linux/timerfd: stop explicitly casting to c_long for timespec.tv_nsec #189
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struct timespec.tv_nsec is implementation-specific (even if the doc says it is c_long). For example, on x32 it is i64. Do not explicitly cast nsec value to c_long, use whatever type needed for the target type. Signed-off-by: Michael Tokarev <[email protected]>
| // nsec always fits in i32 because subsec_nanos is defined to be less than one billion. | ||
| let nsec = dur.subsec_nanos() as i32; | ||
| spec.it_value.tv_nsec = libc::c_long::from(nsec); | ||
| spec.it_value.tv_nsec = dur.subsec_nanos() as _; |
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Very much personal preference but I find as _ to be quite unreadable.
| spec.it_value.tv_nsec = dur.subsec_nanos() as _; | |
| spec.it_value.tv_nsec = dur.subsec_nanos().try_into().unwrap(); |
| // nsec always fits in i32 because subsec_nanos is defined to be less than one billion. | ||
| let nsec = int.subsec_nanos() as i32; | ||
| spec.it_interval.tv_nsec = libc::c_long::from(nsec); | ||
| spec.it_interval.tv_nsec = int.subsec_nanos() as _; |
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Duplicate of 7f7d0f1#r1168297816
| spec.it_interval.tv_nsec = int.subsec_nanos() as _; | |
| spec.it_interval.tv_nsec = int.subsec_nanos().try_into().unwrap(); |
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Once again, this is 2nd day since I looked what rust is, to begin with, so I know nothing about the right constructs required here. I'm fine as long as it works. "My" version has been suggested by someone on IRC, - I didn't even know rust requires explicit type conversion between two different integer types.
FWIW, this issue happens on x32 only. On all the other platforms, timespec.tv_nsec is of long datatype. It is documented as being long. But on x32 it is int64_t. Apparently this is a bug in the architecture specifications. Also, x32 is a very rare thing.
Still, I like the code without explicit integer conversion more. It might also be a good idea to retain the comment which was previously there.
struct timespec.tv_nsec is implementation-specific (even if the doc says it is c_long). For example, on x32 it is i64. Do not explicitly cast nsec value to c_long, use whatever type needed for the target type. This also simplifies the code (avoiding temporary variable).