[haiku-commits] r42086 - haiku/trunk/src/add-ons/kernel/generic/tty
- From: mmlr@xxxxxxxx
- To: haiku-commits@xxxxxxxxxxxxx
- Date: Fri, 10 Jun 2011 19:12:52 +0200 (CEST)
Author: mmlr
Date: 2011-06-10 19:12:51 +0200 (Fri, 10 Jun 2011)
New Revision: 42086
Changeset: https://dev.haiku-os.org/changeset/42086
Modified:
haiku/trunk/src/add-ons/kernel/generic/tty/module.cpp
haiku/trunk/src/add-ons/kernel/generic/tty/tty.cpp
haiku/trunk/src/add-ons/kernel/generic/tty/tty_private.h
Log:
Remove the global lock and the documentation for it. It was specific to the tty
driver and doesn't apply to the generic module.
Modified: haiku/trunk/src/add-ons/kernel/generic/tty/module.cpp
===================================================================
--- haiku/trunk/src/add-ons/kernel/generic/tty/module.cpp 2011-06-10
13:43:06 UTC (rev 42085)
+++ haiku/trunk/src/add-ons/kernel/generic/tty/module.cpp 2011-06-10
17:12:51 UTC (rev 42086)
@@ -68,6 +68,7 @@
0, //B_KEEP_LOADED,
tty_module_std_ops
},
+
&tty_create,
&tty_destroy,
&tty_create_cookie,
Modified: haiku/trunk/src/add-ons/kernel/generic/tty/tty.cpp
===================================================================
--- haiku/trunk/src/add-ons/kernel/generic/tty/tty.cpp 2011-06-10 13:43:06 UTC
(rev 42085)
+++ haiku/trunk/src/add-ons/kernel/generic/tty/tty.cpp 2011-06-10 17:12:51 UTC
(rev 42086)
@@ -41,14 +41,9 @@
Locking
-------
- There are four locks involved. If more than one needs to be held at a
+ There are three locks involved. If more than one needs to be held at a
time, they must be acquired in the order they are listed here.
- gGlobalTTYLock: Guards open/close operations. When held, tty_open(),
- tty_close(), tty_close_cookie() etc. won't be invoked by other threads,
- cookies won't be added to/removed from TTYs, and tty::ref_count,
- tty::open_count, tty_cookie::closed won't change.
-
gTTYCookieLock: Guards the access to the fields
tty_cookie::{thread_count,closed}, or more precisely makes access to
them
atomic. thread_count is the number of threads currently using the cookie
@@ -59,9 +54,8 @@
tty::lock: Guards the access to tty::{input_buffer,settings::{termios,
window_size,pgrp_id}}. Moreover when held guarantees that
tty::open_count
- won't drop to zero (both gGlobalTTYLock and tty::lock must be held to
- decrement it). A tty and the tty connected to it (master and slave)
share
- the same lock.
+ won't drop to zero. A tty and the tty connected to it (master and slave)
+ share the same lock.
gTTYRequestLock: Guards access to tty::{reader,writer}_queue (most
RequestQueue methods do the locking themselves (the lock is a
@@ -863,8 +857,6 @@
#endif // 0
-/*! The global lock must be held.
-*/
tty_cookie*
tty_create_cookie(struct tty* tty, struct tty* otherTTY, uint32 openMode)
{
@@ -896,8 +888,6 @@
}
-/*! The global lock must be held.
-*/
void
tty_destroy_cookie(tty_cookie* cookie)
{
@@ -917,8 +907,6 @@
}
-/*! The global lock must be held.
-*/
void
tty_close_cookie(tty_cookie* cookie)
{
@@ -958,9 +946,7 @@
// For the removal of the cookie acquire the TTY's lock. This ensures,
that
// cookies will not be removed from a TTY (or added -- cf.
add_tty_cookie())
- // as long as the TTY's lock is being held. This is required for the
select
- // support, since we need to iterate through the cookies of a TTY
without
- // having to acquire the global lock.
+ // as long as the TTY's lock is being held.
MutexLocker ttyLocker(cookie->tty->lock);
// remove the cookie from the TTY's cookie list
Modified: haiku/trunk/src/add-ons/kernel/generic/tty/tty_private.h
===================================================================
--- haiku/trunk/src/add-ons/kernel/generic/tty/tty_private.h 2011-06-10
13:43:06 UTC (rev 42085)
+++ haiku/trunk/src/add-ons/kernel/generic/tty/tty_private.h 2011-06-10
17:12:51 UTC (rev 42086)
@@ -142,7 +142,6 @@
};
-extern struct mutex gGlobalTTYLock;
extern struct mutex gTTYCookieLock;
extern struct recursive_lock gTTYRequestLock;
Other related posts:
- » [haiku-commits] r42086 - haiku/trunk/src/add-ons/kernel/generic/tty - mmlr
