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authorFredrik Kuivinen <frekui@gmail.com>2010-01-25 23:51:39 +0100
committerJunio C Hamano <gitster@pobox.com>2010-01-26 09:20:07 -0800
commit5b594f457afcf2cdddb3c79de8bcc571c775aa55 (patch)
treed3014dfa67180a040e0b542f7e46a1f38321158e /builtin-grep.c
parentc8610a2e7eca60a060f719f0aeb20f146e339de4 (diff)
downloadgit-5b594f457afcf2cdddb3c79de8bcc571c775aa55.tar.gz
Threaded grep
Make git grep use threads when it is available. The results below are best of five runs in the Linux repository (on a box with two cores). With the patch: git grep qwerty 1.58user 0.55system 0:01.16elapsed 183%CPU (0avgtext+0avgdata 0maxresident)k 0inputs+800outputs (0major+5774minor)pagefaults 0swaps Without: git grep qwerty 1.59user 0.43system 0:02.02elapsed 100%CPU (0avgtext+0avgdata 0maxresident)k 0inputs+800outputs (0major+3716minor)pagefaults 0swaps And with a pattern with quite a few matches: With the patch: $ /usr/bin/time git grep void 5.61user 0.56system 0:03.44elapsed 179%CPU (0avgtext+0avgdata 0maxresident)k 0inputs+800outputs (0major+5587minor)pagefaults 0swaps Without: $ /usr/bin/time git grep void 5.36user 0.51system 0:05.87elapsed 100%CPU (0avgtext+0avgdata 0maxresident)k 0inputs+800outputs (0major+3693minor)pagefaults 0swaps In either case we gain about 40% by the threading. Signed-off-by: Fredrik Kuivinen <frekui@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Diffstat (limited to 'builtin-grep.c')
-rw-r--r--builtin-grep.c405
1 files changed, 374 insertions, 31 deletions
diff --git a/builtin-grep.c b/builtin-grep.c
index 64cdfefdd1..6cc743d7c5 100644
--- a/builtin-grep.c
+++ b/builtin-grep.c
@@ -16,11 +16,274 @@
#include "quote.h"
#include "dir.h"
+#ifndef NO_PTHREADS
+#include "thread-utils.h"
+#include <pthread.h>
+#endif
+
static char const * const grep_usage[] = {
"git grep [options] [-e] <pattern> [<rev>...] [[--] path...]",
NULL
};
+static int use_threads = 1;
+
+#ifndef NO_PTHREADS
+#define THREADS 8
+static pthread_t threads[THREADS];
+
+static void *load_sha1(const unsigned char *sha1, unsigned long *size,
+ const char *name);
+static void *load_file(const char *filename, size_t *sz);
+
+enum work_type {WORK_SHA1, WORK_FILE};
+
+/* We use one producer thread and THREADS consumer
+ * threads. The producer adds struct work_items to 'todo' and the
+ * consumers pick work items from the same array.
+ */
+struct work_item
+{
+ enum work_type type;
+ char *name;
+
+ /* if type == WORK_SHA1, then 'identifier' is a SHA1,
+ * otherwise type == WORK_FILE, and 'identifier' is a NUL
+ * terminated filename.
+ */
+ void *identifier;
+ char done;
+ struct strbuf out;
+};
+
+/* In the range [todo_done, todo_start) in 'todo' we have work_items
+ * that have been or are processed by a consumer thread. We haven't
+ * written the result for these to stdout yet.
+ *
+ * The work_items in [todo_start, todo_end) are waiting to be picked
+ * up by a consumer thread.
+ *
+ * The ranges are modulo TODO_SIZE.
+ */
+#define TODO_SIZE 128
+static struct work_item todo[TODO_SIZE];
+static int todo_start;
+static int todo_end;
+static int todo_done;
+
+/* Has all work items been added? */
+static int all_work_added;
+
+/* This lock protects all the variables above. */
+static pthread_mutex_t grep_mutex;
+
+/* Used to serialize calls to read_sha1_file. */
+static pthread_mutex_t read_sha1_mutex;
+
+#define grep_lock() pthread_mutex_lock(&grep_mutex)
+#define grep_unlock() pthread_mutex_unlock(&grep_mutex)
+#define read_sha1_lock() pthread_mutex_lock(&read_sha1_mutex)
+#define read_sha1_unlock() pthread_mutex_unlock(&read_sha1_mutex)
+
+/* Signalled when a new work_item is added to todo. */
+static pthread_cond_t cond_add;
+
+/* Signalled when the result from one work_item is written to
+ * stdout.
