El 14/12/18 a les 18:08, Jonas Maebe ha escrit:
On 14/12/18 11:09, Luca Olivetti wrote:
I think that TThread should have a method to kill it for such cases,
using, e.g., pthread_cancel under unix
pthread_cancel() does not not kill a thread. Conceptually, it is exactly
the same as calling TThread.terminate: it just sets a property for the
thread to indicate someone wants it to stop. The thread will only stop
the next time pthread_testcancel() gets subseaquently called from inside
this "cancelled" thread, which should only be done at well-defined
points so the chances at leaving stray locks etc behind are minimalised.
Oh, I'm not familiar with those APIs (that's why I use freepascal ;-), I
just looked at the implementation of a thread class in vdr
(http://www.tvdr.de/) documented this way:
void Cancel(int WaitSeconds = 0);
///< Cancels the thread by first setting 'running' to false, so that
///< the Action() loop can finish in an orderly fashion and then
waiting
///< up to WaitSeconds seconds for the thread to actually end.
If the
///< thread doesn't end by itself, it is killed.
///< If WaitSeconds is -1, only 'running' is set to false and
Cancel()
///< returns immediately, without killing the thread.
and the method uses pthread_cancel. So the documentation of that class
is misleading.
I also read the manual page for pthread_cancel and even when using
pthread_canceltype(PTHREAD_CANCEL_AYNCHRONOUS) "The thread can be
canceled at any time. (Typically, it will be canceled immediately upon
receiving a cancellation request, but the system doesn't guarantee this.)".
Bye
--
Luca
_______________________________________________
fpc-pascal maillist - fpc-pascal@lists.freepascal.org
http://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
