Lazily load the userdiff attributes in match_funcname(). Use a
separate mutex around this loading to protect the (not thread-safe)
attributes machinery. This lets us re-enable threading with -p and
-W while reducing the overhead caused by looking up attributes.
Signed-off-by: Thomas Rast <trast@xxxxxxxxxxxxxxx>
---
builtin/grep.c | 12 +++++++--
grep.c | 74 ++++++++++++++++++++++++++++++++++----------------------
grep.h | 7 +++++
3 files changed, 61 insertions(+), 32 deletions(-)
diff --git a/builtin/grep.c b/builtin/grep.c
index 988ea1d..bc23c3c 100644
--- a/builtin/grep.c
+++ b/builtin/grep.c
@@ -256,6 +256,7 @@ static void start_threads(struct grep_opt *opt)
pthread_mutex_init(&grep_mutex, NULL);
pthread_mutex_init(&read_sha1_mutex, NULL);
+ pthread_mutex_init(&grep_attr_mutex, NULL);
pthread_cond_init(&cond_add, NULL);
pthread_cond_init(&cond_write, NULL);
pthread_cond_init(&cond_result, NULL);
@@ -303,6 +304,7 @@ static int wait_all(void)
pthread_mutex_destroy(&grep_mutex);
pthread_mutex_destroy(&read_sha1_mutex);
+ pthread_mutex_destroy(&grep_attr_mutex);
pthread_cond_destroy(&cond_add);
pthread_cond_destroy(&cond_write);
pthread_cond_destroy(&cond_result);
@@ -1002,17 +1004,21 @@ int cmd_grep(int argc, const char **argv, const char *prefix)
opt.regflags |= REG_ICASE;
#ifndef NO_PTHREADS
- if (online_cpus() == 1 || !grep_threads_ok(&opt))
+ if (online_cpus() == 1)
use_threads = 0;
+#else
+ use_threads = 0;
+#endif
+
+ opt.use_threads = use_threads;
+#ifndef NO_PTHREADS
if (use_threads) {
if (opt.pre_context || opt.post_context || opt.file_break ||
opt.funcbody)
skip_first_line = 1;
start_threads(&opt);
}
-#else
- use_threads = 0;
#endif
compile_grep_patterns(&opt);
diff --git a/grep.c b/grep.c
index 7a070e9..4dd7da2 100644
--- a/grep.c
+++ b/grep.c
@@ -2,6 +2,7 @@
#include "grep.h"
#include "userdiff.h"
#include "xdiff-interface.h"
+#include "thread-utils.h"
void append_header_grep_pattern(struct grep_opt *opt, enum grep_header_field field, const char *pat)
{
@@ -806,10 +807,46 @@ static void show_line(struct grep_opt *opt, char *bol, char *eol,
opt->output(opt, "\n", 1);
}
-static int match_funcname(struct grep_opt *opt, char *bol, char *eol)
+#ifndef NO_PTHREADS
+/*
+ * This lock protects access to the gitattributes machinery, which is
+ * not thread-safe.
