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need help with posix threads

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Old 12-23-2009
need help with posix threads
Hi,

I am new to posix threads. The no of threads to be created depends on the runtime. If I get the number of threads,
I need to forward declare

pthread_t mythread[n];

how to do that can I use pointers and use malloc()??

I also have another question. The pthread_join is used to make sure all the threads are completed right?? If I want to spawn new threads and execute threads when a particular set of threads get completed,How to complete it. Is my understanding of pthread_join correct??


function1()
{
for(//some n)
{

pthread_create(..,task1);
pthread_join(...,task1);
}

}

function2()
{

for(//some n)
{

pthread_create(..,task2);
pthread_join(...,task2);
}

}
Does this thing work for the model I ve said??
Thanks & Regards,
brett.
Last edited by brett01; 12-23-2009 at 04:52 AM..
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LEARN ABOUT CENTOS

xunlockdisplay

XInitThreads(3) 						  XLIB FUNCTIONS						   XInitThreads(3)

NAME

       XInitThreads, XLockDisplay, XUnlockDisplay - multi-threading support

SYNTAX

       Status XInitThreads(void);

       void XLockDisplay(Display *display);

       void XUnlockDisplay(Display *display);

ARGUMENTS

       display	 Specifies the connection to the X server.

DESCRIPTION

       The XInitThreads function initializes Xlib support for concurrent threads.  This function must be the first Xlib function a multi-threaded
       program calls, and it must complete before any other Xlib call is made.	This function returns a nonzero status if initialization was suc-
       cessful; otherwise, it returns zero.  On systems that do not support threads, this function always returns zero.

       It is only necessary to call this function if multiple threads might use Xlib concurrently.  If all calls to Xlib functions are protected
       by some other access mechanism (for example, a mutual exclusion lock in a toolkit or through explicit client programming), Xlib thread ini-
       tialization is not required.  It is recommended that single-threaded programs not call this function.

       The XLockDisplay function locks out all other threads from using the specified display.	Other threads attempting to use the display will
       block until the display is unlocked by this thread.  Nested calls to XLockDisplay work correctly; the display will not actually be unlocked
       until XUnlockDisplay has been called the same number of times as XLockDisplay.  This function has no effect unless Xlib was successfully
       initialized for threads using XInitThreads.

       The XUnlockDisplay function allows other threads to use the specified display again.  Any threads that have blocked on the display are
       allowed to continue.  Nested locking works correctly; if XLockDisplay has been called multiple times by a thread, then XUnlockDisplay must
       be called an equal number of times before the display is actually unlocked.  This function has no effect unless Xlib was successfully ini-
       tialized for threads using XInitThreads.

SEE ALSO

       Xlib - C Language X Interface

X Version 11							   libX11 1.6.0 						   XInitThreads(3)