Formerly, if A was replaced by B, and then B by C before
A finished exiting, we didn't wait for B to finish so it
ended up as a zombie process.
Fix this by queuing all process we spawn for waitpid.
Signed-off-by: Marc-Antoine Perennou <marc-anto...@perennou.com>
---
src/haproxy-systemd-wrapper.c | 45 +++++++++++++++++++++++++++++++++++++++++--
1 file changed, 43 insertions(+), 2 deletions(-)
diff --git a/src/haproxy-systemd-wrapper.c b/src/haproxy-systemd-wrapper.c
index 57e8d7d..3c70271 100644
--- a/src/haproxy-systemd-wrapper.c
+++ b/src/haproxy-systemd-wrapper.c
@@ -24,6 +24,44 @@ static char *pid_file = "/run/haproxy.pid";
static int main_argc;
static char **main_argv;
+static struct {
+ pid_t *queue;
+ int count;
+ int size;
+ int index;
+ int rindex;
+} pids = {
+ .queue = NULL,
+ .count = 0,
+ .size = 8,
+ .index = 0,
+ .rindex = 0
+};
+
+static void pids_push(pid_t pid)
+{
+ if (pids.size == pids.count) {
+ // Double the capacity, write in the new half, rewind reading
head
+ pids.index = pids.size;
+ pids.rindex = 0;
+ pids.size *= 2;
+ pids.queue = realloc(pids.queue, pids.size * sizeof(int));
+ }
+ pids.queue[pids.index++ % pids.size] = pid;
+ pids.count++;
+}
+
+static bool pids_pop(void)
+{
+ if (pids.count == 0)
+ pid = 0;
+ else {
+ pids.count--;
+ pid = pids.queue[pids.rindex++ % pids.size];
+ }
+ return pid != 0;
+}
+
static pid_t spawn_haproxy(char **pid_strv, int nb_pid)
{
pid_t pid = fork();
@@ -76,7 +114,7 @@ static void signal_handler(int signum
__attribute__((unused)))
char **pid_strv = NULL;
int nb_pid = read_pids(&pid_strv);
- pid = spawn_haproxy(pid_strv, nb_pid);
+ pids_push(spawn_haproxy(pid_strv, nb_pid));
for (i = 0; i < nb_pid; ++i)
free(pid_strv[i]);
@@ -106,8 +144,11 @@ int main(int argc, char **argv)
signal(SIGUSR2, &signal_handler);
+ pids.queue = malloc(pids.size * sizeof(int));
pid = spawn_haproxy(NULL, 0);
- while (-1 != waitpid(pid, NULL, 0) || errno == EINTR);
+ while ((-1 != waitpid(pid, NULL, 0) || errno == EINTR) && pids_pop());
+
+ free(pids.queue);
return EXIT_SUCCESS;
}
--
1.8.1.3
