1 | /** |
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2 | * @file |
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3 | * |
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4 | * @ingroup ScoreSMPLock |
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5 | * |
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6 | * @brief SMP Lock API |
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7 | */ |
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8 | |
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9 | /* |
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10 | * COPYRIGHT (c) 1989-2011. |
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11 | * On-Line Applications Research Corporation (OAR). |
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12 | * |
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13 | * Copyright (c) 2013-2015 embedded brains GmbH |
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14 | * |
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15 | * The license and distribution terms for this file may be |
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16 | * found in the file LICENSE in this distribution or at |
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17 | * http://www.rtems.org/license/LICENSE. |
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18 | */ |
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19 | |
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20 | #ifndef _RTEMS_SCORE_SMPLOCK_H |
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21 | #define _RTEMS_SCORE_SMPLOCK_H |
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22 | |
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23 | #include <rtems/score/cpuopts.h> |
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24 | |
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25 | #if defined( RTEMS_SMP ) |
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26 | |
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27 | #include <rtems/score/atomic.h> |
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28 | #include <rtems/score/isrlevel.h> |
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29 | |
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30 | #if defined( RTEMS_PROFILING ) |
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31 | #include <rtems/score/chainimpl.h> |
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32 | #include <string.h> |
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33 | #endif |
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34 | |
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35 | #if defined( RTEMS_PROFILING ) |
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36 | #define RTEMS_SMP_LOCK_DO_NOT_INLINE |
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37 | #endif |
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38 | |
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39 | #ifdef __cplusplus |
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40 | extern "C" { |
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41 | #endif /* __cplusplus */ |
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42 | |
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43 | /** |
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44 | * @defgroup ScoreSMPLock SMP Locks |
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45 | * |
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46 | * @ingroup Score |
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47 | * |
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48 | * @brief The SMP lock provides mutual exclusion for SMP systems at the lowest |
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49 | * level. |
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50 | * |
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51 | * The SMP lock is implemented as a ticket lock. This provides fairness in |
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52 | * case of concurrent lock attempts. |
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53 | * |
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54 | * This SMP lock API uses a local context for acquire and release pairs. Such |
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55 | * a context may be used to implement for example the Mellor-Crummey and Scott |
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56 | * (MCS) locks in the future. |
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57 | * |
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58 | * @{ |
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59 | */ |
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60 | |
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61 | #if defined( RTEMS_PROFILING ) |
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62 | |
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63 | /** |
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64 | * @brief Count of lock contention counters for lock statistics. |
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65 | */ |
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66 | #define SMP_LOCK_STATS_CONTENTION_COUNTS 4 |
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67 | |
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68 | /** |
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69 | * @brief SMP lock statistics. |
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70 | * |
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71 | * The lock acquire attempt instant is the point in time right after the |
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72 | * interrupt disable action in the lock acquire sequence. |
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73 | * |
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74 | * The lock acquire instant is the point in time right after the lock |
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75 | * acquisition. This is the begin of the critical section code execution. |
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76 | * |
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77 | * The lock release instant is the point in time right before the interrupt |
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78 | * enable action in the lock release sequence. |
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79 | * |
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80 | * The lock section time is the time elapsed between the lock acquire instant |
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81 | * and the lock release instant. |
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82 | * |
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83 | * The lock acquire time is the time elapsed between the lock acquire attempt |
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84 | * instant and the lock acquire instant. |
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85 | */ |
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86 | typedef struct { |
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87 | /** |
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88 | * @brief Node for SMP lock statistics chain. |
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89 | */ |
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90 | Chain_Node Node; |
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91 | |
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92 | /** |
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93 | * @brief The maximum lock acquire time in CPU counter ticks. |
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94 | */ |
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95 | CPU_Counter_ticks max_acquire_time; |
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96 | |
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97 | /** |
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98 | * @brief The maximum lock section time in CPU counter ticks. |
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99 | */ |
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100 | CPU_Counter_ticks max_section_time; |
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101 | |
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102 | /** |
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103 | * @brief The count of lock uses. |
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104 | * |
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105 | * This value may overflow. |
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106 | */ |
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107 | uint64_t usage_count; |
