On Monday, February 26, 2024 6:47 PM, Junio C Hamano wrote: ><rsbecker@xxxxxxxxxxxxx> writes: > >>>The code above loops while input_len is non-zero, and correctly >>>decrements it by the number of bytes written by xwrite() after each >>>iteration. >>> >>>Assuming that xwrite()/write(2) works how I think it does on NonStop, >>>I'm not sure I understand why this change is necessary. >> >> NonStop has a limited SSIZE_MAX. xwrite only handles that much so >> anything beyond that gets dropped (not in the above code but in other >> builtins) > >xwrite() caps a single write attempt to MAX_IO_SIZE and can return a short-write, so anything beyound MAX_IO_SIZE will not even be >sent to the underlying write(2). There is a heuristic based on the value of SSIZE_MAX to define MAX_IO_SIZE in <git-compat-util.h>, >and if the value given by that heuristics is too large for your platform, you can tweak your own MAX_IO_SIZE (see the comments in >that header file). > >The caller of xwrite() must be prepared to see a write return with value less than the length it used to call the function, either because >of this MAX_IO_SIZE cut-off, or because of the underlying >write(2) returning after a short write. As long as the caller is prepared, like Taylor pointed out, I am not sure why you'd need to change >it. I understand. I was involved in xwrite() a few years ago. The problem is that users of xwrite() did not account for that and t7704.9 failed as a result. These changes did fix the issue. I am not sure how to proceed based on the above, however. Continue or recode the callers (which is part of what this does)?
