00001 // 00002 // Copyright (c) 2005-2008 Kenichi Watanabe. 00003 // Copyright (c) 2005-2008 Yasuhiro Watari. 00004 // Copyright (c) 2005-2008 Hironori Ichibayashi. 00005 // Copyright (c) 2008-2009 Kazuo Horio. 00006 // Copyright (c) 2009-2013 Naruki Kurata. 00007 // Copyright (c) 2005-2013 Ryota Shioya. 00008 // Copyright (c) 2005-2013 Masahiro Goshima. 00009 // 00010 // This software is provided 'as-is', without any express or implied 00011 // warranty. In no event will the authors be held liable for any damages 00012 // arising from the use of this software. 00013 // 00014 // Permission is granted to anyone to use this software for any purpose, 00015 // including commercial applications, and to alter it and redistribute it 00016 // freely, subject to the following restrictions: 00017 // 00018 // 1. The origin of this software must not be misrepresented; you must not 00019 // claim that you wrote the original software. If you use this software 00020 // in a product, an acknowledgment in the product documentation would be 00021 // appreciated but is not required. 00022 // 00023 // 2. Altered source versions must be plainly marked as such, and must not be 00024 // misrepresented as being the original software. 00025 // 00026 // 3. This notice may not be removed or altered from any source 00027 // distribution. 00028 // 00029 // 00030 00031 00032 #include <pch.h> 00033 00034 #include "Sim/ExecUnit/ExecUnitReserver.h" 00035 00036 using namespace std; 00037 using namespace Onikiri; 00038 00039 ExecUnitReserver::ExecUnitReserver() : 00040 m_unitCount( 0 ), 00041 m_current( 0 ) 00042 { 00043 00044 } 00045 00046 ExecUnitReserver::~ExecUnitReserver() 00047 { 00048 00049 } 00050 00051 void ExecUnitReserver::Initialize( int unitCount, int wheelSize ) 00052 { 00053 m_unitCount = unitCount; 00054 m_wheel.resize( wheelSize, 0 ); 00055 } 00056 00057 int ExecUnitReserver::GetWheelIndex( int delta ) 00058 { 00059 int index = (int)m_current + delta; 00060 int size = (int)m_wheel.size(); 00061 if( index >= size ){ 00062 index -= size; 00063 } 00064 return index; 00065 } 00066 00067 void ExecUnitReserver::Begin() 00068 { 00069 m_resvQueue.clear(); 00070 } 00071 00072 bool ExecUnitReserver::CanReserve( int n, int time, int period ) 00073 { 00074 for( int p = 0; p < period; ++p ){ 00075 int now = time + p; 00076 int index = GetWheelIndex( now ); 00077 int count = m_wheel[ index ]; 00078 00079 for( ReservationQueue::iterator i = m_resvQueue.begin(); i != m_resvQueue.end(); ++i ){ 00080 int begin = i->time; 00081 int end = begin + i->period; 00082 if( begin <= now && now < end ){ 00083 count += i->count; 00084 } 00085 } 00086 00087 if( count + n > m_unitCount ){ 00088 return false; 00089 } 00090 } 00091 return true; 00092 } 00093 00094 void ExecUnitReserver::Reserve( int n, int time, int period ) 00095 { 00096 Reservation res; 00097 res.count = n; 00098 res.time = time; 00099 res.period = period; 00100 m_resvQueue.push_back( res ); 00101 } 00102 00103 void ExecUnitReserver::Update() 00104 { 00105 // Update the reservation wheel based on the reservation queue. 00106 for( ReservationQueue::iterator i = m_resvQueue.begin(); i != m_resvQueue.end(); ++i ){ 00107 for( int cycle = 0; cycle < i->period; ++cycle ){ 00108 int index = GetWheelIndex( i->time + cycle ); 00109 m_wheel[ index ] += i->count; 00110 ASSERT( 00111 m_wheel[ index ] <= m_unitCount, 00112 "Execution units are reserved exceed a limit." 00113 ); 00114 } 00115 } 00116 00117 // Reset a count of this cycle. 00118 m_wheel[ GetWheelIndex(0) ] = 0; 00119 00120 m_current = GetWheelIndex(1); // Get an index for a next cycle. 00121 }