Fix: popen failure make app crash + includes missing

[GasparQ]

Popen error

Encountered issue

When I tryied to generate a ResNet-50, the application n2d2 crashed with a segfault.

Cause

After debug, I found that this crash was made by the function N2D2::Utils::exec :

• The function popen returned a NULL pointer and triggers a runtime_error
• This exception call the destructor of the pipe object (which is a shared_pointer)
• The cpp specification for shared_pointer says that Unlike std::unique_ptr, the deleter of std::shared_ptr is invoked even if the managed pointer is null.
• So, the function pclose (registered as deleter) is called with a NULL pointer and make the app crash

Fix

To fix this Issue, I replaced the shared_ptr by a unique_ptr which is better in that case because :

• The pointer used here is not "shared" but "unique" because created and deleted in the same function
• The cpp specification for unique_ptr says that If get() == nullptr there are no effects. Otherwise, the owned object is destroyed via get_deleter()(get()).

Includes missing

Encountered issue

On Centos7, I couldn't manage to build the n2d2 target because of some includes missing.

Cause

In the file include/RangeStats.hpp, some unordered_map are declared but only the map header is included.

In the file src/RangeStats.hpp, the function assert is called without the inclusion of cassert.

Fix

Just added the missing includes in the files and remove useless ones.

Popen failed ??!!??

In the function N2D2::Utils::exec and at the construction of a N2D2::Gnuplot object, the function popen is called.

At some points, this function can fail and, in my case, it was because I didn't have enough memory on my environment (cf. #47).

Then I decided to improve error messages with strerror and errno in both cases.

[coveralls]

Coverage decreased (-0.0005%) to 19.586% when pulling 3b95d3ced54ca7d2c0948abe6c41498e470ec270 on GasparQ:master into d66da81cdc7c1dce6ac9d29ebf586d5a4fa16d74 on CEA-LIST:master.

[olivierbichler-cea]

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