04-10-2009
Thread local storage on ancient AIX
What I'm given:
Pure C code in one file that has to compile on Windows, SunOS, and AIX. My task is making minimal changes to the code to make it thread safe. I'm not in control of threads - they are created elsewhere. The code has a function invoked externally. The first call to this function is solitary. I.e. I'm guaranteed that no other call in any other thread will be made until it returns. It allows me to initialize mutexes during that call. The task seems very easy to accomplish with pthread library.
However, there is a complication. There are situations, when two consecutive calls to the function within a thread are related, and the first needs to pass some information to the next call. The natural way to accomplish it is to declare a thread local variable in global context. For this I use __thread directive, and it seems to work perfectly on SunOS. For AIX, on the other hand, this does not work. Since for our compilation we use the least common denominator for the broadest support, AIX complains that __thread directive is not compatible with the platform.
1. Is there anything AIX specific that allows to declare thread local variable in global context besides __thread directive?
2. What would be the most elegant (least code changes) work around?
8 More Discussions You Might Find Interesting
1. AIX
Hi:-
What is the best way to determine what type of storage is attached to an AIX server?
Thanks, (2 Replies)
Discussion started by: janet
2 Replies
2. Programming
Hi,
I have a small test c program which tries to dlopen a shared library(libjvm.sl).
But i get error as "Can't dlopen() a library containing Thread Local Storage"
My program is as below
when i run the program i get error
any pointers why the error??
I am using hp-ux . The... (1 Reply)
Discussion started by: shriashishpatil
1 Replies
3. AIX
Hi,
How do I query for unused partition in AIX 4.3 with DAS and SAA storage?
I know most unix administrator don't put all the capacity on the system at once.
thanks,
vene (1 Reply)
Discussion started by: venerayan
1 Replies
4. Shell Programming and Scripting
Hello,
I've been searching your forum for an answer to the following question and whilst I've seen several which may help I'm afraid my inexperience with UNIX systems has got the better of me and I'm incapable of piecing your considerable expertise together.
Problem:
I have a linux box which... (5 Replies)
Discussion started by: julezsht
5 Replies
5. AIX
Hi Friends,
I have this script for ftping files from AIX server to local windows xp.
#!/bin/sh
HOST='localsystem.net'
USER='myid_onlocal'
PASSWD='mypwd_onlocal'
FILE='file.txt' ##This is a file on server(AIX)
ftp -n $HOST <<END_SCRIPT
quote USER $USER
quote PASS $PASSWD
put $FILE... (1 Reply)
Discussion started by: rajsharma
1 Replies
6. Programming
As I know threads share the memory. But, what about the local variables in the thread function? if i call multiple threads would they allocate seperate local variables for themselves?
like
thread_func()
{
int i, j;
string...
}
Are the above local variables defined for each of... (1 Reply)
Discussion started by: saman_glorious
1 Replies
7. Solaris
Hello.
I have a solaris box with several local disks and several come from SYMMETRIX storage. Is there any way to tell format (or other util) to show only local disks? (6 Replies)
Discussion started by: urello
6 Replies
8. Solaris
I am newbies in solaris, hope u guys can help me,
I need to transfer /export/home directory that currently mount at storage and migrate into local disk. may i know the best way to do it?
Thanks (6 Replies)
Discussion started by: Deeo
6 Replies
LEARN ABOUT DEBIAN
iv_task
iv_task(3) ivykis programmer's manual iv_task(3)
NAME
iv_task_register, iv_task_unregister, iv_task_registered - deal with ivykis tasks
SYNOPSIS
#include <iv.h>
struct iv_task {
void *cookie;
void (*handler)(void *);
};
void IV_TASK_INIT(struct iv_task *task);
void iv_task_register(struct iv_task *task);
void iv_task_unregister(struct iv_task *task);
int iv_task_registered(struct iv_task *task);
DESCRIPTION
The functions iv_task_register and iv_task_unregister register, respectively unregister, a task with the current thread's ivykis event
loop. iv_task_registered on a task returns true if that task is currently registered with ivykis.
A task is like a timer, but with an immediate timeout. When a task is registered, unless it is unregistered again first, the callback
function specified by ->handler is guaranteed to be called once, in the thread that the task was registered in, some time after control
returns to the ivykis main loop but before ivykis will sleep for more events, with ->cookie as its first and sole argument. When this hap-
pens, the task is transparently unregistered.
Tasks are mainly used for scheduling code for execution where it is not appropriate to directly run that code in the calling context (for
example, because the current context might be run as a callback function where the caller expects certain conditions to remain invariant
after the callback completes).
The application is allowed to change the ->cookie and ->handler members at any time.
A given struct iv_task can only be registered in one thread at a time, and a task can only be unregistered in the thread that it was regis-
tered from.
There is no limit on the number of tasks registered at once.
See iv_examples(3) for programming examples.
SEE ALSO
ivykis(3), iv_examples(3)
ivykis 2010-08-15 iv_task(3)