capture the exception thrown from second thread

zlly20

say I have two thread A and B, A is the main thread, B is initilized and started from A by using following code
[PHP]
void A::runB()
{
     try
    {
          B *b = new B();
          b->run(); /* the second thread start running */
     }
     catch(Exception error)
     {
     }
}

[/PHP]
After b starts running, an exception is raised, how can I make the try-catch block in A::runB() catch that exception raised in B?????

Thank you

manphiz

Perhaps impossible.

Post by http://gcc.gnu.org/bugs.html#known

Exceptions don't work in multithreaded applications.

    You need to rebuild g++ and libstdc++ with --enable-threads. Remember, C++ exceptions are not like hardware interrupts. You cannot throw an exception in one thread and catch it in another. You cannot throw an exception from a signal handler and catch it in the main thread.

zlly20

Then, how should I handle these kind of exceptions in a multi-threaded application. what is the typical way to do it ???

anyone knows?

manphiz

Perhaps you should just catch the exception in the thread that throws it.

zlly20

but there is some error messge in the exception class, and those message I want to pass to the main thread, how can I do this ???

manphiz

Since different threads don't share same resources, it may be impossible to achieve in the program itself, or I don't know how to manage that.

You may use shared resources such as files, but maybe as a sacrifice in portability.

Anyone have better suggestion?

zlly20

here is a solution pop up into my mind, I can make A and B inherited from C, and in C, declare a variable called Exception error, whenever an exception is thrown in either A or B, error variable is set to that exception type... well, of course, I have to ensure that the exclusive access to error in C....

Does this sound reasonable and doable ????

manphiz

IMHO, it is still impossible since A and B are still at different threads. A in thread A still cannot be informed by B in thread B, because they don't share recourses.