Add the ability to entirely disable threading by having grep.threads=0
in the config or --threads=0 on the command-line.
This was made configurable in commit 89f09dd34e ("grep: add
--threads=<num> option and grep.threads configuration",
2015-12-15). Before that change there was no way to disable threaded
grep other than to recompile Git.
It's very useful for testing & debugging to be able to entirely
disable threading without recompiling with NO_PTHREADS=YesPlease, so
support setting the value to 0 to disable threading.
There was no reason this wasn't the case already other than an
implementation detail in how OPT_INTEGER() works. When it's used
there's no way to tell the difference between an unset value & the
default value. Use OPT_CALLBACK() instead using the same pattern as in
commit b16a991c1b ("cherry-pick: detect bogus arguments to
--mainline", 2017-03-15).
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@xxxxxxxxx>
---
Documentation/git-grep.txt | 4 ++--
builtin/grep.c | 26 ++++++++++++++++++++++----
t/t7810-grep.sh | 10 ++++++++++
3 files changed, 34 insertions(+), 6 deletions(-)
diff --git a/Documentation/git-grep.txt b/Documentation/git-grep.txt
index 71f32f3508..7b52e3fbc4 100644
--- a/Documentation/git-grep.txt
+++ b/Documentation/git-grep.txt
@@ -56,8 +56,8 @@ grep.extendedRegexp::
other than 'default'.
grep.threads::
- Number of grep worker threads to use. If unset (or set to 0),
- 8 threads are used by default (for now).
+ Number of grep worker threads to use. If unset, 8 threads are
+ used by default (for now). Set to 0 to disable threading.
grep.fullName::
If set to true, enable `--full-name` option by default.
diff --git a/builtin/grep.c b/builtin/grep.c
index 65070c52fc..9478ab5dff 100644
--- a/builtin/grep.c
+++ b/builtin/grep.c
@@ -35,7 +35,7 @@ static int grep_submodule_launch(struct grep_opt *opt,
const struct grep_source *gs);
#define GREP_NUM_THREADS_DEFAULT 8
-static int num_threads;
+static int num_threads = -1;
#ifndef NO_PTHREADS
static pthread_t *threads;
@@ -897,6 +897,24 @@ static int context_callback(const struct option *opt, const char *arg,
return 0;
}
+static int thread_callback(const struct option *opt,
+ const char *arg, int unset)
+{
+ int *threads = (int*)opt->value;
+ char *end;
+
+ if (unset) {
+ *threads = GREP_NUM_THREADS_DEFAULT;
+ return 0;
+ }
+
+ *threads = strtol(arg, &end, 10);
+ if (*end || *threads < 0)
+ return opterror(opt, "invalid number of threads specified", 0);
+
+ return 0;
+}
+
static int file_callback(const struct option *opt, const char *arg, int unset)
{
struct grep_opt *grep_opt = opt->value;
@@ -1049,8 +1067,8 @@ int cmd_grep(int argc, const char **argv, const char *prefix)
N_("show <n> context lines before matches")),
OPT_INTEGER('A', "after-context", &opt.post_context,
N_("show <n> context lines after matches")),
- OPT_INTEGER(0, "threads", &num_threads,
- N_("use <n> worker threads")),
+ OPT_CALLBACK(0, "threads", &num_threads, N_("n"),
+ N_("use <n> worker threads"), thread_callback),
OPT_NUMBER_CALLBACK(&opt, N_("shortcut for -C NUM"),
context_callback),
OPT_BOOL('p', "show-function", &opt.funcname,
@@ -1222,7 +1240,7 @@ int cmd_grep(int argc, const char **argv, const char *prefix)
#ifndef NO_PTHREADS
if (list.nr || cached || show_in_pager)
num_threads = 0;
- else if (num_threads == 0)
+ else if (num_threads == -1)
num_threads = GREP_NUM_THREADS_DEFAULT;
else if (num_threads < 0)
die(_("invalid number of threads specified (%d)"), num_threads);
diff --git a/t/t7810-grep.sh b/t/t7810-grep.sh
index cee42097b0..53c2ca05c4 100755
--- a/t/t7810-grep.sh
+++ b/t/t7810-grep.sh
@@ -1505,4 +1505,14 @@ test_expect_success 'grep does not report i-t-a and assume unchanged with -L' '
test_cmp expected actual
'
+test_expect_success 'grep with thread options' '
+ git -c grep.threads=4 grep st.*dio &&
+ git grep --threads=4 st.*dio &&
+ git -c grep.threads=4 grep --threads=6 st.*dio &&
+ test_must_fail git -c grep.threads=-1 grep st.*dio &&
+ test_must_fail git -c grep.threads=-1 grep --threads=-1 st.*dio &&
+ test_must_fail git -c grep.threads=-1 grep --threads=1 st.*dio &&
+ test_must_fail git -c grep.threads=1 grep --threads=-1 st.*dio
+'
+
test_done
--
2.11.0