Revert "drm/ttm: add a way to bo_wait for either the last read or last write"

This reverts commit dfadbbdb57b3f2bb33e14f129a43047c6f0caefa.

Further upstream discussion between Marek and Thomas decided this wasn't
fully baked and needed further work, so revert it before it hits mainline.

Signed-off-by: Dave Airlie <airlied@redhat.com>

12 files changed, 40 insertions, 140 deletions

diff --git a/drivers/gpu/drm/nouveau/nouveau_bo.c b/drivers/gpu/drm/nouveau/nouveau_bo.c
index 424dff5d0aba47..7226f419e178b6 100644
--- a/drivers/gpu/drm/nouveau/nouveau_bo.c
+++ b/drivers/gpu/drm/nouveau/nouveau_bo.c
@@ -1104,8 +1104,7 @@ nouveau_bo_vma_del(struct nouveau_bo *nvbo, struct nouveau_vma *vma)
 	if (vma->node) {
 		if (nvbo->bo.mem.mem_type != TTM_PL_SYSTEM) {
 			spin_lock(&nvbo->bo.bdev->fence_lock);
-			ttm_bo_wait(&nvbo->bo, false, false, false,
-				    TTM_USAGE_READWRITE);
+			ttm_bo_wait(&nvbo->bo, false, false, false);
 			spin_unlock(&nvbo->bo.bdev->fence_lock);
 			nouveau_vm_unmap(vma);
 		}
diff --git a/drivers/gpu/drm/nouveau/nouveau_gem.c b/drivers/gpu/drm/nouveau/nouveau_gem.c
index 322bf62a064567..5f0bc57fdaab5e 100644
--- a/drivers/gpu/drm/nouveau/nouveau_gem.c
+++ b/drivers/gpu/drm/nouveau/nouveau_gem.c
@@ -589,8 +589,7 @@ nouveau_gem_pushbuf_reloc_apply(struct drm_device *dev,
 		}
 
 		spin_lock(&nvbo->bo.bdev->fence_lock);
-		ret = ttm_bo_wait(&nvbo->bo, false, false, false,
-				  TTM_USAGE_READWRITE);
+		ret = ttm_bo_wait(&nvbo->bo, false, false, false);
 		spin_unlock(&nvbo->bo.bdev->fence_lock);
 		if (ret) {
 			NV_ERROR(dev, "reloc wait_idle failed: %d\n", ret);
@@ -826,7 +825,7 @@ nouveau_gem_ioctl_cpu_prep(struct drm_device *dev, void *data,
 	nvbo = nouveau_gem_object(gem);
 
 	spin_lock(&nvbo->bo.bdev->fence_lock);
-	ret = ttm_bo_wait(&nvbo->bo, true, true, no_wait, TTM_USAGE_READWRITE);
+	ret = ttm_bo_wait(&nvbo->bo, true, true, no_wait);
 	spin_unlock(&nvbo->bo.bdev->fence_lock);
 	drm_gem_object_unreference_unlocked(gem);
 	return ret;
diff --git a/drivers/gpu/drm/radeon/radeon_cs.c b/drivers/gpu/drm/radeon/radeon_cs.c
index 14e8531511057e..fae00c0d75aaf1 100644
--- a/drivers/gpu/drm/radeon/radeon_cs.c
+++ b/drivers/gpu/drm/radeon/radeon_cs.c
@@ -80,7 +80,6 @@ int radeon_cs_parser_relocs(struct radeon_cs_parser *p)
 			p->relocs[i].lobj.wdomain = r->write_domain;
 			p->relocs[i].lobj.rdomain = r->read_domains;
 			p->relocs[i].lobj.tv.bo = &p->relocs[i].robj->tbo;
-			p->relocs[i].lobj.tv.usage = TTM_USAGE_READWRITE;
 			p->relocs[i].handle = r->handle;
 			p->relocs[i].flags = r->flags;
 			radeon_bo_list_add_object(&p->relocs[i].lobj,
diff --git a/drivers/gpu/drm/radeon/radeon_object.c b/drivers/gpu/drm/radeon/radeon_object.c
index b8f75f5d344bcb..1c851521f458df 100644
--- a/drivers/gpu/drm/radeon/radeon_object.c
+++ b/drivers/gpu/drm/radeon/radeon_object.c
@@ -527,7 +527,7 @@ int radeon_bo_wait(struct radeon_bo *bo, u32 *mem_type, bool no_wait)
 	if (mem_type)
 		*mem_type = bo->tbo.mem.mem_type;
 	if (bo->tbo.sync_obj)
-		r = ttm_bo_wait(&bo->tbo, true, true, no_wait, false);
+		r = ttm_bo_wait(&bo->tbo, true, true, no_wait);
 	spin_unlock(&bo->tbo.bdev->fence_lock);
 	ttm_bo_unreserve(&bo->tbo);
 	return r;
diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
index 50fc8e4c9a310c..617b64678fc62f 100644
--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -499,7 +499,7 @@ static void ttm_bo_cleanup_refs_or_queue(struct ttm_buffer_object *bo)
 	int ret;
 
