RE: poll with timeout 0 in main loop
this is almost the complete code. you can see all the flow here. basically, the main.c starts the server thread (gm_tcp_server), inside the server thread the application sits waiting for new connection, just sitting waiting consumes 100% of the CPU (without accepting any connection yet), the code of the server is in file gm_tcp_server.c. the rest of the code is just in case you need it for reference. thanks! Date: Fri, 22 Oct 2010 10:17:30 +0100 From: ch...@cvine.freeserve.co.uk To: jpablolorenze...@hotmail.com CC: maginot.jun...@gmail.com; gtk-app-devel-list@gnome.org Subject: Re: poll with timeout 0 in main loop On Fri, 22 Oct 2010 02:57:59 + Juan Pablo L. jpablolorenze...@hotmail.com wrote: hi, this is the code that makes the server socket [snip] There doesn't seem anything especially wrong with this but you have a lot of code missing. In particular, what does your tcp_server_handle_connection_events() callback do, such as when it encounters errors (you specify that the callback is to be entered in a case of G_IO_NVAL and G_IO_ERR), and how do you disconnect sources from the main loop when they are finished with (I notice also you don't unref the sources after attaching them to the main loop). Quite possibly you are looping in a case of errors or defunct sources. Probably the best thing you can do is come up with the smallest test case which demonstrates the error (with say just one socket worker thread) and post it here. This is off topic, but glib's gio makes it trivial to construct new server threads and it does all the hard stuff for you, but you need glib version 2.22 for gio's socket API. Glib's gio has no relationship with GIOChannels, despite the similar names. Chris ___ gtk-app-devel-list mailing list gtk-app-devel-list@gnome.org http://mail.gnome.org/mailman/listinfo/gtk-app-devel-list
RE: poll with timeout 0 in main loop
;
}
gboolean tcp_server_handle_connection_events(GIOChannel *p_source,GIOCondition
p_condition,GMTCPServer *p_server)
{
TCPClientConnection *client = NULL;
struct sockaddr_in sockaddr;
socklen_t client_fd_len;
int client_fd;
//GError *error = NULL;
int set_option = 1;
if(p_condition (G_IO_IN|G_IO_PRI))
{
// accept the connection now
client_fd_len = sizeof(sockaddr);
if((client_fd =
accept(g_io_channel_unix_get_fd(p_server-socket),(struct
sockaddr*)sockaddr,client_fd_len)) 0)
{
g_error(Could not accept new connection: %s,strerror(errno));
return TRUE;
}
fcntl(client_fd,F_SETFL,O_NONBLOCK);// set the socket non-blocking
setsockopt(client_fd,SOL_SOCKET,SO_KEEPALIVE,set_option,sizeof(set_option));//
send keep alive messages
g_message(New connection attempt);
// create a client connection
client = gm_connection_new(client_fd,p_server);
// get the address for this client
if
(inet_ntop(AF_INET,sockaddr.sin_addr.s_addr,client-ip,sizeof(client-ip)) !=
NULL)
{
client-port = ntohs(sockaddr.sin_port);
g_message(Successfully accepted new client connection from
%s:%d,client-ip,client-port);
}
else
{
client-ip[0] = 0;
client-port = -1;
g_message(Successfully accepted new client connection from an
unknown location);
}
// run the connection thread
client-connection_thread =
g_thread_create((GThreadFunc)gm_connection_run,client,TRUE,/*error*/NULL);
if(client-connection_thread == NULL)
{
g_error(Could not start new connection for client: %s:%d, will end
this connection,client-ip,client-port);
gm_connection_destroy(client);
}
else
{
// push it into the client array
g_ptr_array_add(p_server-clients_list,client);
g_message(Successfully started new connection);
}
return TRUE;
}
// an error happened
// show an error message and try to get a description from errno
g_warning(An error occurred on the server socket: %s,strerror(errno));
return TRUE;
}
gboolean tcp_server_remove_connection(TCPClientConnection *p_client)
{
// remove a client
g_ptr_array_remove(p_client-my_server-clients_list,p_client);
return TRUE;
}
and the server is astarted only once from the main thread.
regarding GIO, i like to have like control of things so i m just sticking with
glib, what i need from glib are the special structucures like
array pointers, sometimes the strings as containers and of course, the mail
loop :)
Date: Fri, 22 Oct 2010 10:17:30 +0100
From: ch...@cvine.freeserve.co.uk
To: jpablolorenze...@hotmail.com
CC: maginot.jun...@gmail.com; gtk-app-devel-list@gnome.org
Subject: Re: poll with timeout 0 in main loop
On Fri, 22 Oct 2010 02:57:59 +
Juan Pablo L. jpablolorenze...@hotmail.com wrote:
hi, this is the code that makes the server socket
[snip]
There doesn't seem anything especially wrong with this but you have a
lot of code missing. In particular, what does your
tcp_server_handle_connection_events() callback do, such as when it
encounters errors (you specify that the callback is to be entered in a
case of G_IO_NVAL and G_IO_ERR), and how do you disconnect sources from
the main loop when they are finished with (I notice also you don't
unref the sources after attaching them to the main loop). Quite
possibly you are looping in a case of errors or defunct sources.
