L4Re Operating System Framework – Interface and Usage Documentation
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ipc_timeout_queue
1// vim:set ft=cpp: -*- Mode: C++ -*-
2/*
3 * (c) 2014 Steffen Liebergeld <steffen.liebergeld@kernkonzept.com>
4 *
5 * This file is licensed under the terms of the GNU General Public License 2.
6 * Please see the COPYING-GPL-2 file for details.
7 *
8 * As a special exception, you may use this file as part of a free software
9 * library without restriction. Specifically, if other files instantiate
10 * templates or use macros or inline functions from this file, or you compile
11 * this file and link it with other files to produce an executable, this file
12 * does not by itself cause the resulting executable to be covered by the GNU
13 * General Public License. This exception does not however invalidate any other
14 * reasons why the executable file might be covered by the GNU General Public
15 * License.
16 */
17#pragma once
18
19#include <l4/cxx/hlist>
20#include <l4/sys/cxx/ipc_server_loop>
21
22namespace L4 { namespace Ipc_svr {
23
29{
30 friend class Timeout_queue;
31public:
33 Timeout() : _timeout(0) {}
34
36 virtual ~Timeout() = 0;
37
44 virtual void expired() = 0;
45
53 { return _timeout; }
54
55private:
56 l4_kernel_clock_t _timeout;
57};
58
60
66{
67public:
70
76 {
77 if (auto e = _timeouts.front())
78 return e->timeout();
79
80 return 0;
81 }
82
92 {
94 return (next != 0) && (next <= now);
95 }
96
102 {
103 while (!_timeouts.empty())
104 {
105 Queue::Iterator top = _timeouts.begin();
106 if ((*top)->_timeout > now)
107 return;
108
109 Timeout *t = *top;
110 top = _timeouts.erase(top);
111 t->expired();
112 }
113 }
114
121 void add(Timeout *timeout, l4_kernel_clock_t time)
122 {
123 timeout->_timeout = time;
124 Queue::Iterator i = _timeouts.begin();
125 while (i != _timeouts.end() && (*i)->timeout() < time)
126 ++i;
127
128 _timeouts.insert_before(timeout, i);
129 }
130
136 void remove(Timeout *timeout)
137 {
138 _timeouts.remove(timeout);
139 }
140
141private:
142 typedef cxx::H_list<Timeout> Queue;
143 Queue _timeouts;
144};
145
159template< typename HOOKS, typename BR_MAN = Br_manager_no_buffers >
160class Timeout_queue_hooks : public BR_MAN
161{
162 l4_kernel_clock_t _now()
163 { return static_cast<HOOKS*>(this)->now(); }
164
165 unsigned _timeout_br()
166 { return this->first_free_br(); }
167
168public:
171 {
173 if (t)
174 return l4_timeout(L4_IPC_TIMEOUT_0, l4_timeout_abs(t, _timeout_br()));
176 }
177
180 {
181 // we must handle the timer only when called after a possible reply
182 // otherwise we probably destroy the reply message.
183 if (mode == L4::Ipc_svr::Reply_separate)
184 {
185 l4_kernel_clock_t now = _now();
186 if (queue.timeout_expired(now))
188 }
189
190 BR_MAN::setup_wait(utcb, mode);
191 }
192
195 {
196 // split up reply and wait when a timeout has expired
197 if (queue.timeout_expired(_now()))
200 }
201
213 {
214 queue.add(timeout, time);
215 return 0;
216 }
217
226 {
228 return 0;
229 }
230
232};
233
234}}
unsigned first_free_br() const
Returns 1 as first free buffer.
Loop hooks mixin for integrating a timeout queue into the server loop.
int add_timeout(Timeout *timeout, l4_kernel_clock_t time) override
Add a timeout to the queue for time time.
L4::Ipc_svr::Reply_mode before_reply(l4_msgtag_t, l4_utcb_t *)
server loop hook
int remove_timeout(Timeout *timeout) override
Remove timeout from the queue.
void setup_wait(l4_utcb_t *utcb, L4::Ipc_svr::Reply_mode mode)
setup_wait() for the server loop
l4_timeout_t timeout()
get the time for the next timeout
Timeout_queue queue
Use this timeout queue.
Timeout queue to be used in l4re server loop.
void remove(Timeout *timeout)
Remove timeout from the queue.
L4::Ipc_svr::Timeout Timeout
Provide a local definition of Timeout for backward compatibility.
l4_kernel_clock_t next_timeout() const
Get the time for the next timeout.
void handle_expired_timeouts(l4_kernel_clock_t now)
run the callbacks of expired timeouts
bool timeout_expired(l4_kernel_clock_t now) const
Determine if a timeout has happened.
void add(Timeout *timeout, l4_kernel_clock_t time)
Add a timeout to the queue.
Callback interface for Timeout_queue.
virtual void expired()=0
callback function to be called when timeout happened
virtual ~Timeout()=0
Destroy a timeout.
Timeout()
Make a timeout.
l4_kernel_clock_t timeout() const
return absolute timeout of this callback.
Const_iterator end() const
Return a const iterator to the end of the list.
bool empty() const
Check if the list is empty.
Iterator begin()
Return an iterator to the beginning of the list.
Value_type front() const
Return the first element in the list.
Basic element type for a double-linked H_list.
Definition hlist:34
General double-linked list of unspecified cxx::H_list_item elements.
Definition hlist:81
static Iterator erase(Iterator const &e)
Remove the element at the given iterator position.
Definition hlist:247
static void insert_before(T *e, Iterator const &succ)
Insert an element before the iterator position.
Definition hlist:191
static void remove(T *e)
Remove the given element from its list.
Definition hlist:231
Reply_mode
Reply mode for server loop.
@ Reply_separate
Server shall call reply and wait separately.
@ Reply_compound
Server shall use a compound reply and wait (fast).
l4_uint64_t l4_kernel_clock_t
Kernel clock type.
Definition l4int.h:64
#define L4_IPC_TIMEOUT_0
Timeout constants.
Definition __timeout.h:79
#define L4_IPC_SEND_TIMEOUT_0
0 send timeout
Definition __timeout.h:84
l4_timeout_t l4_timeout(l4_timeout_s snd, l4_timeout_s rcv) L4_NOTHROW
Combine send and receive timeout in a timeout.
Definition __timeout.h:219
l4_timeout_s l4_timeout_abs(l4_kernel_clock_t pint, int br) L4_NOTHROW
Set an absolute timeout.
Definition utcb.h:383
struct l4_utcb_t l4_utcb_t
Opaque type for the UTCB.
Definition utcb.h:67
L4 low-level kernel interface.
Message tag data structure.
Definition types.h:163
Timeout pair.
Definition __timeout.h:59