 	spin_lock(&bdev->fence_lock);
-	(void) ttm_bo_wait(bo, false, false, true, TTM_USAGE_READWRITE);
+	(void) ttm_bo_wait(bo, false, false, true);
 	if (!bo->sync_obj) {
 
 		spin_lock(&glob->lru_lock);
@@ -567,8 +567,7 @@ static int ttm_bo_cleanup_refs(struct ttm_buffer_object *bo,
 
 retry:
 	spin_lock(&bdev->fence_lock);
-	ret = ttm_bo_wait(bo, false, interruptible, no_wait_gpu,
-			  TTM_USAGE_READWRITE);
+	ret = ttm_bo_wait(bo, false, interruptible, no_wait_gpu);
 	spin_unlock(&bdev->fence_lock);
 
 	if (unlikely(ret != 0))
@@ -727,8 +726,7 @@ static int ttm_bo_evict(struct ttm_buffer_object *bo, bool interruptible,
 	int ret = 0;
 
 	spin_lock(&bdev->fence_lock);
-	ret = ttm_bo_wait(bo, false, interruptible, no_wait_gpu,
-			  TTM_USAGE_READWRITE);
+	ret = ttm_bo_wait(bo, false, interruptible, no_wait_gpu);
 	spin_unlock(&bdev->fence_lock);
 
 	if (unlikely(ret != 0)) {
@@ -1075,8 +1073,7 @@ int ttm_bo_move_buffer(struct ttm_buffer_object *bo,
 	 * instead of doing it here.
 	 */
 	spin_lock(&bdev->fence_lock);
-	ret = ttm_bo_wait(bo, false, interruptible, no_wait_gpu,
-			  TTM_USAGE_READWRITE);
+	ret = ttm_bo_wait(bo, false, interruptible, no_wait_gpu);
 	spin_unlock(&bdev->fence_lock);
 	if (ret)
 		return ret;
@@ -1697,83 +1694,34 @@ out_unlock:
 	return ret;
 }
 
-static void ttm_bo_unref_sync_obj_locked(struct ttm_buffer_object *bo,
-					 void *sync_obj,
-					 void **extra_sync_obj)
-{
-	struct ttm_bo_device *bdev = bo->bdev;
-	struct ttm_bo_driver *driver = bdev->driver;
-	void *tmp_obj = NULL, *tmp_obj_read = NULL, *tmp_obj_write = NULL;
-
-	/* We must unref the sync obj wherever it's ref'd.
-	 * Note that if we unref bo->sync_obj, we can unref both the read
-	 * and write sync objs too, because they can't be newer than
-	 * bo->sync_obj, so they are no longer relevant. */
-	if (sync_obj == bo->sync_obj ||
-	    sync_obj == bo->sync_obj_read) {
-		tmp_obj_read = bo->sync_obj_read;
-		bo->sync_obj_read = NULL;
-	}
-	if (sync_obj == bo->sync_obj ||
-	    sync_obj == bo->sync_obj_write) {
-		tmp_obj_write = bo->sync_obj_write;
-		bo->sync_obj_write = NULL;
-	}
-	if (sync_obj == bo->sync_obj) {
-		tmp_obj = bo->sync_obj;
-		bo->sync_obj = NULL;
-	}
-
-	clear_bit(TTM_BO_PRIV_FLAG_MOVING, &bo->priv_flags);
-	spin_unlock(&bdev->fence_lock);
-	if (tmp_obj)
-		driver->sync_obj_unref(&tmp_obj);
-	if (tmp_obj_read)
-		driver->sync_obj_unref(&tmp_obj_read);
-	if (tmp_obj_write)
-		driver->sync_obj_unref(&tmp_obj_write);
-	if (extra_sync_obj)
-		driver->sync_obj_unref(extra_sync_obj);
-	spin_lock(&bdev->fence_lock);
-}
-
 int ttm_bo_wait(struct ttm_buffer_object *bo,
-		bool lazy, bool interruptible, bool no_wait,
-		enum ttm_buffer_usage usage)
+		bool lazy, bool interruptible, bool no_wait)
 {
 	struct ttm_bo_driver *driver = bo->bdev->driver;
 	struct ttm_bo_device *bdev = bo->bdev;
 	void *sync_obj;
 	void *sync_obj_arg;
 	int ret = 0;
-	void **bo_sync_obj;
 
