[rt.cpan.org #79924]

[email protected] ("nyet via RT") Fri, 28 Sep 2012 17:33:54 -0400

Newsgroups	perl.libwin32
Message-ID	<[email protected]>

Fri Sep 28 17:33:53 2012: Request 79924 was acted upon.
Transaction: Ticket created by nyet
       Queue: Win32-Pipe
     Subject: (No subject given)
   Broken in: 0.024
    Severity: Critical
       Owner: Nobody
  Requestors: [email protected]
      Status: new
 Ticket <URL: https://rt.cpan.org/Ticket/Display.html?id=79924 >


Hi,

It seems that the 2nd iteration of Connect() is not blocking anymore. Is
this a correct behavior?

Run Win32API-File.pl first and run Win32-Pipe-Client.pl on another console.

>perl Win32-Pipe.pl
0.024
Creating pipe 'My Named Pipe'
1:Waiting for a client to connect...blocking
Client sent us: Time on XXX is: Fri Sep 28 14:30:57 2012

Disconnecting...
2:Waiting for a client to connect...NOT blocking
3:Waiting for a client to connect...NOT blocking
4:Waiting for a client to connect...NOT blocking
5:Waiting for a client to connect...NOT blocking
6:Waiting for a client to connect...NOT blocking
7:Waiting for a client to connect...NOT blocking
8:Waiting for a client to connect...NOT blocking
9:Waiting for a client to connect...NOT blocking
10:Waiting for a client to connect...NOT blocking
11:Waiting for a client to connect...NOT blocking

Win32API-File.pl (application/octet-stream, 1.8 KB)

use strict;
use Win32;
use Win32::API;
use Win32API::File qw( :Func );

my $PipeName = "My Named Pipe";
use constant { 
    PIPE_NAME => "//./pipe/X"
    , PIPE_ACCESS_INBOUND => 0x00000001
    , FILE_FLAG_FIRST_PIPE_INSTANCE => 0x00080000
    , PIPE_TYPE_MESSAGE => 0x00000004
    , PIPE_READMODE_MESSAGE => 0x00000002
};
my $NULL = 0;

# Note warning on LPSECURITY_ATTRIBUTES, but used only as NULL pointer
Win32::API->Import('kernel32'
  ,'HANDLE CreateNamedPipe( LPCTSTR lpName '
    . ', DWORD dwOpenMode, DWORD dwPipeMode, DWORD nMaxInstances'
    . ', DWORD nOutBufferSize, DWORD nInBufferSize'
    . ', DWORD nDefaultTimeOut'
    . ', LPSECURITY_ATTRIBUTES lpSecurityAttributes)' );

# Note warning on LPOVERLAPPED, but used only as NULL pointer.
Win32::API->Import('kernel32'
  ,'BOOL ConnectNamedPipe(HANDLE hNamedPipe'
    . ', LPOVERLAPPED lpOverlapped )');

Win32::API->Import('kernel32'
  ,'BOOL DisconnectNamedPipe(HANDLE hNamedPipe)');


my $pipehandle = CreateNamedPipe( PIPE_NAME 
        , PIPE_ACCESS_INBOUND + FILE_FLAG_FIRST_PIPE_INSTANCE
        , PIPE_TYPE_MESSAGE + PIPE_READMODE_MESSAGE
        , 1        , 512    , 512    , 10000    , $NULL ) 
    or die "Unable to create pipe:". Win32::GetLastError() ;
my( $res, $message);

my $bServerContinue = 1;
while( $bServerContinue ) {
	print "Waiting for a client to connect...\n";
	ConnectNamedPipe($pipehandle,$NULL) 
		or die "Connect failed: ".  Win32::GetLastError();
	$res = ReadFile($pipehandle,$message, 512, [], [] );
	print "message: $message\n";
	$bServerContinue = 0 if $message eq 'bb';
	$res = DisconnectNamedPipe($pipehandle);
	if( $message eq "exit" ) { 
		last;
	}
}
$res = CloseHandle($pipehandle);

#http://www.perlmonks.org/?node_id=715874
#http://www.perlmonks.org/?node_id=726593

Win32-Pipe-Client.pl (application/octet-stream, 439 B)

use Win32::Pipe;

$PipeName = "\\\\localhost\\pipe\\My Named Pipe";
print "Connecting to $PipeName\n";

if( $Pipe = new Win32::Pipe( $PipeName ) )
{
  my $Data = "Time on " . Win32::NodeName() . " is: " . localtime() . "\n";
  print "\nPipe has been opened, writing data to it...\n";
  
  $Pipe->Write( $Data );
  $Pipe->Close();
}
else
{
  print "Error connecting: " . Win32::FormatMessage( $Win32::Pipe::Error ) . "\n";
}