Re: Exiting blocked threads (socket.accept)
Dne 27.3.2013 22:38, Tim napsal(a):
Thanks! I've never used message passing and I'm currently a bit confused
how it works (I came from the Java-area where message passing isn't
necessary for something like that)... are there any information/examples
about message passing? I sill can't get it to work... I changed my code
as follows:
Hi,
To use message passing, you have to use the std.concurrency module and
then jump through some hoops to execute the code in your class in
separate thread. Right now, you are using core.thread which is lower
level than std.concurrency. Definitely check the page Ali sent you.
I have altered your code a bit to send the interrupt to the thread using
a socketpair. I had to change the signal code, because it was not
working on my windows box (I wasn't sure what to import).
This code still relies on a variable set inside the signal handler,
because writing to a socket is not nothrow. You could overcome this by
using the pipe as Sean suggested.
Martin
import std.socket;
import core.thread;
import core.stdc.signal;
import std.stdio;
__gshared Socket readSock;
__gshared Socket writeSock;
__gshared bool stopServer = false;
class Connection : Thread {
private Socket pSocket;
void run() {
ptrdiff_t received;
ubyte[0x10] buffer;
SocketSet ss = new SocketSet();
mainloop:
while(1) {
ss.reset();
ss.add(pSocket);
ss.add(readSock);
if (Socket.select(ss, null, null) 0) {
if (ss.isSet(pSocket))
{
received = pSocket.receive(buffer);
writeln(Received data);
// process data
}
else if (ss.isSet(readSock))
{
writeln(Received interrupt);
break mainloop;
}
}
}
pSocket.close();
}
this(Socket s) {
super(run);
pSocket = s;
}
}
extern (C) void terminateServer(int s) nothrow {
stopServer = true;
}
void main() {
signal(SIGINT, terminateServer);
TcpSocket s = new TcpSocket();
s.bind(new InternetAddress(2100));
s.listen(0);
auto pair = socketPair();
readSock = pair[0];
writeSock = pair[1];
SocketSet ss = new SocketSet();
while (!stopServer)
{
ss.reset();
ss.add(s);
if (Socket.select(ss, null, null, dur!msecs(20)) 0)
{
writeln(Received new connection);
(new Connection(s.accept)).start();
}
}
writeSock.send([1]);
s.shutdown(SocketShutdown.BOTH);
s.close();
writeln(Finished);
}
Re: Exiting blocked threads (socket.accept)
On Thursday, 28 March 2013 at 07:57:07 UTC, Martin Drašar wrote:
Dne 27.3.2013 22:38, Tim napsal(a):
Thanks! I've never used message passing and I'm currently a
bit confused
how it works (I came from the Java-area where message passing
isn't
necessary for something like that)... are there any
information/examples
about message passing? I sill can't get it to work... I
changed my code
as follows:
Hi,
To use message passing, you have to use the std.concurrency
module and then jump through some hoops to execute the code in
your class in separate thread. Right now, you are using
core.thread which is lower level than std.concurrency.
Definitely check the page Ali sent you.
I have altered your code a bit to send the interrupt to the
thread using a socketpair. I had to change the signal code,
because it was not working on my windows box (I wasn't sure
what to import).
This code still relies on a variable set inside the signal
handler, because writing to a socket is not nothrow. You could
overcome this by using the pipe as Sean suggested.
