From 51ecdb00aa92ca41400589de4f96148feb010412 Mon Sep 17 00:00:00 2001
From: Ingo Weinhold <ingo_weinhold@gmx.de>
Date: Mon, 9 Mar 2009 01:48:28 +0000
Subject: [PATCH] Replaced the recursive lock implementation by the kernel
 implementation (slightly adjusted). It is completely based on mutexes, not
 needing any other problematic features. Not sure why the previous
 implementation was doing it differently. This also adds the previously
 missing recursive_lock_trylock().

git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@29462 a95241bf-73f2-0310-859d-f6bbb57e9c96
---
 .../add-ons/kernel/kernelland_emu/lock.cpp    | 86 +++++++------------
 1 file changed, 32 insertions(+), 54 deletions(-)

diff --git a/src/tests/add-ons/kernel/kernelland_emu/lock.cpp b/src/tests/add-ons/kernel/kernelland_emu/lock.cpp
index 0d1a4c9741..048eaa0a57 100644
--- a/src/tests/add-ons/kernel/kernelland_emu/lock.cpp
+++ b/src/tests/add-ons/kernel/kernelland_emu/lock.cpp
@@ -16,46 +16,28 @@
 int32
 recursive_lock_get_recursion(recursive_lock *lock)
 {
-	thread_id thread = find_thread(NULL);
-
-#if !KDEBUG
-	if (lock->holder == thread)
+	if (RECURSIVE_LOCK_HOLDER(lock) == find_thread(NULL))
 		return lock->recursion;
-#else
-	if (lock->lock.holder == thread)
-		return lock->recursion;
-#endif
 
 	return -1;
 }
 
 
 void
-recursive_lock_init_etc(recursive_lock *lock, const char *name, uint32 flags)
+recursive_lock_init(recursive_lock *lock, const char *name)
 {
-	if (lock == NULL)
-		return;
-
-	if (name == NULL)
-		name = "recursive lock";
-
-#if !KDEBUG
-	lock->holder = -1;
-#else
-	lock->lock.holder = -1;
-#endif
+	mutex_init(&lock->lock, name != NULL ? name : "recursive lock");
+	RECURSIVE_LOCK_HOLDER(lock) = -1;
 	lock->recursion = 0;
-	lock->lock.waiters = (mutex_waiter*)create_sem(1, name);
-
-	if ((sem_id)lock->lock.waiters < B_OK)
-		panic("recursive lock creation failed: %s\n", name);
 }
 
 
 void
-recursive_lock_init(recursive_lock *lock, const char *name)
+recursive_lock_init_etc(recursive_lock *lock, const char *name, uint32 flags)
 {
-	recursive_lock_init_etc(lock, name, 0);
+	mutex_init_etc(&lock->lock, name != NULL ? name : "recursive lock", flags);
+	RECURSIVE_LOCK_HOLDER(lock) = -1;
+	lock->recursion = 0;
 }
 
 
@@ -65,8 +47,7 @@ recursive_lock_destroy(recursive_lock *lock)
 	if (lock == NULL)
 		return;
 
-	delete_sem((sem_id)lock->lock.waiters);
-	lock->lock.waiters = (mutex_waiter*)-1;
+	mutex_destroy(&lock->lock);
 }
 
 
@@ -75,29 +56,33 @@ recursive_lock_lock(recursive_lock *lock)
 {
 	thread_id thread = find_thread(NULL);
 
+	if (thread != RECURSIVE_LOCK_HOLDER(lock)) {
+		mutex_lock(&lock->lock);
 #if !KDEBUG
-	if (thread != lock->holder) {
-		status_t status;
-		do {
-			status = acquire_sem((sem_id)lock->lock.waiters);
-		} while (status == B_INTERRUPTED);
-		if (status < B_OK)
-			return status;
-
 		lock->holder = thread;
+#endif
 	}
-#else
-	if (thread != lock->lock.holder) {
-		status_t status;
-		do {
-			status = acquire_sem((sem_id)lock->lock.waiters);
-		} while (status == B_INTERRUPTED);
-		if (status < B_OK)
+
+	lock->recursion++;
+	return B_OK;
+}
+
+
+status_t
+recursive_lock_trylock(recursive_lock *lock)
+{
+	thread_id thread = find_thread(NULL);
+
+	if (thread != RECURSIVE_LOCK_HOLDER(lock)) {
+		status_t status = mutex_trylock(&lock->lock);
+		if (status != B_OK)
 			return status;
 
-		lock->lock.holder = thread;
-	}
+#if !KDEBUG
+		lock->holder = thread;
 #endif
+	}
+
 	lock->recursion++;
 	return B_OK;
 }
@@ -106,21 +91,14 @@ recursive_lock_lock(recursive_lock *lock)
 void
 recursive_lock_unlock(recursive_lock *lock)
 {
-#if !KDEBUG
-	if (find_thread(NULL) != lock->holder)
+	if (find_thread(NULL) != RECURSIVE_LOCK_HOLDER(lock))
 		panic("recursive_lock %p unlocked by non-holder thread!\n", lock);
-#else
-	if (find_thread(NULL) != lock->lock.holder)
-		panic("recursive_lock %p unlocked by non-holder thread!\n", lock);
-#endif
 
 	if (--lock->recursion == 0) {
 #if !KDEBUG
 		lock->holder = -1;
-#else
-		lock->lock.holder = -1;
 #endif
-		release_sem_etc((sem_id)lock->lock.waiters, 1, 0);
+		mutex_unlock(&lock->lock);
 	}
 }