L4Re::Util::Ref_del_cap< T > Struct Template Reference

Automatic capability that implements automatic free and unmap+delete of the capability selector. More...

#include <cap_alloc>

Collaboration diagram for L4Re::Util::Ref_del_cap< T >:

Detailed Description

template<typename T>
struct L4Re::Util::Ref_del_cap< T >

Automatic capability that implements automatic free and unmap+delete of the capability selector.

Template Parameters

T	Type of the object that is referred by the capability.

This kind of automatic capability implements a counted reference to a capability selector. The capability shall be unmapped and freed when the reference count in the allocator goes to zero. The main difference to Ref_cap is that the unmap is done with the deletion flag enabled and this leads to the deletion of the object if the current task holds appropriate deletion rights.

Usage:

L4Re::Util::Ref_del_cap<L4Re::Dataspace>::Cap global_ds_cap;
 
{
  L4Re::Util::Ref_del_cap<L4Re::Dataspace>::Cap
    ds_cap(L4Re::Util::cap_alloc.alloc<L4Re::Dataspace>());
  // reference count for the allocated cap selector is now 1
 
  // use the dataspace cap
  L4Re::chksys(mem_alloc->alloc(4096, ds_cap.get()));
 
  global_ds_cap = ds_cap;
  // reference count is now 2
  ...
}
// reference count dropped to 1 (ds_cap is no longer existing).
...
global_ds_cap = L4_INVALID_CAP;
// reference count dropped to 0 (data space shall be deleted).

Definition at line 194 of file cap_alloc.

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The documentation for this struct was generated from the following file:

• l4/re/util/cap_alloc