[haiku-commits] BRANCH looncraz-github.CAP-dirty [0d8212774ea5] in src/servers/app/drawing/interface/local: . src/servers/app
- From: looncraz-github.CAP-dirty <community@xxxxxxxxxxxx>
- To: haiku-commits@xxxxxxxxxxxxx
- Date: Thu, 26 Mar 2015 07:31:41 +0100 (CET)
added 1 changeset to branch 'refs/remotes/looncraz-github/CAP-dirty'
old head: be405f1302079b492952399a93c76c48a3f1674d
new head: 0d8212774ea54be930014973d933c00ea30224d0
overview: https://github.com/looncraz/haiku/compare/be405f130207...0d8212774ea5
----------------------------------------------------------------------------
0d8212774ea5: Minor tweaks
Prevent CompositeWindow from setting itself to compositing mode for now,
Add a client auto-locker for WeakLazyLocker.
Fixed a race condition in WeakLazyLocker.
Minor update to set state handling
[ looncraz <looncraz@xxxxxxxxxxxx> ]
----------------------------------------------------------------------------
Commit: 0d8212774ea54be930014973d933c00ea30224d0
Author: looncraz <looncraz@xxxxxxxxxxxx>
Date: Thu Mar 26 06:15:11 2015 UTC
----------------------------------------------------------------------------
5 files changed, 78 insertions(+), 11 deletions(-)
src/servers/app/Desktop.cpp | 5 ++
.../drawing/interface/local/CompositeWindow.cpp | 14 +++---
.../drawing/interface/local/CompositeWindow.h | 2 +
.../drawing/interface/local/WeakLazyLocker.cpp | 19 ++++++--
.../app/drawing/interface/local/WeakLazyLocker.h | 49 ++++++++++++++++++++
----------------------------------------------------------------------------
diff --git a/src/servers/app/Desktop.cpp b/src/servers/app/Desktop.cpp
index fd97f0a..4ddde91 100644
--- a/src/servers/app/Desktop.cpp
+++ b/src/servers/app/Desktop.cpp
@@ -2695,6 +2695,11 @@ Desktop::_DispatchMessage(int32 code,
BPrivate::LinkReceiver& link)
if (error == B_ALREADY_RUNNING) {
CAPTRACE("Already running, but no worries
;-)\n");
error = B_OK;
+ } else if (error != B_OK) {
+ CAPTRACE("ERROR! Unable to set compositing
state!\n");
+ fLink.StartMessage(B_ERROR);
+ fLink.Flush();
+ break;
}
LockSingleWindow();
diff --git a/src/servers/app/drawing/interface/local/CompositeWindow.cpp
b/src/servers/app/drawing/interface/local/CompositeWindow.cpp
index 9017a6f..4008e3f 100644
--- a/src/servers/app/drawing/interface/local/CompositeWindow.cpp
+++ b/src/servers/app/drawing/interface/local/CompositeWindow.cpp
@@ -136,10 +136,9 @@ CompositeWindow::ProcessDirtyRegion(BRegion&
regionOnScreen)
// We don't want to mess with these during the compositer lock
//... which only occurs in single-buffered mode
- ClientLock();
- fDirtyCopyRegion.Include(&dirtyCopyRegion);
- fDirtyAlphaRegion.Include(&dirtyAlphaRegion);
- ClientUnlock();
+ WLAutoClientLock _(&fLazyLock);
+ fDirtyCopyRegion.Include(&dirtyCopyRegion);
+ fDirtyAlphaRegion.Include(&dirtyAlphaRegion);
}
@@ -281,6 +280,7 @@ CompositeWindow::ClientUnlock()
void
CompositeWindow::CompositingEnabled(bool enabled)
{
+ CAPTRACEF("%s\n", enabled ? "ENABLED" : "DISABLED");
// the whole Desktop window list is compositing (by default)
// ... or not...
