run-command API: don't fall back on online_cpus()

When a "jobs = 0" is passed let's BUG() out rather than fall back on
online_cpus(). The default behavior was added when this API was
implemented in c553c72eed6 (run-command: add an asynchronous parallel
child processor, 2015-12-15).

Most of our code in-tree that scales up to "online_cpus()" by default
calls that function by itself. Keeping this default behavior just for
the sake of two callers means that we'd need to maintain this one spot
where we're second-guessing the config passed down into pp_init().

The preceding commit has an overview of the API callers that passed
"jobs = 0". There were only two of them (actually three, but they
resolved to these two config parsing codepaths).

The "fetch.parallel" caller already had a test for the
"fetch.parallel=0" case added in 0353c688189 (fetch: do not run a
redundant fetch from submodule, 2022-05-16), but there was no such
test for "submodule.fetchJobs". Let's add one here.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/fetch.c b/builtin/fetch.c
index 78043fb67effff710c0d81ea3b1bdee4b2ef679f..82f1da14ec15150a8397a746bd1b5d9758386587 100644 (file)
--- a/builtin/fetch.c
+++ b/builtin/fetch.c
@@ -122,6 +122,8 @@ static int git_fetch_config(const char *k, const char *v, void *cb)
                fetch_parallel_config = git_config_int(k, v);
                if (fetch_parallel_config < 0)
                        die(_("fetch.parallel cannot be negative"));
+               if (!fetch_parallel_config)
+                       fetch_parallel_config = online_cpus();
                return 0;
        }
 

diff --git a/run-command.c b/run-command.c
index 14a6e38e8042a3af0dfb2dfdfdbc4450fd2275cd..14ea409375a431e82dab7c9362fdb98a6e448e88 100644 (file)
--- a/run-command.c
+++ b/run-command.c
@@ -1564,8 +1564,8 @@ static void pp_init(struct parallel_processes *pp,
                    task_finished_fn task_finished,
                    void *data, int ungroup)
 {
-       if (n < 1)
-               n = online_cpus();
+       if (!n)
+               BUG("you must provide a non-zero number of processes!");
 
        pp->max_processes = n;
 
@@ -1835,8 +1835,7 @@ void run_processes_parallel_tr2(size_t n, get_next_task_fn get_next_task,
                                task_finished_fn task_finished, void *pp_cb,
                                const char *tr2_category, const char *tr2_label)
 {
-       trace2_region_enter_printf(tr2_category, tr2_label, NULL, "max:%d",
-                                  ((n < 1) ? online_cpus() : n));
+       trace2_region_enter_printf(tr2_category, tr2_label, NULL, "max:%d", n);
 
        run_processes_parallel(n, get_next_task, start_failure,
                               task_finished, pp_cb);

diff --git a/submodule-config.c b/submodule-config.c
index cd7ee236a120bc99d91ec615e94a6cd4240937f0..4dc61b3a78a2916d737edf613af0f9c0e03d39c8 100644 (file)
--- a/submodule-config.c
+++ b/submodule-config.c
@@ -303,6 +303,8 @@ int parse_submodule_fetchjobs(const char *var, const char *value)
        int fetchjobs = git_config_int(var, value);
        if (fetchjobs < 0)
                die(_("negative values not allowed for submodule.fetchJobs"));
+       if (!fetchjobs)
+               fetchjobs = online_cpus();
        return fetchjobs;
 }
 

diff --git a/t/t5526-fetch-submodules.sh b/t/t5526-fetch-submodules.sh
index a301b56db894253829a0934647396ad854ec11b7..a5f494dfcfbafbb468add5589cf9fa2279fcd017 100755 (executable)
--- a/t/t5526-fetch-submodules.sh
+++ b/t/t5526-fetch-submodules.sh
@@ -714,7 +714,13 @@ test_expect_success 'fetching submodules respects parallel settings' '
                GIT_TRACE=$(pwd)/trace.out git fetch &&
                grep "8 tasks" trace.out &&
                GIT_TRACE=$(pwd)/trace.out git fetch --jobs 9 &&
-               grep "9 tasks" trace.out
+               grep "9 tasks" trace.out &&
+               >trace.out &&
+
+               GIT_TRACE=$(pwd)/trace.out git -c submodule.fetchJobs=0 fetch &&
+               grep "preparing to run up to [0-9]* tasks" trace.out &&
+               ! grep "up to 0 tasks" trace.out &&
+               >trace.out
        )
 '