/*
* \brief CPU (processing time) manager session interface
* \author Christian Helmuth
* \date 2006-06-27
*
* :Question:
*
* Why are thread operations not methods of the thread but
* methods of the CPU session?
*
* :Answer:
*
* This enables the CPU session to impose policies on thread
* operations. These policies are based on the session
* construction arguments. If thread operations would be
* provided as thread methods, Thread would need to consult
* its container object (its CPU session) about the authorization
* of each operation and, thereby, would introduce a circular
* dependency between CPU session and Thread.
*/
/*
* Copyright (C) 2006-2013 Genode Labs GmbH
*
* This file is part of the Genode OS framework, which is distributed
* under the terms of the GNU General Public License version 2.
*/
#ifndef _INCLUDE__CPU_SESSION__CPU_SESSION_H_
#define _INCLUDE__CPU_SESSION__CPU_SESSION_H_
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
namespace Genode {
struct Cpu_session : Session
{
/*********************
** Exception types **
*********************/
class Thread_creation_failed : public Exception { };
class State_access_failed : public Exception { };
class Out_of_metadata : public Exception { };
static const char *service_name() { return "CPU"; }
enum { THREAD_NAME_LEN = 48 };
enum { PRIORITY_LIMIT = 1 << 16 };
enum { DEFAULT_PRIORITY = 0 };
typedef Rpc_in_buffer Name;
virtual ~Cpu_session() { }
/**
* Create a new thread
*
* \param name name for the thread
* \param utcb Base of the UTCB that will be used by the thread
* \return capability representing the new thread
* \throw Thread_creation_failed
* \throw Out_of_metadata
*/
virtual Thread_capability create_thread(Name const &name,
addr_t utcb = 0) = 0;
/**
* Get dataspace of the UTCB that is used by the specified thread
*/
virtual Ram_dataspace_capability utcb(Thread_capability thread) = 0;
/**
* Kill an existing thread
*
* \param thread capability of the thread to kill
*/
virtual void kill_thread(Thread_capability thread) = 0;
/**
* Set paging capabilities for thread
*
* \param thread thread to configure
* \param pager capability used to propagate page faults
*/
virtual int set_pager(Thread_capability thread,
Pager_capability pager) = 0;
/**
* Modify instruction and stack pointer of thread - start the
* thread
*
* \param thread thread to start
* \param ip initial instruction pointer
* \param sp initial stack pointer
*
* \return 0 on success
*/
virtual int start(Thread_capability thread, addr_t ip, addr_t sp) = 0;
/**
* Pause the specified thread
*
* After calling this function, the execution of the thread can be
* continued by calling 'resume'.
*/
virtual void pause(Thread_capability thread) = 0;
/**
* Resume the specified thread
*/
virtual void resume(Thread_capability thread) = 0;
/**
* Cancel a currently blocking operation
*
* \param thread thread to unblock
*/
virtual void cancel_blocking(Thread_capability thread) = 0;
/**
* Get the current state of a specific thread
*
* \param thread targeted thread
* \return state of the targeted thread
* \throw State_access_failed
*/
virtual Thread_state state(Thread_capability thread) = 0;
/**
* Override the current state of a specific thread
*
* \param thread targeted thread
* \param state state that shall be applied
* \throw State_access_failed
*/
virtual void state(Thread_capability thread,
Thread_state const &state) = 0;
/**
* Register signal handler for exceptions of the specified thread
*
* If 'thread' is an invalid capability, the default exception
* handler for the CPU session is set. This handler is used for
* all threads that have no explicitly installed exception handler.
* The new default signal handler will take effect for threads
* created after the call.
*
* On Linux, this exception is delivered when the process triggers
* a SIGCHLD. On other platforms, this exception is delivered on
* the occurrence of CPU exceptions such as division by zero.
*/
virtual void exception_handler(Thread_capability thread,
Signal_context_capability handler) = 0;
/**
* Enable/disable single stepping for specified thread.
