Hi, as it was raised in https://gcc.gnu.org/ml/gcc-patches/2015-10/msg01540.html we experiment random failures in gfortran validation when it is run in parallel (-j 8). The issues occurs because of concurrent access to the same file, the first two patches fixed some of them by changing the file names used, but there are still remaining conflicts (6 usages of foo, 8 of test.dat). This is easy to fix and I've a patch for that, but there is another issue and I'd like to have your thoughts on it.
There is a little bit more than 1000 testcases which use IO without explicit file names, ~150 use scratches (a temporary file named gfortrantmp + 6 extra char is created) and the others, which only specify the io unit number, use a file named fort.NN with NN the number of the io unit. We see conflicts on these generated files, as lot of testcases use the same number, the most used are: 10 => 150 99 => 70 6 => 31 11 => 27 1 => 23 I started to change the testcases to use scratches when it is possible and before finding that there is that many to fix, and I also had conflicts on the generated scratch names. The options I see to fix that are: 1- Move all these testcases into an IO subdir and change the testsuite to avoid parallelism in that directory. 2- Use scratches when possible and improve libgfortran file name generation, I don't know well fortran but is it possible to change the file name patterns for scratches and io unit files ? 3- Change the io unit numbers used, as it was suggested on irc, but I find it a bit painful to maintain. Any comments are welcome. Thanks Yvan
