Calling jsonrpc_notification fail in failure route when fr_timer timeout

[ianlin]

Environment

Kamailio 4.3.3
Ubuntu 14.04.1 x86_64

Problem

I'm using t_suspend() and t_continue() for mobile push notification scenario. Before calling t_suspend() I set the fr_timer to 12 seconds and t_on_failure() to my custom failure route (e.g. failure_route[MY_FAILURE_ROUTE]). The scenario is fairly similar to [SR-Users] Timeout after t_suspend and failure route, the only difference is I try to use jsonrpc_notificaion() to notify the user asynchronously in my custom failure route.

There are 2 different results depending on how it goes to the failure route:

1. Caller cancel the call before fr_timer expires
   • jsonrpc_notification can successfully be called in failure route
2. The fr_timer did timeout after 12 seconds
   • An error occurred while calling jsonrpc_notification:
   • jsonrpc_notification(): failed to write to io pipe: Bad file descriptor

Investigation

For the first case that perform normally, the IDs of Kamailio processes being used are the same for both calling t_suspend() and entering failure route, while in the second case the processes are different.

Following added some debug messages in Kamailio's main.c it showed that the process being used in the failure route of case 2 is slow timer process, and from jsonrpc_mod.c's child_init() function, the rank of slow timer process is -1 therefore it doesn't assign the fd to this process.

My workaround was just assigning the fd to each child during child_init() in jsonrpc_mod.c but that's definitely not a good way to go. I am appreciated if you can give me some advice to solve this problem correctly.

Cheers,
Ian

[miconda]

Can you paste here the patch to the solution you tried?

[ianlin]

Thanks for replying. Here it is. As I said this is not a good solution.

--- jsonrpc_mod.c.orig
+++ jsonrpc_mod.c
@@ -120,7 +120,6 @@
 {
    int pid;

-   if (rank>PROC_MAIN)
        cmd_pipe = pipe_fds[1];

    if (rank!=PROC_MAIN)

[miconda]

Thanks, finally got back to this one after holidays season, pushing a slightly different patch to master branch (it will be backported).

[ianlin]

Thanks!