git/preload-index.c
Junio C Hamano 26b80a841a Merge branch 'nd/pthreads'
The codebase has been cleaned up to reduce "#ifndef NO_PTHREADS".

* nd/pthreads:
  Clean up pthread_create() error handling
  read-cache.c: initialize copy_len to shut up gcc 8
  read-cache.c: reduce branching based on HAVE_THREADS
  read-cache.c: remove #ifdef NO_PTHREADS
  pack-objects: remove #ifdef NO_PTHREADS
  preload-index.c: remove #ifdef NO_PTHREADS
  grep: clean up num_threads handling
  grep: remove #ifdef NO_PTHREADS
  attr.c: remove #ifdef NO_PTHREADS
  name-hash.c: remove #ifdef NO_PTHREADS
  index-pack: remove #ifdef NO_PTHREADS
  send-pack.c: move async's #ifdef NO_PTHREADS back to run-command.c
  run-command.h: include thread-utils.h instead of pthread.h
  thread-utils: macros to unconditionally compile pthreads API
2018-11-18 18:23:52 +09:00

158 lines
3.7 KiB
C

/*
* Copyright (C) 2008 Linus Torvalds
*/
#include "cache.h"
#include "pathspec.h"
#include "dir.h"
#include "fsmonitor.h"
#include "config.h"
#include "progress.h"
#include "thread-utils.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 progress_data {
unsigned long n;
struct progress *progress;
pthread_mutex_t mutex;
};
struct thread_data {
pthread_t pthread;
struct index_state *index;
struct pathspec pathspec;
struct progress_data *progress;
int offset, nr;
};
static void *preload_thread(void *_data)
{
int nr, last_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;
last_nr = nr;
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_skip_worktree(ce))
continue;
if (ce->ce_flags & CE_FSMONITOR_VALID)
continue;
if (p->progress && !(nr & 31)) {
struct progress_data *pd = p->progress;
pthread_mutex_lock(&pd->mutex);
pd->n += last_nr - nr;
display_progress(pd->progress, pd->n);
pthread_mutex_unlock(&pd->mutex);
last_nr = nr;
}
if (!ce_path_match(index, 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|CE_MATCH_IGNORE_FSMONITOR))
continue;
ce_mark_uptodate(ce);
mark_fsmonitor_valid(ce);
} while (--nr > 0);
if (p->progress) {
struct progress_data *pd = p->progress;
pthread_mutex_lock(&pd->mutex);
display_progress(pd->progress, pd->n + last_nr);
pthread_mutex_unlock(&pd->mutex);
}
cache_def_clear(&cache);
return NULL;
}
void preload_index(struct index_state *index,
const struct pathspec *pathspec,
unsigned int refresh_flags)
{
int threads, i, work, offset;
struct thread_data data[MAX_PARALLEL];
struct progress_data pd;
if (!HAVE_THREADS || !core_preload_index)
return;
threads = index->cache_nr / THREAD_COST;
if ((index->cache_nr > 1) && (threads < 2) && git_env_bool("GIT_TEST_PRELOAD_INDEX", 0))
threads = 2;
if (threads < 2)
return;
trace_performance_enter();
if (threads > MAX_PARALLEL)
threads = MAX_PARALLEL;
offset = 0;
work = DIV_ROUND_UP(index->cache_nr, threads);
memset(&data, 0, sizeof(data));
memset(&pd, 0, sizeof(pd));
if (refresh_flags & REFRESH_PROGRESS && isatty(2)) {
pd.progress = start_delayed_progress(_("Refreshing index"), index->cache_nr);
pthread_mutex_init(&pd.mutex, NULL);
}
for (i = 0; i < threads; i++) {
struct thread_data *p = data+i;
int err;
p->index = index;
if (pathspec)
copy_pathspec(&p->pathspec, pathspec);
p->offset = offset;
p->nr = work;
if (pd.progress)
p->progress = &pd;
offset += work;
err = pthread_create(&p->pthread, NULL, preload_thread, p);
if (err)
die(_("unable to create threaded lstat: %s"), strerror(err));
}
for (i = 0; i < threads; i++) {
struct thread_data *p = data+i;
if (pthread_join(p->pthread, NULL))
die("unable to join threaded lstat");
}
stop_progress(&pd.progress);
trace_performance_leave("preload index");
}
int read_index_preload(struct index_state *index,
const struct pathspec *pathspec,
unsigned int refresh_flags)
{
int retval = read_index(index);
preload_index(index, pathspec, refresh_flags);
return retval;
}