_num);
+
+       std::map<GLuint, std::pair<GLuint, GLuint> >::iterator shader_it =
+               program_shaders.find(glsl_program_num);
+       assert(shader_it != program_shaders.end());
+
+       glDeleteShader(shader_it->second.first);
+       glDeleteShader(shader_it->second.second);
+       program_shaders.erase(shader_it);
+}
+
+GLuint ResourcePool::compile_glsl_program(const string& vertex_shader, const string& fragment_shader)
+{
+       GLuint glsl_program_num;
+       pthread_mutex_lock(&lock);
+       const pair<string, string> key(vertex_shader, fragment_shader);
+       if (programs.count(key)) {
+               // Already in the cache. Increment the refcount, or take it off the freelist
+               // if it's zero.
+               glsl_program_num = programs[key];
+               map<GLuint, int>::iterator refcount_it = program_refcount.find(glsl_program_num);
+               if (refcount_it != program_refcount.end()) {
+                       ++refcount_it->second;
+               } else {
+                       list<GLuint>::iterator freelist_it =
+                               find(program_freelist.begin(), program_freelist.end(), glsl_program_num);
+                       assert(freelist_it != program_freelist.end());
+                       program_freelist.erase(freelist_it);
+                       program_refcount.insert(make_pair(glsl_program_num, 1));
+               }
+       } else {
+               // Not in the cache. Compile the shaders.
+               glsl_program_num = glCreateProgram();
+               GLuint vs_obj = compile_shader(vertex_shader, GL_VERTEX_SHADER);
+               GLuint fs_obj = compile_shader(fragment_shader, GL_FRAGMENT_SHADER);
+               glAttachShader(glsl_program_num, vs_obj);
+               check_error();
+               glAttachShader(glsl_program_num, fs_obj);
+               check_error();
+               glLinkProgram(glsl_program_num);
+               check_error();
+
+               if (movit_debug_level == MOVIT_DEBUG_ON) {
+                       // Output shader to a temporary file, for easier debugging.
+                       static int compiled_shader_num = 0;
+                       char filename[256];
+                       sprintf(filename, "chain-%03d.frag", compiled_shader_num++);
+                       FILE *fp = fopen(filename, "w");
+                       if (fp == NULL) {
+                               perror(filename);
+                               exit(1);
+                       }
+                       fprintf(fp, "%s\n", fragment_shader.c_str());
+                       fclose(fp);
+               }
+
+               programs.insert(make_pair(key, glsl_program_num));
+               program_refcount.insert(make_pair(glsl_program_num, 1));
+               program_shaders.insert(make_pair(glsl_program_num, make_pair(vs_obj, fs_obj)));
+       }
+       pthread_mutex_unlock(&lock);
+       return glsl_program_num;
+}
+
+void ResourcePool::release_glsl_program(GLuint glsl_program_num)
+{
+       pthread_mutex_lock(&lock);
+       map<GLuint, int>::iterator refcount_it = program_refcount.find(glsl_program_num);
+       assert(refcount_it != program_refcount.end());
+
+       if (--refcount_it->second == 0) {
+               program_refcount.erase(refcount_it);
+               assert(find(program_freelist.begin(), program_freelist.end(), glsl_program_num)
+                       == program_freelist.end());
+               program_freelist.push_front(glsl_program_num);
+               if (program_freelist.size() > program_freelist_max_length) {
+                       delete_program(program_freelist.back());
+                       program_freelist.pop_back();
+               }
+       }
+
+       pthread_mutex_unlock(&lock);
+}