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108 | |
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109 | /** |
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110 | * @brief Total lock acquire time in nanoseconds. |
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111 | * |
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112 | * The average lock acquire time is the total acquire time divided by the |
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113 | * lock usage count. The ration of the total section and total acquire times |
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114 | * gives a measure for the lock contention. |
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115 | * |
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116 | * This value may overflow. |
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117 | */ |
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118 | uint64_t total_acquire_time; |
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119 | |
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120 | /** |
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121 | * @brief The counts of lock acquire operations by contention. |
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122 | * |
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123 | * The contention count for index N corresponds to a lock acquire attempt |
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124 | * with an initial queue length of N. The last index corresponds to all |
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125 | * lock acquire attempts with an initial queue length greater than or equal |
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126 | * to SMP_LOCK_STATS_CONTENTION_COUNTS minus one. |
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127 | * |
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128 | * The values may overflow. |
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129 | */ |
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130 | uint64_t contention_counts[SMP_LOCK_STATS_CONTENTION_COUNTS]; |
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131 | |
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132 | /** |
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133 | * @brief Total lock section time in CPU counter ticks. |
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134 | * |
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135 | * The average lock section time is the total section time divided by the |
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136 | * lock usage count. |
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137 | * |
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138 | * This value may overflow. |
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139 | */ |
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140 | uint64_t total_section_time; |
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141 | |
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142 | /** |
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143 | * @brief The lock name. |
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144 | */ |
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145 | const char *name; |
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146 | } SMP_lock_Stats; |
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147 | |
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148 | /** |
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149 | * @brief Local context for SMP lock statistics. |
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150 | */ |
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151 | typedef struct { |
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152 | /** |
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153 | * @brief The last lock acquire instant in CPU counter ticks. |
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154 | * |
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155 | * This value is used to measure the lock section time. |
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156 | */ |
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157 | CPU_Counter_ticks acquire_instant; |
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158 | |
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159 | /** |
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160 | * @brief The lock stats used for the last lock acquire. |
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161 | */ |
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162 | SMP_lock_Stats *stats; |
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163 | } SMP_lock_Stats_context; |
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164 | |
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165 | /** |
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166 | * @brief SMP lock statistics initializer for static initialization. |
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167 | */ |
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168 | #define SMP_LOCK_STATS_INITIALIZER( name ) \ |
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169 | { { NULL, NULL }, 0, 0, 0, 0, { 0, 0, 0, 0 }, 0, name } |
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170 | |
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171 | /** |
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172 | * @brief Initializes an SMP lock statistics block. |
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173 | * |
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174 | * @param[in, out] stats The SMP lock statistics block. |
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175 | * @param[in] name The name for the SMP lock statistics. This name must be |
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176 | * persistent throughout the life time of this statistics block. |
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177 | */ |
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178 | static inline void _SMP_lock_Stats_initialize( |
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179 | SMP_lock_Stats *stats, |
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180 | const char *name |
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181 | ) |
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182 | { |
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183 | SMP_lock_Stats init = SMP_LOCK_STATS_INITIALIZER( name ); |
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184 | |
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185 | *stats = init; |
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186 | } |
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187 | |
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188 | /** |
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189 | * @brief Destroys an SMP lock statistics block. |
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190 | * |
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191 | * @param[in] stats The SMP lock statistics block. |
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192 | */ |
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193 | static inline void _SMP_lock_Stats_destroy( SMP_lock_Stats *stats ); |
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194 | |
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195 | /** |
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196 | * @brief Updates an SMP lock statistics block during a lock release. |
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197 | * |
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198 | * @param[in] stats_context The SMP lock statistics context. |
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199 | */ |
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200 | static inline void _SMP_lock_Stats_release_update( |
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201 | const SMP_lock_Stats_context *stats_context |
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202 | ); |
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203 | |
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204 | #else /* RTEMS_PROFILING */ |
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205 | |
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206 | #define _SMP_lock_Stats_initialize( stats, name ) do { } while ( 0 ) |
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207 | |
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208 | #define _SMP_lock_Stats_destroy( stats ) do { } while ( 0 ) |
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209 | |
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210 | #endif /* RTEMS_PROFILING */ |
