| Function report | 
| Source Code: ipc\sem.c | Create Date:2022-07-28 16:45:14 | 
| Last Modify:2020-03-12 14:18:49 | Copyright©Brick | 
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| Annotation kernel can get tool activity | Download SCCT | Chinese | 
Name:If the task doesn't already have a undo_list, then allocate one* here. We guarantee there is only one thread using this undo list,* and current is THE ONE* If this allocation and assignment succeeds, but later
Proto:static inline int get_undo_list(struct sem_undo_list **undo_listp)
Type:int
Parameter:
| Type | Parameter | Name | 
|---|---|---|
| struct sem_undo_list ** | undo_listp | 
| 1837 | If Not undo_list Then | 
| 1838 | undo_list = kzalloc - allocate memory. The memory is set to zero.*@size: how many bytes of memory are required.*@flags: the type of memory to allocate (see kmalloc). | 
| 1841 | Process spin lock initialization( & lock) | 
| 1847 | undo_listp = undo_list | 
| 1848 | Return 0 | 
| Name | Describe | 
|---|---|
| find_alloc_undo | d_alloc_undo - lookup (and if not present create) undo array*@ns: namespace*@semid: semaphore array id* The function looks up (and if not present creates) the undo structure.* The size of the undo structure depends on the size of the semaphore | 
| copy_semundo | If CLONE_SYSVSEM is set, establish sharing of SEM_UNDO state between* parent and child tasks. | 
| Source code conversion tool public plug-in interface | X | 
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