rewrite message-passing, no signals needed!

1 files changed, 20 insertions, 74 deletions

diff --git a/src/server_reqs.c b/src/server_reqs.c
index 01e8e16..a17f333 100644
--- a/src/server_reqs.c
+++ b/src/server_reqs.c
@@ -27,6 +27,7 @@ static volatile sig_atomic_t num_acks_wanted, num_acks_recvd, inc_acks = 0;
 static void send_packet(struct child_data *child, unsigned char cmd,
                         void *data, size_t datalen)
 {
+    assert(datalen < MSG_MAX);
     unsigned char pkt[MSG_MAX];
     pkt[0] = cmd;
     if(datalen)
@@ -40,10 +41,6 @@ static void req_pass_msg(unsigned char *data, size_t datalen,
     (void) sender;
 
     send_packet(child, REQ_BCASTMSG, data, datalen);
-
-    union sigval nothing = { 0 };
-    sigqueue(child->pid, SIGRTMIN, nothing);
-    ++num_acks_wanted;
 }
 
 static void req_send_clientinfo(unsigned char *data, size_t datalen,
@@ -81,14 +78,9 @@ static void req_change_state(unsigned char *data, size_t datalen,
 {
     (void) data; (void) datalen; (void) child; (void) sender;
     if(datalen == sizeof(sender->state))
-    {
         sender->state = *((int*)data);
-        debugf("State changed to %d\n", sender->state);
-    }
     else
-    {
         debugf("State data is of the wrong size %*s\n", datalen, data);
-    }
 }
 
 static void req_change_user(unsigned char *data, size_t datalen,
@@ -115,11 +107,7 @@ static void req_kick_client(unsigned char *data, size_t datalen,
     {
         pid_t kicked_pid = *((pid_t*)data);
         if(kicked_pid == child->pid)
-        {
             send_packet(child, REQ_BCASTMSG, data + sizeof(pid_t), datalen - sizeof(pid_t));
-            union sigval nothing = { 0 };
-            sigqueue(child->pid, SIGRTMIN, nothing);
-        }
     }
 }
 
@@ -172,16 +160,14 @@ static void req_move_room(unsigned char *data, size_t datalen, struct child_data
     /* TODO: checking */
     sig_debugf("Moving in direction %d\n", dir);
     room_id new = current->adjacent[dir];
-    bool status;
+    int status = 0;
     if(new != ROOM_NONE)
     {
         child_set_room(sender, new);
-        status = true;
-    }
-    else
-    {
-        status = false;
+        status = 1;
     }
+    sig_debugf("server status: %d\n", status);
+
     send_packet(sender, REQ_MOVE, &status, sizeof(status));
 }
 
