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 <string>
31
32#include "systemc/ext/channel/messages.hh"
33#include "systemc/ext/channel/sc_semaphore.hh"
34#include "systemc/ext/core/sc_module.hh" // for sc_gen_unique_name
35#include "systemc/ext/utils/sc_report_handler.hh"
36
37namespace sc_core
38{
39
40sc_semaphore::sc_semaphore(int value) :
41    sc_semaphore(sc_gen_unique_name("semaphore"), value)
42{}
43
44sc_semaphore::sc_semaphore(const char *_name, int value) :
45        sc_interface(), sc_semaphore_if(), sc_object(_name), _value(value)
46{
47    if (value < 0) {
48        std::string msg = "semaphore '" + std::string(name()) + "'";
49        SC_REPORT_ERROR(SC_ID_INVALID_SEMAPHORE_VALUE_, msg.c_str());
50    }
51}
52
53int
54sc_semaphore::wait()
55{
56    while (trywait() == -1)
57        ::sc_core::wait(posted);
58    return 0;
59}
60
61int
62sc_semaphore::trywait()
63{
64    if (!_value)
65        return -1;
66
67    _value--;
68    return 0;
69}
70
71int
72sc_semaphore::post()
73{
74    if (_value++ == 0)
75        posted.notify();
76    return 0;
77}
78
79int sc_semaphore::get_value() const { return _value; }
80
81} // namespace sc_core
82