From e4eb7d51b4d8d7cff6374cc42d2e5eef41792e5c Mon Sep 17 00:00:00 2001 From: David Phillips Date: Sat, 6 Jun 2015 22:23:07 +1200 Subject: Tweaks, comments and to-dos --- README.md | 2 +- mbrot-gen.c | 21 ++++++++++++--------- 2 files changed, 13 insertions(+), 10 deletions(-) diff --git a/README.md b/README.md index 53dc179..0832dbd 100644 --- a/README.md +++ b/README.md @@ -21,7 +21,7 @@ Notes ----- 1. This has your CPU over a barrel. - It spawns twice as many threads as you have cores, so have fun with that. + It spawns as many threads as you have cores, so have fun with that. I'm looking at adding an option to override the number of threads. diff --git a/mbrot-gen.c b/mbrot-gen.c index 08e438d..53be6d6 100644 --- a/mbrot-gen.c +++ b/mbrot-gen.c @@ -36,17 +36,17 @@ int main(int argc, char **argv) iterat = atoi(argv[2]); power = atof(argv[3]); + // Fetch number of cores available on machine, so we can use lots of them to speed things up cores = sysconf (_SC_NPROCESSORS_ONLN); // cores = 8; - - fprintf(stderr, "Found %d cores. I'll spawn as many threads and let the scheduler sort it out.\n", cores); - - + // TO DO: assertions for size, iterat, power and cores + fprintf(stderr, "Found %d cores. I'll spawn as many threads and let the scheduler sort it out.\n", cores); + // TO DO: move to top of function int x,y,s; data_section* sections = malloc(sizeof(data_section)*cores); @@ -55,6 +55,7 @@ int main(int argc, char **argv) // Spawn all the threads! Something something interlacing for (i = 0; i < cores; i++) { + // Has to be a better way sections[i].core = i; sections[i].cores = cores; sections[i].size = size; @@ -65,17 +66,17 @@ int main(int argc, char **argv) pthread_create(§ions[i].thread, NULL, &generate_section, &(sections[i])); } - + // Wait for each thread to complete for (i = 0; i < cores; i++) pthread_join(sections[i].thread, NULL); - - + // Vomit the data segments back onto the screen, deinterlacing + // TO DO: look at fwrite performance benefits over putchar for (y = 0; y < size; y++) for (x = 0; x < size; x++) - printf("%c", sections[y%cores].data[(y/cores)*size + x]); - + putchar(sections[y%cores].data[(y/cores)*size + x]); + // Free the memory we allocated for point data for (s = 0; s < cores; s++) free(sections[s].data); @@ -94,6 +95,8 @@ void *generate_section(void *section) int idx = 0; + // TO DO: assert malloc succeeded + for (y = d->core, b = (d->core*(3.5f/d->size)-1.75f); y < d->size; b+=((d->cores*3.5f)/d->size), y+=d->cores) { for (x = 0, a = -2.5f; x < d->size; a+=(3.5f/d->size), x++) -- cgit v1.1