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foc/l4/pkg/l4re-core/l4sys/include/task
2018-06-25 15:44:17 +02:00

223 lines
8.3 KiB
C++

// vi:set ft=cpp: -*- Mode: C++ -*-
/**
* \file
* Common task related definitions.
*/
/*
* (c) 2008-2009 Adam Lackorzynski <adam@os.inf.tu-dresden.de>,
* Alexander Warg <warg@os.inf.tu-dresden.de>
* economic rights: Technische Universität Dresden (Germany)
*
* This file is part of TUD:OS and distributed under the terms of the
* GNU General Public License 2.
* Please see the COPYING-GPL-2 file for details.
*
* As a special exception, you may use this file as part of a free software
* library without restriction. Specifically, if other files instantiate
* templates or use macros or inline functions from this file, or you compile
* this file and link it with other files to produce an executable, this
* file does not by itself cause the resulting executable to be covered by
* the GNU General Public License. This exception does not however
* invalidate any other reasons why the executable file might be covered by
* the GNU General Public License.
*/
#pragma once
#include <l4/sys/task.h>
#include <l4/sys/capability>
namespace L4 {
/**
* C++ interface of the Task kernel object.
*
* The L4::Task class represents a combination of the address spaces provided
* by the L4Re micro kernel. A task consists of at least a memory address space
* and an object address space. On IA32 there is also an IO-port address space
* associated with an L4::Task.
*
* L4::Task objects are created using the L4::Factory interface.
* \includefile{l4/sys/task}
*/
class Task :
public Kobject_t<Task, Kobject, L4_PROTO_TASK,
Type_info::Demand_t<2> >
{
public:
/**
* Map resources available in the source task to a destination task.
*
* \param src_task Capability selector of the source task.
* \param snd_fpage Send flexpage that describes an area in the address
* space or object space of the source task.
* \param snd_base Send base that describes an offset in the receive window
* of the destination task. The lower bits contain additional
* map control flags.
* \param utcb UTCB pointer of the calling thread.
*
* \return Syscall return tag.
*
* This method allows for asynchronous rights delegation from one task to
* another. It can be used to share memory as well as to delegate access to
* objects.
* The destination task is the task referenced by the capability invoking map
* and the receive window is the whole address space of said task.
*/
l4_msgtag_t map(Cap<Task> const &src_task,
l4_fpage_t const &snd_fpage, l4_addr_t snd_base,
l4_utcb_t *utcb = l4_utcb()) throw()
{ return l4_task_map_u(cap(), src_task.cap(), snd_fpage, snd_base, utcb); }
/**
* Revoke rights from the task.
*
* \param fpage Flexpage that describes an area in the address space or
* object space of `this` task
* \param map_mask Unmap mask, see #l4_unmap_flags_t
* \param utcb UTCB pointer of the calling thread.
*
* \return Syscall return tag
*
* This method allows to revoke rights from the destination task and from all the
* tasks that got the rights delegated from that task (i.e., this operation
* does a recursive rights revocation).
*
* \note If the capability possesses delete rights or if it is the last
* capability pointing to the object, calling this function might
* destroy the object itself.
*/
l4_msgtag_t unmap(l4_fpage_t const &fpage,
l4_umword_t map_mask,
l4_utcb_t *utcb = l4_utcb()) throw()
{ return l4_task_unmap_u(cap(), fpage, map_mask, utcb); }
/**
* Revoke rights from a task.
*
* \param fpages An array of flexpages. Each item describes an area in
* the address or object space of `this` task.
* \param num_fpages Number of fpages in the `fpages` array.
* \param map_mask Unmap mask, see #l4_unmap_flags_t.
* \param utcb UTCB pointer of the calling thread.
*
* This method allows to revoke rights from the destination task and from all
* the tasks that got the rights delegated from that task (i.e., this
* operation does a recursive rights revocation).
*
* \pre The caller needs to take care that `num_fpages` is not bigger
* than L4_UTCB_GENERIC_DATA_SIZE - 2.
