run-command API: have run_process_parallel() take an "opts" struct
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.
Since we need to change all of the occurrences of "n" to
"opt->SOMETHING" let's take the opportunity and rename the terse "n"
to "processes". We could also have picked "max_processes", "jobs",
"threads" etc., but as the API is named "run_processes_parallel()"
let's go with "processes".
Since the new "run_processes_parallel()" function is able to take an
optional "tr2_category" and "tr2_label" via the struct we can at this
point migrate all of the users of "run_processes_parallel_tr2()" over
to it.
But let's not migrate all the API users yet, only the two users that
passed the "ungroup" parameter via the
"run_processes_parallel_ungroup" global
1. https://lore.kernel.org/git/cover-v2-0.8-00000000000-20220518T195858Z-avarab@gmail.com/
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Ævar Arnfjörð Bjarmason committedOct 12, 2022 at 23:02 UTC6e5ba0bae447dba2adabea588b248b5fc6f59cd6
4 files changed+121-59
hook.c
+14-9
index a493939a4f..a4fa1031f2 100644--- a/hook.c+++ b/hook.c@@ -114,8 +114,20 @@ int run_hooks_opt(const char *hook_name, struct run_hooks_opt *options) .options = options, }; const char *const hook_path = find_hook(hook_name);- int jobs = 1; int ret = 0;+ const struct run_process_parallel_opts opts = {+ .tr2_category = "hook",+ .tr2_label = hook_name,++ .processes = 1,+ .ungroup = 1,++ .get_next_task = pick_next_hook,+ .start_failure = notify_start_failure,+ .task_finished = notify_hook_finished,++ .data = &cb_data,+ }; if (!options) BUG("a struct run_hooks_opt must be provided to run_hooks");@@ -137,14 +149,7 @@ int run_hooks_opt(const char *hook_name, struct run_hooks_opt *options) cb_data.hook_path = abs_path.buf; }- run_processes_parallel_ungroup = 1;- run_processes_parallel_tr2(jobs,- pick_next_hook,- notify_start_failure,- notify_hook_finished,- &cb_data,- "hook",- hook_name);+ run_processes_parallel(&opts); ret = cb_data.rc; cleanup: strbuf_release(&abs_path);
run-command.c
+31-23
index b69deb1cc5..2858ec7bef 100644--- a/run-command.c+++ b/run-command.c@@ -1496,7 +1496,6 @@ enum child_state { GIT_CP_WAIT_CLEANUP, };-int run_processes_parallel_ungroup; struct parallel_processes { void *const data;@@ -1558,11 +1557,12 @@ static void handle_children_on_signal(int signo) } static void pp_init(struct parallel_processes *pp,- get_next_task_fn get_next_task,- start_failure_fn start_failure,- task_finished_fn task_finished)+ const struct run_process_parallel_opts *opts) {- const size_t n = pp->max_processes;+ const size_t n = opts->processes;+ 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 (!n) BUG("you must provide a non-zero number of processes!");@@ -1769,27 +1769,27 @@ static int pp_collect_finished(struct parallel_processes *pp) return result; }-void run_processes_parallel(size_t n,- get_next_task_fn get_next_task,- start_failure_fn start_failure,- task_finished_fn task_finished,- void *pp_cb)+void run_processes_parallel(const struct run_process_parallel_opts *opts) { int i, code; int output_timeout = 100; int spawn_cap = 4;- int ungroup = run_processes_parallel_ungroup; struct parallel_processes pp = {- .max_processes = n,- .data = pp_cb,+ .max_processes = opts->processes,+ .data = opts->data, .buffered_output = STRBUF_INIT,- .ungroup = ungroup,+ .ungroup = opts->ungroup, };+ /* options */+ const char *tr2_category = opts->tr2_category;+ const char *tr2_label = opts->tr2_label;+ const int do_trace2 = tr2_category && tr2_label;- /* unset for the next API user */- run_processes_parallel_ungroup = 0;+ if (do_trace2)+ trace2_region_enter_printf(tr2_category, tr2_label, NULL,+ "max:%d", opts->processes);- pp_init(&pp, get_next_task, start_failure, task_finished);+ pp_init(&pp, opts); while (1) { for (i = 0; i < spawn_cap && !pp.shutdown &&@@ -1806,7 +1806,7 @@ void run_processes_parallel(size_t n, } if (!pp.nr_processes) break;- if (ungroup) {+ if (opts->ungroup) { for (size_t i = 0; i < pp.max_processes; i++) pp.children[i].state = GIT_CP_WAIT_CLEANUP; } else {@@ -1822,19 +1822,27 @@ void run_processes_parallel(size_t n, } pp_cleanup(&pp);++ if (do_trace2)+ trace2_region_leave(tr2_category, tr2_label, NULL); }-void run_processes_parallel_tr2(size_t n, get_next_task_fn get_next_task,+void run_processes_parallel_tr2(size_t processes, 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) {- trace2_region_enter_printf(tr2_category, tr2_label, NULL, "max:%d", n);+ const struct run_process_parallel_opts opts = {+ .tr2_category = tr2_category,+ .tr2_label = tr2_label,+ .processes = processes,- run_processes_parallel(n, get_next_task, start_failure,- task_finished, pp_cb);+ .get_next_task = get_next_task,+ .start_failure = start_failure,+ .task_finished = task_finished,+ };- trace2_region_leave(tr2_category, tr2_label, NULL);+ run_processes_parallel(&opts); } int run_auto_maintenance(int quiet)
run-command.h
+55-17
index 6f7604e114..aabdaf684d 100644--- a/run-command.h+++ b/run-command.h@@ -459,17 +459,64 @@ typedef int (*task_finished_fn)(int result, void *pp_task_cb); /**- * 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+ * Option used by run_processes_parallel(), { 0 }-initialized means no+ * options.+ */+struct run_process_parallel_opts+{+ /**+ * tr2_category & tr2_label: sets the trace2 category and label for+ * logging. These must either be unset, or both of them must be set.+ */+ const char *tr2_category;+ const char *tr2_label;++ /**+ * processes: see 'processes' in run_processes_parallel() below.+ */+ size_t processes;++ /**+ * 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;+};++/**+ * Options are passed via the "struct run_process_parallel_opts" above.+ *+ * Runs N 'processes' at the same time. Whenever a process can be+ * started, the callback opts.get_next_task is called to obtain the data * required to start another child process. * * The children started via this function run in parallel. Their output * (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@@ -479,19 +526,10 @@ typedef int (*task_finished_fn)(int result, * NULL "struct strbuf *out" parameter, and are responsible for * emitting their own output, including dealing with any race * conditions due to writing in parallel to stdout and stderr.- * The "ungroup" option can be enabled by setting the global- * "run_processes_parallel_ungroup" to "1" before invoking- * run_processes_parallel(), it will be set back to "0" as soon as the- * API reads that setting. */-extern int run_processes_parallel_ungroup;-void run_processes_parallel(size_t n,- get_next_task_fn,- start_failure_fn,- task_finished_fn,- void *pp_cb);-void run_processes_parallel_tr2(size_t n, get_next_task_fn, start_failure_fn,- task_finished_fn, void *pp_cb,+void run_processes_parallel(const struct run_process_parallel_opts *opts);+void run_processes_parallel_tr2(size_t processes, get_next_task_fn,+ start_failure_fn, task_finished_fn, void *pp_cb, const char *tr2_category, const char *tr2_label); /**