Memory
Overview
Provides APIs for memory management.
@Syscap SystemCapability.CommonLibrary.PurgeableMemory
Since
10
Summary
Files
| Name | Description |
|---|---|
| purgeable_memory.h | Declares the APIs for managing purgeable memory at the native layer. File to include: <purgeable_memory/purgeable_memory.h> Library: libpurgeable_memory_ndk.z.so |
Types
| Name | Description |
|---|---|
| OH_PurgeableMemory | Defines the type name of the OH_PurgeableMemory data. |
| (*OH_PurgeableMemory_ModifyFunc) (void *, size_t, void *) | Defines the function for rebuilding purgeable memory data. |
Functions
| Name | Description |
|---|---|
| *OH_PurgeableMemory_Create (size_t size, OH_PurgeableMemory_ModifyFunc func, void *funcPara) | Creates a PurgeableMemory object. |
| OH_PurgeableMemory_Destroy (OH_PurgeableMemory *purgObj) | Destroys a PurgeableMemory object. |
| OH_PurgeableMemory_BeginRead (OH_PurgeableMemory *purgObj) | Starts a read operation on a PurgeableMemory object. If purgeable memory is reclaimed, the rebuilding function is called to rebuild it. |
| OH_PurgeableMemory_EndRead (OH_PurgeableMemory *purgObj) | Ends a read operation on a PurgeableMemory object. Now the system can reclaim purgeable memory. |
| OH_PurgeableMemory_BeginWrite (OH_PurgeableMemory *purgObj) | Begins a write operation on the PurgeableMemory object. If purgeable memory is reclaimed, the rebuilding function is called to rebuild it. |
| OH_PurgeableMemory_EndWrite (OH_PurgeableMemory *purgObj) | Ends a write operation on the PurgeableMemory object. Now the system can reclaim purgeable memory. |
| OH_PurgeableMemory_GetContent (OH_PurgeableMemory *purgObj) | Obtains the memory data of a PurgeableMemory object. |
| OH_PurgeableMemory_ContentSize (OH_PurgeableMemory *purgObj) | Obtains the memory data size of a PurgeableMemory object. |
| OH_PurgeableMemory_AppendModify (OH_PurgeableMemory *purgObj, OH_PurgeableMemory_ModifyFunc func, void *funcPara) | Adds a function for modifying a PurgeableMemory object. |
Type Description
OH_PurgeableMemory
typedef struct PurgMem OH_PurgeableMemory
Description
Defines the type name of the OH_PurgeableMemory data.
Since
10
OH_PurgeableMemory_ModifyFunc
typedef bool(* OH_PurgeableMemory_ModifyFunc) (void *, size_t, void *)
Description
Defines the function for rebuilding purgeable memory data.
Parameters
| Name | Description |
|---|---|
| void * | Pointer to the address of purgeable memory. |
| size_t | Size of the memory data to rebuild. |
| void * | Pointer to the parameters used for rebuilding. |
Returns
Returns a success message if the operation is successful; returns a failure message otherwise.
Since
10
Function Description
OH_PurgeableMemory_AppendModify()
bool OH_PurgeableMemory_AppendModify (OH_PurgeableMemory * purgObj, OH_PurgeableMemory_ModifyFunc func, void * funcPara )
Description
Adds a function for modifying a PurgeableMemory object.
Parameters
| Name | Description |
|---|---|
| purgObj | Pointer to the PurgeableMemory object. |
| func | Function pointer to the modify function, which is used for further modification after the purgeable memory data is rebuilt. |
| funcPara | Pointer to the parameters of the modify function. |
Returns
Returns a success message if the operation is successful; returns a failure message otherwise.
Since
10
OH_PurgeableMemory_BeginRead()
bool OH_PurgeableMemory_BeginRead (OH_PurgeableMemory * purgObj)
Description
Starts a read operation on a PurgeableMemory object. If purgeable memory is reclaimed, the rebuilding function is called to rebuild it.
Parameters
| Name | Description |
|---|---|
| purgObj | Pointer to the PurgeableMemory object. |
Returns
Returns a success message if the purgeable memory data is ready; returns a failure message if purgeable memory has been reclaimed and fails to be rebuilt.
Since
10
OH_PurgeableMemory_BeginWrite()
bool OH_PurgeableMemory_BeginWrite (OH_PurgeableMemory * purgObj)
Description
Begins a write operation on the PurgeableMemory object. If purgeable memory is reclaimed, the rebuilding function is called to rebuild it.
Parameters
| Name | Description |
|---|---|
| purgObj | Pointer to the PurgeableMemory object. |
Returns
Returns a success message if the purgeable memory data is ready; returns a failure message if purgeable memory has been reclaimed and fails to be rebuilt.
Since
10
OH_PurgeableMemory_ContentSize()
size_t OH_PurgeableMemory_ContentSize (OH_PurgeableMemory * purgObj)
Description
Obtains the memory data size of a PurgeableMemory object.
Parameters
| Name | Description |
|---|---|
| purgObj | Pointer to the PurgeableMemory object. |
Returns
Returns the memory data size.
Since
10
OH_PurgeableMemory_Create()
OH_PurgeableMemory* OH_PurgeableMemory_Create (size_t size, OH_PurgeableMemory_ModifyFunc func, void * funcPara )
Description
Creates a PurgeableMemory object.
Parameters
| Name | Description |
|---|---|
| size | Size of the PurgeableMemory object. |
| func | Function pointer to the rebuilding function, which is used to restore the reclaimed purgeable memory data. |
| funcPara | Pointer to the parameters of the rebuilding function. |
Returns
Returns the PurgeableMemory object.
Since
10
OH_PurgeableMemory_Destroy()
bool OH_PurgeableMemory_Destroy (OH_PurgeableMemory * purgObj)
Description
Destroys a PurgeableMemory object.
Parameters
| Name | Description |
|---|---|
| purgObj | Pointer to the PurgeableMemory object. |
Returns
Returns a success message if the operation is successful; returns a failure message otherwise. If no value is passed, a failure message is returned. If a success message is returned, the value of purgObj will be cleared to avoid Use-After-Free (UAF).
Since
10
OH_PurgeableMemory_EndRead()
void OH_PurgeableMemory_EndRead (OH_PurgeableMemory * purgObj)
Description
Ends a read operation on a PurgeableMemory object. Now the system can reclaim purgeable memory.
Parameters
| Name | Description |
|---|---|
| purgObj | Pointer to the PurgeableMemory object. |
Since
10
OH_PurgeableMemory_EndWrite()
void OH_PurgeableMemory_EndWrite (OH_PurgeableMemory * purgObj)
Description
Ends a write operation on the PurgeableMemory object. Now the system can reclaim purgeable memory.
Parameters
| Name | Description |
|---|---|
| purgObj | Pointer to the PurgeableMemory object. |
Since
10
OH_PurgeableMemory_GetContent()
void* OH_PurgeableMemory_GetContent (OH_PurgeableMemory * purgObj)
Description
Obtains the memory data of a PurgeableMemory object.
Parameters
| Name | Description |
|---|---|
| purgObj | Pointer to the PurgeableMemory object. |
Returns
Returns the pointer to the purgeable memory address.
Since
10