-	switch (usage) {
-	case TTM_USAGE_READ:
-		bo_sync_obj = &bo->sync_obj_read;
-		break;
-	case TTM_USAGE_WRITE:
-		bo_sync_obj = &bo->sync_obj_write;
-		break;
-	case TTM_USAGE_READWRITE:
-	default:
-		bo_sync_obj = &bo->sync_obj;
-	}
-
-	if (likely(*bo_sync_obj == NULL))
+	if (likely(bo->sync_obj == NULL))
 		return 0;
 
-	while (*bo_sync_obj) {
+	while (bo->sync_obj) {
 
-		if (driver->sync_obj_signaled(*bo_sync_obj, bo->sync_obj_arg)) {
-			ttm_bo_unref_sync_obj_locked(bo, *bo_sync_obj, NULL);
+		if (driver->sync_obj_signaled(bo->sync_obj, bo->sync_obj_arg)) {
+			void *tmp_obj = bo->sync_obj;
+			bo->sync_obj = NULL;
+			clear_bit(TTM_BO_PRIV_FLAG_MOVING, &bo->priv_flags);
+			spin_unlock(&bdev->fence_lock);
+			driver->sync_obj_unref(&tmp_obj);
+			spin_lock(&bdev->fence_lock);
 			continue;
 		}
 
 		if (no_wait)
 			return -EBUSY;
 
-		sync_obj = driver->sync_obj_ref(*bo_sync_obj);
+		sync_obj = driver->sync_obj_ref(bo->sync_obj);
 		sync_obj_arg = bo->sync_obj_arg;
 		spin_unlock(&bdev->fence_lock);
 		ret = driver->sync_obj_wait(sync_obj, sync_obj_arg,
@@ -1784,9 +1732,16 @@ int ttm_bo_wait(struct ttm_buffer_object *bo,
 			return ret;
 		}
 		spin_lock(&bdev->fence_lock);
-		if (likely(*bo_sync_obj == sync_obj &&
+		if (likely(bo->sync_obj == sync_obj &&
 			   bo->sync_obj_arg == sync_obj_arg)) {
-			ttm_bo_unref_sync_obj_locked(bo, *bo_sync_obj, &sync_obj);
+			void *tmp_obj = bo->sync_obj;
+			bo->sync_obj = NULL;
+			clear_bit(TTM_BO_PRIV_FLAG_MOVING,
+				  &bo->priv_flags);
+			spin_unlock(&bdev->fence_lock);
+			driver->sync_obj_unref(&sync_obj);
+			driver->sync_obj_unref(&tmp_obj);
+			spin_lock(&bdev->fence_lock);
 		} else {
 			spin_unlock(&bdev->fence_lock);
 			driver->sync_obj_unref(&sync_obj);
@@ -1810,7 +1765,7 @@ int ttm_bo_synccpu_write_grab(struct ttm_buffer_object *bo, bool no_wait)
 	if (unlikely(ret != 0))
 		return ret;
 	spin_lock(&bdev->fence_lock);
-	ret = ttm_bo_wait(bo, false, true, no_wait, TTM_USAGE_READWRITE);
+	ret = ttm_bo_wait(bo, false, true, no_wait);
 	spin_unlock(&bdev->fence_lock);
 	if (likely(ret == 0))
 		atomic_inc(&bo->cpu_writers);
@@ -1884,7 +1839,7 @@ static int ttm_bo_swapout(struct ttm_mem_shrink *shrink)
 	 */
 
