cvs commit: src/sys/kern tty.c tty_inq.c tty_outq.c src/sys/sys ttyqueue.h

[Ed Schouten]

ed          2008-08-30 09:18:27 UTC

  FreeBSD src repository

  Modified files:
    sys/kern             tty.c tty_inq.c tty_outq.c 
    sys/sys              ttyqueue.h 
  Log:
  SVN rev 182471 on 2008-08-30 09:18:27Z by ed
  
  Fix some edge cases in the TTY queues:
  
  - In the current design, when a TTY decreases its baud rate, it tries to
    shrink the queues. This may not always be possible, because it will
    not free any blocks that are still filled with data.
  
    Change the TTY queues to store a `quota' value as well, which means it
    will not free any blocks when changing the baud rate, but when placing
    blocks back into the queue. When the amount of blocks exceeds the
    quota, they get freed.
  
    It also fixes some edge cases, where TIOCSETA during read()/
    write()-calls could actually make the queue a tiny bit bigger than in
    normal cases.
  
  - Don't leak blocks of memory when calling TIOCSETA when the device
    driver abandons the TTY while allocating memory.
  
  - Create ttyoutq_init() and ttyinq_init() to initialize the queues,
    instead of initializing them by hand. The new TTY snoop driver also
    creates an outq, so it's good to have a proper interface to do this.
  
  Obtained from:  //depot/projects/mpsafetty/...
  
  Revision  Changes    Path
  1.286     +10 -22    src/sys/kern/tty.c
  1.2       +23 -42    src/sys/kern/tty_inq.c
  1.3       +29 -42    src/sys/kern/tty_outq.c
  1.2       +18 -0     src/sys/sys/ttyqueue.h