Correct some comments

This commit is contained in:
Gregory Nutt 2016-07-26 13:39:20 -06:00
parent 0c7f5d62e4
commit 59e0c4411f

View File

@ -33,14 +33,14 @@
*
****************************************************************************/
/* TODO: O_NONBLOCK is not yet supported. Currently, the pipes are opened
* nonblocking so only blocking behavior is supported. This driver must be
* able to support multiple clients that have have a PTY device opened in
* blocking and non-blocking modes simultaneously.
/* TODO: O_NONBLOCK is not yet supported. Currently, the source and sink
* pipes are opened nonblocking so only blocking behavior is supported.
* This driver must be able to support multiple clients that have have a PTY
* device opened in blocking and non-blocking modes simultaneously.
*
* There are two different possible implementations under consideration:
*
* 1. Keep the pipes in blockingmode, but use a test based on FIONREAD (for
* 1. Keep the pipes in blocking mode, but use a test based on FIONREAD (for
* the source pipe) or FIONSPACE (for the sink pipe) to determine if the
* read or write would block. There is existing logic like this in
* pty_read() to handle the case of a single byte reads which must never
@ -67,6 +67,11 @@
* mode in the open flags of the PTY device, and (2) logic to restore
* the default pipe mode after the file_read/write() operation and
* before the pipe is unlocked.
*
* There are existing locks to support (1) destruction of the driver
* (pp_exclsem) and (2) slave PTY locking (pp_slavesem). Care must be
* taken with any new source/sink pipe locking to assure that deadlocks
* are not possible.
*/
/****************************************************************************