From 023bf5fcda8c37eb8e295784608ce818384a0ca5 Mon Sep 17 00:00:00 2001
From: Ingo Weinhold <ingo_weinhold@gmx.de>
Date: Tue, 22 Apr 2008 21:46:23 +0000
Subject: [PATCH] * Added support for timeouts. * Added support for
 non-published condition variables. One has to call   Init() on those, and add
 entries directly with the   ConditionVariable::Add() method.

git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@25110 a95241bf-73f2-0310-859d-f6bbb57e9c96
---
 headers/private/kernel/condition_variable.h | 17 +++++-
 src/system/kernel/condition_variable.cpp    | 65 +++++++++++++++------
 2 files changed, 62 insertions(+), 20 deletions(-)

diff --git a/headers/private/kernel/condition_variable.h b/headers/private/kernel/condition_variable.h
index ffd76f1e6f..7f22e41f7f 100644
--- a/headers/private/kernel/condition_variable.h
+++ b/headers/private/kernel/condition_variable.h
@@ -28,11 +28,17 @@ public:
 #endif
 
 			bool				Add(const void* object, uint32 flags = 0);
-			status_t			Wait();
-			status_t			Wait(const void* object, uint32 flags = 0);
+			status_t			Wait(uint32 timeoutFlags = 0,
+									bigtime_t timeout = 0);
+			status_t			Wait(const void* object, uint32 flags = 0,
+									bigtime_t timeout = 0);
 
 	inline	ConditionVariable* Variable() const		{ return fVariable; }
 
+private:
+	inline	void				AddToVariable(ConditionVariable* variable,
+									uint32 flags);
+
 private:
 			ConditionVariable*	fVariable;
 			struct thread*		fThread;
@@ -43,6 +49,10 @@ private:
 
 class ConditionVariable : protected HashTableLink<ConditionVariable> {
 public:
+			void				Init(const void* object,
+									const char* objectType);
+									// for anonymous (unpublished) cvars
+
 			void				Publish(const void* object,
 									const char* objectType);
 			void				Unpublish(bool threadsLocked = false);
@@ -50,6 +60,9 @@ public:
 	inline	void				NotifyOne(bool threadsLocked = false);
 	inline	void				NotifyAll(bool threadsLocked = false);
 
+			void				Add(ConditionVariableEntry* entry,
+									uint32 flags = 0);
+
 			const void*			Object() const	{ return fObject; }
 
 	static	void				ListAll();
diff --git a/src/system/kernel/condition_variable.cpp b/src/system/kernel/condition_variable.cpp
index af03e0b4ca..6e95aea18e 100644
--- a/src/system/kernel/condition_variable.cpp
+++ b/src/system/kernel/condition_variable.cpp
@@ -96,18 +96,16 @@ ConditionVariableEntry::Add(const void* object, uint32 flags)
 
 	fThread = thread_get_current_thread();
 
-	InterruptsLocker _;
-	SpinLocker locker(sConditionVariablesLock);
+	InterruptsSpinLocker _(sConditionVariablesLock);
 
 	fVariable = sConditionVariableHash.Lookup(object);
 
-	struct thread* thread = thread_get_current_thread();
-	thread_prepare_to_block(thread, flags, THREAD_BLOCK_TYPE_CONDITION_VARIABLE,
-		fVariable);
+	thread_prepare_to_block(fThread, flags,
+		THREAD_BLOCK_TYPE_CONDITION_VARIABLE, fVariable);
 
 	if (fVariable == NULL) {
 		SpinLocker threadLocker(thread_spinlock);
-		thread_unblock_locked(thread, B_ENTRY_NOT_FOUND);
+		thread_unblock_locked(fThread, B_ENTRY_NOT_FOUND);
 		return false;
 	}
 
@@ -119,7 +117,7 @@ ConditionVariableEntry::Add(const void* object, uint32 flags)
 
 
 status_t
-ConditionVariableEntry::Wait()
+ConditionVariableEntry::Wait(uint32 timeoutFlags, bigtime_t timeout)
 {
 	if (!are_interrupts_enabled()) {
 		panic("wait_for_condition_variable_entry() called with interrupts "
@@ -130,7 +128,11 @@ ConditionVariableEntry::Wait()
 	InterruptsLocker _;
 
 	SpinLocker threadLocker(thread_spinlock);
-	status_t error = thread_block_locked(thread_get_current_thread());
+	status_t error;
+	if ((timeoutFlags & (B_RELATIVE_TIMEOUT | B_ABSOLUTE_TIMEOUT)) != 0)
+		error = thread_block_with_timeout_locked(timeoutFlags, timeout);
+	else
+		error = thread_block_locked(thread_get_current_thread());
 	threadLocker.Unlock();
 
 	SpinLocker locker(sConditionVariablesLock);
@@ -146,17 +148,45 @@ ConditionVariableEntry::Wait()
 
 
 status_t
-ConditionVariableEntry::Wait(const void* object, uint32 flags)
+ConditionVariableEntry::Wait(const void* object, uint32 flags,
+	bigtime_t timeout)
 {
 	if (Add(object, flags))
-		return Wait();
+		return Wait(flags, timeout);
 	return B_ENTRY_NOT_FOUND;
 }
 
 
+inline void
+ConditionVariableEntry::AddToVariable(ConditionVariable* variable, uint32 flags)
+{
+	fThread = thread_get_current_thread();
+
+	thread_prepare_to_block(fThread, flags,
+		THREAD_BLOCK_TYPE_CONDITION_VARIABLE, fVariable);
+
+	// add to the variable
+	InterruptsSpinLocker _(sConditionVariablesLock);
+
+	fVariable = variable;
+	fVariable->fEntries.Add(this);
+}
+
+
 // #pragma mark - ConditionVariable
 
 
+/*!	Initialization method for anonymous (unpublished) condition variables.
+*/
+void
+ConditionVariable::Init(const void* object, const char* objectType)
+{
+	fObject = object;
+	fObjectType = objectType;
+	new(&fEntries) EntryList;
+}
+
+
 void
 ConditionVariable::Publish(const void* object, const char* objectType)
 {
@@ -202,6 +232,13 @@ ConditionVariable::Unpublish(bool threadsLocked)
 }
 
 
+void
+ConditionVariable::Add(ConditionVariableEntry* entry, uint32 flags)
+{
+	entry->AddToVariable(this, flags);
+}
+
+
 /*static*/ void
 ConditionVariable::ListAll()
 {
@@ -242,14 +279,6 @@ ConditionVariable::_Notify(bool all, bool threadsLocked)
 	SpinLocker threadLocker(threadsLocked ? NULL : &thread_spinlock);
 	SpinLocker locker(sConditionVariablesLock);
 
-#if KDEBUG
-	ConditionVariable* variable = sConditionVariableHash.Lookup(fObject);
-	if (variable != this) {
-		panic("Condition variable %p not published, found: %p", this, variable);
-		return;
-	}
-#endif
-
 	if (!fEntries.IsEmpty())
 		_NotifyChecked(all, B_OK);
 }