/* * Copyright (C) 2008 Linus Torvalds */ #include "cache.h" #include "pathspec.h" #include "dir.h" #ifdef NO_PTHREADS static void preload_index(struct index_state *index, const struct pathspec *pathspec) { ; /* nothing */ } #else #include <pthread.h> /* * Mostly randomly chosen maximum thread counts: we * cap the parallelism to 20 threads, and we want * to have at least 500 lstat's per thread for it to * be worth starting a thread. */ #define MAX_PARALLEL (20) #define THREAD_COST (500) struct thread_data { pthread_t pthread; struct index_state *index; struct pathspec pathspec; int offset, nr; }; static void *preload_thread(void *_data) { int nr; struct thread_data *p = _data; struct index_state *index = p->index; struct cache_entry **cep = index->cache + p->offset; struct cache_def cache = CACHE_DEF_INIT; nr = p->nr; if (nr + p->offset > index->cache_nr) nr = index->cache_nr - p->offset; do { struct cache_entry *ce = *cep++; struct stat st; if (ce_stage(ce)) continue; if (S_ISGITLINK(ce->ce_mode)) continue; if (ce_uptodate(ce)) continue; if (!ce_path_match(ce, &p->pathspec, NULL)) continue; if (threaded_has_symlink_leading_path(&cache, ce->name, ce_namelen(ce))) continue; if (lstat(ce->name, &st)) continue; if (ie_match_stat(index, ce, &st, CE_MATCH_RACY_IS_DIRTY)) continue; ce_mark_uptodate(ce); } while (--nr > 0); cache_def_clear(&cache); return NULL; } static void preload_index(struct index_state *index, const struct pathspec *pathspec) { int threads, i, work, offset; struct thread_data data[MAX_PARALLEL]; if (!core_preload_index) return; threads = index->cache_nr / THREAD_COST; if (threads < 2) return; if (threads > MAX_PARALLEL) threads = MAX_PARALLEL; offset = 0; work = DIV_ROUND_UP(index->cache_nr, threads); memset(&data, 0, sizeof(data)); for (i = 0; i < threads; i++) { struct thread_data *p = data+i; p->index = index; if (pathspec) copy_pathspec(&p->pathspec, pathspec); p->offset = offset; p->nr = work; offset += work; if (pthread_create(&p->pthread, NULL, preload_thread, p)) die("unable to create threaded lstat"); } for (i = 0; i < threads; i++) { struct thread_data *p = data+i; if (pthread_join(p->pthread, NULL)) die("unable to join threaded lstat"); } } #endif int read_index_preload(struct index_state *index, const struct pathspec *pathspec) { int retval = read_index(index); preload_index(index, pathspec); return retval; }