readme_countingsemdemo.txt

对Vxworks进程通讯的信号量详细介绍

FLE LIST -
	      countingSemDemo.c

DESCRIPTION -
	      Counting semaphore example.  Using binary semaphores for task
	      synchronization may, if the events can occur rapidly enough, cause
	      a loss of data, i.e. an event can be missed if the events can 
	      occur faster then a task can process them.
	      Using counting semaphores may solve this problem. This 
	      program demonstrates task synchronization using counting 
	      semaphores. The user can also select to use a binary semaphore 
	      instead of a counting semaphore in this demonstration, for
	      comparision between the two semaphores.

	      To run this code invoke the function countingSemDemo()

RUNNING DEMO -
	      Place the countingSemDemo.c file in your <Tornado> dir. Depending 
	      on the target you have, define the CPU in your compile line and
	      use the Makefile in the BSP dir. to compile.

	      Run countingSemDemo() on vxworks target.

TESTED ON -   Host/Target : Solaris 2.5.1 / mv1604
	      VxWorks     : 5.3.1

	      EXAMPLE COMPILE LINE - 
			    make CPU=PPC604 countingSemDemo.o

% make countingSemDemo.o
ccppc -B/petaluma1/mayur/tor101-ppc/host/sun4-solaris2/lib/gcc-lib/ 
-mstrict-align -ansi -nostdinc -O2 -fvolatile -fno-builtin -fno-for-scope 
-Wall -I/h   -I. -I/petaluma1/mayur/tor101-ppc/target/config/all 
-I/petaluma1/mayur/tor101-ppc/target/h 
-I/petaluma1/mayur/tor101-ppc/target/src/config 
-I/petaluma1/mayur/tor101-ppc/target/src/drv -DCPU=PPC604  -DMV1600 
-DTARGET_DIR="\"mv1604\""   -c countingSemDemo.c

OUTPUTS/LOGFILE -

On VxWorks target:
==================

-> sp countingSemDemo, 'c'
task spawned: id = 5b7b40, name = u0
value = 5995328 = 0x5b7b40

The Output on Console:
======================
Semaphore Id        : 0x7fd238    
Semaphore Type      : COUNTING  
Task Queuing        : PRIORITY  
Pended Tasks        : 0         
Count               : 2         

semaphore taken 1 times

Semaphore Id        : 0x7fd238    
Semaphore Type      : COUNTING  
Task Queuing        : PRIORITY  
Pended Tasks        : 0         
Count               : 1         

semaphore taken 2 times

Semaphore Id        : 0x7fd238    
Semaphore Type      : COUNTING  
Task Queuing        : PRIORITY  
Pended Tasks        : 0         
Count               : 0         

semaphore taken 3 times

On VxWorks target:
==================

-> sp countingSemDemo, 'b'
task spawned: id = 5b7b40, name = u1
value = 5995328 = 0x5b7b40

The Output on Console:
======================
Semaphore Id        : 0x7fd238    
Semaphore Type      : BINARY    
Task Queuing        : PRIORITY  
Pended Tasks        : 0         
State               : FULL      

semaphore taken 1 times

Semaphore Id        : 0x7fd238    
Semaphore Type      : BINARY    
Task Queuing        : PRIORITY  
Pended Tasks        : 0         
State               : EMPTY     

semaphore taken 2 times