README.TXT

Fast Copy Routines 
 
 
The UNBUFCPY sample consists of two parts: UNBUFCP1 and UNBUFCP2. 
 
The UNBUFCP1 sample shows a fast copy routine that uses I/O completion  
ports. It is intended to demonstrate using a single thread to complete I/O  
requests from multiple file handles. 
 
Only one thread and one I/O completion port is used. The file handles for  
the source and destination files are both associated with the same port. The  
thread starts by posting a number of overlapped reads from the source file.  
It then waits on the I/O completion port. Whenever a read completes, it  
immediately turns it into a write to the destination file. Whenever a write  
completes, it immediately posts the next read from the source file. 
 
The UNBUFCP2 sample shows a fast copy routine that uses I/O completion  
ports. It is intended to demonstrate how to complete I/O in a different  
thread than the thread that started the I/O. 
 
Two threads are used. The first thread posts overlapped reads from the  
source file. These reads complete to an I/O completion port the second  
thread is waiting on. The second thread sees the I/O completion and posts  
an overlapped write to the destination file. The write completes to another I/O completion  
port that the first thread is waiting on. The first thread sees the I/O  
completion and posts another overlapped read.