[ECOS] Thread-specific data

[ECOS] Thread-specific data

[Jamie Guinan]

Hello,

I have a question about thread-specific data in eCos.

I have a library in which I would like to associate
an integer value with the calling thread.

Can the value returned by cyg_thread_new_data_index()
be shared by all threads that want to index thread-specific 
data based on a specific key?

In other words, is it true that the cyg_ucount32 returned
by cyg_thread_new_data_index() is _not_ a per-thread datum 
itself?  I would hope not, but I just wanted to clarify the 
issue.

Thanks,
-Jamie

Re: [ECOS] Thread-specific data

[Jonathan Larmour]

In article < Pine.LNX.3.96.990618144410.26479B-100000@newt.home.net > you write:
>
>In other words, is it true that the cyg_ucount32 returned
>by cyg_thread_new_data_index() is _not_ a per-thread datum 
>itself?  I would hope not, but I just wanted to clarify the 
>issue.

Yes, it (quite sensibly) is not a per-thread value itself :-).

The map of free thread data indexes can be found in the Cyg_Thread class
in kernel/v1_2_1/include/thread.hxx as:

    // Map of free thread_data indexes. Each bit represents an index
    // and is 1 if that index is free, and 0 if it is in use.
    static cyg_ucount32        thread_data_map;

The "static" stops it from being thread-specific.

HTH,

Jifl
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