#include <string.h>
#include <errno.h>
#include <signal.h>
+#include <assert.h>
enum state {
SENDING_GREETING,
RECEIVING_USER_QUESTION,
+ SENDING_OTHER_QUESTION_PREFIX,
+ SENDING_OTHER_QUESTION,
+ RECEIVING_OTHER_ANSWER,
SENDING_ANSWER_PREFIX,
SENDING_ANSWER,
FINISHED
static uint16_t state_flag_map[] = {
[SENDING_GREETING] = TEVENT_FD_WRITE,
[RECEIVING_USER_QUESTION] = TEVENT_FD_READ,
+ [SENDING_OTHER_QUESTION_PREFIX] = TEVENT_FD_WRITE,
+ [SENDING_OTHER_QUESTION] = TEVENT_FD_WRITE,
+ [RECEIVING_OTHER_ANSWER] = TEVENT_FD_READ,
[SENDING_ANSWER_PREFIX] = TEVENT_FD_WRITE,
[SENDING_ANSWER] = TEVENT_FD_WRITE,
[FINISHED] = 0
/* The question we read from client. */
char *question;
/* The answer to the client. */
- const char *answer;
+ char *answer;
/* How many bytes of the reply we sent so far. */
size_t bytes_sent;
/* Our server. */
struct oserver *oserver;
+ /* Whose question this client is answering. */
+ struct client *subclient;
+ /* Who is answering our question. */
+ struct client *oracle;
};
struct oserver {
struct client *clients[5];
int fd;
struct tevent_fd *fde;
- const char *last_answer;
};
static ssize_t write_string(int fd, const char *str)
return true;
}
+static bool get_subclient(struct client *me)
+{
+ unsigned int i;
+
+ for (i = 0; i < ARRAY_SIZE(me->oserver->clients); i++) {
+ struct client *c = me->oserver->clients[i];
+ if (!c || c == me)
+ continue;
+ if (c->oracle == NULL && input_finished(c->question)) {
+ me->subclient = c;
+ c->oracle = me;
+ return true;
+ }
+ }
+ return false;
+}
+
+static bool get_oracle(struct client *me)
+{
+ unsigned int i;
+
+ for (i = 0; i < ARRAY_SIZE(me->oserver->clients); i++) {
+ struct client *c = me->oserver->clients[i];
+ if (!c || c == me)
+ continue;
+ if (c->subclient == NULL && input_finished(c->question)) {
+ me->oracle = c;
+ c->subclient = me;
+ return true;
+ }
+ }
+ return false;
+}
+
+static void wakeup(struct client *c)
+{
+ tevent_fd_set_flags(c->fde, state_flag_map[c->state]);
+}
+
static void service_client(struct tevent_context *ev,
struct tevent_fd *fde, uint16_t flags, void *_c)
{
len = read_string(c->fd, &c->question);
if (len <= 0)
goto fail;
- if (input_finished(c->question)) {
- c->answer = talloc_steal(c, c->oserver->last_answer);
- c->oserver->last_answer
- = talloc_steal(c->oserver, c->question);
+ if (input_finished(c->question))
+ set_state(c, SENDING_OTHER_QUESTION_PREFIX);
+ break;
+ case SENDING_OTHER_QUESTION_PREFIX:
+ if (!c->subclient)
+ goto need_subclient;
+ if (!send_string(c, "While the Oracle ponders,"
+ " please answer the following question:\n"))
+ goto fail;
+ break;
+ case SENDING_OTHER_QUESTION:
+ if (!c->subclient)
+ goto need_subclient;
+ if (!send_string(c, c->subclient->question))
+ goto fail;
+ break;
+ case RECEIVING_OTHER_ANSWER:
+ if (!c->subclient)
+ goto need_subclient;
+ len = read_string(c->fd, &c->subclient->answer);
+ if (len <= 0)
+ goto fail;
+ if (input_finished(c->subclient->answer)) {
set_state(c, SENDING_ANSWER_PREFIX);
+ wakeup(c->subclient);
}
break;
case SENDING_ANSWER_PREFIX:
- if (!send_string(c, "I believe a better question is "))
+ if (!input_finished(c->answer))
+ goto need_answer;
+ if (!send_string(c, "The Oracle spake thus:\n"))
goto fail;
break;
case SENDING_ANSWER:
if (c->state != FINISHED)
return;
-
fail:
talloc_free(c);
+ return;
+
+need_subclient:
+ if (!get_subclient(c)) {
+ /* We can't get one: go to sleep until someone find_oracle() */
+ tevent_fd_set_flags(c->fde, 0);
+ } else
+ /* In case they are waiting... */
+ wakeup(c->subclient);
+ return;
+
+need_answer:
+ /* If we don't have an oracle and find one, that's OK. */
+ if (!c->oracle && get_oracle(c)) {
+ /* In case they are waiting... */
+ wakeup(c->oracle);
+ return;
+ }
+
+ /* Either our oracle is not finished, or we don't have one: sleep. */
+ tevent_fd_set_flags(c->fde, 0);
}
static int cleanup_client(struct client *client)
{
unsigned int i;
+ /* We were an oracle? */
+ if (client->subclient)
+ client->subclient->oracle = NULL;
+
+ /* We had an oracle? */
+ if (client->oracle)
+ client->oracle->subclient = NULL;
+
for (i = 0; i < ARRAY_SIZE(client->oserver->clients); i++) {
if (client->oserver->clients[i] == client) {
client->oserver->clients[i] = NULL;
client->bytes_sent = 0;
client->question = talloc_strdup(client, "");
client->oserver = oserver;
+ client->oracle = NULL;
+ client->subclient = NULL;
+ client->answer = talloc_strdup(client, "");
client->fde = tevent_add_fd(ev, client, client->fd,
state_flag_map[client->state],
service_client, client);
return 0;
}
+static void talloc_dump(struct tevent_context *ev,
+ struct tevent_signal *se,
+ int signum,
+ int count,
+ void *siginfo,
+ void *_oserver)
+{
+ struct oserver *oserver = _oserver;
+ FILE *f = fopen("/var/run/oserver/talloc.dump", "w");
+ if (f) {
+ talloc_report_full(oserver, f);
+ fclose(f);
+ }
+}
+
struct oserver *oserver_setup(struct tevent_context *ev, unsigned short port)
{
struct oserver *oserver;
talloc_free(oserver);
return NULL;
}
- oserver->last_answer = talloc_strdup(oserver,
- "how many manly men mendaciously"
- " mention mending mansions?\n");
talloc_set_destructor(oserver, destroy_oserver);
/* Don't kill us if client dies. */
signal(SIGPIPE, SIG_IGN);
+ /* Show talloc tree on SIGUSR1. */
+ tevent_add_signal(ev, oserver, SIGUSR1, SA_RESTART,
+ talloc_dump, oserver);
+
return oserver;
}