From 787a6034170b59d55afe8d0a12cb0904f20cb74d Mon Sep 17 00:00:00 2001
From: Justus Winter <4winter@informatik.uni-hamburg.de>
Date: Sun, 16 Aug 2015 02:18:47 +0200
Subject: codify locking contracts

Conflicts:
	vm/vm_page.h
---
 vm/vm_object.c | 19 ++++++++++++++++++-
 1 file changed, 18 insertions(+), 1 deletion(-)

(limited to 'vm/vm_object.c')

diff --git a/vm/vm_object.c b/vm/vm_object.c
index 4b31482..836f5ef 100644
--- a/vm/vm_object.c
+++ b/vm/vm_object.c
@@ -188,6 +188,8 @@ struct lock vm_object_cache_lock_data;
 		lock_try_write(&vm_object_cache_lock_data)
 #define vm_object_cache_unlock()	\
 		lock_write_done(&vm_object_cache_lock_data)
+#define have_vm_object_cache_lock()		\
+		have_write_lock(&vm_object_cache_lock_data)
 
 /*
  *	Number of physical pages referenced by cached objects.
@@ -516,7 +518,6 @@ void vm_object_deallocate(
 		 *	Destroy the object; the cache lock will
 		 *	be released in the process.
 		 */
-
 		vm_object_terminate(object);
 
 		/*
@@ -554,6 +555,9 @@ void vm_object_terminate(
 	vm_external_t	existence_info;
 #endif	/* MACH_PAGEMAP */
 
+	assert(have_vm_object_lock(object));
+	assert(have_vm_object_cache_lock());
+
 	/*
 	 *	Make sure the object isn't already being terminated
 	 */
@@ -754,6 +758,8 @@ void vm_object_abort_activity(
 	vm_page_t	p;
 	vm_page_t	next;
 
+	assert(have_vm_object_lock(object));
+
 	/*
 	 *	Abort all activity that would be waiting
 	 *	for a result on this memory object.
@@ -791,6 +797,7 @@ void vm_object_abort_activity(
 
 	object->pager_ready = TRUE;
 	vm_object_wakeup(object, VM_OBJECT_EVENT_PAGER_READY);
+	assert(have_vm_object_lock(object));
 }
 
 /*
@@ -889,6 +896,7 @@ void vm_object_deactivate_pages(
 {
 	vm_page_t	p;
 
+	assert(have_vm_object_lock(object));
 	queue_iterate(&object->memq, p, vm_page_t, listq) {
 		vm_page_lock_queues();
 		if (!p->busy)
@@ -1348,6 +1356,8 @@ kern_return_t vm_object_copy_call(
 	vm_object_t	new_object;
 	vm_page_t	p;
 
+	assert(have_vm_object_lock(src_object));
+
 	/*
 	 *	Create a memory object port to be associated
 	 *	with this new vm_object.
@@ -2196,6 +2206,7 @@ restart:
 	/*
 	 *	[At this point, the object must be locked]
 	 */
+	assert(have_vm_object_lock(object));
 
 	/*
 	 *	Wait for the work above to be done by the first
@@ -2325,6 +2336,8 @@ void vm_object_remove(
 {
 	ipc_port_t port;
 
+	assert(have_vm_object_cache_lock());
+
 	if ((port = object->pager) != IP_NULL) {
 		if (ip_kotype(port) == IKOT_PAGER)
 			ipc_kobject_set(port, IKO_NULL,
@@ -2380,6 +2393,8 @@ void vm_object_collapse(
 	vm_page_t	p, pp;
 	ipc_port_t 	old_name_port;
 
+	assert(have_vm_object_lock(object));
+
 	if (!vm_object_collapse_allowed)
 		return;
 
@@ -2729,6 +2744,8 @@ void vm_object_page_remove(
 {
 	vm_page_t	p, next;
 
+	assert(have_vm_object_lock(object));
+
 	/*
 	 *	One and two page removals are most popular.
 	 *	The factor of 16 here is somewhat arbitrary.
-- 
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