User guide

3.3. GLOBAL FUNCTIONS 51

This call causes the time stamp in datv t o be converted to three strings v, v+5 and

v+10. The string at v is set to the date in the form dd-mmm-yyyy. The string at v+5 is

set to th e the current time in the form hh:mm:ss, and the string at v+10 is set to the

day of the week. The upper bound of v should be at least 14 to be safe. The time stamp

is typically obtaine d by a call of datstamp(datv) which sets datv!0 to the number of

days since 1 January 1970, datv!1 to the number of milli-seconds since midnight and

datv!2 to -1 indicting that the new date and time format is being used.

delay(msecs) CIN:y, POS:y, NAT:y

This call suspends ex e c ut i on for at least m s ecs milli-seconds. Under Cintpos, this is

achieved by sending a suitable packet to the clock device (using sendpkt) and waiting

for it to be returned.

delayuntil(days, msecs) CIN:y, POS:y, NAT:y

This call suspends execution until the speciﬁed date and time is reached. days

speciﬁes the date as the number of days si n ce 1 January 1970 and msecs i s the number

of mi l l i - se cond s since midnight. Under Cintpos, the delay is achieved by sending a

suitable packet to the clock dev i ce (using sendpkt) and wait i ng for it to be returned.

deleteco(cptr) CIN:y, POS:y, NAT:y

This call takes a coroutine poi nter as argument and, after checking that the corre-

sponding coroutine has no parent, deletes it by returning its stack to free store.

dcb := deletedev(devid) CIN:n, POS:y, NAT:n

This Cintpos function closes down the speciﬁed device and deallocates it device

identiﬁer, but it does not return its device control block (DCB) to free store. It returns

any packets still on its work queue to the requesting tasks with both the pkt

res1 and

pkt

res2 ﬁelds set to -1. If successful, it retur ns the DCB of the deleted device. On

failure, it returns zero with result2 set to 101 indicating that devid was invalid. If any

of the released packets cause a higher priority task to b e com e runnable, the control

passes to the highest priority one leaving the current task suspended in RUN state.

The clock device has identiﬁer -1 and is permanently resident and cannot be deleted.

ﬂag := deletefile(name) CIN:y, POS:y, NAT:y

This call deletes the named ﬁle, returning if succe ssf ul , and FALSE otherwise.

res := deleteself(pkt, seg) CIN:n, POS:y, NAT:n

This Cintpos function ﬁrst calls qpkt to return the packet if pkt is non zero, then

calls unloadseg(seg

⁀

) i f seg is non z er o, before de l et i ng the current task. This function

is deﬁned in klib since it would be unsafe for it to be in a segment that may be

unloaded whil e it is being executes. It returns a non zero value if successful but, of

course, this value will never be seen! On failure, i t retur n zero with result2 set to 108

indicating that the curre nt task is not deletable.

res := deletetask(taskid) CIN:n, POS:y, NAT:n

This Cintpos function attempts to delete the speciﬁed task which must have an

empty work queue and be either the current task or in DEAD state. Its task control