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19025d77ad
Reorganized. Created a new top level include directory that will hold all of Trick's header files. Moved all of the Trick headers to this directory. Created a libexec directory that holds all of the executables that users don't need to execute directly. Changed all of the executables remaining in bin to start with "trick-". In the sim_services directories changed all source files to find the Trick headers in their new location. Since all of the include files are gone in sim_services, removed the src directories as well, moving all of the source files up a level. Moved the makefiles, docs, man, and other architecture independent files into a top level share directory. Renamed lib_${TRICK_HOST_CPU} to lib64 or lib depending on the platform we're currently on.
refs #63
93 lines
2.7 KiB
Plaintext
93 lines
2.7 KiB
Plaintext
/**
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@page LEVEL2 Sleep Timer Design
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After all jobs in an execution frame have run, the default behavior (the timer is disabled)
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is that the simulation will spin on the clock until real-time has caught up to simulation time.
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Enabling the sleep timer gives control to the timer's pause() function, in which it may
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release the processor and regain control when the timer elapses.
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@section LEVEL3 Base Sleep Timer
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The base Timer object provides a common interface for all Timers for the
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following functions.
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-# Enabling the Timer
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-# Disabling the Timer
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-# Getting the enabled/disabled status
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The base Timer object provides an interface for the following operations. The
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base Timer does not implement the following operations.
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-# Initializing the Timer hardware
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-# Setting the frame time for timer
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-# Starting the timer
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-# Resetting the timer
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-# Pausing for the timer to expire
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-# Stopping the timer
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-# Shutting down the Timer hardware
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@section LEVEL3 ITimer
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The ITimer is a Timer object that derives from the the Base Sleep Timer. The
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ITimer uses system itimer functionality to allow the simulation to release the
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cpu while waiting for the timer to expire. When the itimer expires it uses
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the SIGALRM signal to set a semaphore. When the semaphore is set the simulation
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wakes up.
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The itimer does not expire exactly at the desired period. It actually exipres after
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the desired period by up to 1ms. To compensate for the delay we subtract 2ms from
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the desired period. The RealtimeSync class "spins" on the clock the remaining
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1-2ms the timer does not sleep for.
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The ITimer implements the interface laid out by the base Timer class
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@section LEVEL4 Initialization
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@copydetails Trick::ITimer::init()
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Trick::ITimer::init()
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@section LEVEL4 Setting the Frame Time
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@copydetails Trick::ITimer::set_frame_times()
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Trick::ITimer::set_frame_times()
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@section LEVEL4 Starting the timer.
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@copydetails Trick::ITimer::start()
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Trick::ITimer::start()
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@section LEVEL4 Restarting the timer.
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@copydetails Trick::ITimer::reset()
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Trick::ITimer::reset()
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@section LEVEL4 Pausing for the Timer to Expire
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Pausing for the timer has 2 parts. The first is the signal handler that posts
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a semaphore in response to a SIGALRM signal. The signal handler is assigned
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to SIGALRM during the initialization routine. The second is the pause routine
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that waits for the semaphore to be posted.
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@section LEVEL5 Signal Handler
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@copydetails Trick::ITimer::it_handler()
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Trick::ITimer::it_handler()
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@section LEVEL4 Pause for Semaphore
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@copydetails Trick::ITimer::pause()
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Trick::ITimer::pause()
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@section LEVEL4 Stopping the timer.
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@copydetails Trick::ITimer::stop()
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Trick::ITimer::stop()
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@section LEVEL4 Shutting Down the Timer
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@copydetails Trick::ITimer::shutdown()
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Trick::ITimer::shutdown()
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*/
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