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211 | |
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212 | /** |
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213 | * @brief SMP ticket lock control. |
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214 | */ |
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215 | typedef struct { |
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216 | Atomic_Uint next_ticket; |
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217 | Atomic_Uint now_serving; |
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218 | } SMP_ticket_lock_Control; |
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219 | |
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220 | /** |
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221 | * @brief SMP ticket lock control initializer for static initialization. |
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222 | */ |
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223 | #define SMP_TICKET_LOCK_INITIALIZER \ |
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224 | { \ |
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225 | ATOMIC_INITIALIZER_UINT( 0U ), \ |
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226 | ATOMIC_INITIALIZER_UINT( 0U ) \ |
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227 | } |
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228 | |
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229 | /** |
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230 | * @brief Initializes an SMP ticket lock. |
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231 | * |
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232 | * Concurrent initialization leads to unpredictable results. |
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233 | * |
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234 | * @param[in] lock The SMP ticket lock control. |
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235 | * @param[in] name The name for the SMP ticket lock. This name must be |
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236 | * persistent throughout the life time of this lock. |
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237 | */ |
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238 | static inline void _SMP_ticket_lock_Initialize( |
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239 | SMP_ticket_lock_Control *lock |
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240 | ) |
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241 | { |
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242 | _Atomic_Init_uint( &lock->next_ticket, 0U ); |
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243 | _Atomic_Init_uint( &lock->now_serving, 0U ); |
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244 | } |
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245 | |
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246 | /** |
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247 | * @brief Destroys an SMP ticket lock. |
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248 | * |
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249 | * Concurrent destruction leads to unpredictable results. |
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250 | * |
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251 | * @param[in] lock The SMP ticket lock control. |
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252 | */ |
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253 | static inline void _SMP_ticket_lock_Destroy( SMP_ticket_lock_Control *lock ) |
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254 | { |
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255 | (void) lock; |
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256 | } |
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257 | |
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258 | static inline void _SMP_ticket_lock_Do_acquire( |
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259 | SMP_ticket_lock_Control *lock |
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260 | #if defined( RTEMS_PROFILING ) |
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261 | , |
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262 | SMP_lock_Stats *stats, |
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263 | SMP_lock_Stats_context *stats_context |
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264 | #endif |
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265 | ) |
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266 | { |
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267 | unsigned int my_ticket; |
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268 | unsigned int now_serving; |
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269 | |
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270 | #if defined( RTEMS_PROFILING ) |
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271 | CPU_Counter_ticks first; |
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272 | CPU_Counter_ticks second; |
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273 | CPU_Counter_ticks delta; |
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274 | unsigned int initial_queue_length; |
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275 | |
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276 | first = _CPU_Counter_read(); |
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277 | #endif |
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278 | |
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279 | my_ticket = |
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280 | _Atomic_Fetch_add_uint( &lock->next_ticket, 1U, ATOMIC_ORDER_ACQ_REL ); |
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281 | |
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282 | #if defined( RTEMS_PROFILING ) |
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283 | now_serving = |
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284 | _Atomic_Load_uint( &lock->now_serving, ATOMIC_ORDER_ACQUIRE ); |
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285 | initial_queue_length = my_ticket - now_serving; |
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286 | |
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287 | if ( initial_queue_length > 0 ) { |
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288 | #endif |
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289 | |
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290 | do { |
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291 | now_serving = |
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292 | _Atomic_Load_uint( &lock->now_serving, ATOMIC_ORDER_ACQUIRE ); |
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293 | } while ( now_serving != my_ticket ); |
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294 | |
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295 | #if defined( RTEMS_PROFILING ) |
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296 | } |
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297 | |
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298 | second = _CPU_Counter_read(); |
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299 | stats_context->acquire_instant = second; |
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300 | delta = _CPU_Counter_difference( second, first ); |
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301 | |
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302 | ++stats->usage_count; |
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303 | |
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304 | stats->total_acquire_time += delta; |
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305 | |
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306 | if ( stats->max_acquire_time < delta ) { |
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307 | stats->max_acquire_time = delta; |
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308 | } |
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309 | |
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310 | if ( initial_queue_length >= SMP_LOCK_STATS_CONTENTION_COUNTS ) { |
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311 | initial_queue_length = SMP_LOCK_STATS_CONTENTION_COUNTS - 1; |
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312 | } |
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313 | ++stats->contention_counts[initial_queue_length]; |
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314 | |
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315 | stats_context->stats = stats; |
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316 | #endif |