Probably the best thing you can do is come up with the smallest test
case which demonstrates the error (with say just one socket worker
thread) and post it here.
This is off topic, but glib's gio makes it trivial to construct new
server threads and it does all the hard stuff for you, but you need
glib version 2.22 for gio's socket API. Glib's gio has no relationship
with GIOChannels, despite the similar names.
Chris
___
gtk-app-devel-list mailing list
gtk-app-devel-list@gnome.org
http://mail.gnome.org/mailman/listinfo/gtk-app-devel-list
Re: poll with timeout 0 in main loop
On Fri, 22 Oct 2010 10:37:01 + Juan Pablo L. jpablolorenze...@hotmail.com wrote: i attached the code but did not make thru, here is the server code: Something odd is going on. I see you are using GIOChannel not to do any reading, but in order to notify you that a connection is available. poll()/select() of course support this in unix-like systems, but I don't know if GIOChannel does (I have never tried). Possibly it only works if you set the channel as non-blocking with g_io_channel_set_flags() rather than by manipulating the file descriptor directly, which you have done. Again, I don't know. Sending snippets of code really isn't going to help. It could of course be other things, such as you not having initialized glib for threads correctly. You need to send the simplest test case which demonstrates the problem, in compilable form: given the nature of the problem you should be able to reproduce it with very simple code. Chris ___ gtk-app-devel-list mailing list gtk-app-devel-list@gnome.org http://mail.gnome.org/mailman/listinfo/gtk-app-devel-list
Re: poll with timeout 0 in main loop
On Fri, 22 Oct 2010 13:53:55 +0100 Chris Vine ch...@cvine.freeserve.co.uk wrote: On Fri, 22 Oct 2010 10:37:01 + Juan Pablo L. jpablolorenze...@hotmail.com wrote: i attached the code but did not make thru, here is the server code: Something odd is going on. I see you are using GIOChannel not to do any reading, but in order to notify you that a connection is available. poll()/select() of course support this in unix-like systems, but I don't know if GIOChannel does (I have never tried). Possibly it only works if you set the channel as non-blocking with g_io_channel_set_flags() rather than by manipulating the file descriptor directly, which you have done. Again, I don't know. Actually, in this usage (attaching the file descriptor of a listening socket to a main loop) there is no need to make the file descriptor non-blocking since you will not make any blocking calls on it until you actually get to call accept() to establish the connection, and you may get undefined behaviour if you do - I don't know what POSIX says about that when you attempt to use poll() with it. Once poll() indicates that a connection is available, accept() can't block anyway. Does it work if you omit your call to fctl()? Chris ___ gtk-app-devel-list mailing list gtk-app-devel-list@gnome.org http://mail.gnome.org/mailman/listinfo/gtk-app-devel-list
RE: poll with timeout 0 in main loop
Hi Chris, yes it works without setting it as non-blocking so i decided to leave
none blocking just in case .. :) anyways
i was preparing the test code to send to you guys but i discovered that in the
test code the cpu usage is 0% (as i would expect in the real application) ...
the code i was going to send was a stripped version of the original code so
that ... but there is something that might be very important but have not
mention yet . i also created a GSource to run functions in other main loops
(for example i use this to fire the connection cleaning code in the server when
a connection dies) asynchronously, anyways, this is makes me very suspicious
now:
static gboolean async_callback_prepare(GSource *p_source,int *p_timeout)
{
AsyncCallbackSource *async_source = (AsyncCallbackSource *)p_source;
gboolean ret;
*p_timeout = 0;
g_mutex_lock(async_source-mutex1);
ret = g_queue_is_empty(async_source-callback_list);
g_mutex_unlock(async_source-mutex1);
return !ret;
}
i think i misunderstood the documentation here and maybe this is the 0 being
passed to poll ??? i think i will test this in the real code and let you know
asap
Date: Fri, 22 Oct 2010 14:27:54 +0100
From: ch...@cvine.freeserve.co.uk
To: ch...@cvine.freeserve.co.uk
CC: jpablolorenze...@hotmail.com; gtk-app-devel-list@gnome.org
Subject: Re: poll with timeout 0 in main loop
On Fri, 22 Oct 2010 13:53:55 +0100
Chris Vine ch...@cvine.freeserve.co.uk wrote:
On Fri, 22 Oct 2010 10:37:01 +
Juan Pablo L. jpablolorenze...@hotmail.com wrote:
i attached the code but did not make thru, here is the server code:
Something odd is going on.
