{ Views Help - Space-Time View }
{ The Space-Time View shows the status of individual }
{ tasks as they execute across all hosts.  Each task }
{ is represented by a horizontal bar along a common time }
{ axis, where the color of the bar at each time indicates }
{ the state of the task. }
{}
{ The "Computing" color shows those times when the task }
{ is busy executing useful user computations.  The "Overhead" }
{ color marks the places where the task executes PVM system }
{ routines for communication, task control, etc.  The }
{ "Waiting" color indicates those time periods spent }
{ waiting for messages from other tasks, i.e. the idle }
{ time due to synchronization. }
{}
{ Communication activity among tasks is also shown, using }
{ lines drawn between the task bars at the corresponding }
{ message send and receive times. }
{}
{ The default colors for these states are green for }
{ computing, yellow for overhead, white for waiting, }
{ and red for messages. }
{}
{ A vertical, blue line marks the latest trace event time, }
{ as shown in the trace control panel "Time" display. }
{}
{ Queries }
{ ------- }
{}
{ More detailed information regarding specific task states }
{ or messages can be extracted from the Space-Time view by }
{ clicking and holding on the view area with the Left mouse }
{ button.  When a task bar is clicked on, the information line }
{ at the bottom of the view changes to display the precise }
{ times that the task state began and ended, plus info on }
{ the PVM system routine that was called at the start of }
{ the state (or in some cases perhaps more appropriately }
{ the end of the last state).  Double-clicking on an item }
{ will hold the view information text for full examination. }
{}
{ Individual messages can be clicked on as well to determine }
{ the time when the send was initiated, and the time when the }
{ message receipt was completed, plus the number of bytes sent }
{ and the message code. }
{}
{ Note also that any time the mouse pointer enters the }
{ main Space-Time canvas, a blue vertical line appears }
{ to mark a constant time axis in the view.  The actual }
{ time represented by the location of this line is }
{ displayed in the information line at the bottom of }
{ the view. }
{}
{ Also note that the Utilization and Space-Time Views are }
{ tightly coupled, and whenever a time line is shown in }
{ one view, the other view will show a similar line at }
{ the same time instant. }
{}
{ Zooming }
{ ------- }
{}
{ The Space-Time View can be "zoomed" in or out to view }
{ different perspectives on the same trace data.  To zoom }
{ in on a particular area of the Space-Time, click and hold }
{ on the main canvas with the Middle mouse button, and sweep }
{ across the area that is to be blown up.  When the mouse }
{ button is released, that swept area will be enlarged }
{ horizontally to fill the canvas area. }
{}
{ To "unzoom" back to the previous zoom level, or out to some }
{ lower magnification level if no zoom had been previously }
{ applied, simply press the Right mouse button. }
{}
{ To summarize: }
{}
{	Mouse Left        Mouse Middle        Mouse Right }
{}
{	  Query             Zoom IN             Zoom Out }
{}
{ Like the time lines above, the Utilization View is }
{ automagically zoomed in or out to match the Space-Time }
{ View's time scale. }
{}
{ Task Height }
{ ----------- }
{}
{ In cases where large or small numbers of tasks are being }
{ displayed, the height of the horizontal task bars can shrink }
{ and grow via two buttons at the bottom of the view.  These }
{ buttons also affect the spacing on the Call Trace View. }
{}