@@ -251,19 +237,19 @@ static const struct child_request {
     unsigned char cmd_to_send;
 } requests[] = {
     { REQ_NOP,         false, CHILD_NONE,           NULL,                NULL,              REQ_NOP         },
-    { REQ_BCASTMSG,    true,  CHILD_ALL,            req_pass_msg,        NULL,              REQ_BCASTMSG    },
-    { REQ_LISTCLIENTS, false, CHILD_ALL,            req_send_clientinfo, req_send_geninfo,  REQ_BCASTMSG    },
+    { REQ_BCASTMSG,    true,  CHILD_ALL,            req_pass_msg,        NULL,              REQ_NOP         },
+    { REQ_LISTCLIENTS, false, CHILD_ALL,            req_send_clientinfo, req_send_geninfo,  REQ_NOP         },
     { REQ_CHANGESTATE, true,  CHILD_SENDER,         req_change_state,    NULL,              REQ_NOP         },
     { REQ_CHANGEUSER,  true,  CHILD_SENDER,         req_change_user,     NULL,              REQ_NOP         },
     { REQ_KICK,        true,  CHILD_ALL,            req_kick_client,     NULL,              REQ_NOP         },
     { REQ_WAIT,        false, CHILD_NONE,           NULL,                req_wait,          REQ_NOP         },
-    { REQ_GETROOMDESC, false, CHILD_NONE,           NULL,                req_send_desc,     REQ_BCASTMSG    },
-    { REQ_GETROOMNAME, false, CHILD_NONE,           NULL,                req_send_roomname, REQ_BCASTMSG    },
+    { REQ_GETROOMDESC, false, CHILD_NONE,           NULL,                req_send_desc,     REQ_NOP         },
+    { REQ_GETROOMNAME, false, CHILD_NONE,           NULL,                req_send_roomname, REQ_NOP         },
     { REQ_SETROOM,     true,  CHILD_NONE,           NULL,                req_set_room,      REQ_NOP         },
-    { REQ_MOVE,        true,  CHILD_NONE,           NULL,                req_move_room,     REQ_MOVE        },
-    { REQ_GETUSERDATA, true,  CHILD_NONE,           NULL,                req_send_user,     REQ_GETUSERDATA },
-    { REQ_DELUSERDATA, true,  CHILD_NONE,           NULL,                req_del_user,      REQ_DELUSERDATA },
-    { REQ_ADDUSERDATA, true,  CHILD_NONE,           NULL,                req_add_user,      REQ_ADDUSERDATA },
+    { REQ_MOVE,        true,  CHILD_NONE,           NULL,                req_move_room,     REQ_NOP         },
+    { REQ_GETUSERDATA, true,  CHILD_NONE,           NULL,                req_send_user,     REQ_NOP         },
+    { REQ_DELUSERDATA, true,  CHILD_NONE,           NULL,                req_del_user,      REQ_NOP         },
+    { REQ_ADDUSERDATA, true,  CHILD_NONE,           NULL,                req_add_user,      REQ_NOP         },
     //{ REQ_ROOMMSG,     true,  CHILD_ALL,            req_send_room_msg,   NULL,              REQ_BCASTMSG },
 };
 
@@ -308,6 +294,9 @@ bool handle_child_req(int in_fd)
 
     ssize_t packet_len = read(in_fd, packet, MSG_MAX);
 
+    if(packet_len <= 0)
+        goto fail;
+
     pid_t sender_pid;
     memcpy(&sender_pid, packet, sizeof(pid_t));
     sig_debugf("Got request from PID %d\n", sender_pid);
@@ -327,16 +316,6 @@ bool handle_child_req(int in_fd)
 
     struct child_request *req = hash_lookup(request_map, &cmd);
 
-    sigset_t old, block;
-
-    sigemptyset(&block);
-    sigaddset(&block, SIGRTMIN+1);
-    sigprocmask(SIG_BLOCK, &block, &old);
-
-    num_acks_wanted = 1;
-    num_acks_recvd  = 0;
-    inc_acks = 1;
-
     if(!req)
     {
         sig_debugf("Unknown request.\n");
@@ -382,47 +361,14 @@ bool handle_child_req(int in_fd)
 
 finish:
 
-    //if(req)
-    //{
-    //    send_packet(sender, req->cmd_to_send, NULL, 0);
-    //}
-
-    if(req && req->finalize)
-        req->finalize(data, datalen, sender);
-
-    union sigval junk = { 0 };
-    if(sender)
-        sigqueue(sender->pid, SIGRTMIN, junk);
-    else
-        sig_debugf("Unknown PID sent request.\n");
-
-    /* 5 ms */
-#define ACK_TIMEOUT 5000
-
-    struct timespec timeout;
-    timeout.tv_sec = 0;
-    timeout.tv_nsec = ACK_TIMEOUT;
-
-    while(num_acks_recvd < MIN(num_clients,num_acks_wanted))
+    if(req)
     {
-        if(sigtimedwait(&old, NULL, &timeout) < 0 && errno == EAGAIN)
-            break;
+        send_packet(sender, req->cmd_to_send, NULL, 0);
     }
 
-    inc_acks = 0;
-
-    sigprocmask(SIG_SETMASK, &old, NULL);
+    if(req && req->finalize)
+        req->finalize(data, datalen, sender);
 
 fail:
     return true;
 }
-
-void master_ack_handler(int s, siginfo_t *info, void *v)
-{
-    (void) s;
-    (void) v;
-    if(inc_acks && hash_lookup(child_map, &info->si_pid))
-    {
-        ++num_acks_recvd;
-    }
-}