1 | /* -*- C++ -*- */ |
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2 | |
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3 | /* |
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4 | |
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5 | Heap Layers: An Extensible Memory Allocation Infrastructure |
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6 | |
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7 | Copyright (C) 2000-2006 by Emery Berger |
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8 | http://www.cs.umass.edu/~emery |
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9 | emery@cs.umass.edu |
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10 | |
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11 | This program is free software; you can redistribute it and/or modify |
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12 | it under the terms of the GNU General Public License as published by |
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13 | the Free Software Foundation; either version 2 of the License, or |
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14 | (at your option) any later version. |
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15 | |
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16 | This program is distributed in the hope that it will be useful, |
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17 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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18 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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19 | GNU General Public License for more details. |
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20 | |
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21 | You should have received a copy of the GNU General Public License |
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22 | along with this program; if not, write to the Free Software |
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23 | Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
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24 | |
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25 | */ |
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26 | |
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27 | #ifndef _SPINLOCK_H_ |
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28 | #define _SPINLOCK_H_ |
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29 | |
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30 | #if defined(unix) |
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31 | #include <sched.h> |
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32 | #endif |
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33 | |
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34 | #if defined(__SVR4) |
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35 | #include <thread.h> |
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36 | #endif |
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37 | |
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38 | #if defined(__sgi) |
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39 | #include <mutex.h> |
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40 | #endif |
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41 | |
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42 | #if defined(__APPLE__) |
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43 | #include <libkern/OSAtomic.h> |
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44 | #endif |
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45 | |
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46 | #include "hldefines.h" |
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47 | #include "cpuinfo.h" |
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48 | |
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49 | #if defined(_MSC_VER) |
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50 | |
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51 | #if !defined(NO_INLINE) |
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52 | #pragma inline_depth(255) |
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53 | #define NO_INLINE __declspec(noinline) |
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54 | #define INLINE __forceinline |
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55 | #define inline __forceinline |
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56 | #endif // !defined(NO_INLINE) |
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57 | |
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58 | #else |
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59 | |
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60 | #endif // defined(_MSC_VER) |
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61 | |
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62 | |
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63 | #if defined(__SUNPRO_CC) |
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64 | // x86-interchange.il, x86_64-interchange.il contributed by Markus Bernhardt. |
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65 | extern "C" unsigned long MyInterlockedExchange (unsigned long * oldval, |
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66 | unsigned long newval); |
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67 | #endif |
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68 | |
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69 | #if defined(_WIN32) && !defined(_WIN64) |
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70 | #define _WIN32_WINNT 0x0500 |
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71 | |
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72 | // NOTE: Below is the new "pause" instruction, which is inocuous for |
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73 | // previous architectures, but crucial for Intel chips with |
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74 | // hyperthreading. See |
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75 | // http://www.usenix.org/events/wiess02/tech/full_papers/nakajima/nakajima.pdf |
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76 | // for discussion. |
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77 | |
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78 | #define _MM_PAUSE {__asm{_emit 0xf3};__asm {_emit 0x90}} |
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79 | #include <windows.h> |
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80 | #else |
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81 | #define _MM_PAUSE |
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82 | #endif // defined(_WIN32) && !defined(_WIN64) |
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83 | |
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84 | extern volatile int anyThreadCreated; |
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85 | |
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86 | namespace HL { |
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87 | |
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88 | class SpinLockType { |
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89 | private: |
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90 | |
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91 | enum { UNLOCKED = 0, LOCKED = 1 }; |
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92 | |
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93 | public: |
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94 | |
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95 | SpinLockType (void) |
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96 | #if defined(__APPLE__) |
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97 | : mutex (OS_SPINLOCK_INIT) |
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98 | #else |
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99 | : mutex (UNLOCKED) |
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100 | #endif |
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101 | {} |
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102 | |
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103 | ~SpinLockType (void) |
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104 | {} |
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105 | |
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106 | inline void lock (void) { |
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107 | if (anyThreadCreated) { |
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108 | #if defined(__APPLE__) |
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109 | OSSpinLockLock(&mutex); |
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110 | #else |
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111 | // A yielding lock (with an initial spin). |
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112 | if (MyInterlockedExchange (const_cast<unsigned long *>(&mutex), LOCKED) |
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113 | != UNLOCKED) { |
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114 | contendedLock(); |
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115 | } |
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116 | #endif |
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117 | } else { |
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118 | mutex = LOCKED; |
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119 | } |
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120 | } |
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121 | |
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122 | |
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123 | inline void unlock (void) { |
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124 | #if defined(__APPLE__) |
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125 | OSSpinLockUnlock(&mutex); |
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126 | #else |
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127 | if (anyThreadCreated) { |
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128 | #if defined(_WIN32) && !defined(_WIN64) |
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129 | __asm {} |
