On Thu, Apr 21, 2022 at 02:25:26PM +0200, Ævar Arnfjörð Bjarmason wrote:
>
> Add a new "struct run_process_parallel_opts" to cover the trace2
> use-case added in ee4512ed481 (trace2: create new combined trace
> facility, 2019-02-22). A subsequent commit will add more options, and
> having a proliferation of new functions or extra parameters would
> result in needless churn.
>
> It makes for a smaller change to make run_processes_parallel() and
> run_processes_parallel_tr2() wrapper functions for the new "static"
> run_processes_parallel_1(), which contains the main logic. We pass
> down "opts" to the *_1() function even though it isn't used there
> yet (only in the *_tr2() function), a subsequent commit will make more
> use of it.
>
> Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@xxxxxxxxx>
> ---
> builtin/fetch.c | 15 ++++++++------
> builtin/submodule--helper.c | 12 +++++++----
> hook.c | 13 ++++++------
> run-command.c | 40 +++++++++++++++++++++++++++----------
> run-command.h | 26 ++++++++++++++++--------
> submodule.c | 13 ++++++------
> t/helper/test-run-command.c | 13 ++++++------
> 7 files changed, 84 insertions(+), 48 deletions(-)
>
> diff --git a/builtin/fetch.c b/builtin/fetch.c
> index e3791f09ed5..9bc99183191 100644
> --- a/builtin/fetch.c
> +++ b/builtin/fetch.c
> @@ -1948,14 +1948,17 @@ static int fetch_multiple(struct string_list *list, int max_children)
>
> if (max_children != 1 && list->nr != 1) {
> struct parallel_fetch_state state = { argv.v, list, 0, 0 };
> + struct run_process_parallel_opts run_opts = {
> + .tr2_category = "fetch",
> + .tr2_label = "parallel/fetch",
> + };
>
> strvec_push(&argv, "--end-of-options");
> - result = run_processes_parallel_tr2(max_children,
> - &fetch_next_remote,
> - &fetch_failed_to_start,
> - &fetch_finished,
> - &state,
> - "fetch", "parallel/fetch");
> + result = run_processes_parallel(max_children,
> + &fetch_next_remote,
> + &fetch_failed_to_start,
> + &fetch_finished, &state,
> + &run_opts);
>
> if (!result)
> result = state.result;
> diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
> index 2c87ef9364f..c3d1aace546 100644
> --- a/builtin/submodule--helper.c
> +++ b/builtin/submodule--helper.c
> @@ -2652,12 +2652,16 @@ static int update_submodules(struct update_data *update_data)
> {
> int i, res = 0;
> struct submodule_update_clone suc = SUBMODULE_UPDATE_CLONE_INIT;
> + struct run_process_parallel_opts run_opts = {
> + .tr2_category = "submodule",
> + .tr2_label = "parallel/update",
> + };
Hm, so now it is possible for a callsite to forget to set these, rather
than to grep for "run_processes_parallel" and notice that everybody else
is already calling "run_processes_parallel_tr2". There are not any
callers of 'run_processes_parallel()' except for a test helper today, so
why do we make this seem optional?
If I'm being honest, I'd rather see everything _but_ the trace2 stuff go
into an opts struct, and then see the same entry points we have today
(run_processes_parallel that takes a struct, run_processes_parallel_tr2
that takes a struct and two tr2 string args). Or, I guess, a single
run_processes_parallel() that only takes a struct, does the right thing
with the trace args, and entirely removes the
run_processes_parallel_tr2 call.
>
> suc.update_data = update_data;
> - run_processes_parallel_tr2(suc.update_data->max_jobs, update_clone_get_next_task,
> - update_clone_start_failure,
> - update_clone_task_finished, &suc, "submodule",
> - "parallel/update");
> + run_processes_parallel(suc.update_data->max_jobs,
> + update_clone_get_next_task,
> + update_clone_start_failure,
> + update_clone_task_finished, &suc, &run_opts);
>
> /*
> * We saved the output and put it out all at once now.