+ */
+pthread_mutex_t grep_attr_mutex;
+
+static inline void grep_attr_lock(struct grep_opt *opt)
+{
+ if (opt->use_threads)
+ pthread_mutex_lock(&grep_attr_mutex);
+}
+
+static inline void grep_attr_unlock(struct grep_opt *opt)
+{
+ if (opt->use_threads)
+ pthread_mutex_unlock(&grep_attr_mutex);
+}
+#else
+#define grep_attr_lock(opt)
+#define grep_attr_unlock(opt)
+#endif
+
+static int match_funcname(struct grep_opt *opt, const char *name, char *bol, char *eol)
{
xdemitconf_t *xecfg = opt->priv;
- if (xecfg && xecfg->find_func) {
+ if (xecfg && !xecfg->find_func) {
+ struct userdiff_driver *drv;
+ grep_attr_lock(opt);
+ drv = userdiff_find_by_path(name);
+ grep_attr_unlock(opt);
+ if (drv && drv->funcname.pattern) {
+ const struct userdiff_funcname *pe = &drv->funcname;
+ xdiff_set_find_func(xecfg, pe->pattern, pe->cflags);
+ } else {
+ xecfg = opt->priv = NULL;
+ }
+ }
+
+ if (xecfg) {
char buf[1];
return xecfg->find_func(bol, eol - bol, buf, 1,
xecfg->find_func_priv) >= 0;
@@ -835,7 +872,7 @@ static void show_funcname_line(struct grep_opt *opt, const char *name,
if (lno <= opt->last_shown)
break;
- if (match_funcname(opt, bol, eol)) {
+ if (match_funcname(opt, name, bol, eol)) {
show_line(opt, bol, eol, name, lno, '=');
break;
}
@@ -848,7 +885,7 @@ static void show_pre_context(struct grep_opt *opt, const char *name, char *buf,
unsigned cur = lno, from = 1, funcname_lno = 0;
int funcname_needed = !!opt->funcname;
- if (opt->funcbody && !match_funcname(opt, bol, end))
+ if (opt->funcbody && !match_funcname(opt, name, bol, end))
funcname_needed = 2;
if (opt->pre_context < lno)
@@ -864,7 +901,7 @@ static void show_pre_context(struct grep_opt *opt, const char *name, char *buf,
while (bol > buf && bol[-1] != '\n')
bol--;
cur--;
- if (funcname_needed && match_funcname(opt, bol, eol)) {
+ if (funcname_needed && match_funcname(opt, name, bol, eol)) {
funcname_lno = cur;
funcname_needed = 0;
}
@@ -942,19 +979,6 @@ static int look_ahead(struct grep_opt *opt,
return 0;
}
-int grep_threads_ok(const struct grep_opt *opt)
-{
- /* If this condition is true, then we may use the attribute
- * machinery in grep_buffer_1. The attribute code is not
- * thread safe, so we disable the use of threads.
- */
- if ((opt->funcname || opt->funcbody)
- && !opt->unmatch_name_only && !opt->status_only && !opt->name_only)
- return 0;
-
- return 1;
-}
-
static void std_output(struct grep_opt *opt, const void *buf, size_t size)
{
fwrite(buf, size, 1, stdout);
@@ -1008,16 +1032,8 @@ static int grep_buffer_1(struct grep_opt *opt, const char *name,
}
memset(&xecfg, 0, sizeof(xecfg));
- if ((opt->funcname || opt->funcbody)
- && !opt->unmatch_name_only && !opt->status_only &&
- !opt->name_only && !binary_match_only && !collect_hits) {
- struct userdiff_driver *drv = userdiff_find_by_path(name);
- if (drv && drv->funcname.pattern) {
- const struct userdiff_funcname *pe = &drv->funcname;
- xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
- opt->priv = &xecfg;
- }
- }
+ opt->priv = &xecfg;
+
try_lookahead = should_lookahead(opt);
while (left) {
@@ -1093,7 +1109,7 @@ static int grep_buffer_1(struct grep_opt *opt, const char *name,
show_function = 1;
goto next_line;
}
- if (show_function && match_funcname(opt, bol, eol))
+ if (show_function && match_funcname(opt, name, bol, eol))
show_function = 0;
if (show_function ||
(last_hit && lno <= last_hit + opt->post_context)) {
diff --git a/grep.h b/grep.h
index a652800..15d227c 100644
--- a/grep.h
+++ b/grep.h
@@ -115,6 +115,7 @@ struct grep_opt {
int show_hunk_mark;
int file_break;
int heading;
+ int use_threads;
void *priv;
void (*output)(struct grep_opt *opt, const void *data, size_t size);
@@ -131,4 +132,10 @@ struct grep_opt {
extern struct grep_opt *grep_opt_dup(const struct grep_opt *opt);
extern int grep_threads_ok(const struct grep_opt *opt);
+#ifndef NO_PTHREADS
+/* Mutex used around access to the attributes machinery if
+ * opt->use_threads. Must be initialized/destroyed by callers! */
+extern pthread_mutex_t grep_attr_mutex;
+#endif
+
#endif
--
1.7.8.431.g2abf2
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