run-command: add first helper for pp child states

There is a recurring pattern of testing parallel process child states
and file descriptors to determine if a child is running, receiving any
input or if it's ready for cleanup.

Name the pp_child structure and introduce a first helper to make these
checks more readable. Next commits will add more helpers and checks.

Suggested-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Adrian Ratiu <adrian.ratiu@collabora.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/run-command.c b/run-command.c
index ed9575bd6a8cbbab0f25b92e09cf9c2752498523..82eeac38bf0c10d2432b2b3b67b2125f997db728 100644 (file)
--- a/run-command.c
+++ b/run-command.c
@@ -1478,15 +1478,22 @@ enum child_state {
        GIT_CP_WAIT_CLEANUP,
 };
 
+struct parallel_child {
+       enum child_state state;
+       struct child_process process;
+       struct strbuf err;
+       void *data;
+};
+
+static int child_is_working(const struct parallel_child *pp_child)
+{
+       return pp_child->state == GIT_CP_WORKING;
+}
+
 struct parallel_processes {
        size_t nr_processes;
 
-       struct {
-               enum child_state state;
-               struct child_process process;
-               struct strbuf err;
-               void *data;
-       } *children;
+       struct parallel_child *children;
        /*
         * The struct pollfd is logically part of *children,
         * but the system call expects it as its own array.
@@ -1509,7 +1516,7 @@ static void kill_children(const struct parallel_processes *pp,
                          int signo)
 {
        for (size_t i = 0; i < opts->processes; i++)
-               if (pp->children[i].state == GIT_CP_WORKING)
+               if (child_is_working(&pp->children[i]))
                        kill(pp->children[i].process.pid, signo);
 }
 
@@ -1665,7 +1672,7 @@ static void pp_buffer_stderr(struct parallel_processes *pp,
 
        /* Buffer output from all pipes. */
        for (size_t i = 0; i < opts->processes; i++) {
-               if (pp->children[i].state == GIT_CP_WORKING &&
+               if (child_is_working(&pp->children[i]) &&
                    pp->pfd[i].revents & (POLLIN | POLLHUP)) {
                        int n = strbuf_read_once(&pp->children[i].err,
                                                 pp->children[i].process.err, 0);
@@ -1683,7 +1690,7 @@ static void pp_output(const struct parallel_processes *pp)
 {
        size_t i = pp->output_owner;
 
-       if (pp->children[i].state == GIT_CP_WORKING &&
+       if (child_is_working(&pp->children[i]) &&
            pp->children[i].err.len) {
                strbuf_write(&pp->children[i].err, stderr);
                strbuf_reset(&pp->children[i].err);
@@ -1748,7 +1755,7 @@ static int pp_collect_finished(struct parallel_processes *pp,
                         * running process time.
                         */
                        for (i = 0; i < n; i++)
-                               if (pp->children[(pp->output_owner + i) % n].state == GIT_CP_WORKING)
+                               if (child_is_working(&pp->children[(pp->output_owner + i) % n]))
                                        break;
                        pp->output_owner = (pp->output_owner + i) % n;
                }