 |
L4Re Operating System Framework
Interface and Usage Documentation
|
|
L4Re Operating System Framework
Interface and Usage Documentation
|
Memory allocation interface. More...
#include <mem_alloc>
Inheritance diagram for L4Re::Mem_alloc: Collaboration diagram for L4Re::Mem_alloc:Public Types | |
| enum | Mem_alloc_flags { Continuous = 0x01 , Pinned = 0x02 , Super_pages = 0x04 , Fixed_paddr = 0x08 } |
| Flags for the allocator. More... | |
Public Member Functions | |
| long | alloc (long size, L4::Cap< Dataspace > mem, unsigned long flags=0, unsigned long align=0, l4_addr_t paddr=0) const noexcept |
| Allocate anonymous memory. | |
| Public Member Functions inherited from L4::Factory | |
| S | create (Cap< void > target, long obj, l4_utcb_t *utcb=l4_utcb()) noexcept |
| Generic create call to the factory. | |
| template<typename OBJ > | |
| S | create (Cap< OBJ > target, l4_utcb_t *utcb=l4_utcb()) noexcept |
| Create call for typed capabilities. | |
| l4_msgtag_t | create_task (Cap< Task > const &target_cap, l4_fpage_t *utcb_area, l4_utcb_t *utcb=l4_utcb()) noexcept |
| Create a new task. | |
| l4_msgtag_t | create_factory (Cap< Factory > const &target_cap, unsigned long limit, l4_utcb_t *utcb=l4_utcb()) noexcept |
| Create a new factory. | |
| l4_msgtag_t | create_gate (Cap< void > const &target_cap, Cap< Thread > const &thread_cap, l4_umword_t label, l4_utcb_t *utcb=l4_utcb()) noexcept |
| Create a new IPC gate. | |
| Public Member Functions inherited from L4::Kobject | |
| l4_msgtag_t | dec_refcnt (l4_mword_t diff, l4_utcb_t *utcb=l4_utcb()) |
| Decrement the in kernel reference counter for the object. | |
Additional Inherited Members | |
| Protected Types inherited from L4::Kobject_t< Mem_alloc, L4::Factory, L4::PROTO_EMPTY > | |
| typedef Mem_alloc | Class |
| The target interface type (inheriting from Kobject_t) | |
| typedef Typeid::Iface< PROTO, Mem_alloc > | __Iface |
| The interface description for the derived class. | |
| typedef Typeid::Merge_list< Typeid::Iface_list< __Iface >, typename Base::__Iface_list > | __Iface_list |
| The list of all RPC interfaces provided directly or through inheritance. | |
| Protected Types inherited from L4::Kobject_t< Factory, Kobject, L4_PROTO_FACTORY > | |
| typedef Factory | Class |
| The target interface type (inheriting from Kobject_t) | |
| typedef Typeid::Iface< PROTO, Factory > | __Iface |
| The interface description for the derived class. | |
| typedef Typeid::Merge_list< Typeid::Iface_list< __Iface >, typename Base::__Iface_list > | __Iface_list |
| The list of all RPC interfaces provided directly or through inheritance. | |
| Protected Member Functions inherited from L4::Kobject_t< Mem_alloc, L4::Factory, L4::PROTO_EMPTY > | |
| L4::Cap< Class > | c () const noexcept |
| Get the capability to ourselves. | |
| Protected Member Functions inherited from L4::Kobject_t< Factory, Kobject, L4_PROTO_FACTORY > | |
| L4::Cap< Class > | c () const noexcept |
| Get the capability to ourselves. | |
| Protected Member Functions inherited from L4::Kobject | |
| l4_cap_idx_t | cap () const noexcept |
| Return capability selector. | |
| Static Protected Member Functions inherited from L4::Kobject_t< Mem_alloc, L4::Factory, L4::PROTO_EMPTY > | |
| static void | __check_protocols__ () noexcept |
| Helper to check for protocol conflicts. | |
| Static Protected Member Functions inherited from L4::Kobject_t< Factory, Kobject, L4_PROTO_FACTORY > | |
| static void | __check_protocols__ () noexcept |
| Helper to check for protocol conflicts. | |
Memory allocation interface.
The memory-allocator API is the basic API to allocate memory from the L4Re subsystem. The memory is allocated in terms of dataspaces (see L4Re::Dataspace). The provided dataspaces have at least the property that data written to such a dataspace is available as long as the dataspace is not freed or the data is not overwritten. In particular, the memory backing a dataspace from an allocator need not be allocated instantly, but may be allocated lazily on demand.
A memory allocator can provide dataspaces with additional properties, such as physically contiguous memory, pre-allocated memory, or pinned memory. To request memory with an additional property the L4Re::Mem_alloc::alloc() method provides a flags parameter. If the concrete implementation of a memory allocator does not support or allow allocation of memory with a certain property, the allocation may be refused.
Flags for the allocator.
They describe requested properties of the allocated memory. Support of these properties by the dataspace provider is optional.
| Enumerator | |
|---|---|
| Continuous | Allocate physically contiguous memory. |
| Pinned | Deprecated, use L4Re::Dma_space instead. |
| Super_pages | Allocate super pages. |
| Fixed_paddr | Allocate at fixed physical address. Only honored on no-MMU systems. Will fail on MMU systems. |
|
noexcept |
Allocate anonymous memory.
| size | Size in bytes to be requested. Allocation granularity is (super)pages, however, the allocator will store the byte-granular given size as the size of the dataspace and consecutively will use this byte-granular size for servicing the dataspace. Allocators may optionally also implement a maximum allocation strategy: if size is a negative value and flags set the Mem_alloc_flags::Continuous bit, the allocator tries to allocate as much memory as possible leaving an amount of at least -size bytes within the associated quota. | |
| [out] | mem | Capability slot where the capability to the dataspace is received. |
| flags | Special dataspace properties, see Mem_alloc_flags | |
| align | Log2 alignment of dataspace if supported by allocator, will be at least L4_PAGESHIFT, with Super_pages flag set at least L4_SUPERPAGESHIFT | |
| paddr | The physical address where the dataspace should be allocated if Mem_alloc_flags::Fixed flag is set. |
| 0 | Success |
| -L4_ERANGE | Given size not supported. |
| -L4_ENOMEM | Not enough memory available. |
| <0 | IPC error |
Definition at line 35 of file mem_alloc_impl.h.
References l4_error().
Here is the call graph for this function:
1.9.8