interruptible_sleep_on

Hi there,

I've two threads respectively used for reading from and writing to a
device through device driver. In order  to efficiently use the CPU
resources, respected system-level read or write function has the
ability to put the calling thread to sleep. Here are my questions:

For instance in the device driver code below, i) how do I know that the
&ivm_wq_out is referring to the calling thread, READThread?

Device driver:

      my_read(..)
      {
        if ( condition_true )
          interruptible_sleep_on(&my_wq_out);
      }

similar, ii) how do I know that the &my_wq_in is referring to the
calling thread, WRITEThread.
     my_write(..)
      {
        if ( condition_true )
          interruptible_sleep_on(&my_wq_in);
      }


User application:

READThread(void)
{
while(1)
{
      ..
      read(fd, buf, len);
     ..
}

WRITEThread(void)
{
while(1)
{
      ..
      write(fd, buf, len);
     ..
}


Thanks in advance. Very appreciate your comments.
vib