*
* Since this functions is currently supported by a small number of
* platforms, we provide a default implementation
*
* \param thread thread to set into single step mode
* \param enable true = enable single-step mode; false = disable
*/
virtual void single_step(Thread_capability, bool) {}
/**
* Return affinity space of CPU nodes available to the CPU session
*
* The dimension of the affinity space as returned by this function
* represent the physical CPUs that are available.
*/
virtual Affinity::Space affinity_space() const = 0;
/**
* Define affinity of thread to one or multiple CPU nodes
*
* In the normal case, a thread is assigned to a single CPU.
* Specifying more than one CPU node is supposed to principally
* allow a CPU service to balance the load of threads among
* multiple CPUs.
*/
virtual void affinity(Thread_capability thread,
Affinity::Location affinity) = 0;
/**
* Translate generic priority value to kernel-specific priority levels
*
* \param pf_prio_limit maximum priority used for the kernel, must
* be power of 2
* \param prio generic priority value as used by the CPU
* session interface
* \param inverse order of platform priorities, if true
* 'pf_prio_limit' corresponds to the highest
* priority, otherwise it refers to the
* lowest priority.
* \return platform-specific priority value
*/
static unsigned scale_priority(unsigned pf_prio_limit, unsigned prio,
bool inverse = true)
{
/* if no priorities are used, use the platform priority limit */
if (prio == 0) return pf_prio_limit;
/*
* Generic priority values are (0 is highest, 'PRIORITY_LIMIT'
* is lowest. On platforms where priority levels are defined
* the other way round, we have to invert the priority value.
*/
prio = inverse ? Cpu_session::PRIORITY_LIMIT - prio : prio;
/* scale value to platform priority range 0..pf_prio_limit */
return (prio*pf_prio_limit)/Cpu_session::PRIORITY_LIMIT;
}
/*********************
** RPC declaration **
*********************/
GENODE_RPC_THROW(Rpc_create_thread, Thread_capability, create_thread,
GENODE_TYPE_LIST(Thread_creation_failed, Out_of_metadata),
Name const &, addr_t);
GENODE_RPC(Rpc_utcb, Ram_dataspace_capability, utcb, Thread_capability);
GENODE_RPC(Rpc_kill_thread, void, kill_thread, Thread_capability);
GENODE_RPC(Rpc_set_pager, int, set_pager, Thread_capability, Pager_capability);
GENODE_RPC(Rpc_start, int, start, Thread_capability, addr_t, addr_t);
GENODE_RPC(Rpc_pause, void, pause, Thread_capability);
GENODE_RPC(Rpc_resume, void, resume, Thread_capability);
GENODE_RPC(Rpc_cancel_blocking, void, cancel_blocking, Thread_capability);
GENODE_RPC_THROW(Rpc_get_state, Thread_state, state,
GENODE_TYPE_LIST(State_access_failed),
Thread_capability);
GENODE_RPC_THROW(Rpc_set_state, void, state,
GENODE_TYPE_LIST(State_access_failed),
Thread_capability, Thread_state const &);
GENODE_RPC(Rpc_exception_handler, void, exception_handler,
Thread_capability, Signal_context_capability);
GENODE_RPC(Rpc_single_step, void, single_step, Thread_capability, bool);
GENODE_RPC(Rpc_affinity_space, Affinity::Space, affinity_space);
GENODE_RPC(Rpc_affinity, void, affinity, Thread_capability, Affinity::Location);
/*
* 'GENODE_RPC_INTERFACE' declaration done manually
*
* The number of RPC function of this interface exceeds the maximum
* number of elements supported by 'Meta::Type_list'. Therefore, we
* construct the type list by hand using nested type tuples instead
* of employing the convenience macro 'GENODE_RPC_INTERFACE'.
*/
typedef Meta::Type_tuple
> > > > > > > > > > > > > Rpc_functions;
};
}
#endif /* _INCLUDE__CPU_SESSION__CPU_SESSION_H_ */