 	spin_lock(&bo->bdev->fence_lock);
-	ret = ttm_bo_wait(bo, false, false, false, TTM_USAGE_READWRITE);
+	ret = ttm_bo_wait(bo, false, false, false);
 	spin_unlock(&bo->bdev->fence_lock);
 
 	if (unlikely(ret != 0))
diff --git a/drivers/gpu/drm/ttm/ttm_bo_util.c b/drivers/gpu/drm/ttm/ttm_bo_util.c
index 6135f58169ce7c..ae3c6f5dd2b71a 100644
--- a/drivers/gpu/drm/ttm/ttm_bo_util.c
+++ b/drivers/gpu/drm/ttm/ttm_bo_util.c
@@ -436,8 +436,6 @@ static int ttm_buffer_object_transfer(struct ttm_buffer_object *bo,
 	atomic_set(&fbo->cpu_writers, 0);
 
 	fbo->sync_obj = driver->sync_obj_ref(bo->sync_obj);
-	fbo->sync_obj_read = driver->sync_obj_ref(bo->sync_obj_read);
-	fbo->sync_obj_write = driver->sync_obj_ref(bo->sync_obj_write);
 	kref_init(&fbo->list_kref);
 	kref_init(&fbo->kref);
 	fbo->destroy = &ttm_transfered_destroy;
@@ -620,30 +618,20 @@ int ttm_bo_move_accel_cleanup(struct ttm_buffer_object *bo,
 	struct ttm_mem_reg *old_mem = &bo->mem;
 	int ret;
 	struct ttm_buffer_object *ghost_obj;
-	void *tmp_obj = NULL, *tmp_obj_read = NULL, *tmp_obj_write = NULL;
+	void *tmp_obj = NULL;
 
 	spin_lock(&bdev->fence_lock);
-	if (bo->sync_obj)
+	if (bo->sync_obj) {
 		tmp_obj = bo->sync_obj;
-	if (bo->sync_obj_read)
-		tmp_obj_read = bo->sync_obj_read;
-	if (bo->sync_obj_write)
-		tmp_obj_write = bo->sync_obj_write;
-
+		bo->sync_obj = NULL;
+	}
 	bo->sync_obj = driver->sync_obj_ref(sync_obj);
-	bo->sync_obj_read = driver->sync_obj_ref(sync_obj);
-	bo->sync_obj_write = driver->sync_obj_ref(sync_obj);
 	bo->sync_obj_arg = sync_obj_arg;
 	if (evict) {
-		ret = ttm_bo_wait(bo, false, false, false,
-				  TTM_USAGE_READWRITE);
+		ret = ttm_bo_wait(bo, false, false, false);
 		spin_unlock(&bdev->fence_lock);
 		if (tmp_obj)
 			driver->sync_obj_unref(&tmp_obj);
-		if (tmp_obj_read)
-			driver->sync_obj_unref(&tmp_obj_read);
-		if (tmp_obj_write)
-			driver->sync_obj_unref(&tmp_obj_write);
 		if (ret)
 			return ret;
 
