From: Phillip Wood Date: Fri, 07 Oct 2022 09:55:42 GMT Subject: Re: [PATCH 10/15] run-command API: add nascent "struct run_process_parallel_opts" Message-ID: <5ee14b82-aebd-731d-1c6f-a113c9127000@gmail.com> In-Reply-To: On 30/09/2022 12:28, Ævar Arnfjörð Bjarmason wrote: > As noted in fd3aaf53f71 (run-command: add an "ungroup" option to > run_process_parallel(), 2022-06-07) which added the "ungroup" passing > it to "run_process_parallel()" via the global > "run_processes_parallel_ungroup" variable was a compromise to get the > smallest possible regression fix for "maint" at the time. > > This follow-up to that is a start at passing that parameter and others > via a new "struct run_process_parallel_opts", as the earlier > version[1] of what became fd3aaf53f71 did. > > For now we're only changing how data is passed internally to > "run-command.c", i.e. from "run_process_parallel()" to > pp_init(). Subsequent commits will change "run_processes_parallel()" > itself, as well as the "run_processes_parallel_tr2()" wrapper > function. This is a very welcome change, but I'd have found it easier to follow if patches 10-12 were squashed together. There is a lot of code that gets added only to be deleted or moved in a following commit. A single patch would be bigger but they'd be less changes to review overall. As far as I can tell the overall change is good. Best Wishes Phillip > 1. https://lore.kernel.org/git/cover-v2-0.8-00000000000-20220518T195858Z-avarab@gmail.com/ > > Signed-off-by: Ævar Arnfjörð Bjarmason > --- > run-command.c | 38 ++++++++++++++++++++++---------------- > run-command.h | 44 +++++++++++++++++++++++++++++++++++++++++--- > 2 files changed, 63 insertions(+), 19 deletions(-) > > diff --git a/run-command.c b/run-command.c > index 31a856f8b9a..f82fc7f1515 100644 > --- a/run-command.c > +++ b/run-command.c > @@ -1563,21 +1563,21 @@ static void handle_children_on_signal(int signo) > } > > static void pp_init(struct parallel_processes *pp, > - unsigned int jobs, > - get_next_task_fn get_next_task, > - start_failure_fn start_failure, > - task_finished_fn task_finished, > - void *data, int ungroup) > + const struct run_process_parallel_opts *opts) > { > unsigned int i; > + void *data = opts->data; > + get_next_task_fn get_next_task = opts->get_next_task; > + start_failure_fn start_failure = opts->start_failure; > + task_finished_fn task_finished = opts->task_finished; > > - if (!jobs) > + if (!opts->jobs) > BUG("you must provide a non-zero number of jobs!"); > > - pp->max_processes = jobs; > + pp->max_processes = opts->jobs; > > trace_printf("run_processes_parallel: preparing to run up to %d tasks", > - jobs); > + opts->jobs); > > pp->data = data; > if (!get_next_task) > @@ -1590,12 +1590,12 @@ static void pp_init(struct parallel_processes *pp, > pp->nr_processes = 0; > pp->output_owner = 0; > pp->shutdown = 0; > - pp->ungroup = ungroup; > - CALLOC_ARRAY(pp->children, jobs); > + pp->ungroup = opts->ungroup; > + CALLOC_ARRAY(pp->children, opts->jobs); > if (!pp->ungroup) > - CALLOC_ARRAY(pp->pfd, jobs); > + CALLOC_ARRAY(pp->pfd, opts->jobs); > > - for (i = 0; i < jobs; i++) { > + for (i = 0; i < opts->jobs; i++) { > strbuf_init(&pp->children[i].err, 0); > child_process_init(&pp->children[i].process); > if (pp->pfd) { > @@ -1793,14 +1793,20 @@ void run_processes_parallel(unsigned int jobs, > int i, code; > int output_timeout = 100; > int spawn_cap = 4; > - int ungroup = run_processes_parallel_ungroup; > struct parallel_processes pp = PARALLEL_PROCESSES_INIT; > + const struct run_process_parallel_opts opts = { > + .jobs = jobs, > + .get_next_task = get_next_task, > + .start_failure = start_failure, > + .task_finished = task_finished, > + .ungroup = run_processes_parallel_ungroup, > + .data = pp_cb, > + }; > > /* unset for the next API user */ > run_processes_parallel_ungroup = 0; > > - pp_init(&pp, jobs, get_next_task, start_failure, task_finished, pp_cb, > - ungroup); > + pp_init(&pp, &opts); > while (1) { > for (i = 0; > i < spawn_cap && !pp.shutdown && > @@ -1817,7 +1823,7 @@ void run_processes_parallel(unsigned int jobs, > } > if (!pp.nr_processes) > break; > - if (ungroup) { > + if (opts.ungroup) { > int i; > > for (i = 0; i < pp.max_processes; i++) > diff --git a/run-command.h b/run-command.h > index 4502bdc64dc..210fb9e8bc4 100644 > --- a/run-command.h > +++ b/run-command.h > @@ -458,6 +458,47 @@ typedef int (*task_finished_fn)(int result, > void *pp_cb, > void *pp_task_cb); > > +/** > + * Option used by run_processes_parallel(), { 0 }-initialized means no > + * options. > + */ > +struct run_process_parallel_opts > +{ > + /** > + * jobs: see 'jobs' in run_processes_parallel() below. > + */ > + int jobs; > + > + /** > + * ungroup: see 'ungroup' in run_processes_parallel() below. > + */ > + unsigned int ungroup:1; > + > + /** > + * get_next_task: See get_next_task_fn() above. This must be > + * specified. > + */ > + get_next_task_fn get_next_task; > + > + /** > + * start_failure: See start_failure_fn() above. This can be > + * NULL to omit any special handling. > + */ > + start_failure_fn start_failure; > + > + /** > + * task_finished: See task_finished_fn() above. This can be > + * NULL to omit any special handling. > + */ > + task_finished_fn task_finished; > + > + /** > + * data: user data, will be passed as "pp_cb" to the callback > + * parameters. > + */ > + void *data; > +}; > + > /** > * Runs up to 'jobs' processes at the same time. Whenever a process can be > * started, the callback get_next_task_fn is called to obtain the data > @@ -467,9 +508,6 @@ typedef int (*task_finished_fn)(int result, > * (both stdout and stderr) is routed to stderr in a manner that output > * from different tasks does not interleave (but see "ungroup" below). > * > - * start_failure_fn and task_finished_fn can be NULL to omit any > - * special handling. > - * > * If the "ungroup" option isn't specified, the API will set the > * "stdout_to_stderr" parameter in "struct child_process" and provide > * the callbacks with a "struct strbuf *out" parameter to write output