[patch] testsuite: Fix multiple runs in parallel on a single host [Re: RFC: parallelize "make check"]

[Jan Kratochvil <jan dot kratochvil at redhat dot com>]

On Mon, 29 Jun 2009 23:16:57 +0200, Jan Kratochvil wrote:
> On Mon, 29 Jun 2009 20:05:10 +0200, Tom Tromey wrote:
> >     gdb.base/watchpoint.exp
(This is a FSF GDB HEAD problem watchpoints are not distributed across threads.)


> >     gdb.mi/mi-file-transfer.exp, gdb.server/file-transfer.exp,

These + others get fixed by the patch below.

>  Running ../../../gdb/testsuite/gdb.server/file-transfer.exp ...
> -PASS: gdb.server/file-transfer.exp: put binary file
> -PASS: gdb.server/file-transfer.exp: get binary file
...
> +ERROR: tcl error sourcing ../../../gdb/testsuite/gdb.server/file-transfer.exp.
> +ERROR: : spawn id exp18 not open
> +    while executing
> +"expect_background -nobrace -i exp18 full_buffer { } eof {
...

It normally mostly always happens with multiple parallel testsuite runs on the
same host.  Now with the parallel check there is also a (low probability) it
would bite even during a single testsuite parallel run.

Regression tested on FSF GDB HEAD on {x86_64,i686}-fedora-linux-gnu.


Thanks,
Jan


gdb/testsuite/
2009-07-01  Jan Kratochvil  <jan.kratochvil@redhat.com>

	* lib/gdbserver-support.exp (gdbserver_start): Loop spawning
	gdbserver increasing $portnum if "Can't bind address" has been seen.

--- a/gdb/testsuite/lib/gdbserver-support.exp
+++ b/gdb/testsuite/lib/gdbserver-support.exp
@@ -209,26 +209,39 @@ proc gdbserver_start { options arguments } {
 
     set gdbserver [find_gdbserver]
 
-    # Export the host:port pair.
-    set gdbport $debughost$portnum
-
-    # Fire off the debug agent.
-    set gdbserver_command "$gdbserver"
-    if { $options != "" } {
-	append gdbserver_command " $options"
-    }
-    append gdbserver_command " :$portnum"
-    if { $arguments != "" } {
-	append gdbserver_command " $arguments"
-    }
-
-    set server_spawn_id [remote_spawn target $gdbserver_command]
+    # Loop till we find a free port.
+    while 1 {
+	# Export the host:port pair.
+	set gdbport $debughost$portnum
+
+	# Fire off the debug agent.
+	set gdbserver_command "$gdbserver"
+	if { $options != "" } {
+	    append gdbserver_command " $options"
+	}
+	append gdbserver_command " :$portnum"
+	if { $arguments != "" } {
+	    append gdbserver_command " $arguments"
+	}
 
-    # Wait for the server to open its TCP socket, so that GDB can connect.
-    expect {
-	-i $server_spawn_id
-	-notransfer
-	-re "Listening on" { }
+	set server_spawn_id [remote_spawn target $gdbserver_command]
+
+	# Wait for the server to open its TCP socket, so that GDB can connect.
+	expect {
+	    -i $server_spawn_id
+	    -notransfer
+	    -re "Listening on" { }
+	    -re "Can't bind address: Address already in use\\.\r\n" {
+		verbose -log "Port $portnum is already in use."
+		if ![target_info exists gdb,socketport] {
+		    # Bump the port number to avoid the conflict.
+		    wait -i $expect_out(spawn_id)
+		    incr portnum
+		    continue
+		}
+	    }
+	}
+	break
     }
 
     # We can't just call close, because if gdbserver is local then that means