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130 | #elif defined(__GNUC__) |
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131 | asm volatile ("" : : : "memory"); |
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132 | #endif |
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133 | } |
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134 | mutex = UNLOCKED; |
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135 | #endif |
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136 | } |
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137 | |
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138 | |
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139 | #if !defined(__SUNPRO_CC) |
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140 | inline static volatile unsigned long MyInterlockedExchange (unsigned long *,unsigned long); |
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141 | #endif |
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142 | |
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143 | private: |
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144 | |
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145 | #if defined(__APPLE__) |
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146 | OSSpinLock mutex; |
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147 | |
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148 | #else |
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149 | |
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150 | NO_INLINE |
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151 | void contendedLock (void) { |
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152 | while (1) { |
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153 | if (MyInterlockedExchange (const_cast<unsigned long *>(&mutex), LOCKED) |
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154 | == UNLOCKED) { |
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155 | return; |
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156 | } |
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157 | while (mutex == LOCKED) { |
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158 | _MM_PAUSE; |
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159 | yieldProcessor(); |
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160 | } |
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161 | } |
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162 | } |
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163 | |
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164 | // Is this system a multiprocessor? |
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165 | inline bool onMultiprocessor (void) { |
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166 | static CPUInfo cpuInfo; |
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167 | return (cpuInfo.getNumProcessors() > 1); |
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168 | } |
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169 | |
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170 | inline void yieldProcessor (void) { |
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171 | #if defined(_WIN32) |
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172 | Sleep(0); |
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173 | #elif defined(__SVR4) |
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174 | thr_yield(); |
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175 | #else |
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176 | sched_yield(); |
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177 | #endif |
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178 | } |
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179 | |
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180 | enum { MAX_SPIN_LIMIT = 1024 }; |
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181 | |
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182 | union { |
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183 | volatile unsigned long mutex; |
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184 | }; |
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185 | #endif |
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186 | |
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187 | }; |
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188 | |
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189 | } |
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190 | |
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191 | // Atomically: |
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192 | // retval = *oldval; |
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193 | // *oldval = newval; |
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194 | // return retval; |
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195 | |
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196 | #if !defined(__SUNPRO_CC) && !defined(__APPLE__) |
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197 | inline volatile unsigned long |
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198 | HL::SpinLockType::MyInterlockedExchange (unsigned long * oldval, |
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199 | unsigned long newval) |
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200 | { |
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201 | #if defined(_WIN32) && defined(_MSC_VER) |
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202 | return InterlockedExchange ((volatile LONG *) oldval, newval); |
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203 | |
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204 | #elif defined(__sparc) |
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205 | asm volatile ("swap [%1],%0" |
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206 | :"=r" (newval) |
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207 | :"r" (oldval), "0" (newval) |
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208 | : "memory"); |
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209 | |
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210 | #elif defined(__i386__) |
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211 | asm volatile ("lock; xchgl %0, %1" |
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212 | : "=r" (newval) |
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213 | : "m" (*oldval), "0" (newval) |
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214 | : "memory"); |
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215 | |
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216 | #elif defined(__sgi) |
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217 | newval = test_and_set (oldval, newval); |
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218 | |
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219 | #elif defined(__x86_64__) |
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220 | // Contributed by Kurt Roeckx. |
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221 | asm volatile ("lock; xchgq %0, %1" |
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222 | : "=r" (newval) |
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223 | : "m" (*oldval), "0" (newval) |
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224 | : "memory"); |
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225 | |
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226 | #elif defined(__ppc) || defined(__powerpc__) || defined(PPC) |
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227 | // PPC assembly contributed by Maged Michael. |
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228 | int ret; |
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229 | asm volatile ( |
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230 | "La..%=0: lwarx %0,0,%1 ;" |
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231 | " cmpw %0,%2;" |
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232 | " beq La..%=1;" |
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233 | " stwcx. %2,0,%1;" |
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234 | " bne- La..%=0;" |
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235 | "La..%=1: isync;" |
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236 | : "=&r"(ret) |
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237 | : "r"(oldval), "r"(newval) |
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238 | : "cr0", "memory"); |
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239 | return ret; |
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240 | |
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241 | #elif defined(__arm__) |
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242 | // Contributed by Bo Granlund. |
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243 | long result; |
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244 | asm volatile ( |
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245 | "\n\t" |
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246 | "swp %0,%2,[%1] \n\t" |
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247 | "" |
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248 | : "=&r"(result) |
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249 | : "r"(oldval), "r"(newval) |
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250 | : "memory"); |
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251 | return (result); |
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252 | #else |
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253 | #error "No spin lock implementation is available for this platform." |
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254 | #endif |
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255 | return newval; |
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256 | } |
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257 | |
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258 | |
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259 | #endif |
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260 | |
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261 | #endif // _SPINLOCK_H_ |
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