@@ -667,10 +655,6 @@ int ttm_bo_move_accel_cleanup(struct ttm_buffer_object *bo,
 		spin_unlock(&bdev->fence_lock);
 		if (tmp_obj)
 			driver->sync_obj_unref(&tmp_obj);
-		if (tmp_obj_read)
-			driver->sync_obj_unref(&tmp_obj_read);
-		if (tmp_obj_write)
-			driver->sync_obj_unref(&tmp_obj_write);
 
 		ret = ttm_buffer_object_transfer(bo, &ghost_obj);
 		if (ret)
diff --git a/drivers/gpu/drm/ttm/ttm_bo_vm.c b/drivers/gpu/drm/ttm/ttm_bo_vm.c
index ff1e26f4b094f8..221b924acebe27 100644
--- a/drivers/gpu/drm/ttm/ttm_bo_vm.c
+++ b/drivers/gpu/drm/ttm/ttm_bo_vm.c
@@ -122,7 +122,7 @@ static int ttm_bo_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 
 	spin_lock(&bdev->fence_lock);
 	if (test_bit(TTM_BO_PRIV_FLAG_MOVING, &bo->priv_flags)) {
-		ret = ttm_bo_wait(bo, false, true, false, TTM_USAGE_READWRITE);
+		ret = ttm_bo_wait(bo, false, true, false);
 		spin_unlock(&bdev->fence_lock);
 		if (unlikely(ret != 0)) {
 			retval = (ret != -ERESTARTSYS) ?
diff --git a/drivers/gpu/drm/ttm/ttm_execbuf_util.c b/drivers/gpu/drm/ttm/ttm_execbuf_util.c
index 36d111a882328a..3832fe10b4dffe 100644
--- a/drivers/gpu/drm/ttm/ttm_execbuf_util.c
+++ b/drivers/gpu/drm/ttm/ttm_execbuf_util.c
@@ -221,18 +221,8 @@ void ttm_eu_fence_buffer_objects(struct list_head *list, void *sync_obj)
 
 	list_for_each_entry(entry, list, head) {
 		bo = entry->bo;
-		entry->old_sync_obj_read = NULL;
-		entry->old_sync_obj_write = NULL;
 		entry->old_sync_obj = bo->sync_obj;
 		bo->sync_obj = driver->sync_obj_ref(sync_obj);
-		if (entry->usage & TTM_USAGE_READ) {
-			entry->old_sync_obj_read = bo->sync_obj_read;
-			bo->sync_obj_read = driver->sync_obj_ref(sync_obj);
-		}
-		if (entry->usage & TTM_USAGE_WRITE) {
-			entry->old_sync_obj_write = bo->sync_obj_write;
-			bo->sync_obj_write = driver->sync_obj_ref(sync_obj);
-		}
 		bo->sync_obj_arg = entry->new_sync_obj_arg;
 		ttm_bo_unreserve_locked(bo);
 		entry->reserved = false;
@@ -241,15 +231,8 @@ void ttm_eu_fence_buffer_objects(struct list_head *list, void *sync_obj)
 	spin_unlock(&bdev->fence_lock);
 
 	list_for_each_entry(entry, list, head) {
-		if (entry->old_sync_obj) {
+		if (entry->old_sync_obj)
 			driver->sync_obj_unref(&entry->old_sync_obj);
-		}
-		if (entry->old_sync_obj_read) {
-			driver->sync_obj_unref(&entry->old_sync_obj_read);
-		}
-		if (entry->old_sync_obj_write) {
-			driver->sync_obj_unref(&entry->old_sync_obj_write);
-		}
 	}
 }
 EXPORT_SYMBOL(ttm_eu_fence_buffer_objects);
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
index b8eb8cdcfb78ba..13afddc1f03444 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
@@ -244,7 +244,7 @@ static void vmw_dummy_query_bo_prepare(struct vmw_private *dev_priv)
 
 	ttm_bo_reserve(bo, false, false, false, 0);
 	spin_lock(&bdev->fence_lock);
-	ret = ttm_bo_wait(bo, false, false, false, TTM_USAGE_READWRITE);
+	ret = ttm_bo_wait(bo, false, false, false);
 	spin_unlock(&bdev->fence_lock);
 	if (unlikely(ret != 0))
 		(void) vmw_fallback_wait(dev_priv, false, true, 0, false,
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c b/drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c
index 28e1c35aec6f28..40932fbdac0f1a 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c
@@ -89,7 +89,6 @@ static int vmw_bo_to_validate_list(struct vmw_sw_context *sw_context,
 	if (unlikely(val_node == sw_context->cur_val_buf)) {
 		val_buf->new_sync_obj_arg = NULL;
 		val_buf->bo = ttm_bo_reference(bo);
-		val_buf->usage = TTM_USAGE_READWRITE;
 		list_add_tail(&val_buf->head, &sw_context->validate_nodes);
 		++sw_context->cur_val_buf;
 	}
diff --git a/include/drm/ttm/ttm_bo_api.h b/include/drm/ttm/ttm_bo_api.h
index da957bf3fe449e..42e34698518643 100644
--- a/include/drm/ttm/ttm_bo_api.h
+++ b/include/drm/ttm/ttm_bo_api.h
@@ -44,11 +44,6 @@ struct ttm_bo_device;
 
 struct drm_mm_node;
 
