[sane-devel] scan can not be stopped: possible problems with sanei_thread?

[Oliver Rauch]

Hello.

After an update to the cvs version of sane-backends I released that it
is not possible to stop a scan or a preview scan any more with the umax
backend. This is tested with scanimage and xsane.

AFAIR I did not make any changes relevant to this points in the umax
backend or in xsane. (And scanimage has the same problem).

To stop a scan in the umax backend the function sane_cancel calls
do_cancel that uses sanei_thread to kill the reader process and waits
for the reader process. But sanei_thread_waitpid() never returns.

Here is the relevant code in do_cancel:

static SANE_Status do_cancel(Umax_Scanner *scanner)
{
int pid, status;

  DBG(DBG_sane_proc,"do_cancel\n");

  scanner->scanning = SANE_FALSE;

  if (scanner->reader_pid > 0)
  {
    DBG(DBG_sane_info,"killing reader_process\n");

    sanei_thread_kill(scanner->reader_pid);
    pid = sanei_thread_waitpid(scanner->reader_pid, &status);

Does anyone remember a change that could have caused this problem?
Does anyone has also problems to stop a scan or preview scan?
Does anyone know from which sane-backends version it stopped working?

Note: USE_PTHREAD is not defined


Best regards
Oliver