+ */
+static pthread_cond_t cond_write;
+
+/* Signalled when we are finished with everything. */
+static pthread_cond_t cond_result;
+
+static void add_work(enum work_type type, char *name, void *id)
+{
+ grep_lock();
+
+ while ((todo_end+1) % ARRAY_SIZE(todo) == todo_done) {
+ pthread_cond_wait(&cond_write, &grep_mutex);
+ }
+
+ todo[todo_end].type = type;
+ todo[todo_end].name = name;
+ todo[todo_end].identifier = id;
+ todo[todo_end].done = 0;
+ strbuf_reset(&todo[todo_end].out);
+ todo_end = (todo_end + 1) % ARRAY_SIZE(todo);
+
+ pthread_cond_signal(&cond_add);
+ grep_unlock();
+}
+
+static struct work_item *get_work(void)
+{
+ struct work_item *ret;
+
+ grep_lock();
+ while (todo_start == todo_end && !all_work_added) {
+ pthread_cond_wait(&cond_add, &grep_mutex);
+ }
+
+ if (todo_start == todo_end && all_work_added) {
+ ret = NULL;
+ } else {
+ ret = &todo[todo_start];
+ todo_start = (todo_start + 1) % ARRAY_SIZE(todo);
+ }
+ grep_unlock();
+ return ret;
+}
+
+static void grep_sha1_async(struct grep_opt *opt, char *name,
+ const unsigned char *sha1)
+{
+ unsigned char *s;
+ s = xmalloc(20);
+ memcpy(s, sha1, 20);
+ add_work(WORK_SHA1, name, s);
+}
+
+static void grep_file_async(struct grep_opt *opt, char *name,
+ const char *filename)
+{
+ add_work(WORK_FILE, name, xstrdup(filename));
+}
+
+static void work_done(struct work_item *w)
+{
+ int old_done;
+
+ grep_lock();
+ w->done = 1;
+ old_done = todo_done;
+ for(; todo[todo_done].done && todo_done != todo_start;
+ todo_done = (todo_done+1) % ARRAY_SIZE(todo)) {
+ w = &todo[todo_done];
+ write_or_die(1, w->out.buf, w->out.len);
+ free(w->name);
+ free(w->identifier);
+ }
+
+ if (old_done != todo_done)
+ pthread_cond_signal(&cond_write);
+
+ if (all_work_added && todo_done == todo_end)
+ pthread_cond_signal(&cond_result);
+
+ grep_unlock();
+}
+
+static void *run(void *arg)
+{
+ int hit = 0;
+ struct grep_opt *opt = arg;
+
+ while (1) {
+ struct work_item *w = get_work();
+ if (!w)
+ break;
+
+ opt->output_priv = w;
+ if (w->type == WORK_SHA1) {
+ unsigned long sz;
+ void* data = load_sha1(w->identifier, &sz, w->name);
+
+ if (data) {
+ hit |= grep_buffer(opt, w->name, data, sz);
+ free(data);
+ }
+ } else if (w->type == WORK_FILE) {
+ size_t sz;
+ void* data = load_file(w->identifier, &sz);
+ if (data) {
+ hit |= grep_buffer(opt, w->name, data, sz);
+ free(data);
+ }
+ } else {
+ assert(0);
+ }
+
+ work_done(w);
+ }
+
+ return (void*) (intptr_t) hit;
+}
+
+static void strbuf_out(struct grep_opt *opt, const void *buf, size_t size)
+{
+ struct work_item *w = opt->output_priv;
+ strbuf_add(&w->out, buf, size);
+}
+
+static void start_threads(struct grep_opt *opt)
+{
+ int i;
+
+ pthread_mutex_init(&grep_mutex, NULL);
+ pthread_mutex_init(&read_sha1_mutex, NULL);
+ pthread_cond_init(&cond_add, NULL);
+ pthread_cond_init(&cond_write, NULL);
+ pthread_cond_init(&cond_result, NULL);
+
+ for (i = 0; i < ARRAY_SIZE(todo); i++) {
+ strbuf_init(&todo[i].out, 0);
+ }
+
+ for (i = 0; i < ARRAY_SIZE(threads); i++) {
+ int err;
+ struct grep_opt *o = grep_opt_dup(opt);
+ o->output = strbuf_out;
+ compile_grep_patterns(o);
+ err = pthread_create(&threads[i], NULL, run, o);
+
+ if (err)
+ die("grep: failed to create thread: %s",
+ strerror(err));
+ }
+}
+
+static int wait_all(void)
+{
+ int hit = 0;
+ int i;
+
+ grep_lock();
+ all_work_added = 1;
+
+ /* Wait until all work is done. */
+ while (todo_done != todo_end)
+ pthread_cond_wait(&cond_result, &grep_mutex);
+
+ /* Wake up all the consumer threads so they can see that there
+ * is no more work to do.
