diff options
| -rw-r--r-- | libdimension/raytrace.c | 102 | ||||
| -rw-r--r-- | libdimension/threads.c | 51 | ||||
| -rw-r--r-- | libdimension/threads.h | 20 |
3 files changed, 93 insertions, 80 deletions
diff --git a/libdimension/raytrace.c b/libdimension/raytrace.c index ff89d6f..4e762f3 100644 --- a/libdimension/raytrace.c +++ b/libdimension/raytrace.c @@ -25,7 +25,6 @@ #include "dimension-impl.h" #include <stdlib.h> -#include <pthread.h> /* * Boilerplate for multithreading @@ -36,22 +35,21 @@ typedef struct { dmnsn_progress *progress; dmnsn_scene *scene; dmnsn_prtree *prtree; - - /* For multithreading */ - unsigned int index, threads; } dmnsn_raytrace_payload; -/** Background thread callback. */ -static int dmnsn_raytrace_scene_thread(void *ptr); - /* Raytrace a scene */ void dmnsn_raytrace_scene(dmnsn_scene *scene) { dmnsn_progress *progress = dmnsn_raytrace_scene_async(scene); - dmnsn_finish_progress(progress); + if (dmnsn_finish_progress(progress) != 0) { + dmnsn_error(DMNSN_SEVERITY_HIGH, "Error occured while raytracing."); + } } +/** Background thread callback. */ +static int dmnsn_raytrace_scene_thread(void *ptr); + /* Raytrace a scene in the background */ dmnsn_progress * dmnsn_raytrace_scene_async(dmnsn_scene *scene) @@ -69,7 +67,8 @@ dmnsn_raytrace_scene_async(dmnsn_scene *scene) } /** Worker thread callback. */ -static void *dmnsn_raytrace_scene_multithread_thread(void *ptr); +static int dmnsn_raytrace_scene_concurrent(void *ptr, unsigned int thread, + unsigned int nthreads); /* Thread callback -- set up the multithreaded engine */ static int @@ -85,82 +84,19 @@ dmnsn_raytrace_scene_thread(void *ptr) payload->prtree = dmnsn_new_prtree(payload->scene->objects); dmnsn_complete_timer(payload->scene->bounding_timer); - dmnsn_raytrace_payload *payloads; - pthread_t *threads; - - int nthreads = payload->scene->nthreads; - /* Sanity check */ - if (nthreads < 1) - nthreads = 1; - - payloads = dmnsn_malloc(nthreads*sizeof(dmnsn_raytrace_payload)); - threads = dmnsn_malloc(nthreads*sizeof(pthread_t)); - /* Set up the progress object */ dmnsn_set_progress_total(payload->progress, payload->scene->canvas->height); - /* Create the payloads */ - for (int i = 0; i < nthreads; ++i) { - payloads[i] = *payload; - payloads[i].index = i; - payloads[i].threads = nthreads; - } - /* Time the render itself */ payload->scene->render_timer = dmnsn_new_timer(); - /* Create the threads */ - for (int i = 0; i < nthreads; ++i) { - if (pthread_create(&threads[i], NULL, - &dmnsn_raytrace_scene_multithread_thread, - &payloads[i]) != 0) - { - dmnsn_error(DMNSN_SEVERITY_HIGH, - "Couldn't start worker thread in raytrace engine."); - } - } - - /* Join the rest of the threads after detecting an error, so we don't - free anything out from under them */ - bool join_failed = false; - bool error_seen = false; - for (int i = 0; i < nthreads; ++i) { - void *ptr = NULL; - if (pthread_join(threads[i], &ptr) != 0) - join_failed = true; - if (!ptr) - error_seen = true; - } - if (join_failed) { - dmnsn_error(DMNSN_SEVERITY_MEDIUM, - "Couldn't join worker thread in raytrace engine."); - } - if (error_seen) { - dmnsn_error(DMNSN_SEVERITY_HIGH, "Error occurred in worker thread."); - } + int ret = dmnsn_execute_concurrently(&dmnsn_raytrace_scene_concurrent, + payload, payload->scene->nthreads); dmnsn_complete_timer(payload->scene->render_timer); - dmnsn_free(threads); - dmnsn_free(payloads); dmnsn_delete_prtree(payload->prtree); dmnsn_free(payload); - return 0; -} - -/** Actual raytracing implementation. */ -static void dmnsn_raytrace_scene_impl(dmnsn_progress *progress, - dmnsn_scene *scene, - dmnsn_prtree *prtree, - unsigned int index, unsigned int threads); - -/* Multi-threading thread callback */ -static void * -dmnsn_raytrace_scene_multithread_thread(void *ptr) -{ - dmnsn_raytrace_payload *payload = ptr; - dmnsn_raytrace_scene_impl(payload->progress, payload->scene, - payload->prtree, payload->index, payload->threads); - return payload; /* Return non-NULL for success */ + return ret; } /* @@ -192,11 +128,15 @@ static dmnsn_color dmnsn_raytrace_shoot(dmnsn_raytrace_state *state, dmnsn_line ray); /* Actually raytrace a scene */ -static void -dmnsn_raytrace_scene_impl(dmnsn_progress *progress, dmnsn_scene *scene, - dmnsn_prtree *prtree, - unsigned int index, unsigned int threads) +static int +dmnsn_raytrace_scene_concurrent(void *ptr, unsigned int thread, + unsigned int nthreads) { + const dmnsn_raytrace_payload *payload = ptr; + dmnsn_progress *progress = payload->progress; + dmnsn_scene *scene = payload->scene; + dmnsn_prtree *prtree = payload->prtree; + dmnsn_raytrace_state state = { .parent = NULL, .scene = scene, @@ -204,7 +144,7 @@ dmnsn_raytrace_scene_impl(dmnsn_progress *progress, dmnsn_scene *scene, }; /* Iterate through each pixel */ - for (size_t y = index; y < scene->canvas->height; y += threads) { + for (size_t y = thread; y < scene->canvas->height; y += nthreads) { for (size_t x = 0; x < scene->canvas->width; ++x) { /* Get the ray corresponding to the (x,y)'th pixel */ dmnsn_line ray = dmnsn_camera_ray( @@ -223,6 +163,8 @@ dmnsn_raytrace_scene_impl(dmnsn_progress *progress, dmnsn_scene *scene, dmnsn_increment_progress(progress); } + + return 0; } /** Get the intersection texture. */ diff --git a/libdimension/threads.c b/libdimension/threads.c index 5e39fdc..35127ac 100644 --- a/libdimension/threads.c +++ b/libdimension/threads.c @@ -71,3 +71,54 @@ dmnsn_new_thread(dmnsn_progress *progress, dmnsn_thread_fn *thread_fn, dmnsn_error(DMNSN_SEVERITY_HIGH, "Couldn't start thread."); } } + +typedef struct dmnsn_concurrent_thread_payload { + dmnsn_concurrent_thread_fn *thread_fn; + void *arg; + unsigned int thread, nthreads; + int ret; +} dmnsn_concurrent_thread_payload; + +static void * +dmnsn_concurrent_thread(void *ptr) +{ + dmnsn_concurrent_thread_payload *payload = ptr; + payload->ret = (*payload->thread_fn)(payload->arg, payload->thread, + payload->nthreads); + return NULL; +} + +int +dmnsn_execute_concurrently(dmnsn_concurrent_thread_fn *thread_fn, + void *arg, unsigned int nthreads) +{ + pthread_t threads[nthreads]; + dmnsn_concurrent_thread_payload payloads[nthreads]; + + for (unsigned int i = 0; i < nthreads; ++i) { + payloads[i].thread_fn = thread_fn; + payloads[i].arg = arg; + payloads[i].thread = i; + payloads[i].nthreads = nthreads; + payloads[i].ret = -1; + if (pthread_create(&threads[i], NULL, &dmnsn_concurrent_thread, + &payloads[i]) != 0) + { + dmnsn_error(DMNSN_SEVERITY_HIGH, "Couldn't start worker thread."); + } + } + + int ret = 0; + for (unsigned int i = 0; i < nthreads; ++i) { + if (pthread_join(threads[i], NULL) == 0) { + if (payloads[i].ret != 0) { + ret = payloads[i].ret; + } + } else { + dmnsn_error(DMNSN_SEVERITY_MEDIUM, "Couldn't join worker thread."); + ret = -1; + } + } + + return ret; +} diff --git a/libdimension/threads.h b/libdimension/threads.h index 7ae6288..fdf2df7 100644 --- a/libdimension/threads.h +++ b/libdimension/threads.h @@ -34,6 +34,16 @@ typedef int dmnsn_thread_fn(void *ptr); /** + * Thread callback type for parallel tasks. + * @param[in,out] ptr An arbitrary pointer. + * @param[in] thread An ID for this thread, in [0, \p nthreads). + * @param[in] nthreads The number of concurrent threads. + * @return 0 on success, non-zero on failure. + */ +typedef int dmnsn_concurrent_thread_fn(void *ptr, unsigned int thread, + unsigned int nthreads); + +/** * Create a thread that cleans up after itself on errors. * @param[in,out] progress The progress object to associate with the thread. * @param[in] thread_fn The thread callback. @@ -42,4 +52,14 @@ typedef int dmnsn_thread_fn(void *ptr); void dmnsn_new_thread(dmnsn_progress *progress, dmnsn_thread_fn *thread_fn, void *arg); +/** + * Run \p nthreads threads in parallel. + * @param[in] thread_fn The routine to run in each concurrent thread. + * @param[in,out] arg The pointer to pass to the thread callbacks. + * @param[in] nthreads The number of concurrent threads to run. + * @return 0 if all threads were successful, and an error code otherwise. + */ +int dmnsn_execute_concurrently(dmnsn_concurrent_thread_fn *thread_fn, + void *arg, unsigned int nthreads); + #endif /* DIMENSION_IMPL_THREADS_H */ |