// Before this is called, we can't assume that to be the case, so this
is
@@ -296,7 +296,8 @@ CompositeWindow::CompositingEnabled(bool enabled)
void
CompositeWindow::CompositingEnabling()
{
- fIsCompositeWindow = true;
+ CAPTRACE("\n");
+ //fIsCompositeWindow = true;
// allocate our buffers, set enabled, trigger client redraw
}
@@ -304,7 +305,8 @@ CompositeWindow::CompositingEnabling()
void
CompositeWindow::CompositingDisabling()
{
- fIsCompositeWindow = false;
+ CAPTRACE("\n");
+ //fIsCompositeWindow = false;
// delete our buffers, trigger client redraw
}
diff --git a/src/servers/app/drawing/interface/local/CompositeWindow.h
b/src/servers/app/drawing/interface/local/CompositeWindow.h
index 9a9e593..2d85141 100644
--- a/src/servers/app/drawing/interface/local/CompositeWindow.h
+++ b/src/servers/app/drawing/interface/local/CompositeWindow.h
@@ -101,4 +101,6 @@ private:
WeakLazyLocker fLazyLock;
};
+
+
#endif // CAP_COMPOSITE_WINDOW_H
diff --git a/src/servers/app/drawing/interface/local/WeakLazyLocker.cpp
b/src/servers/app/drawing/interface/local/WeakLazyLocker.cpp
index 2ec7485..a974a68 100644
--- a/src/servers/app/drawing/interface/local/WeakLazyLocker.cpp
+++ b/src/servers/app/drawing/interface/local/WeakLazyLocker.cpp
@@ -69,13 +69,16 @@ WeakLazyLocker::UnsetLazyServerLock()
bool
WeakLazyLocker::ServerLock(bigtime_t timeout)
{
+ if (fServerLock)
+ return true;
+
fServerLazyLock = true;
if (fLock.LockWithTimeout(timeout) == B_OK)
fServerLock = true;
fServerLazyLock = false;
- return IsServerLocked();
+ return fServerLock;
}
@@ -93,11 +96,17 @@ WeakLazyLocker::ClientLock(bigtime_t timeout)
{
bigtime_t start = system_time();
- while (fServerLazyLock
- && system_time() - start < timeout)
- snooze(250);
- if (fServerLazyLock)
+ bool timedOut = false;
+ while (fServerLazyLock) {
+ snooze(500);
+ if (system_time() - start > timeout) {
+ timedOut = true;
+ break;
+ }
+ }
+
+ if (timedOut)
return false;
if (fLock.LockWithTimeout(timeout - (system_time() - start)) == B_OK)
diff --git a/src/servers/app/drawing/interface/local/WeakLazyLocker.h
b/src/servers/app/drawing/interface/local/WeakLazyLocker.h
index cb8db77..eaa630e 100644
--- a/src/servers/app/drawing/interface/local/WeakLazyLocker.h
+++ b/src/servers/app/drawing/interface/local/WeakLazyLocker.h
@@ -17,6 +17,23 @@
This enables CompositeWindow and WindowBuffer to be lazily prepared for
interacting with the CompositeEngine with a very low risk of stalling
the
CompositeEngine.
+
+ TODO: find way to avoid use of BLocker
+ Our specific usage pattern (and general safety regarding
accessing
+ memory concurrently) means that the occassional improper lock
+ acquisition will not be a problem, but then we run the risk of
+ corrupting our state.
+
+ There are x86 instructions (assembly) and c++11 atomics that
would be
+ safe, but we would limit compositing to those platforms, and
this would
+ be a really bad reason to do so.
+
+ See, the ServerLock should be *really* fast. We don't want to
stall
+ even for the default 50us if we don't need to (especially if we
fail
+ to get the lock!).
+
+ To minimize this, of course, we have a "lazy" lock, which
prevents
+ any more client locks.
*/
@@ -48,6 +65,38 @@ private:
};
+class WLAutoClientLock {
+ WeakLazyLocker* fLock;
+ bool fLocked;
+public:
+ WLAutoClientLock(WeakLazyLocker* lock)
+ :
+ fLock(lock),
+ fLocked(true)
+ {
+ fLock->ClientLock();
+ }
+
+ ~WLAutoClientLock()
+ {
+ if (fLocked)
+ fLock->ClientUnlock();
+ }
+
+ bool IsLocked() const
+ {
+ return fLocked;
+ }
+
+
+ void Unlock()
+ {
+ if (fLocked) {
+ fLocked = false;
+ fLock->ClientUnlock();
+ }
+ }
+};
#endif // CAP_WEAK_LAZY_LOCKER_H
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