+ */
+ pthread_cond_broadcast(&cond_add);
+ grep_unlock();
+
+ for (i = 0; i < ARRAY_SIZE(threads); i++) {
+ void *h;
+ pthread_join(threads[i], &h);
+ hit |= (int) (intptr_t) h;
+ }
+
+ pthread_mutex_destroy(&grep_mutex);
+ pthread_mutex_destroy(&read_sha1_mutex);
+ pthread_cond_destroy(&cond_add);
+ pthread_cond_destroy(&cond_write);
+ pthread_cond_destroy(&cond_result);
+
+ return hit;
+}
+#else /* !NO_PTHREADS */
+#define read_sha1_lock()
+#define read_sha1_unlock()
+
+static int wait_all(void)
+{
+ return 0;
+}
+#endif
+
static int grep_config(const char *var, const char *value, void *cb)
{
struct grep_opt *opt = cb;
@@ -144,37 +407,64 @@ static int pathspec_matches(const char **paths, const char *name, int max_depth)
return 0;
}
-static int grep_sha1(struct grep_opt *opt, const unsigned char *sha1, const char *name, int tree_name_len)
+static void *load_sha1(const unsigned char *sha1, unsigned long *size,
+ const char *name)
{
- unsigned long size;
- char *data;
enum object_type type;
- int hit;
- struct strbuf pathbuf = STRBUF_INIT;
+ char *data;
- data = read_sha1_file(sha1, &type, &size);
- if (!data) {
+ read_sha1_lock();
+ data = read_sha1_file(sha1, &type, size);
+ read_sha1_unlock();
+
+ if (!data)
error("'%s': unable to read %s", name, sha1_to_hex(sha1));
- return 0;
- }
+
+ return data;
+}
+
+static int grep_sha1(struct grep_opt *opt, const unsigned char *sha1,
+ const char *filename, int tree_name_len)
+{
+ struct strbuf pathbuf = STRBUF_INIT;
+ char *name;
+
if (opt->relative && opt->prefix_length) {
- quote_path_relative(name + tree_name_len, -1, &pathbuf, opt->prefix);
- strbuf_insert(&pathbuf, 0, name, tree_name_len);
- name = pathbuf.buf;
+ quote_path_relative(filename + tree_name_len, -1, &pathbuf,
+ opt->prefix);
+ strbuf_insert(&pathbuf, 0, filename, tree_name_len);
+ } else {
+ strbuf_addstr(&pathbuf, filename);
+ }
+
+ name = strbuf_detach(&pathbuf, NULL);
+
+#ifndef NO_PTHREADS
+ if (use_threads) {
+ grep_sha1_async(opt, name, sha1);
+ return 0;
+ } else
+#endif
+ {
+ int hit;
+ unsigned long sz;
+ void *data = load_sha1(sha1, &sz, name);
+ if (!data)
+ hit = 0;
+ else
+ hit = grep_buffer(opt, name, data, sz);
+
+ free(data);
+ free(name);
+ return hit;
}
- hit = grep_buffer(opt, name, data, size);
- strbuf_release(&pathbuf);
- free(data);
- return hit;
}
-static int grep_file(struct grep_opt *opt, const char *filename)
+static void *load_file(const char *filename, size_t *sz)
{
struct stat st;
- int i;
char *data;
- size_t sz;
- struct strbuf buf = STRBUF_INIT;
+ int i;
if (lstat(filename, &st) < 0) {
err_ret:
@@ -184,25 +474,52 @@ static int grep_file(struct grep_opt *opt, const char *filename)
}
if (!S_ISREG(st.st_mode))
return 0;
