I want to create a program that creates 2 child process, and each of them creates 2 threads, and each thread prints its thread id. I0ve allread done that the outuput isn't the outuput i want.
When a run the following comand "$./a.out | sort -u | wc -l" I have the folowing output 2
$:
It should be 6.
Thanks in advance
Hello,
i have 2 questions:
1. Can I get the current memory usage of a thread?
2. Can I use a member-function as (void*)(*)(void*) method to create a new thread with "pthread_create(...)"??
I would be happy about any suggestion.
Regards,
Rolf (2 Replies)
Hi all!
I am implementing an http server in c++ using the posix thread, but i am having a memory leak and i cannot find the reason.
I have already commented out the section that initializes the threads and i found out, the problem is when i initialize/run the threads.
In the threads i have... (1 Reply)
Hello,
I have created program that run threads one by one, maximum 100. Each thread will process one block of data, and once it`s finished, new thread is created with new block of data....etc
I have array of values to control status of each thread, like this:
array_thread_status=1... (11 Replies)
I am facing a strange error while creating posix threads:
Given below are two snippets of code, the first one works whereas the second one gives a garbage value in the output.
Snippet 1
This works:
--------------
int *threadids;
threadids = (int *) malloc (num_threads * sizeof(int));
... (4 Replies)
i am creating threads in my program using the POSIX interface.
when the thread starts executing i run out of memory and get a core dump.
i have tried to increase the threads stack size using pthread_attr_setstacksize, but of no use since i guess the dynamic memory is allocated on the heap and... (1 Reply)
Discussion started by: aniketkadu2002
1 Replies
LEARN ABOUT X11R4
pthread_join
PTHREAD_JOIN(3) Linux Programmer's Manual PTHREAD_JOIN(3)NAME
pthread_join - join with a terminated thread
SYNOPSIS
#include <pthread.h>
int pthread_join(pthread_t thread, void **retval);
Compile and link with -pthread.
DESCRIPTION
The pthread_join() function waits for the thread specified by thread to terminate. If that thread has already terminated, then
pthread_join() returns immediately. The thread specified by thread must be joinable.
If retval is not NULL, then pthread_join() copies the exit status of the target thread (i.e., the value that the target thread supplied to
pthread_exit(3)) into the location pointed to by retval. If the target thread was canceled, then PTHREAD_CANCELED is placed in the loca-
tion pointed to by retval.
If multiple threads simultaneously try to join with the same thread, the results are undefined. If the thread calling pthread_join() is
canceled, then the target thread will remain joinable (i.e., it will not be detached).
RETURN VALUE
On success, pthread_join() returns 0; on error, it returns an error number.
ERRORS
EDEADLK
A deadlock was detected (e.g., two threads tried to join with each other); or thread specifies the calling thread.
EINVAL thread is not a joinable thread.
EINVAL Another thread is already waiting to join with this thread.
ESRCH No thread with the ID thread could be found.
ATTRIBUTES
For an explanation of the terms used in this section, see attributes(7).
+---------------+---------------+---------+
|Interface | Attribute | Value |
+---------------+---------------+---------+
|pthread_join() | Thread safety | MT-Safe |
+---------------+---------------+---------+
CONFORMING TO
POSIX.1-2001, POSIX.1-2008.
NOTES
After a successful call to pthread_join(), the caller is guaranteed that the target thread has terminated. The caller may then choose to
do any clean-up that is required after termination of the thread (e.g., freeing memory or other resources that were allocated to the target
thread).
Joining with a thread that has previously been joined results in undefined behavior.
Failure to join with a thread that is joinable (i.e., one that is not detached), produces a "zombie thread". Avoid doing this, since each
zombie thread consumes some system resources, and when enough zombie threads have accumulated, it will no longer be possible to create new
threads (or processes).
There is no pthreads analog of waitpid(-1, &status, 0), that is, "join with any terminated thread". If you believe you need this function-
ality, you probably need to rethink your application design.
All of the threads in a process are peers: any thread can join with any other thread in the process.
EXAMPLE
See pthread_create(3).
SEE ALSO pthread_cancel(3), pthread_create(3), pthread_detach(3), pthread_exit(3), pthread_tryjoin_np(3), pthreads(7)COLOPHON
This page is part of release 4.15 of the Linux man-pages project. A description of the project, information about reporting bugs, and the
latest version of this page, can be found at https://www.kernel.org/doc/man-pages/.
Linux 2017-09-15 PTHREAD_JOIN(3)