event.cc revision 11988 
1/*
2 * Copyright (c) 2017 ARM Limited
3 * All rights reserved
4 *
5 * The license below extends only to copyright in the software and shall
6 * not be construed as granting a license to any other intellectual
7 * property including but not limited to intellectual property relating
8 * to a hardware implementation of the functionality of the software
9 * licensed hereunder.  You may use the software subject to the license
10 * terms below provided that you ensure that this notice is replicated
11 * unmodified and in its entirety in all distributions of the software,
12 * modified or unmodified, in source code or in binary form.
13 *
14 * Copyright (c) 2006 The Regents of The University of Michigan
15 * Copyright (c) 2013 Advanced Micro Devices, Inc.
16 * Copyright (c) 2013 Mark D. Hill and David A. Wood
17 * All rights reserved.
18 *
19 * Redistribution and use in source and binary forms, with or without
20 * modification, are permitted provided that the following conditions are
21 * met: redistributions of source code must retain the above copyright
22 * notice, this list of conditions and the following disclaimer;
23 * redistributions in binary form must reproduce the above copyright
24 * notice, this list of conditions and the following disclaimer in the
25 * documentation and/or other materials provided with the distribution;
26 * neither the name of the copyright holders nor the names of its
27 * contributors may be used to endorse or promote products derived from
28 * this software without specific prior written permission.
29 *
30 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
31 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
32 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
33 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
34 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
35 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
36 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
37 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
38 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
39 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
40 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
41 *
42 * Authors: Nathan Binkert
43 *          Andreas Sandberg
44 */
45
46#include "pybind11/pybind11.h"
47#include "pybind11/stl.h"
48
49#include "sim/eventq.hh"
50#include "sim/sim_events.hh"
51#include "sim/sim_exit.hh"
52#include "sim/simulate.hh"
53
54namespace py = pybind11;
55
56/**
57 * PyBind wrapper for Events
58 *
59 * We need to wrap the Event class with some Python glue code to
60 * enable method overrides in Python and memory management. Unlike its
61 * C++ cousin, PyEvents need to override __call__ instead of
62 * Event::process().
63 *
64 * Memory management is mostly done using reference counting in
65 * Python. However, PyBind can't keep track of the reference the event
66 * queue holds to a scheduled event. We therefore need to inhibit
67 * deletion and hand over ownership to the event queue in case a
68 * scheduled event loses all of its Python references.
69 */
70class PyEvent : public Event
71{
72  public:
73    struct Deleter {
74        void operator()(PyEvent *ev) {
75            assert(!ev->isAutoDelete());
76            if (ev->scheduled()) {
77                // The event is scheduled, give ownership to the event
78                // queue.
79                ev->setFlags(Event::AutoDelete);
80            } else {
81                // The event isn't scheduled, hence Python owns it and
82                // we need to free it here.
83                delete ev;
84            }
85        }
86    };
87
88    PyEvent(Event::Priority priority)
89        : Event(priority)
90    { }
91
92    void process() override {
93        if (isAutoDelete()) {
94            // Ownership of the event was handed over to the event queue
95            // because the last revference in Python land was GCed. We
96            // need to claim the object again since we're creating a new
97            // Python reference.
98            clearFlags(AutoDelete);
99        }
100
101        // Call the Python implementation as __call__. This provides a
102        // slightly more Python-friendly interface.
103        PYBIND11_OVERLOAD_PURE_NAME(void, PyEvent, "__call__", process);
104    }
105};
106
107void
108pybind_init_event(py::module &m_native)
109{
110    py::module m = m_native.def_submodule("event");
111
112    m.def("simulate", &simulate,
113          py::arg("ticks") = MaxTick);
114    m.def("exitSimLoop", &exitSimLoop);
115    m.def("getEventQueue", []() { return curEventQueue(); },
116          py::return_value_policy::reference);
117    m.def("setEventQueue", [](EventQueue *q) { return curEventQueue(q); });
118    m.def("getEventQueue", &getEventQueue,
119          py::return_value_policy::reference);
120
121    py::class_<EventQueue>(m, "EventQueue")
122        .def("name",  [](EventQueue *eq) { return eq->name(); })
123        .def("dump", &EventQueue::dump)
124        .def("schedule", [](EventQueue *eq, PyEvent *e, Tick t) {
125                eq->schedule(e, t);
126            }, py::arg("event"), py::arg("when"))
127        .def("deschedule", [](EventQueue *eq, PyEvent *e) {
128                eq->deschedule(e);
129            }, py::arg("event"))
130        .def("reschedule", [](EventQueue *eq, PyEvent *e, Tick t, bool alw) {
131                eq->reschedule(e, t, alw);
132            }, py::arg("event"), py::arg("tick"), py::arg("always") = false)
133        ;
134
135    // TODO: Ownership of global exit events has always been a bit
136    // questionable. We currently assume they are owned by the C++
137    // word. This is what the old SWIG code did, but that will result
138    // in memory leaks.
139    py::class_<GlobalSimLoopExitEvent,
140               std::unique_ptr<GlobalSimLoopExitEvent, py::nodelete>>(
141               m, "GlobalSimLoopExitEvent")
142        .def("getCause", &GlobalSimLoopExitEvent::getCause)
143        .def("getCode", &GlobalSimLoopExitEvent::getCode)
144        ;
145
146    // TODO: We currently export a wrapper class and not the Event
147    // base class. This wil be problematic if we ever return an event
148    // from C++.
149    py::class_<PyEvent, std::unique_ptr<PyEvent, PyEvent::Deleter>>
150        c_event(m, "Event");
151    c_event
152        .def(py::init<Event::Priority>(),
153             py::arg("priority") = (int)Event::Default_Pri)
154        .def("name", &Event::name)
155        .def("dump", &Event::dump)
156        .def("scheduled", &Event::scheduled)
157        .def("squash", &Event::squash)
158        .def("squashed", &Event::squashed)
159        .def("isExitEvent", &Event::isExitEvent)
160        .def("isAutoDelete", &Event::isAutoDelete)
161        .def("when", &Event::when)
162        .def("priority", &Event::priority)
163        ;
164
165#define PRIO(n) c_event.attr(# n) = py::cast((int)Event::n)
166    PRIO(Minimum_Pri);
167    PRIO(Minimum_Pri);
168    PRIO(Debug_Enable_Pri);
169    PRIO(Debug_Break_Pri);
170    PRIO(CPU_Switch_Pri);
171    PRIO(Delayed_Writeback_Pri);
172    PRIO(Default_Pri);
173    PRIO(DVFS_Update_Pri);
174    PRIO(Serialize_Pri);
175    PRIO(CPU_Tick_Pri);
176    PRIO(Stat_Event_Pri);
177    PRIO(Progress_Event_Pri);
178    PRIO(Sim_Exit_Pri);
179    PRIO(Maximum_Pri);
180}
181