sigbus การใช้

On POSIX-compliant platforms, bus errors usually result in the SIGBUS signal being sent to the process that caused the error.
SIGBUS can also be caused by any general device fault that the computer detects, though a bus error rarely means that the computer hardware is physically broken it is normally caused by a program's source code.
In fact, on some architectures ( such as the Motorola 68000 family ), unaligned memory accesses will result in an exception being raised ( usually resulting in a software exception being raised like POSIX's SIGBUS ).
I / O errors on the underlying file ( eg . its removable drive is unplugged or optical media is ejected, disk full when writing, etc . ) while accessing its mapped memory are reported to the application as the SIGSEGV / SIGBUS signals on POSIX, and the EXECUTE _ IN _ PAGE _ ERROR structured exception on Windows.
Some architectures mandate than n-size objects be on n-bit boundaries; to try to address them more finely either makes for un-compilable code ( where the assembly can't be rendered into machine code, because that granularity is implicit in the instruction coding ) or code that will SIGBUS . Even on architectures which do allow mis-aligned access ( IA32, SPARC ( kinda ) ) there is often a penalty of additional cycles to pay.