From 9bad361832b024c93ce9582bfff9ddef778b3324 Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Tue, 25 Jan 2011 11:01:25 +1030 Subject: [PATCH] lca2011: avoid loops during dumping. CDUMP_IGNORE the client->oserver back-pointer, and switch the subclient and oracle to be indices into oserver->clients[] rather than pointers. --- ccan/oserver/oserver.c | 68 ++++++++++++++++-------------------- ccan/oserver/oserver_types.h | 12 ++++--- 2 files changed, 38 insertions(+), 42 deletions(-) diff --git a/ccan/oserver/oserver.c b/ccan/oserver/oserver.c index 317a01c..0ec1b68 100644 --- a/ccan/oserver/oserver.c +++ b/ccan/oserver/oserver.c @@ -86,9 +86,9 @@ static bool get_subclient(struct client *me) 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; + if (c->oracle == -1 && input_finished(c->question)) { + me->subclient = c->id; + c->oracle = me->id; return true; } } @@ -103,9 +103,9 @@ static bool get_oracle(struct client *me) 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; + if (c->subclient == -1 && input_finished(c->question)) { + me->oracle = c->id; + c->subclient = me->id; return true; } } @@ -136,27 +136,29 @@ static void service_client(struct tevent_context *ev, set_state(c, SENDING_OTHER_QUESTION_PREFIX); break; case SENDING_OTHER_QUESTION_PREFIX: - if (!c->subclient) + if (c->subclient == -1) 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) + if (c->subclient == -1) goto need_subclient; - if (!send_string(c, c->subclient->question)) + if (!send_string(c, + c->oserver->clients[c->subclient]->question)) goto fail; break; case RECEIVING_OTHER_ANSWER: - if (!c->subclient) + if (c->subclient == -1) goto need_subclient; - len = read_string(c->fd, &c->subclient->answer); + len = read_string(c->fd, + &c->oserver->clients[c->subclient]->answer); if (len <= 0) goto fail; - if (input_finished(c->subclient->answer)) { + if (input_finished(c->oserver->clients[c->subclient]->answer)) { set_state(c, SENDING_ANSWER_PREFIX); - wakeup(c->subclient); + wakeup(c->oserver->clients[c->subclient]); } break; case SENDING_ANSWER_PREFIX: @@ -185,14 +187,14 @@ need_subclient: tevent_fd_set_flags(c->fde, 0); } else /* In case they are waiting... */ - wakeup(c->subclient); + wakeup(c->oserver->clients[c->subclient]); return; need_answer: /* If we don't have an oracle and find one, that's OK. */ - if (!c->oracle && get_oracle(c)) { + if (c->oracle == -1 && get_oracle(c)) { /* In case they are waiting... */ - wakeup(c->oracle); + wakeup(c->oserver->clients[c->oracle]); return; } @@ -202,25 +204,18 @@ need_answer: static int cleanup_client(struct client *client) { - unsigned int i; /* We were an oracle? */ - if (client->subclient) - client->subclient->oracle = NULL; + if (client->subclient >= 0) + client->oserver->clients[client->subclient]->oracle = -1; /* 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; - tevent_fd_set_flags(client->oserver->fde, - TEVENT_FD_READ); - return 0; - } - } - abort(); + if (client->oracle >= 0) + client->oserver->clients[client->oracle]->subclient = -1; + + assert(client->oserver->clients[client->id] == client); + client->oserver->clients[client->id] = NULL; + return 0; } static void add_client(struct tevent_context *ev, @@ -228,7 +223,6 @@ static void add_client(struct tevent_context *ev, { struct oserver *oserver = _oserver; struct client *client; - unsigned int i; client = talloc(oserver, struct client); client->fd = accept(oserver->fd, NULL, 0); @@ -239,8 +233,8 @@ static void add_client(struct tevent_context *ev, client->bytes_sent = 0; client->question = talloc_strdup(client, ""); client->oserver = oserver; - client->oracle = NULL; - client->subclient = NULL; + client->oracle = -1; + client->subclient = -1; client->answer = talloc_strdup(client, ""); client->fde = tevent_add_fd(ev, client, client->fd, state_flag_map[client->state], @@ -248,12 +242,12 @@ static void add_client(struct tevent_context *ev, tevent_fd_set_auto_close(client->fde); /* Find empty slot in array for this client. */ - for (i = 0; oserver->clients[i]; i++); - oserver->clients[i] = client; + for (client->id = 0; oserver->clients[client->id]; client->id++); + oserver->clients[client->id] = client; talloc_set_destructor(client, cleanup_client); /* Full? Stop listening... */ - if (i == ARRAY_SIZE(oserver->clients)-1) + if (client->id == ARRAY_SIZE(oserver->clients)-1) tevent_fd_set_flags(oserver->fde, 0); } diff --git a/ccan/oserver/oserver_types.h b/ccan/oserver/oserver_types.h index 4eabc67..72717e8 100644 --- a/ccan/oserver/oserver_types.h +++ b/ccan/oserver/oserver_types.h @@ -20,6 +20,8 @@ CDUMP_SAVED struct client { /* Our event info, and the file descriptor. */ struct tevent_fd *fde CDUMP_IGNORE; int fd; + /* Position in oserver's clients array. */ + unsigned int id; /* The question we read from client. */ char *question; /* The answer to the client. */ @@ -27,11 +29,11 @@ CDUMP_SAVED struct client { /* 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 *oserver CDUMP_IGNORE; + /* Whose question this client is answering (-1 for none) */ + int subclient; + /* Who is answering our question (-1 for none) */ + int oracle; }; CDUMP_SAVED struct oserver { -- 2.39.2