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author | Mattias Andrée <maandree@kth.se> | 2017-12-11 23:13:37 +0100 |
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committer | Mattias Andrée <maandree@kth.se> | 2017-12-11 23:13:37 +0100 |
commit | e35ba8684be9951fa2129503477ccd5ed6e4e5fc (patch) | |
tree | 756292d5a18ad6011a9311fdea8159f474385b65 /bus_poll.3 | |
parent | typo (diff) | |
download | bus-e35ba8684be9951fa2129503477ccd5ed6e4e5fc.tar.gz bus-e35ba8684be9951fa2129503477ccd5ed6e4e5fc.tar.bz2 bus-e35ba8684be9951fa2129503477ccd5ed6e4e5fc.tar.xz |
Simplify, do not install examples or info manual, and change license3.1.7
Signed-off-by: Mattias Andrée <maandree@kth.se>
Diffstat (limited to 'bus_poll.3')
-rw-r--r-- | bus_poll.3 | 79 |
1 files changed, 79 insertions, 0 deletions
diff --git a/bus_poll.3 b/bus_poll.3 new file mode 100644 index 0000000..f916237 --- /dev/null +++ b/bus_poll.3 @@ -0,0 +1,79 @@ +.TH BUS_POLL 3 BUS +.SH NAME +bus_poll_start, bus_poll_stop, bus_poll, bus_poll_timed - Wait a message to be broadcasted +.SH SYNOPSIS +.LP +.nf +#include <bus.h> +.P +int bus_poll_start(bus_t *\fIbus\fP); +int bus_poll_stop(const bus_t *\fIbus\fP); +const char *bus_poll(bus_t *\fIbus\fP, int \fIflags\fP); +const char *bus_poll_timed(bus_t *\fIbus\fP, const struct timespec *\fItimeout\fP, clockid_t \fIclockid\fP); +.fi +.SH DESCRIPTION +The +.BR bus_poll () +function waits for a message to be broadcasted on the \fIbus\fP, and return +the message it receives. The function fails if (\fIflags\fP &BUS_NOWAIT) +and there is not already a message waiting on the bus. Received messages +shall be copied and parsed, and acted upon, in a separate thread, and +.BR bus_poll () +or +.BR bus_poll_stop () +called again as soon as possible. +.PP +The +.BR bus_poll_start () +funcion must be called before +.BR bus_poll () +is called for the first time. When the process is done listening on the +bus it must call the +.BR bus_poll_stop () +function. +.PP +The +.BR bus_poll_timed () +function behaves like +.BR bus_poll (), +except if it is not able to read a message within the specified time, +it will fail and set \fIerrno\fP to \fBEAGAIN\fP. The time is specified +as an absolute time using the parameter \fItimeout\fP. The behaviour is +unspecified if \fItimeout\fP is \fINULL\fP. \fItimeout\fP is measured +with the clock whose ID is specified by the \fIclockid\fP parameter. This +clock must be a predicitable clock. +.SH RETURN VALUES +Upon successful completion, the functions +.BR bus_poll_start () +and +.BR bus_poll_stop () +returns 0. Otherwise the functions returns -1 and sets \fIerrno\fP to +indicate the error. +.PP +Upon successful completion, the functions +.BR bus_poll () +and +.BR bus_poll_timed () +returns the received message. Otherwise the function returns \fINULL\fP +and sets \fIerrno\fP to indicate the error. +.SH ERRORS +The +.BR bus_poll (3), +.BR bus_poll_start (3) +and +.BR bus_poll_stop (3) +functions may fail and set \fIerrno\fP to any of the errors specified for +.BR semop (3). +The +.BR bus_poll_timed (3) +function may also set \fIerrno\fP to any of the errors specified for +.BR clock_gettime (3). +.SH SEE ALSO +.BR bus-create (1), +.BR bus (5), +.BR libbus (7), +.BR bus_open (3), +.BR bus_write (3), +.BR bus_read (3), +.BR semop (3), +.BR clock_gettime (3) |