> diff --git a/hook.c b/hook.c
> index 1d51be3b77a..eadb2d58a7b 100644
> --- a/hook.c
> +++ b/hook.c
> @@ -123,6 +123,10 @@ int run_hooks_opt(const char *hook_name, struct run_hooks_opt *options)
> const char *const hook_path = find_hook(hook_name);
> int jobs = 1;
> int ret = 0;
> + struct run_process_parallel_opts run_opts = {
> + .tr2_category = "hook",
> + .tr2_label = hook_name,
> + };
>
> if (!options)
> BUG("a struct run_hooks_opt must be provided to run_hooks");
> @@ -144,13 +148,8 @@ int run_hooks_opt(const char *hook_name, struct run_hooks_opt *options)
> cb_data.hook_path = abs_path.buf;
> }
>
> - run_processes_parallel_tr2(jobs,
> - pick_next_hook,
> - notify_start_failure,
> - notify_hook_finished,
> - &cb_data,
> - "hook",
> - hook_name);
> + run_processes_parallel(jobs, pick_next_hook, notify_start_failure,
> + notify_hook_finished, &cb_data, &run_opts);
> ret = cb_data.rc;
> cleanup:
> strbuf_release(&abs_path);
> diff --git a/run-command.c b/run-command.c
> index a8501e38ceb..7b8159aa235 100644
> --- a/run-command.c
> +++ b/run-command.c
> @@ -1738,11 +1738,11 @@ static int pp_collect_finished(struct parallel_processes *pp)
> return result;
> }
>
> -int run_processes_parallel(int n,
> - get_next_task_fn get_next_task,
> - start_failure_fn start_failure,
> - task_finished_fn task_finished,
> - void *pp_cb)
> +static int run_processes_parallel_1(int n, get_next_task_fn get_next_task,
> + start_failure_fn start_failure,
> + task_finished_fn task_finished,
> + void *pp_cb,
> + struct run_process_parallel_opts *opts)
> {
> int i, code;
> int output_timeout = 100;
> @@ -1780,24 +1780,42 @@ int run_processes_parallel(int n,
> return 0;
> }
>
> -int run_processes_parallel_tr2(int n, get_next_task_fn get_next_task,
> - start_failure_fn start_failure,
> - task_finished_fn task_finished, void *pp_cb,
> - const char *tr2_category, const char *tr2_label)
> +static int run_processes_parallel_tr2(int n, get_next_task_fn get_next_task,
> + start_failure_fn start_failure,
> + task_finished_fn task_finished,
> + void *pp_cb,
> + struct run_process_parallel_opts *opts)
> {
> + const char *tr2_category = opts->tr2_category;
> + const char *tr2_label = opts->tr2_label;
> int result;
>
> trace2_region_enter_printf(tr2_category, tr2_label, NULL, "max:%d",
> ((n < 1) ? online_cpus() : n));
>
> - result = run_processes_parallel(n, get_next_task, start_failure,
> - task_finished, pp_cb);
> + result = run_processes_parallel_1(n, get_next_task, start_failure,
> + task_finished, pp_cb, opts);
>
> trace2_region_leave(tr2_category, tr2_label, NULL);
>
> return result;
> }
>
> +int run_processes_parallel(int n, get_next_task_fn get_next_task,
> + start_failure_fn start_failure,
> + task_finished_fn task_finished, void *pp_cb,
> + struct run_process_parallel_opts *opts)
> +{
> + if (opts->tr2_category && opts->tr2_label)
> + return run_processes_parallel_tr2(n, get_next_task,
> + start_failure, task_finished,
> + pp_cb, opts);
What is the point for this extra layer of indirection? I am confused why
we might not just change the arg list for run_processes_parallel_tr2 and
call it good.
If the final result was to reduce the number of run_processes_parallel.*
functions available I'd be happy to see this change, but as it
introduces even more various entry points into run_processes_parallel.*
I'm not so sure.
> +
> + return run_processes_parallel_1(n, get_next_task, start_failure,
> + task_finished, pp_cb, opts);
> +}
> +
> +
> int run_auto_maintenance(int quiet)
> {
> int enabled;
> diff --git a/run-command.h b/run-command.h
> index 07bed6c31b4..66e7bebd88a 100644
> --- a/run-command.h
> +++ b/run-command.h
> @@ -458,6 +458,19 @@ typedef int (*task_finished_fn)(int result,
> void *pp_cb,
> void *pp_task_cb);
>
> +/**
> + * Options to pass to run_processes_parallel(), { 0 }-initialized
> + * means no options. Fields:
> + *
> + * tr2_category & tr2_label: sets the trace2 category and label for
> + * logging. These must either be unset, or both of them must be set.
