pthread_create returns -1?

[malletelf]

Hi all.
Anyone had any trouble with pthread_create returning -1? I'm not sure what to do about it, so any and all suggestions would be appreciated!

Thanks in advance!

// Code:
/////////////////////////////////////////////////////////////////

coid *Client(coid *);

void main(){
......
pthread_t clientid[MAXCLIENTS] /* MAXCLIENTS == 32 */

pthread_attr_init(&attr);
pthread_attr_setscope(&attr, PTHREAD_SCOPE_SYSTEM);
......
for ( ; ; ){
......
pthread_create(&clientid[i], &attr, Client, (void *) i);
......
}
}

[dimm_coder]

Is it a real code? But here U dont check for pthread_create return code.
for(;; ) ???
Did U try to create only 32 as declared above?

Possible error for pthread_create is only EAGAIN, which means no more system resources available,
ofcourse if U write for(;; ) and try to create unbounded count of threads.

[malletelf]

Attached is the entire server code.

I will add checking to make sure I only allow 32 clients.

http://www.opengroup.org/onlinepubs/007908799/xsh/pthread_create.html

ERRORS

The pthread_create() function will fail if:

[EAGAIN]
The system lacked the necessary resources to create another thread, or the system-imposed limit on the total number of threads in a process PTHREAD_THREADS_MAX would be exceeded.
[EINVAL]
The value specified by attr is invalid.
[EPERM]
The caller does not have appropriate permission to set the required scheduling parameters or scheduling policy.

The pthread_create() function will not return an error code of [EINTR].

[dimm_coder]

It returns -1 on the 1-st step of iteration?
Look system errno variable for error code.

[malletelf]

Yes, it returns -1 on the first iteration.

perror/errno return an error code of 0.

Were you able to see my attached files? That was the first time I've tried and I wasn't sure how it worked.

[dimm_coder]

Strange that 0 :confused:
That means no error.
Are U try setscope for return code?

[malletelf]

I tried setscope, and everything else dealing with the thread. All variables are correct and all parameters seem to be correct.

I have class shortly, I can ask the professor. Hopefully he can shed some light on it, but I'm not so sure.

As this assignment is due in 15 1/2 hours, and there's plenty left to do, don't be surprised to see more posts here, lol.

[dimm_coder]

U can attach here your sources if it will be possible for U. May be it will give some light.

[malletelf]

Hopefully these clear things up a little.

Thanks for all your help!!

[dimm_coder]

I compiled your server, run it, then with telnet opened a connection. So all was OK! No any error with pthread_create(). perror gave "Invalid seek" for pthread_attr_setscope(). Why do U use it? This default value for posix linux threads, as I remember, or U use another UNIX?
So for some time it works until telnet breaked it. I put printf() into Client() - function and it worked.
So I hadn't error with pthread_create().

[malletelf]

I'm working from a Sparc server running SunOS 5.8.

I'll have to say it is the computers that make the difference, because even doing what you did, I can't make it work.

Sometimes if feels as though I'm beating a dead horse with the network programming we've been doing.

[malletelf]

Well, what can I say?
I'm terribly sorry to have wasted your time on this.

Turns out that I didn't include the proper compiler directives in my make file.

I guess that's why I'm a student though.

Thanks again.

[dimm_coder]

I didn't work with Spark platform and SunOS. This is very simple sample U 've provided. And quike view didn't recognise any problems with network part. Of course, it has it, but they cannot make problem U have.
So I don't know, may be it depends of Sun posix realization or something else.
Did U try this without pthread_attr_setscope()?

Else why fork()? U create a child process, then create thread in it, but then after a little a child process is ended and thread U created too.
It is enough to call pthread_create() to create a client thread.