* The rw_lock now behaves just like a recursive locker if KDEBUG_RW_LOCK_DEBUG

is defined to 1; this allows asserting the read lock case, too.
* Added ASSERT_{READ|WRITE}_LOCKED_RW_LOCK() macros. The read assertion is only
  working when KDEBUG_RW_LOCK_DEBUG is defined to 1, the write assertion works
  always.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@26686 a95241bf-73f2-0310-859d-f6bbb57e9c96

headers/private/fs_shell/fssh_api_wrapper.h

@@ -976,6 +976,8 @@
 
 #define ASSERT_LOCKED_RECURSIVE(r)	FSSH_ASSERT_LOCKED_RECURSIVE(r)
 #define ASSERT_LOCKED_MUTEX(m)		FSSH_ASSERT_LOCKED_MUTEX(m)
+#define ASSERT_WRITE_LOCKED_RW_LOCK(l) FSSH_ASSERT_WRITE_LOCKED_RW_LOCK(l)
+#define ASSERT_READ_LOCKED_RW_LOCK(l) FSSH_ASSERT_READ_LOCKED_RW_LOCK(l)
 
 #define MUTEX_INITIALIZER(name)		FSSH_MUTEX_INITIALIZER(name)
 #define RECURSIVE_LOCK_INITIALIZER(name) FSSH_RECURSIVE_LOCK_INITIALIZER(name)

headers/private/fs_shell/fssh_lock.h

@@ -40,6 +40,8 @@ typedef struct fssh_rw_lock {
 
 #define FSSH_ASSERT_LOCKED_RECURSIVE(r)
 #define FSSH_ASSERT_LOCKED_MUTEX(m)
+#define FSSH_ASSERT_WRITE_LOCKED_RW_LOCK(l)
+#define FSSH_ASSERT_READ_LOCKED_RW_LOCK(l)
 
 // static initializers
 #define FSSH_MUTEX_INITIALIZER(name)			{ name, NULL, 0, 0 }

headers/private/kernel/lock.h

@@ -54,12 +54,25 @@ typedef struct rw_lock {
 
 
 #if KDEBUG
+#	define KDEBUG_RW_LOCK_DEBUG 0
+		// Define to 1 if you want to use ASSERT_READ_LOCKED_RW_LOCK().
+		// The rw_lock will just behave like a recursive locker then.
 #	define ASSERT_LOCKED_RECURSIVE(r) \
 		{ ASSERT(find_thread(NULL) == (r)->lock.holder); }
 #	define ASSERT_LOCKED_MUTEX(m) { ASSERT(find_thread(NULL) == (m)->holder); }
+#	define ASSERT_WRITE_LOCKED_RW_LOCK(l) \
+		{ ASSERT(find_thread(NULL) == (l)->holder); }
+#	if KDEBUG_RW_LOCK_DEBUG
+#		define ASSERT_READ_LOCKED_RW_LOCK(l) \
+			{ ASSERT(find_thread(NULL) == (l)->holder); }
+#	else
+#		define ASSERT_READ_LOCKED_RW_LOCK(l) do {} while (false)
+#	endif
 #else
-#	define ASSERT_LOCKED_RECURSIVE(r)	do {} while (false)
-#	define ASSERT_LOCKED_MUTEX(m)		do {} while (false)
+#	define ASSERT_LOCKED_RECURSIVE(r)		do {} while (false)
+#	define ASSERT_LOCKED_MUTEX(m)			do {} while (false)
+#	define ASSERT_WRITE_LOCKED_RW_LOCK(m)	do {} while (false)
+#	define ASSERT_READ_LOCKED_RW_LOCK(l)	do {} while (false)
 #endif
 
 

src/system/kernel/lock.cpp

@@ -280,6 +280,9 @@ rw_lock_destroy(rw_lock* lock)
 status_t
 rw_lock_read_lock(rw_lock* lock)
 {
+#if KDEBUG_RW_LOCK_DEBUG
+	return rw_lock_write_lock(lock);
+#else
 	InterruptsSpinLocker locker(thread_spinlock);
 
 	if (lock->writer_count == 0) {
@@ -292,12 +295,16 @@ rw_lock_read_lock(rw_lock* lock)
 	}
 
 	return rw_lock_wait(lock, false);
+#endif
 }
 
 
 status_t
 rw_lock_read_unlock(rw_lock* lock)
 {
+#if KDEBUG_RW_LOCK_DEBUG
+	return rw_lock_write_unlock(lock);
+#else
 	InterruptsSpinLocker locker(thread_spinlock);
 
 	if (lock->holder == thread_get_current_thread_id()) {
@@ -321,6 +328,7 @@ rw_lock_read_unlock(rw_lock* lock)
 
 	rw_lock_unblock(lock);
 	return B_OK;
+#endif
 }