I see you are using GIOChannel not to do any reading, but in order to
notify you that a connection is available. poll()/select() of course
support this in unix-like systems, but I don't know if GIOChannel
does (I have never tried). Possibly it only works if you set the
channel as non-blocking with g_io_channel_set_flags() rather than by
manipulating the file descriptor directly, which you have done.
Again, I don't know.
Actually, in this usage (attaching the file descriptor of a listening
socket to a main loop) there is no need to make the file descriptor
non-blocking since you will not make any blocking calls on it until you
actually get to call accept() to establish the connection, and you may
get undefined behaviour if you do - I don't know what POSIX says about
that when you attempt to use poll() with it. Once poll() indicates
that a connection is available, accept() can't block anyway.
Does it work if you omit your call to fctl()?
Chris
___
gtk-app-devel-list mailing list
gtk-app-devel-list@gnome.org
http://mail.gnome.org/mailman/listinfo/gtk-app-devel-list
poll with timeout 0 in main loop
Hi, i have a problem with an application i m building with glib-2.24.2 on linux, i create a server socket which i use to create a GIOChannel and add it to a main loop, everything was fine until i found that the application consumes 99.8% of the CPU while waiting for connections (doing nothing else just sitting there waiting for connections) and it gets even worse as new connections come in because i create a new loop in each connection (i create a thread for each connection) to deal with the incoming packages and each connection has N handlers to process the requests, each handler has its main loop for asynchronous communication between them and the connection thread that owns the handlers, so i did a strace and found out that the time out being passed to poll is 0 so for each iteration the poll returns inmediatly therefore i m stuck with a busy wait in all main loops, so i have read the documentation trying to find out how to modify this bahaviour but i could find nothing ab out it, can you please tell me why this is happenning ?? thanks! ___ gtk-app-devel-list mailing list gtk-app-devel-list@gnome.org http://mail.gnome.org/mailman/listinfo/gtk-app-devel-list
Re: poll with timeout 0 in main loop
On Thu, Oct 21, 2010 at 11:27 PM, Juan Pablo L. jpablolorenze...@hotmail.com wrote: Hi, i have a problem with an application i m building with glib-2.24.2 on linux, i create a server socket which i use to create a GIOChannel and add it to a main loop, everything was fine until i found that the application consumes 99.8% of the CPU while waiting for connections (doing nothing else just sitting there waiting for connections) and it gets even worse as new connections come in because i create a new loop in each connection (i create a thread for each connection) to deal with the incoming packages and each connection has N handlers to process the requests, each handler has its main loop for asynchronous communication between them and the connection thread that owns the handlers, so i did a strace and found out that the time out being passed to poll is 0 so for each iteration the poll returns inmediatly therefore i m stuck with a busy wait in all main loops, so i have read the documentation trying to find out how to modify this bahaviour but i could find nothing ab out it, can you please tell me why this is happenning ?? thanks! ___ gtk-app-devel-list mailing list gtk-app-devel-list@gnome.org http://mail.gnome.org/mailman/listinfo/gtk-app-devel-list Can you post an snipt of your code? And if you started a Thread and a loop inside it, it will stay interacting if you don't stop it, this will consume CPU for sure. I think you must work with signals or interrupts, I'm not sure about GIOChannel, maybe a snipt would clear a bit. [ ]'s -- Maginot Júnior LPIC 1 - LPIC 2 - LPIC 3 - CCNA - CLA - Forensics Analyst ___ gtk-app-devel-list mailing list gtk-app-devel-list@gnome.org http://mail.gnome.org/mailman/listinfo/gtk-app-devel-list
Re: poll with timeout 0 in main loop
2010/10/22 Juan Pablo L. jpablolorenze...@hotmail.com
hi, this is the code that makes the server socket
// create the server socket and return the file descriptor
fd = tcp_server_listerner_new(new_server-configurations,error);
