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RTEMS
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The Partition Manager provides facilities to dynamically allocate memory in fixed-size units. More...
Files | |
| file | part.h |
| This header file defines the Partition Manager API. | |
Macros | |
| #define | RTEMS_PARTITION_ALIGNMENT CPU_SIZEOF_POINTER |
| This constant defines the minimum alignment of a partition buffer in bytes. More... | |
Functions | |
| rtems_status_code | rtems_partition_create (rtems_name name, void *starting_address, uintptr_t length, size_t buffer_size, rtems_attribute attribute_set, rtems_id *id) |
| Creates a partition. More... | |
| rtems_status_code | rtems_partition_delete (rtems_id id) |
| Deletes the specified partition. More... | |
| rtems_status_code | rtems_partition_get_buffer (rtems_id id, void **buffer) |
| Tries to get a buffer from the specified partition. More... | |
| rtems_status_code | rtems_partition_ident (rtems_name name, uint32_t node, rtems_id *id) |
| Identifies a partition object by the specified object name. More... | |
| rtems_status_code | rtems_partition_return_buffer (rtems_id id, void *buffer) |
| Returns a buffer to the specified partition. More... | |
The Partition Manager provides facilities to dynamically allocate memory in fixed-size units.
| #define RTEMS_PARTITION_ALIGNMENT CPU_SIZEOF_POINTER |
This constant defines the minimum alignment of a partition buffer in bytes.
Use it with RTEMS_ALIGNED() to define the alignment of partition buffer types or statically allocated partition buffer areas.
| rtems_status_code rtems_partition_create | ( | rtems_name | name, |
| void * | starting_address, | ||
| uintptr_t | length, | ||
| size_t | buffer_size, | ||
| rtems_attribute | attribute_set, | ||
| rtems_id * | id | ||
| ) |
Creates a partition.
This directive creates a partition of fixed size buffers from a physically contiguous memory space which starts at starting_address and is length bytes in size. Each allocated buffer is to be of buffer_size in bytes. The assigned partition identifier is returned in id. This partition identifier is used to access the partition with other partition related directives.
The attribute set is built through a bitwise or of the attribute constants described below. Attributes not mentioned below are not evaluated by this directive and have no effect.
The partition can have local or global scope in a multiprocessing network (this attribute does not refer to SMP systems).
This directive may cause the calling task to be preempted due to an obtain and release of the object allocator mutex.
The partition buffer area specified by the starting_address must be properly aligned. It must be possible to directly store target architecture pointers and also the user data. For example, if the user data contains some long double or vector data types, the partition buffer area and the buffer size must take the alignment of these types into account which is usually larger than the pointer alignment. A cache line alignment may be also a factor. Use RTEMS_PARTITION_ALIGNMENT to specify the minimum alignment of a partition buffer type.
The buffer_size parameter must be an integral multiple of the pointer size on the target architecture. Additionally, buffer_size must be large enough to hold two pointers on the target architecture. This is required for RTEMS to manage the buffers when they are free.
For control and maintenance of the partition, RTEMS allocates a PTCB from the local PTCB free pool and initializes it. Memory from the partition buffer area is not used by RTEMS to store the PTCB.
The PTCB for a global partition is allocated on the local node. Partitions should not be made global unless remote tasks must interact with the partition. This is to avoid the overhead incurred by the creation of a global partition. When a global partition is created, the partition's name and identifier must be transmitted to every node in the system for insertion in the local copy of the global object table.
The total number of global objects, including partitions, is limited by the value of the CONFIGURE_MP_MAXIMUM_GLOBAL_OBJECTS application configuration option.
| name | is the name of the partition. |
| starting_address | is the starting address of the buffer area used by the partition. |
| length | is the length in bytes of the buffer area used by the partition. |
| buffer_size | is the size in bytes of a buffer managed by the partition. |
| attribute_set | is the attribute set of the partition. |
| id | is the pointer to an object identifier variable. The identifier of the created partition object will be stored in this variable, in case of a successful operation. |
| RTEMS_SUCCESSFUL | The requested operation was successful. |
| RTEMS_INVALID_NAME | The partition name was invalid. |
| RTEMS_INVALID_ADDRESS | The id parameter was NULL. |
| RTEMS_INVALID_SIZE | The length parameter was 0. |
| RTEMS_INVALID_SIZE | The buffer_size parameter was 0. |
| RTEMS_INVALID_SIZE | The length parameter was less than the buffer_size parameter. |
| RTEMS_INVALID_SIZE | The buffer_size parameter was not an integral multiple of the pointer size. |
| RTEMS_INVALID_SIZE | The buffer_size parameter was less than two times the pointer size. |
| RTEMS_INVALID_ADDRESS | The starting_address parameter was not on a pointer size boundary. |
Definition at line 30 of file partcreate.c.
| rtems_status_code rtems_partition_delete | ( | rtems_id | id | ) |
Deletes the specified partition.
null This directive deletes the partition specified by the id parameter. The partition cannot be deleted if any of its buffers are still allocated. The PTCB for the deleted partition is reclaimed by RTEMS.
