Dear Fons, dear Rooters,
>The idea is that you, for example, create two mapped files and write down the
>starting address for each file. Next in the other program you now connect to
>these
>files using:
> TMapFile::SetMapAddress(0x40eb9000);
> TMapFile *mfile1 = TMapFile::Create("file1.map");
> TMapFile::SetMapAddress(0x41843000);
> TMapFile *mfile2 = TMapFile::Create("file2.map");
>be sure that the "other" program does not have any other objects mapped
>in this addess space. Check that by creating a new mapped file in that
>process (without mapping any other TMapFile) and check that the map address
>of the file is smaller than that of the first program.
I have tried what you have suggested in your last mail. I am not sure,
however, that I have understood correctly what you want to tell me. So
far, I have tried the following:
- I have tried to open two "TMapFile"s in the same Producer program
following your suggestions concerning writing down preferred addresses
and passing them to the program via the "SetMapAddress" method. This
leads always to Segmentation fault, when I try to write into the second
shared mem area.
- What I actually want works even less. I want two different producer
programs that open two different "TMapFile"s that then are read from one
consumer program. The problem is that I can set the address by hand via
SetMapAddress but that this leads to a crash. Either I overwrite memory
areas that are occupied by the system ( how can I find out about really
free space ?) or it crashes for some other reason. Moreover, I can not
set the address always by hand, as my program is supposed to run on
different machines, so that this address would have to be changed for
each machine before starting the program. The project is to realize an
event display that reads in an infinite loop data from DAQ and passes
these data as histos to a "displaying" consumer which itself is supposed
to be manipulated via shared memory by a little GUI. Which ever
combination that I have tried with producers and consumers and more than
one shared memory it has crashed except for the case in which more than
one consumer reads from one TMapFile.
Any input on this will be appreciated :-))
Regards and Thanks in advance
Tom
--
Thomas Eberl Phone: (+49 89) 289 1 2425
Physik-Department E12, Technische Universitaet Muenchen
James-Franck-Strasse *** 85748 Garching b. Muenchen
Email: Thomas.Eberl@physik.tu-muenchen.de
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