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If applicable, add the following below this CDDL HEADER, with the fields enclosed by brackets "[]" replaced with your own identifying information: Portions Copyright [yyyy] [name of copyright owner] .TH PORT_GET 3C "Jan 31, 2007" .SH NAME port_get, port_getn \- retrieve event information from a port .SH SYNOPSIS .LP .nf #include \fBint\fR \fBport_get\fR(\fBint\fR \fIport\fR, \fBport_event_t *\fR\fIpe\fR, \fBconst timespec_t *\fR\fItimeout\fR); .fi .LP .nf \fBint\fR \fBport_getn\fR(\fBint\fR \fIport\fR, \fBport_event_t\fR \fIlist\fR[], \fBuint_t\fR \fImax\fR, \fBuint_t *\fR\fInget\fR, \fBconst timespec_t *\fR\fItimeout\fR); .fi .SH DESCRIPTION .sp .LP The \fBport_get()\fR and \fBport_getn()\fR functions retrieve events from a port. The \fBport_get()\fR function retrieves at most a single event. The \fBport_getn()\fR function can retrieve multiple events. .sp .LP The \fIpe\fR argument points to an uninitialized \fBport_event_t\fR structure that is filled in by the system when the \fBport_get()\fR function returns successfully. .sp .LP The \fBport_event_t\fR structure contains the following members: .sp .in +2 .nf int portev_events; /* detected events */ ushort_t portev_source; /* event source */ uintptr_t portev_object; /* specific to event source */ void *portev_user; /* user defined cookie */ .fi .in -2 .sp .LP The \fBportev_events\fR and \fBportev_object\fR members are specific to the event source. The \fBportev_events\fR denotes the delivered events. The \fBportev_object\fR refers to the associated object (see \fBport_create\fR(3C)). The \fBportev_source\fR member specifies the source of the event. The \fBportev_user\fR member is a user-specified value. .sp .LP If the \fItimeout\fR pointer is \fINULL\fR, the \fBport_get()\fR function blocks until an event is available. To poll for an event without waiting, \fItimeout\fR should point to a zeroed \fBtimespec\fR. A non-zeroed \fBtimespec\fR specifies the desired time to wait for events. The \fBport_get()\fR function returns before the timeout elapses if an event is available, a signal occurs, a port is closed by another thread, or the port is in or enters alert mode. See \fBport_alert\fR(3C) for details on alert mode. .sp .LP The \fBport_getn()\fR function can retrieve multiple events from a port. The \fIlist\fR argument is an array of uninitialized \fBport_event_t\fR structures that is filled in by the system when the \fBport_getn()\fR function returns succesfully. The \fInget\fR argument points to the desired number of events to be retrieved. The \fImax\fR parameter specifies the maximum number of events that can be returned in \fIlist\fR[]. If \fImax\fR is 0, the value pointed to by \fInget\fR is set to the number of events available on the port. The \fBport_getn()\fR function returns immediately but no events are retrieved. .sp .LP The \fBport_getn()\fR function block until the desired number of events are available, the timeout elapses, a signal occurs, a port is closed by another thread, or the port is in or enters alert mode. .sp .LP On return, the value pointed to by \fInget\fR is updated to the actual number of events retrieved in list. .sp .LP Threads calling the \fBport_get()\fR function might starve threads waiting in the \fBport_getn()\fR function for more than one event. Similarly, threads calling the \fBport_getn()\fR function for \fIn\fR events might starve threads waiting in the \fBport_getn()\fR function for more than \fIn\fR events. .sp .LP The \fBport_get()\fR and the \fBport_getn()\fR functions ignore non-shareable events (see \fBport_create\fR(3C)) generated by other processes. .SH RETURN VALUES .sp .LP Upon succesful completion, 0 is returned. Otherwise, -1 is returned and errno is set to indicate the error. .SH ERRORS .sp .LP The \fBport_get()\fR and \fBport_getn()\fR functions will fail if: .sp .ne 2 .na \fB\fBEBADF\fR\fR .ad .RS 10n The \fIport\fR identifier is not valid. .RE .sp .ne 2 .na \fB\fBEBADFD\fR\fR .ad .RS 10n The \fIport\fR argument is not an event port file descriptor. .RE .sp .ne 2 .na \fB\fBEFAULT\fR\fR .ad .RS 10n Event or event list can not be delivered (\fIlist\fR[] pointer and/or user space reserved to accomodate the list of events is not reasonable), or the \fItimeout\fR argument is not reasonable. .RE .sp .ne 2 .na \fB\fBEINTR\fR\fR .ad .RS 10n A signal was caught during the execution of the function. .RE .sp .ne 2 .na \fB\fBEINVAL\fR\fR .ad .RS 10n The \fItimeout\fR element \fBtv_sec\fR is < 0 or the \fItimeout\fR element \fBtv_nsec\fR is < 0 or > 1000000000. .RE .sp .ne 2 .na \fB\fBETIME\fR\fR .ad .RS 10n The time interval expired before the expected number of events have been posted to the port. .RE .sp .LP The \fBport_getn()\fR function will fail if: .sp .ne 2 .na \fB\fBEINVAL\fR\fR .ad .RS 10n The \fIlist\fR[] argument is \fINULL\fR, the \fInget\fR argument is \fINULL\fR, or the content of \fInget\fR is > \fImax\fR and \fImax\fR is > 0. .RE .sp .ne 2 .na \fB\fBEFAULT\fR\fR .ad .RS 10n The \fItimeout\fR argument is not reasonable. .RE .sp .ne 2 .na \fB\fBETIME\fR\fR .ad .RS 10n The time interval expired before the expected number of events have been posted to the port (original value in \fInget\fR), or \fInget\fR is updated with the number of returned \fBport_event_t\fR structures in \fIlist\fR[]. .RE .SH EXAMPLES .LP \fBExample 1 \fRSend a user event (PORT_SOURCE_USER) to a port and retrieve it with \fBport_get()\fR. .sp .LP The following example sends a user event (\fBPORT_SOURCE_USER\fR) to a port and retrieves it with \fBport_get()\fR. The \fBportev_user\fR and \fBportev_events\fR members of the \fBport_event_t\fR structure are the same as the corresponding user and events arguments of the \fBport_send\fR(3C) function. .sp .in +2 .nf #include int myport; port_event_t pe; struct timespec timeout; int ret; void *user; uintptr_t object; myport = port_create(); if (myport < 0) { /* port creation failed ... */ ... return(...); } \&... events = 0x01; /* own event definition(s) */ object = ; user = ; ret = port_send(myport, events, user); if (ret == -1) { /* error detected ... */ ... close(myport); return (...); } /* * The following code could also be executed in another thread or * process. */ timeout.tv_sec = 1; /* user defined */ timeout.tv_nsec = 0; ret = port_get(myport, &pe, &timeout); if (ret == -1) { /* * error detected : * - EINTR or ETIME : log error code and try again ... * - Other kind of errors : may have to close the port ... */ return(...); } /* * After port_get() returns successfully, the port_event_t * structure will be filled with: * pe.portev_source = PORT_SOURCE_USER * pe.portev_events = 0x01 * pe.portev_object = * pe.portev_user = */ \&... close(myport); .fi .in -2 .SH ATTRIBUTES .sp .LP See \fBattributes\fR(5) for descriptions of the following attributes: .sp .sp .TS box; c | c l | l . ATTRIBUTE TYPE ATTRIBUTE VALUE _ Architecture all _ Interface Stability Evolving _ MT-Level Safe .TE .SH SEE ALSO .sp .LP \fBport_alert\fR(3C), \fBport_associate\fR(3C), \fBport_create\fR(3C), \fBport_send\fR(3C), \fBattributes\fR(5)