Martin
import std.socket;
import core.thread;
import core.stdc.signal;
import std.stdio;
__gshared Socket readSock;
__gshared Socket writeSock;
__gshared bool stopServer = false;
class Connection : Thread {
private Socket pSocket;
void run() {
ptrdiff_t received;
ubyte[0x10] buffer;
SocketSet ss = new SocketSet();
mainloop:
while(1) {
ss.reset();
ss.add(pSocket);
ss.add(readSock);
if (Socket.select(ss, null, null) 0) {
if (ss.isSet(pSocket))
{
received = pSocket.receive(buffer);
writeln(Received data);
// process data
}
else if (ss.isSet(readSock))
{
writeln(Received interrupt);
break mainloop;
}
}
}
pSocket.close();
}
this(Socket s) {
super(run);
pSocket = s;
}
}
extern (C) void terminateServer(int s) nothrow {
stopServer = true;
}
void main() {
signal(SIGINT, terminateServer);
TcpSocket s = new TcpSocket();
s.bind(new InternetAddress(2100));
s.listen(0);
auto pair = socketPair();
readSock = pair[0];
writeSock = pair[1];
SocketSet ss = new SocketSet();
while (!stopServer)
{
ss.reset();
ss.add(s);
if (Socket.select(ss, null, null, dur!msecs(20)) 0)
{
writeln(Received new connection);
(new Connection(s.accept)).start();
}
}
writeSock.send([1]);
s.shutdown(SocketShutdown.BOTH);
s.close();
writeln(Finished);
}
Thanks Martin and Ali. Your solution works as long as I use the
receive()-method, but what about using SocketStreams? I replaced
socket.receive() with socketStream.readLine() which isn't broken
by the solution above...
Re: Exiting blocked threads (socket.accept)
On 28.3.2013 11:23, Tim wrote: Thanks Martin and Ali. Your solution works as long as I use the receive()-method, but what about using SocketStreams? I replaced socket.receive() with socketStream.readLine() which isn't broken by the solution above... If you check the documentation, you will see that the SocketStream is a stream for blocking socket. You can't easily make it work with nonblocking select() calls. However, if you want to use the stream interface, you can write the non-blocking stream yourself. If you check the SocketStream at github (https://github.com/D-Programming-Language/phobos/blob/master/std/socketstream.d), you will see that it is pretty small and easy. You can transfer the interrupt code inside the readBlock() method. However, it will probably be for the best to just write your own method to read for socket until the end of the line. Martin
Re: Exiting blocked threads (socket.accept)
On Thursday, 28 March 2013 at 12:28:05 UTC, Martin Drasar wrote:
On 28.3.2013 11:23, Tim wrote:
Thanks Martin and Ali. Your solution works as long as I use the
receive()-method, but what about using SocketStreams? I
replaced
socket.receive() with socketStream.readLine() which isn't
broken by the
solution above...
If you check the documentation, you will see that the
SocketStream is a
stream for blocking socket. You can't easily make it work with
nonblocking select() calls.
However, if you want to use the stream interface, you can write
the
non-blocking stream yourself. If you check the SocketStream at
github
(https://github.com/D-Programming-Language/phobos/blob/master/std/socketstream.d),
you will see that it is pretty small and easy. You can transfer
the
interrupt code inside the readBlock() method.
However, it will probably be for the best to just write your
own method
to read for socket until the end of the line.
Martin
Thanks for everything, but I'm still having some problems with
this solution... I implemented a simple ftp server which looks as
follows:
import std.socket;
import core.thread;
import core.stdc.signal;
import std.stdio;
import std.string;
import std.conv : to;
__gshared Socket readSock;
__gshared Socket writeSock;
__gshared bool stopServer = false;
class DataChannel {
Socket datasocket;
this() {
datasocket = new TcpSocket();
