thread c

Hi all,

I have an application that has a simple command lined interface, which gets command and executes them. Since I try to create a media application, I use the gstreamer framework and I want my interface back after I execute a program.

First I created the interface, the gstreamer framework and combined them. Everything worked perfectly, except that I only get my interface back after a complete run of a file. Here is what I do in short:

while(quit != 0){
if(strcmp(command, "play")==0)
		{
			scanf("%s", file);
			printf("inputfile: %s\n", file);
			pthread_create( &thread1, NULL, playfile(file), NULL);
                        pthread_join( thread1, NULL);
}
}

The file is played, but after that I get back in my shell, so somehow my thread broke out the while loop...

if I instead use:

while(quit != 0){
if(strcmp(command, "play")==0)
		{
			scanf("%s", file);
			printf("inputfile: %s\n", file);
			playfile(file);
}
}

I do get back on while loop.

Anyone has a suggestion to help me out?

Thanx in advance,

Jurrian

"pthread_join (one_thread)" means "Wait until the thread one_thread is finished. Another thing I'm not sure that's clear for you is that when a process ends, it kills all its thread.
So the design of your program will depend on what you want. If you really want to start the play and directly come back to the shell, I think you'd better make simple program (without thread nor fork) and run it with a "&" at the end of your command line, thus the shell will start it as a background job. You can do that into your program with the "fork" function, I don't know if it's really the same thing, but it really look the same, but then your force the "background job" policy, I think it's better that the program user have the choice to start it with or without "&".

I think you misunderstand me a little. My program has an own command line interface, and a & behind the start of my program will give me back the terminal command line.

Anyone has another suggestion?

Originally Posted by Jurrian I think you misunderstand me a little

to me it seems not.

what ever the reply in the second post, it is quite ok.

Originally Posted by Jurrian pthread_join( thread1, NULL);

try comment this line and execute the code. check if it is doing what u want.

Try to write it out like this:

1. start program
2. start thread          --> 1. top of loop
3. wait for thread (join)    2. do stuff, maybe break loop
4. exit program              3. go to 1

Modify that with what you expect to happen (and maybe also what you think is happening) so we have a better idea of what's going on.
ta0kira

This is what I want it to do:

1. start program
2. start loop
3a. start thread          --> 1. top of loop
3b execute other command
4 if other command is not exit, goto 1
5 exit program

I took out the wait to join, and put that on the end, so my program will first terminate the thread and then finish.

Do you terminate with pthread_cancel? If so, that doesn't work well with pthread_join except under certain conditions (I'll elaborate if that's the case.) Also, what does the thread do? You didn't specify. Does the main thread continually execute a command in 3b because of looping to 1, or is that jumping to the 1 in the thread? Are you just trying to wait until the command exits? By command, do you mean a new process, or the execution of a function?
ta0kira

1. start program
2. start loop
3a. start thread and start playing a media file  --> 1. top of loop
3b execute other command (like pause, mute, help, exit)
4 if other command is not exit, goto 1
5 exit program

After 3a, the program needs to go straight to 2, else a mute command or pause command will be pretty useless.

I am not using pthread_cancel, nor using p_thread_exit().

I found a mistake myself, the call to p_thread_create should be:

pthread_create( &thread1, NULL, (void *) playfile, file);

fixed it, thanx all for help