NAME

       pmTimeConnect, pmTimeDisconnect, pmTimeRecv, pmTimeSendAck, pmTimeShowDialog - time control functions for
       synchronizing the archive position and update interval between one or more applications

C SYNOPSIS

       #include <pcp/pmtime.h>

       int pmTimeConnect(int port, pmTime *state);
       int pmTimeDisconnect(int fd);
       int pmTimeSendAck(int fd, struct timeval *fetchTime);
       int pmTimeShowDialog(int fd, int show);
       int pmTimeRecv(int fd, pmTime *state);

       cc ... -lpcp_gui

DESCRIPTION

       These  functions  form part of the Performance Metrics Applications Programming Interface (PMAPI) and are
       intended to provide a uniform mechanism for applications to both replay archive data and report live data
       in a time synchronized manner.

       The pmTime structure has the following fields:
         typedef struct {
             unsigned int        magic;
             unsigned int        length;
             pm_tctl_command     command;
             pm_tctl_source      source;
             pm_tctl_state       state;
             pm_tctl_mode        mode;
             struct timeval      delta;
             struct timeval      position;
             struct timeval      start;     /* archive only */
             struct timeval      end;       /* archive only */
             char                data[0];   /* arbitrary length info (TZ) */
         } pmTime;

       In the simplest case, the application should call pmTimeConnect to connect to the  time  control  server,
       pmtime(1),  and then repeatedly call pmTimeRecv in the main loop of the application.  On success, pmTime‐
       Connect returns a non-negative file descriptor.  In applications which have multiple threads of  control,
       rather  than  simply  blocking  in pmTimeRecv, the file descriptor may be used in calls to select(2).  In
       graphical applications, the file descriptor may be used to interface with the event loop.

       The port parameter to pmTimeConnect is the port number of the socket on which the time control server  is
       (or will be) listening for new connections.

       The state parameter to pmTimeConnect is used to initialize a new time control server or to pass addition‐
       al  information to an existing time control server.  The start and finish fields indicate the chronologi‐
       cal bounds interesting to the application.  The showgui field indicates whether the time  control  server
       should  initially  show  or  hide  the dialog.  The position, delta, and data fields indicate the initial
       archive position, update interval, time zone string and time zone label string.

       pmTimeRecv blocks until the time control server sends a command message.  It then updates the state para‐
       meter and returns one of the PM_TCTL_* command identifiers.

       The PM_TCTL_SET command indicates the application should seek to the archive position (see  pmSetMode(3))
       returned in the position field of the state parameter.

       The  PM_TCTL_STEP command indicates the application should perform an update, i.e. advance (or rewind, if
       delta is negative) to the time indicated by position and then fetch new metric values, update the display
       or whatever.  In order for several application to remain synchronized, the time control server will  wait
       until  all applications have acknowledged that they have completed the step command.  Applications should
       call pmTimeSendAck when the step command has been processed.  Note that PM_TCTL_STEP is the only  command
       that requires an explicit acknowledgement.

       The PM_TCTL_VCRMODE command is used by the time control server to indicate the current VCR mode.

       The  value  is  returned in the mode field of the state parameter passed to pmTimeRecv, and remains valid
       until the next PM_TCTL_VCRMODE command is received.

       The PM_TCTL_TZ command indicates the application should use a new time- zone, as indicated in the newzone
       field of the state parameter.

       The PM_TCTL_BOUNDS command is sent to all applications when the time control server changes  its  chrono‐
       logical  bounds.   This  may occur when a new application connects to the time control server or the user
       changes the bounds manually.  Most applications will ignore this command.

       The PM_TCTL_GUIHIDE or PM_TCTL_GUISHOW commands will be sent to all applications when the  visibility  of
       the  time  control server changes.  This allows applications to alter the text in menus or buttons to re‐
       flect this change.  Applications may change the visibility of the  time  control  dialog  using  the  pm‐
       TimeShowDialog function.  The initial visibility is determined when the time control dialog is first cre‐
       ated by an application calling pmTimeConnect with the showgui field in the state parameter set to the de‐
       sired value.

       The  pmTimeDisconnect  function may be used to close the command socket to the time control server.  This
       is useful when applications need to change the connection mode, e.g. to divorce the current time  control
       server and connect to a new one.

SEE ALSO

       pmtime(1), PMAPI(3) and pmSetMode(3).

Performance Co-Pilot                                 Aconex                                            PMTIME(3)