*
* \note If the capability possesses delete rights or if it is the last
* capability pointing to the object, calling this function might
* destroy the object itself.
*/
l4_msgtag_t unmap_batch(l4_fpage_t const *fpages,
unsigned num_fpages,
l4_umword_t map_mask,
l4_utcb_t *utcb = l4_utcb()) throw()
{ return l4_task_unmap_batch_u(cap(), fpages, num_fpages, map_mask, utcb); }
/**
* Release capability and delete object.
*
* \param obj Capability selector of the object to delete.
* \param utcb UTCB pointer of the calling thread.
*
* \return Syscall return tag
*
* The object will be deleted if the `obj` has sufficient rights. No error
* will be reported if the rights are insufficient, however, the capability
* is removed in all cases.
*/
l4_msgtag_t delete_obj(L4::Cap<void> obj,
l4_utcb_t *utcb = l4_utcb()) throw()
{ return l4_task_delete_obj_u(cap(), obj.cap(), utcb); }
/**
* Release capability.
*
* \param cap Capability selector to release.
* \param utcb UTCB pointer of the calling thread.
*
* \return Syscall return tag.
*
* This operation unmaps the capability from `this` task.
*/
l4_msgtag_t release_cap(L4::Cap<void> cap,
l4_utcb_t *utcb = l4_utcb()) throw()
{ return l4_task_release_cap_u(this->cap(), cap.cap(), utcb); }
/**
* Check whether a capability is present (refers to an object).
*
* \param cap Capability to check for presence.
* \utcb{utcb}
*
* \retval tag.label() > 0 Capability is present (refers to an object).
* \retval tag.label() == 0 No capability present (void object).
*
* A capability is considered present when it refers to an existing
* kernel object.
*/
l4_msgtag_t cap_valid(Cap<void> const &cap,
l4_utcb_t *utcb = l4_utcb()) throw()
{ return l4_task_cap_valid_u(this->cap(), cap.cap(), utcb); }
/**
* Test whether a capability has child mappings (in another task).
*
* \param cap Capability selector to look up in the destination task.
* \param utcb UTCB pointer of the calling thread.
*
* \retval tag.label() = 1: The capability has at least on child mapping in
* another task.
* \retval tag.label() = 0: No child mappings.
*
* \deprecated Do not use. Undetermined future, might be removed.
*/
l4_msgtag_t cap_has_child(Cap<void> const &cap,
l4_utcb_t *utcb = l4_utcb()) throw()
L4_DEPRECATED("Do not use. Future uncertain.")
{ return l4_task_cap_has_child_u(this->cap(), cap.cap(), utcb); }
/**
* Test whether two capabilities point to the same object with the same
* rights.
*
* \param cap_a First capability selector to compare.
* \param cap_b Second capability selector to compare.
* \param utcb Optional: UTCB pointer of the calling thread.
*
* \retval tag.label() = 1: `cap_a` and `cap_b` point to the same object.
* \retval tag.label() = 0: The two caps do **not** point to the same
* object.
*/
l4_msgtag_t cap_equal(Cap<void> const &cap_a,
Cap<void> const &cap_b,
l4_utcb_t *utcb = l4_utcb()) throw()
{ return l4_task_cap_equal_u(cap(), cap_a.cap(), cap_b.cap(), utcb); }
/**
* Add kernel-user memory.
*
* \param fpage Flexpage describing the virtual area the memory goes to.
* \param utcb UTCP pointer of the calling thread.
*
* \note
* The amount of kernel-user memory that can be allocated at once is limited
* by the used kernel implementation. The minimum allocatable amount is one
* page (`L4_PAGESIZE`). A portable implementation should not depend on
* allocations greater than 16KiB to succeed.
*
* \return Syscall return tag
*/
l4_msgtag_t add_ku_mem(l4_fpage_t const &fpage,
l4_utcb_t *utcb = l4_utcb()) throw()
{ return l4_task_add_ku_mem_u(cap(), fpage, utcb); }
};
}