src/systemc/channel/sc_semaphore.cc

   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
  37 namespace sc_core
  38 {
  39
  40 sc_semaphore::sc_semaphore(int value) :
  41     sc_semaphore(sc_gen_unique_name("semaphore"), value)
  42 {}
  43
  44 sc_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
  53 int
  54 sc_semaphore::wait()
  55 {
  56     while (trywait() == -1)
  57         ::sc_core::wait(posted);
  58     return 0;
  59 }
  60
  61 int
  62 sc_semaphore::trywait()
  63 {
  64     if (!_value)
  65         return -1;
  66
  67     _value--;
  68     return 0;
  69 }
  70
  71 int
  72 sc_semaphore::post()
  73 {
  74     if (_value++ == 0)
  75         posted.notify();
  76     return 0;
  77 }
  78
  79 int sc_semaphore::get_value() const { return _value; }
  80
  81 } // namespace sc_core