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Diffstat (limited to 'man/10/splhi')
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diff --git a/man/10/splhi b/man/10/splhi new file mode 100644 index 00000000..9ac9cb3f --- /dev/null +++ b/man/10/splhi @@ -0,0 +1,55 @@ +.TH SPLHI 10.2 +.SH NAME +splhi, spllo, splx, islo \- enable and disable interrupts +.SH SYNOPSIS +.ta \w'\fLvoid 'u +.B +int spllo(void) +.PP +.B +int splhi(void) +.PP +.B +void splx(int x) +.PP +.B +int islo(void) +.SH DESCRIPTION +These primitives enable and disable maskable interrupts on the current +processor. +Generally, device drivers should use +.I ilock +(see +.IR lock (10.2)), +.IR sleep (10.2), +or the functions in +.IR qio (10.2) +to control interaction between processes and interrupt handlers. +Those routines (but not these) provide correct synchronisation on multiprocessors. +.PP +.I Spllo +enables interrupts and returns a flag representing the previous interrupt enable state. +It must not normally be called from interrupt level. +.PP +.I Splhi +disables all maskable interrupts and returns the previous interrupt enable state. +The period during which interrupts are disabled had best be short, +or real-time applications will suffer. +.PP +.I Splx +restores the interrupt enable state +state to +.IR x , +which must be a value returned +by a previous call to +.I splhi +or +.IR spllo . +.PP +.I Islo +returns true (non-zero) if interrupts are currently enabled, and 0 otherwise. +.SH SEE ALSO +.IR lock (10.2), +.IR qio (10.2), +.IR sleep (10.2), +.IR intrenable (10.2) |