if(fd 0)
{
g_error(Could not create listener, server creation aborted:
%s,error-message);
g_error_free(error);
return NULL;
}
// create the GIOChannel for the server socket
new_server-socket = g_io_channel_unix_new(fd);
// set the encoding safe to read binary data on the server GIOChannel
g_io_channel_set_encoding(new_server-socket,NULL,NULL);
// create a source for connection events on the server socket
new_server-event_source =
g_io_create_watch(new_server-socket,G_IO_IN|G_IO_PRI|G_IO_ERR|G_IO_HUP|G_IO_NVAL);
// set the callback function to handle connection events
g_source_set_callback(new_server-event_source,(GSourceFunc)tcp_server_handle_connection_events,new_server,NULL);
// attach the server socket connection event source to the server
context
g_source_attach(new_server-event_source,new_server-context);
new_server-main_loop = g_main_loop_new(new_server-context,FALSE);
and this is how i run the main loop:
void tcp_server_run(GMTCPServer *p_server)
{
// run the main loop now
g_main_loop_run(p_server-main_loop);
g_thread_exit(NULL);
}
this method is run from the main thread like this:
gm_tcp_server-server_thread =
g_thread_create((GThreadFunc)tcp_server_run,gm_tcp_server,TRUE,/*error*/NULL);
and this is how i create the server socket:
int tcp_server_listerner_new(const Configurations *p_configurations,GError
**p_error)
{
int fd;
struct sockaddr_in servAddr;
int set_option = 1;
// create the socket
fd = socket(AF_INET,SOCK_STREAM,IPPROTO_TCP);
if(fd 0)
{
*p_error =
g_error_new(G_IO_CHANNEL_ERROR,G_IO_CHANNEL_ERROR_FAILED,Could not create
server socket: %s,strerror(errno));
return -1;
}
// set some options on the socket
fcntl(fd,F_SETFL,O_NONBLOCK);// set the socket non-blocking
setsockopt(fd,SOL_SOCKET,SO_REUSEADDR,set_option,sizeof(set_option));//
reuse address
setsockopt(fd,SOL_SOCKET,SO_KEEPALIVE,set_option,sizeof(set_option));//
send keep alive messages
// construct local address structure
memset(servAddr,0x00, sizeof(servAddr));
servAddr.sin_family = AF_INET;
servAddr.sin_addr.s_addr =
inet_addr(p_configurations-tcp_server.interface);
servAddr.sin_port = htons(p_configurations-tcp_server.port);
// Bind to the local address
if(bind(fd,(struct sockaddr*)servAddr,sizeof(servAddr)) 0)
{
*p_error =
g_error_new(G_IO_CHANNEL_ERROR,G_IO_CHANNEL_ERROR_FAILED,Could not bind
server socket: %s,strerror(errno));
// close the socket
close(fd);
return -1;
}
if(listen(fd,10) 0)
{
*p_error =
g_error_new(G_IO_CHANNEL_ERROR,G_IO_CHANNEL_ERROR_FAILED,Could not start
listening on the server socket: %s,strerror(errno));
// close the socket
close(fd);
return -1;
}
return fd;
}
thanks !
--
Date: Fri, 22 Oct 2010 00:06:08 -0200
Subject: Re: poll with timeout 0 in main loop
From: maginot.jun...@gmail.com
To: jpablolorenze...@hotmail.com
CC: gtk-app-devel-list@gnome.org
On Thu, Oct 21, 2010 at 11:27 PM, Juan Pablo L.
jpablolorenze...@hotmail.com wrote:
Hi, i have a problem with an application i m building with glib-2.24.2 on
linux, i create a server socket which i use to create a GIOChannel and add
it to a main loop, everything was fine until i found that the application
consumes 99.8% of the CPU while waiting for connections (doing nothing else
just sitting there waiting for connections) and it gets even worse as new
connections come in because i create a new loop in each connection (i create
a thread for each connection) to deal with the incoming packages and each
connection has N handlers to process the requests, each handler has its main
loop for asynchronous communication between them and the connection thread
that owns the handlers, so i did a strace and found out that the time out
being passed to poll is 0 so for each iteration the poll returns inmediatly
therefore i m stuck with a busy wait in all main loops, so i have read the
documentation trying to find out how to modify this bahaviour but i could
find nothing ab
out it, can you please tell me why this is happenning ?? thanks!
___
gtk-app-devel-list mailing list
gtk-app-devel-list@gnome.org
http://mail.gnome.org/mailman/listinfo/gtk-app-devel-list
Can you post an snipt of your code?
And if you started a Thread and a loop inside it, it will stay interacting
if you don't stop it, this will consume CPU for sure. I think you must work
with signals or interrupts