This directive may cause the calling task to be preempted due to an obtain and release of the object allocator mutex.
The calling task does not have to be the task that created the partition. Any local task that knows the partition identifier can delete the partition.
When a global partition is deleted, the partition identifier must be transmitted to every node in the system for deletion from the local copy of the global object table.
The partition must reside on the local node, even if the partition was created with the RTEMS_GLOBAL attribute.
| id | is the partition identifier. |
| RTEMS_SUCCESSFUL | The requested operation was successful. |
| RTEMS_INVALID_ID | There was no partition with the specified identifier. |
| RTEMS_ILLEGAL_ON_REMOTE_OBJECT | The partition resided on a remote node. |
| RTEMS_RESOURCE_IN_USE | There were buffers of the partition still in use. |
Definition at line 24 of file partdelete.c.
| rtems_status_code rtems_partition_get_buffer | ( | rtems_id | id, |
| void ** | buffer | ||
| ) |
Tries to get a buffer from the specified partition.
This directive allows a buffer to be obtained from the partition specified in the id parameter. The address of the allocated buffer is returned through the buffer parameter.
This directive will not cause the running task to be preempted.
All buffers begin on a four byte boundary.
A task cannot wait on a buffer to become available.
Getting a buffer from a global partition which does not reside on the local node will generate a request telling the remote node to allocate a buffer from the specified partition.
| id | is the partition identifier. | |
| [out] | buffer | is the pointer to a buffer pointer variable. The pointer to the allocated buffer will be stored in this variable, in case of a successful operation. |
| RTEMS_SUCCESSFUL | The requested operation was successful. |
| RTEMS_INVALID_ID | There was no partition with the specified identifier. |
| RTEMS_INVALID_ADDRESS | The buffer parameter was NULL. |
| RTEMS_UNSATISFIED | There was no free buffer available to return. |
Definition at line 23 of file partgetbuffer.c.
| rtems_status_code rtems_partition_ident | ( | rtems_name | name, |
| uint32_t | node, | ||
| rtems_id * | id | ||
| ) |
Identifies a partition object by the specified object name.
This directive obtains the partition identifier associated with the partition name specified in name.
The node to search is specified in node. It shall be
If the partition name is not unique, then the partition identifier will match the first partition with that name in the search order. However, this partition identifier is not guaranteed to correspond to the desired partition. The partition identifier is used with other partition related directives to access the partition.
If node is RTEMS_SEARCH_ALL_NODES, all nodes are searched with the local node being searched first. All other nodes are searched with the lowest numbered node searched first.
If node is a valid node number which does not represent the local node, then only the partitions exported by the designated node are searched.
This directive does not generate activity on remote nodes. It accesses only the local copy of the global object table.
| name | is the object name to look up. | |
| node | is the node or node set to search for a matching object. | |
| [out] | id | is the pointer to an object identifier variable. The object identifier of an object with the specified name will be stored in this variable, in case of a successful operation. |
| RTEMS_SUCCESSFUL | The requested operation was successful. |
| RTEMS_INVALID_ADDRESS | The id parameter was NULL. |
| RTEMS_INVALID_NAME | The name parameter was 0. |
| RTEMS_INVALID_NAME | There was no object with the specified name on the specified nodes. |
| RTEMS_INVALID_NODE | In multiprocessing configurations, the specified node was invalid. |
Definition at line 44 of file partident.c.
| rtems_status_code rtems_partition_return_buffer | ( | rtems_id | id, |
| void * | buffer | ||
| ) |
Returns a buffer to the specified partition.
This directive returns the buffer specified by buffer to the partition specified by id.
This directive will not cause the running task to be preempted.
Returning a buffer to a global partition which does not reside on the local node will generate a request telling the remote node to return the buffer to the specified partition.
Returning a buffer multiple times is an error. It will corrupt the internal state of the partition.
| id | is the partition identifier. |
| buffer | is the pointer to the buffer to return. |
| RTEMS_SUCCESSFUL | The requested operation was successful. |
| RTEMS_INVALID_ID | There was no partition with the specified identifier. |
| RTEMS_INVALID_ADDRESS | The buffer referenced by buffer was no in the specified partition. |
Definition at line 19 of file partreturnbuffer.c.
1.8.14