Talk:Pthreads

Latest comment: 4 years ago by Lasse Hillerøe Petersen in topic Example description slightly incorrect?

interix not native edit

I believe from the following: "The Interix Pthread implementation is built upon the thread functionality already provided by the Windows kernel. " from http://technet.microsoft.com/en-us/library/bb463209.aspx#EEAA that the interix implementation is a wrapper as much as the other windows implementations. If nobody corrects me here in a week or two I'll go ahead and update it as such. Rogerdpack (talk) 04:59, 22 July 2012 (UTC)Reply

use of rand() edit

Running the sample code on cygwin in windows, the rand() function seems to have the same seed value in each thread that it's called in, meaning that I always get a 4 second sleep for every thread. Is this specific to my environment? I'm not much of a C programmer, so won't edit the page directly, but perhaps a good change would be to seed based on time in main() and then pass the sleep value as another argument to each thread initialisation, or keep it a bit more noddy and write which will at least give some different values for each thread.

  int sleep_time =  (index * 3) % NUM_THREADS;

Example description slightly incorrect? edit

In the description of the example it is stated: "If a programmer wanted the threads to communicate with each other, this would require defining a variable outside of the scope of any of the functions, making it a global variable."

This seems to be incorrect? Whatever function is starting the thread could pass a more complex structure as thread_args, there is no need for global variables in the way that term is normally used in C (a variable declared outside the scope of any function.) --Lasse Hillerøe Petersen (talk) 12:25, 5 April 2020 (UTC)Reply

Use of rand() in multiple threads edit

Isn't rand() thread unsafe? Use rand_r() instead if it is. The example program seems a bit off. A good (though long) example program can be found here: https://man7.org/linux/man-pages/man3/pthread_create.3.html