1/*
2 * Copyright 2018 Google, Inc.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions are
6 * met: redistributions of source code must retain the above copyright
7 * notice, this list of conditions and the following disclaimer;
8 * redistributions in binary form must reproduce the above copyright
9 * notice, this list of conditions and the following disclaimer in the
10 * documentation and/or other materials provided with the distribution;
11 * neither the name of the copyright holders nor the names of its
12 * contributors may be used to endorse or promote products derived from
13 * this software without specific prior written permission.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
17 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
18 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
19 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
20 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
21 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
25 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 *
27 * Authors: Gabe Black
28 */
29
30#include "systemc/core/scheduler.hh"
31#include "systemc/ext/channel/sc_mutex.hh"
32#include "systemc/ext/core/sc_module.hh" // for sc_gen_unique_name
33
34namespace sc_core
35{
36
37sc_mutex::sc_mutex() : sc_interface(), sc_mutex_if(),
38        sc_object(sc_gen_unique_name("mutex"))
39{}
40
41sc_mutex::sc_mutex(const char *name) :
42        sc_interface(), sc_mutex_if(), sc_object(name)
43{}
44
45int
46sc_mutex::lock()
47{
48    while (trylock() == -1)
49        wait(unlockEvent);
50    return 0;
51}
52
53int
54sc_mutex::trylock()
55{
56    if (holder.valid())
57        return -1;
58    holder = ::sc_gem5::scheduler.current();
59    return 0;
60}
61
62int
63sc_mutex::unlock()
64{
65    if (holder != ::sc_gem5::scheduler.current())
66        return -1;
67
68    holder = nullptr;
69    unlockEvent.notify();
70    return 0;
71}
72
73} // namespace sc_core
74