datasocket.bind(new InternetAddress(0));
datasocket.listen(0);
}
}
class Connection : Thread {
private Socket pSocket;
void run() {
int i = 0x00;
DataChannel datachannel;
ptrdiff_t received;
ubyte[0x20] buffer;
SocketSet ss = new SocketSet();
pSocket.send(220 FTP ready.\r\n);
datachannel = new DataChannel();
mainloop:
while(1) {
i++;
ss.reset();
ss.add(pSocket);
ss.add(readSock);
if (Socket.select(ss, null, null) 0) {
if (ss.isSet(pSocket))
{
received = pSocket.receive(buffer);
if (i == 1)
pSocket.send(331 Password required for anyUser\r\n);
else if (i == 2)
pSocket.send(230 User anyUser logged in\r\n);
else if (i == 3)
pSocket.send(257 / is the current directory.\r\n);
else if (i == 4)
pSocket.send(215 UNIX Type: L8\r\n);
else if (i == 5)
pSocket.send(200 Type set to I\r\n);
else if (i == 6) {
string[] lip = split(pSocket.localAddress.toAddrString, .);
auto port = (cast(InternetAddress)
datachannel.datasocket.localAddress).port;
pSocket.send(227 Entering Passive Mode( ~ lip[0x00] ~ , ~
lip[0x01] ~ , ~ lip[0x02] ~ , ~ lip[0x03] ~ , ~
to!(string)(port / 256) ~ , ~ to!(string)(port % 256) ~
)\r\n);
}
else if (i == 7)
pSocket.send(150 Here comes the directory listing.\r\n226
Directory listing complete\r\n);
else if (i == 8)
pSocket.send(250 CWD command successful.\r\n);
else if (i == 9)
pSocket.send(257 / is the current directory.\r\n);
}
// process data
}
else if (ss.isSet(readSock))
{
writeln(Received interrupt);
break mainloop;
}
}
pSocket.close();
}
this(Socket s) {
super(run);
pSocket = s;
}
}
extern (C) void terminateServer(int s) nothrow {
stopServer = true;
}
void main() {
signal(SIGINT, terminateServer);
TcpSocket s = new TcpSocket();
s.bind(new InternetAddress(2100));
s.listen(0);
auto pair = socketPair();
readSock = pair[0];
writeSock = pair[1];
SocketSet ss = new SocketSet();
while (!stopServer)
{
ss.reset();
ss.add(s);
if (Socket.select(ss, null, null, dur!msecs(20)) 0)
{
writeln(Received new connection);
(new Connection(s.accept)).start();
}
}
writeSock.send([1]);
s.shutdown(SocketShutdown.BOTH);
s.close();
writeln(Finished);
}
I know... that's not only a dirty solution, but a terrible (and
wrong) solution, but it's for demonstration purposes only. By
connecting to this server using a ftp client (let's say FileZilla
or gFTP), I can connect until I get an error (which comes because
of the dirty solution... but that's not the point here). When I
press CTRL+C to terminate the server, this doesn't work anymore.
I don't know why (probably because of the datachannel? But there
is no loop or something else in the datachannel-class - no
accept() or similar)... I've a rfc959-based implemented version
of the ftp-server, but the result is the same... pressing CTRL+C
doesn't work in some cases.
Re: Exiting blocked threads (socket.accept)
On Thursday, 28 March 2013 at 17:57:47 UTC, Tim wrote:
On Thursday, 28 March 2013 at 12:28:05 UTC, Martin Drasar wrote:
On 28.3.2013 11:23, Tim wrote:
Thanks Martin and Ali. Your solution works as long as I use
the
receive()-method, but what about using SocketStreams? I
replaced
socket.receive() with socketStream.readLine() which isn't
broken by the
solution above...
If you check the documentation, you will see that the
SocketStream is a
stream for blocking socket. You can't easily make it work with
nonblocking select() calls.
However, if you want to use the stream interface, you can
write the
non-blocking stream yourself. If you check the SocketStream at
github
(https://github.com/D-Programming-Language/phobos/blob/master/std/socketstream.d),
you will see that it is pretty small and easy. You can
transfer the
interrupt code inside the readBlock() method.
However, it will probably be for the best to just write your
own method
to read for socket until the end of the line.
