> On April 4, 2018, 3:12 p.m., John Kordich wrote: > > 3rdparty/stout/include/stout/os/windows/jobobject.hpp > > Lines 139 (patched) > > <https://reviews.apache.org/r/66420/diff/1/?file=1992229#file1992229line139> > > > > This is interesting. I understand how you're using this template > > function to allocate this structure on the stack which you use a > > reinterpret_cast on later as a substitute for the > > JOBOBJECT_BASIC_PROCESS_ID_LIST. > > > > But is this really worth doing? Allocation and deallocation would > > happen entirely within this function. I imagine the data we need will be > > copied out before deallocation during the insert calls below on the > > set<Process> object, so the only real issue is the extra time associated > > with dynamic memory allocation/deallocation. > > > > What's hairy about the size calculations? I imagine it's not that bad, > > probably nothing you wouldn't do normally in C :) > > > > If you do end up staying with this structure, is there a reason the > > ProcessIdList member is a DWORD and not a ULONG_PTR, as per > > https://msdn.microsoft.com/en-us/library/windows/desktop/ms684150(v=vs.85).aspx > > ? > > > > It's probably the case that on x86_64 that they are the same size, but > > why not mirror the structure identically?
> probably nothing you wouldn't do normally in C Precisely. This isn't C, so why manually allocate and calculate and deallocate when we don't need to? It's too easy to screw up. > is there a reason the ProcessIdList member is a DWORD and not a ULONG_PTR Yes. The type of the identifer in the Windows struct (because it's the pointer to the beginning of an "array") is `ULONG_PTR`, but it is not actually an array. The arary itself (which you would have to allocate in the correct location for this struct) is an array of `DWORD` (since it's an array of PIDs); so when we declare an actual array of PIDs, we declare a `DWORD array[n]`. The C struct in the Windows API ends with a `ULONG_PTR` because the actual defined struct does not contain an array. It instead expects you to allocate a contiguous block large enough to hold the struct and the array, and then the type in the struct is just the array pointer of type `ULONG_PTR`. And this is why we do it this why, and not Windows's way. It's too easy to get wrong. - Andrew ----------------------------------------------------------- This is an automatically generated e-mail. To reply, visit: https://reviews.apache.org/r/66420/#review200502 ----------------------------------------------------------- On April 3, 2018, 10:46 p.m., Andrew Schwartzmeyer wrote: > > ----------------------------------------------------------- > This is an automatically generated e-mail. To reply, visit: > https://reviews.apache.org/r/66420/ > ----------------------------------------------------------- > > (Updated April 3, 2018, 10:46 p.m.) > > > Review request for mesos, Akash Gupta, Eric Mumau, John Kordich, Joseph Wu, > and Michael Park. > > > Repository: mesos > > > Description > ------- > > The functions written to deal with job objects on Windows had become > large enough to warrant being refactored into their own file. Also > was the perfect opportunity to fix formatting issues. > > When including `jobobject.hpp` for `killtree.hpp`, other unnecessary > headers were removed. > > > Diffs > ----- > > 3rdparty/stout/include/Makefile.am 742bfc44d68d978dd2249ece500d6f64e4d7f02a > 3rdparty/stout/include/stout/os/windows/jobobject.hpp PRE-CREATION > 3rdparty/stout/include/stout/os/windows/killtree.hpp > ce8bdcd18305ffb758f22a6c2bbc7393675aebdf > 3rdparty/stout/include/stout/windows/os.hpp > 739ee4da3f09d2a9597d4451e755e77903e9287d > > > Diff: https://reviews.apache.org/r/66420/diff/1/ > > > Testing > ------- > > > Thanks, > > Andrew Schwartzmeyer > >