- sz = xsize_t(st.st_size);
+ *sz = xsize_t(st.st_size);
i = open(filename, O_RDONLY);
if (i < 0)
goto err_ret;
- data = xmalloc(sz + 1);
- if (st.st_size != read_in_full(i, data, sz)) {
+ data = xmalloc(*sz + 1);
+ if (st.st_size != read_in_full(i, data, *sz)) {
error("'%s': short read %s", filename, strerror(errno));
close(i);
free(data);
return 0;
}
close(i);
- data[sz] = 0;
+ data[*sz] = 0;
+ return data;
+}
+
+static int grep_file(struct grep_opt *opt, const char *filename)
+{
+ struct strbuf buf = STRBUF_INIT;
+ char *name;
+
if (opt->relative && opt->prefix_length)
- filename = quote_path_relative(filename, -1, &buf, opt->prefix);
- i = grep_buffer(opt, filename, data, sz);
- strbuf_release(&buf);
- free(data);
- return i;
+ quote_path_relative(filename, -1, &buf, opt->prefix);
+ else
+ strbuf_addstr(&buf, filename);
+ name = strbuf_detach(&buf, NULL);
+
+#ifndef NO_PTHREADS
+ if (use_threads) {
+ grep_file_async(opt, name, filename);
+ return 0;
+ } else
+#endif
+ {
+ int hit;
+ size_t sz;
+ void *data = load_file(filename, &sz);
+ if (!data)
+ hit = 0;
+ else
+ hit = grep_buffer(opt, name, data, sz);
+
+ free(data);
+ free(name);
+ return hit;
+ }
}
static int grep_cache(struct grep_opt *opt, const char **paths, int cached)
@@ -287,7 +604,10 @@ static int grep_tree(struct grep_opt *opt, const char **paths,
void *data;
unsigned long size;
+ read_sha1_lock();
data = read_sha1_file(entry.sha1, &type, &size);
+ read_sha1_unlock();
+
if (!data)
die("unable to read tree (%s)",
sha1_to_hex(entry.sha1));
@@ -581,6 +901,17 @@ int cmd_grep(int argc, const char **argv, const char *prefix)
opt.regflags |= REG_ICASE;
if ((opt.regflags != REG_NEWLINE) && opt.fixed)
die("cannot mix --fixed-strings and regexp");
+
+#ifndef NO_PTHREADS
+ if (online_cpus() == 1 || !grep_threads_ok(&opt))
+ use_threads = 0;
+
+ if (use_threads)
+ start_threads(&opt);
+#else
+ use_threads = 0;
+#endif
+
compile_grep_patterns(&opt);
/* Check revs and then paths */
@@ -618,17 +949,26 @@ int cmd_grep(int argc, const char **argv, const char *prefix)
}
if (!use_index) {
+ int hit;
if (cached)
die("--cached cannot be used with --no-index.");
if (list.nr)
die("--no-index cannot be used with revs.");
- return !grep_directory(&opt, paths);
+ hit = grep_directory(&opt, paths);
+ if (use_threads)
+ hit |= wait_all();
+ return !hit;
}
if (!list.nr) {
+ int hit;
if (!cached)
setup_work_tree();
- return !grep_cache(&opt, paths, cached);
+
+ hit = grep_cache(&opt, paths, cached);
+ if (use_threads)
+ hit |= wait_all();
+ return !hit;
}
if (cached)
@@ -643,6 +983,9 @@ int cmd_grep(int argc, const char **argv, const char *prefix)
break;
}
}
+
+ if (use_threads)
+ hit |= wait_all();
free_grep_patterns(&opt);
return !hit;
}