Martin
Thanks for everything, but I'm still having some problems with
this solution... I implemented a simple ftp server which looks
as follows:
import std.socket;
import core.thread;
import core.stdc.signal;
import std.stdio;
import std.string;
import std.conv : to;
__gshared Socket readSock;
__gshared Socket writeSock;
__gshared bool stopServer = false;
class DataChannel {
Socket datasocket;
this() {
datasocket = new TcpSocket();
datasocket.bind(new InternetAddress(0));
datasocket.listen(0);
}
}
class Connection : Thread {
private Socket pSocket;
void run() {
int i = 0x00;
DataChannel datachannel;
ptrdiff_t received;
ubyte[0x20] buffer;
SocketSet ss = new SocketSet();
pSocket.send(220 FTP ready.\r\n);
datachannel = new DataChannel();
mainloop:
while(1) {
i++;
ss.reset();
ss.add(pSocket);
ss.add(readSock);
if (Socket.select(ss, null, null) 0) {
if (ss.isSet(pSocket))
{
received = pSocket.receive(buffer);
if (i == 1)
pSocket.send(331 Password required for anyUser\r\n);
else if (i == 2)
pSocket.send(230 User anyUser logged in\r\n);
else if (i == 3)
pSocket.send(257 / is the current directory.\r\n);
else if (i == 4)
pSocket.send(215 UNIX Type: L8\r\n);
else if (i == 5)
pSocket.send(200 Type set to I\r\n);
else if (i == 6) {
string[] lip = split(pSocket.localAddress.toAddrString, .);
auto port = (cast(InternetAddress)
datachannel.datasocket.localAddress).port;
pSocket.send(227 Entering Passive Mode( ~ lip[0x00] ~ , ~
lip[0x01] ~ , ~ lip[0x02] ~ , ~ lip[0x03] ~ , ~
to!(string)(port / 256) ~ , ~ to!(string)(port % 256) ~
)\r\n);
}
else if (i == 7)
pSocket.send(150 Here comes the directory listing.\r\n226
Directory listing complete\r\n);
else if (i == 8)
pSocket.send(250 CWD command successful.\r\n);
else if (i == 9)
pSocket.send(257 / is the current directory.\r\n);
}
// process data
}
else if (ss.isSet(readSock))
{
writeln(Received interrupt);
break mainloop;
}
}
pSocket.close();
}
this(Socket s) {
super(run);
pSocket = s;
}
}
extern (C) void terminateServer(int s) nothrow {
stopServer = true;
}
void main() {
signal(SIGINT, terminateServer);
TcpSocket s = new TcpSocket();
s.bind(new InternetAddress(2100));
s.listen(0);
auto pair = socketPair();
readSock = pair[0];
writeSock = pair[1];
SocketSet ss = new SocketSet();
while (!stopServer)
{
ss.reset();
ss.add(s);
if (Socket.select(ss, null, null, dur!msecs(20)) 0)
{
writeln(Received new connection);
(new Connection(s.accept)).start();
}
}
writeSock.send([1]);
s.shutdown(SocketShutdown.BOTH);
s.close();
writeln(Finished);
}
I know... that's not only a dirty solution, but a terrible (and
wrong) solution, but it's for demonstration purposes only. By
connecting to this server using a ftp client (let's say
FileZilla or gFTP), I can connect until I get an error (which
comes because of the dirty solution... but that's not the point
here). When I press CTRL+C to terminate the server, this
doesn't work anymore. I don't know why (probably because of the
datachannel? But there is no loop or something else in the
datachannel-class - no accept() or similar)... I've a
rfc959-based implemented version of the ftp-server, but the
result is the same... pressing CTRL+C doesn't work in some
cases.
I should better double check the documentation... the reason for
the problem is the if-then-elseif... I've changed this to:
if (ss.isSet(pSocket)) {
// ... do stuff here
}
if (ss.isSet(readSock)) {
break mainloop;
}
As I
Re: Exiting blocked threads (socket.accept)
Have each thread select() on the read end of a pipe that the main thread writes to when it wants to trigger a wakeup--write() is legal even in signal handlers.
Re: Exiting blocked threads (socket.accept)
Dne 27.3.2013 18:51, Tim napsal(a):
That works as expected, except the fact that pressing CTRL+C which stops
the while(!stopServer) doesn't terminate the mainloop in my
Connection-class (run()-method). This thread is blocked because of the
receive()-method... but how can I force this thread to exit? Is there
any chance to do that? I already tried to set the accepted socket to
blocking(false) without any success...
Thanks in advance for any reply!
Hi Tim,
you have to pass the termination information to the thread. It does not
know about it and waits for receive() to return.