> + */
> +struct run_process_parallel_opts
> +{
> + const char *tr2_category;
> + const char *tr2_label;
> +};
> +
> /**
> * Runs up to n processes at the same time. Whenever a process can be
> * started, the callback get_next_task_fn is called to obtain the data
> @@ -469,15 +482,12 @@ typedef int (*task_finished_fn)(int result,
> *
> * start_failure_fn and task_finished_fn can be NULL to omit any
> * special handling.
> + *
> + * Options are passed via a "struct run_process_parallel_opts".
> */
> -int run_processes_parallel(int n,
> - get_next_task_fn,
> - start_failure_fn,
> - task_finished_fn,
> - void *pp_cb);
> -int run_processes_parallel_tr2(int n, get_next_task_fn, start_failure_fn,
> - task_finished_fn, void *pp_cb,
> - const char *tr2_category, const char *tr2_label);
> +int run_processes_parallel(int n, get_next_task_fn, start_failure_fn,
> + task_finished_fn, void *pp_cb,
> + struct run_process_parallel_opts *opts);
>
> /**
> * Convenience function which prepares env_array for a command to be run in a
> diff --git a/submodule.c b/submodule.c
> index 86c8f0f89db..256c6bb4b8f 100644
> --- a/submodule.c
> +++ b/submodule.c
> @@ -1817,6 +1817,10 @@ int fetch_submodules(struct repository *r,
> {
> int i;
> struct submodule_parallel_fetch spf = SPF_INIT;
> + struct run_process_parallel_opts run_opts = {
> + .tr2_category = "submodule",
> + .tr2_label = "parallel/fetch",
> + };
>
> spf.r = r;
> spf.command_line_option = command_line_option;
> @@ -1838,12 +1842,9 @@ int fetch_submodules(struct repository *r,
>
> calculate_changed_submodule_paths(r, &spf.changed_submodule_names);
> string_list_sort(&spf.changed_submodule_names);
> - run_processes_parallel_tr2(max_parallel_jobs,
> - get_next_submodule,
> - fetch_start_failure,
> - fetch_finish,
> - &spf,
> - "submodule", "parallel/fetch");
> + run_processes_parallel(max_parallel_jobs, get_next_submodule,
> + fetch_start_failure, fetch_finish, &spf,
> + &run_opts);
>
> if (spf.submodules_with_errors.len > 0)
> fprintf(stderr, _("Errors during submodule fetch:\n%s"),
> diff --git a/t/helper/test-run-command.c b/t/helper/test-run-command.c
> index f3b90aa834a..9b21f2f9f83 100644
> --- a/t/helper/test-run-command.c
> +++ b/t/helper/test-run-command.c
> @@ -183,7 +183,7 @@ static int testsuite(int argc, const char **argv)
> (uintmax_t)suite.tests.nr, max_jobs);
>
> ret = run_processes_parallel(max_jobs, next_test, test_failed,
> - test_finished, &suite);
> + test_finished, &suite, NULL);
>
> if (suite.failed.nr > 0) {
> ret = 1;
> @@ -371,6 +371,7 @@ int cmd__run_command(int argc, const char **argv)
> {
> struct child_process proc = CHILD_PROCESS_INIT;
> int jobs;
> + struct run_process_parallel_opts opts = { 0 };
>
> if (argc > 1 && !strcmp(argv[1], "testsuite"))
> exit(testsuite(argc - 1, argv + 1));
> @@ -413,15 +414,15 @@ int cmd__run_command(int argc, const char **argv)
>
> if (!strcmp(argv[1], "run-command-parallel"))
> exit(run_processes_parallel(jobs, parallel_next,
> - NULL, NULL, &proc));
> + NULL, NULL, &proc, &opts));
>
> if (!strcmp(argv[1], "run-command-abort"))
> - exit(run_processes_parallel(jobs, parallel_next,
> - NULL, task_finished, &proc));
> + exit(run_processes_parallel(jobs, parallel_next, NULL,
> + task_finished, &proc, &opts));
>
> if (!strcmp(argv[1], "run-command-no-jobs"))
> - exit(run_processes_parallel(jobs, no_job,
> - NULL, task_finished, &proc));
> + exit(run_processes_parallel(jobs, no_job, NULL, task_finished,
> + &proc, &opts));
>
> fprintf(stderr, "check usage\n");
> return 1;
> --
> 2.36.0.893.g80a51c675f6
>