-enum ttm_buffer_usage {
-    TTM_USAGE_READ = 1,
-    TTM_USAGE_WRITE = 2,
-    TTM_USAGE_READWRITE = TTM_USAGE_READ | TTM_USAGE_WRITE
-};
 
 /**
  * struct ttm_placement
@@ -179,10 +174,7 @@ struct ttm_tt;
  * the bo_device::lru_lock.
  * @reserved: Deadlock-free lock used for synchronization state transitions.
  * @sync_obj_arg: Opaque argument to synchronization object function.
- * @sync_obj: Pointer to a synchronization object of a last read or write,
- * whichever is later.
- * @sync_obj_read: Pointer to a synchronization object of a last read.
- * @sync_obj_write: Pointer to a synchronization object of a last write.
+ * @sync_obj: Pointer to a synchronization object.
  * @priv_flags: Flags describing buffer object internal state.
  * @vm_rb: Rb node for the vm rb tree.
  * @vm_node: Address space manager node.
@@ -266,8 +258,6 @@ struct ttm_buffer_object {
 
 	void *sync_obj_arg;
 	void *sync_obj;
-	void *sync_obj_read;
-	void *sync_obj_write;
 	unsigned long priv_flags;
 
 	/**
@@ -335,7 +325,6 @@ ttm_bo_reference(struct ttm_buffer_object *bo)
  * @bo:  The buffer object.
  * @interruptible:  Use interruptible wait.
  * @no_wait:  Return immediately if buffer is busy.
- * @usage:  Whether to wait for the last read and/or the last write.
  *
  * This function must be called with the bo::mutex held, and makes
  * sure any previous rendering to the buffer is completed.
@@ -345,8 +334,7 @@ ttm_bo_reference(struct ttm_buffer_object *bo)
  * Returns -ERESTARTSYS if interrupted by a signal.
  */
 extern int ttm_bo_wait(struct ttm_buffer_object *bo, bool lazy,
-		       bool interruptible, bool no_wait,
-		       enum ttm_buffer_usage usage);
+		       bool interruptible, bool no_wait);
 /**
  * ttm_bo_validate
  *
diff --git a/include/drm/ttm/ttm_execbuf_util.h b/include/drm/ttm/ttm_execbuf_util.h
index 375f29902295d2..26cc7f9ffa411a 100644
--- a/include/drm/ttm/ttm_execbuf_util.h
+++ b/include/drm/ttm/ttm_execbuf_util.h
@@ -41,26 +41,20 @@
  * @bo:             refcounted buffer object pointer.
  * @new_sync_obj_arg: New sync_obj_arg for @bo, to be used once
  * adding a new sync object.
- * @usage           Indicates how @bo is used by the device.
  * @reserved:       Indicates whether @bo has been reserved for validation.
  * @removed:        Indicates whether @bo has been removed from lru lists.
  * @put_count:      Number of outstanding references on bo::list_kref.
  * @old_sync_obj:   Pointer to a sync object about to be unreferenced
- * @old_sync_obj_read: Pointer to a read sync object about to be unreferenced.
- * @old_sync_obj_write: Pointer to a write sync object about to be unreferenced.
  */
 
 struct ttm_validate_buffer {
 	struct list_head head;
 	struct ttm_buffer_object *bo;
 	void *new_sync_obj_arg;
-	enum ttm_buffer_usage usage;
 	bool reserved;
 	bool removed;
 	int put_count;
 	void *old_sync_obj;
-	void *old_sync_obj_read;
-	void *old_sync_obj_write;
 };
 
 /**