diff options
Diffstat (limited to 'ACE/performance-tests/Misc/context_switch_time.cpp')
| -rw-r--r-- | ACE/performance-tests/Misc/context_switch_time.cpp | 113 |
1 files changed, 54 insertions, 59 deletions
diff --git a/ACE/performance-tests/Misc/context_switch_time.cpp b/ACE/performance-tests/Misc/context_switch_time.cpp index 70e9a0610a0..293f687d434 100644 --- a/ACE/performance-tests/Misc/context_switch_time.cpp +++ b/ACE/performance-tests/Misc/context_switch_time.cpp @@ -1,48 +1,45 @@ -// $Id$ - -// ============================================================================ -// -// = LIBRARY -// (none) -// -// = FILENAME -// context_switch_time.cpp -// -// = DESCRIPTION -// Program that calculates context switch time between threads. -// The Suspend-Resume test is based on the Task Context Switching -// measurement approach described in: -// Darren Cathey<br> -// "RTOS Benchmarking -- All Things Considered . . ."<br> -// <a href="http://www.realtime-info.be"><em>Real-Time Magazine</em></a>, -// Second Quarter 1993, -// <em>reprinted by <a href="http://www.wrs.com/artreqfm.html">Wind River -// Systems</a></em><p> -// which in turn is based on Superconducting Super Collider (SSC) -// Laboratory Ping Suspend/Resume Task and Suspend/Resume Task benchmarks. -// It measures two different times: -// 1) The time to resume a blocked high priority task, which does -// nothing other than block immediately. A lower priority task -// resumes the high priority task, so the elapsed time includes -// two context switches, one task suspend, and one task resume. -// 2) The time to suspend and resume a low priority task that does -// nothing. There is no context switching. This time is subtracted -// from the one described in 1) above, and the result is divided by -// two to yield the context switch time. -// -// Notes: -// On Solaris 2.5.1, it appears that the lowest context switching times, -// at least on a single-CPU machine, are obtained _without_ creating new -// LWPs for new threads (THR_NEW_LWP). The -n option enables the use of -// THR_NEW_LWP for testing. -// -// = CREATION DATE -// 17 January 1997 -// -// = AUTHOR -// David L. Levine -// -// ============================================================================ + +//============================================================================= +/** + * @file context_switch_time.cpp + * + * $Id$ + * + * Program that calculates context switch time between threads. + * The Suspend-Resume test is based on the Task Context Switching + * measurement approach described in: + * Darren Cathey<br> + * "RTOS Benchmarking -- All Things Considered . . ."<br> + * <a href="http://www.realtime-info.be"><em>Real-Time Magazine</em></a>, + * Second Quarter 1993, + * <em>reprinted by <a href="http://www.wrs.com/artreqfm.html">Wind River + * Systems</a></em><p> + * which in turn is based on Superconducting Super Collider (SSC) + * Laboratory Ping Suspend/Resume Task and Suspend/Resume Task benchmarks. + * It measures two different times: + * 1) The time to resume a blocked high priority task, which does + * nothing other than block immediately. A lower priority task + * resumes the high priority task, so the elapsed time includes + * two context switches, one task suspend, and one task resume. + * 2) The time to suspend and resume a low priority task that does + * nothing. There is no context switching. This time is subtracted + * from the one described in 1) above, and the result is divided by + * two to yield the context switch time. + * + * Notes: + * On Solaris 2.5.1, it appears that the lowest context switching times, + * at least on a single-CPU machine, are obtained _without_ creating new + * LWPs for new threads (THR_NEW_LWP). The -n option enables the use of + * THR_NEW_LWP for testing. + * + * = CREATION DATE + * 17 January 1997 + * + * + * @author David L. Levine + */ +//============================================================================= + static const char usage [] = "[-? |\n" " [-c <repeat counter, 0 means forever>]\n" @@ -61,8 +58,6 @@ static const char usage [] = "[-? |\n" #include "ace/OS_NS_unistd.h" #include "ace/OS_NS_errno.h" -ACE_RCSID(Misc, context_switch_time, "$Id$") - #if defined (ACE_HAS_THREADS) #if !defined (ACE_DEBUG_CST) @@ -667,11 +662,11 @@ public: ACE_hrtime_t elapsed_time () const { return elapsed_time_; } private: + /// Mutex used for acquire/release time measurement. ACE_Thread_Mutex mutex_; - // Mutex used for acquire/release time measurement. + /// Semaphore used for acquire/release time measurement. ACE_Thread_Semaphore sem_; - // Semaphore used for acquire/release time measurement. const ACE_UINT32 iterations_; @@ -749,9 +744,9 @@ public: virtual int svc (); + /// Called by other task: it returns when this task is ready to + /// continue void ready () { initialized_.acquire (); } - // Called by other task: it returns when this task is ready to - // continue void done (); @@ -765,17 +760,17 @@ private: int terminate_; ACE_UINT32 iterations_; + /// Semaphore used to resume the task. ACE_Thread_Semaphore &sem_; - // Semaphore used to resume the task. + /// Mutex used to block the task. ACE_Thread_Mutex &mutex_; - // Mutex used to block the task. + /// Clock shared between low and high priority tasks. ACE_High_Res_Timer &timer_; - // Clock shared between low and high priority tasks. + /// Running total context switch time, nsec. ACE_hrtime_t total_time_; - // Running total context switch time, nsec. // Force proper construction of independent instances. High_Priority_Synchronized_Task (); @@ -924,17 +919,17 @@ public: private: const ACE_UINT32 iterations_; + /// Used by the low priority thread to resume the high priority thread. ACE_Thread_Semaphore sem_; - // Used by the low priority thread to resume the high priority thread. + /// Used by the low priority thread to block the high priority thread. ACE_Thread_Mutex mutex_; - // Used by the low priority thread to block the high priority thread. + /// Clock shared between low and high priority tasks. ACE_High_Res_Timer timer_; - // Clock shared between low and high priority tasks. + /// The high priority task. High_Priority_Synchronized_Task high_; - // The high priority task. ACE_hrtime_t elapsed_time_; |