You will have to employ the select() call to some extent.
1) You can have some form of global variable that indicates termination
or you can send the termination info using Tid.send(). The code can then
look like this:
threadSocket.blocking(false);
auto ss = new SocketSet();
while (!shouldEnd)
{
ss.reset();
ss.add(threadSocket);
auto rc = Socket.select(ss, null, null, dur!msecs(timeout));
if (rc == 1)
{
// process your data
}
}
And it would take at most timeout miliseconds for thread to react to
termination message.
2) Use what Sean Kelly wrote. Either using a pipe or socketpair.
Martin
Re: Exiting blocked threads (socket.accept)
On Wednesday, 27 March 2013 at 20:16:39 UTC, Martin Drašar wrote:
Dne 27.3.2013 18:51, Tim napsal(a):
That works as expected, except the fact that pressing CTRL+C
which stops
the while(!stopServer) doesn't terminate the mainloop in my
Connection-class (run()-method). This thread is blocked
because of the
receive()-method... but how can I force this thread to exit?
Is there
any chance to do that? I already tried to set the accepted
socket to
blocking(false) without any success...
Thanks in advance for any reply!
Hi Tim,
you have to pass the termination information to the thread. It
does not know about it and waits for receive() to return.
You will have to employ the select() call to some extent.
1) You can have some form of global variable that indicates
termination or you can send the termination info using
Tid.send(). The code can then look like this:
threadSocket.blocking(false);
auto ss = new SocketSet();
while (!shouldEnd)
{
ss.reset();
ss.add(threadSocket);
auto rc = Socket.select(ss, null, null, dur!msecs(timeout));
if (rc == 1)
{
// process your data
}
}
And it would take at most timeout miliseconds for thread to
react to termination message.
2) Use what Sean Kelly wrote. Either using a pipe or socketpair.
Martin
Thanks! I've never used message passing and I'm currently a bit
confused how it works (I came from the Java-area where message
passing isn't necessary for something like that)... are there any
information/examples about message passing? I sill can't get it
to work... I changed my code as follows:
class Connection : Thread {
private Socket pSocket;
void run() {
ptrdiff_t received;
ubyte[0x10] buffer;
SocketSet ss = new SocketSet();
mainloop:
while(!stopServer) {
ss.reset();
ss.add(pSocket);
if (Socket.select(ss, null, null, dur!msecs(10)) 0)
{
received = pSocket.receive(buffer);
// do some more stuff here
if (buffer[0 .. received] == QUIT)
break mainloop;
}
}
}
this(Socket s) {
super(run);
pSocket = s;
}
}
extern(C) void terminateServer(int s) {
stopServer = true;
}
private bool stopServer = false;
void main() {
sigaction_t sig;
sig.sa_handler = terminateServer;
sigemptyset(sig.sa_mask);
sig.sa_flags = 0;
sigaction(SIGINT, sig, null);
TcpSocket s = new TcpSocket();
s.bind(new InternetAddress(2100));
//s.blocking(false);
s.listen(0);
SocketSet ss = new SocketSet();
while(!stopServer) {
ss.reset();
ss.add(s);
if (Socket.select(ss, null, null, dur!msecs(10)) 0)
(new Connection(s.accept)).start();
}
writeln(Server stopped);
s.shutdown(SocketShutdown.BOTH);
s.close();
}
Alright... let's connect to the server... the server accepts,
creates an instance of Connection and starts a new thread. Now...
I set stopServer to true (CTRL+C). This should stop the server
and I also get the message in my main()-method that the server
stopped. But the other thread (Connection-thread) doesn't
terminate... it runs as long as the connection to the client is
alive... by killing the connection from the client-side, the
connection thread also terminates (and throws an exception).
Re: Exiting blocked threads (socket.accept)
On 03/27/2013 02:38 PM, Tim wrote: are there any information/examples about message passing? The following chapter is about the std.concurrency module of Phobos: http://ddili.org/ders/d.en/concurrency.html Some of the examples in there send a special 'struct Exit' message to tell the workers to exit. Ali