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317 | } |
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318 | |
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319 | /** |
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320 | * @brief Acquires an SMP ticket lock. |
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321 | * |
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322 | * This function will not disable interrupts. The caller must ensure that the |
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323 | * current thread of execution is not interrupted indefinite once it obtained |
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324 | * the SMP ticket lock. |
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325 | * |
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326 | * @param[in] lock The SMP ticket lock control. |
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327 | * @param[in] stats The SMP lock statistics. |
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328 | * @param[out] stats_context The SMP lock statistics context. |
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329 | */ |
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330 | #if defined( RTEMS_PROFILING ) |
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331 | #define _SMP_ticket_lock_Acquire( lock, stats, stats_context ) \ |
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332 | _SMP_ticket_lock_Do_acquire( lock, stats, stats_context ) |
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333 | #else |
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334 | #define _SMP_ticket_lock_Acquire( lock, stats, stats_context ) \ |
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335 | _SMP_ticket_lock_Do_acquire( lock ) |
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336 | #endif |
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337 | |
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338 | static inline void _SMP_ticket_lock_Do_release( |
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339 | SMP_ticket_lock_Control *lock |
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340 | #if defined( RTEMS_PROFILING ) |
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341 | , |
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342 | const SMP_lock_Stats_context *stats_context |
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343 | #endif |
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344 | ) |
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345 | { |
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346 | unsigned int current_ticket = |
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347 | _Atomic_Load_uint( &lock->now_serving, ATOMIC_ORDER_RELAXED ); |
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348 | unsigned int next_ticket = current_ticket + 1U; |
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349 | |
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350 | #if defined( RTEMS_PROFILING ) |
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351 | _SMP_lock_Stats_release_update( stats_context ); |
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352 | #endif |
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353 | |
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354 | _Atomic_Store_uint( &lock->now_serving, next_ticket, ATOMIC_ORDER_RELEASE ); |
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355 | } |
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356 | |
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357 | /** |
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358 | * @brief Releases an SMP ticket lock. |
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359 | * |
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360 | * @param[in] lock The SMP ticket lock control. |
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361 | * @param[in] stats_context The SMP lock statistics context. |
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362 | */ |
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363 | #if defined( RTEMS_PROFILING ) |
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364 | #define _SMP_ticket_lock_Release( lock, stats_context ) \ |
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365 | _SMP_ticket_lock_Do_release( lock, stats_context ) |
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366 | #else |
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367 | #define _SMP_ticket_lock_Release( lock, stats_context ) \ |
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368 | _SMP_ticket_lock_Do_release( lock ) |
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369 | #endif |
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370 | |
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371 | /** |
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372 | * @brief SMP lock control. |
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373 | */ |
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374 | typedef struct { |
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375 | SMP_ticket_lock_Control Ticket_lock; |
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376 | #if defined( RTEMS_PROFILING ) |
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377 | SMP_lock_Stats Stats; |
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378 | #endif |
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379 | } SMP_lock_Control; |
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380 | |
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381 | /** |
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382 | * @brief Local SMP lock context for acquire and release pairs. |
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383 | */ |
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384 | typedef struct { |
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385 | ISR_Level isr_level; |
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386 | #if defined( RTEMS_PROFILING ) |
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387 | SMP_lock_Stats_context Stats_context; |
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388 | #endif |
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389 | } SMP_lock_Context; |
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390 | |
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391 | /** |
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392 | * @brief SMP lock control initializer for static initialization. |
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393 | */ |
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394 | #if defined( RTEMS_PROFILING ) |
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395 | #define SMP_LOCK_INITIALIZER( name ) \ |
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396 | { SMP_TICKET_LOCK_INITIALIZER, SMP_LOCK_STATS_INITIALIZER( name ) } |
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397 | #else |
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398 | #define SMP_LOCK_INITIALIZER( name ) { SMP_TICKET_LOCK_INITIALIZER } |
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399 | #endif |
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400 | |
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401 | /** |
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402 | * @brief Initializes an SMP lock. |
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403 | * |
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404 | * Concurrent initialization leads to unpredictable results. |
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405 | * |
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406 | * @param[in] lock The SMP lock control. |
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407 | * @param[in] name The name for the SMP lock statistics. This name must be |
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408 | * persistent throughout the life time of this statistics block. |
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409 | */ |
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410 | #if defined( RTEMS_SMP_LOCK_DO_NOT_INLINE ) |
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411 | void _SMP_lock_Initialize( |
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412 | SMP_lock_Control *lock, |
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413 | const char *name |
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414 | ); |
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415 | |
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416 | static inline void _SMP_lock_Initialize_body( |
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417 | #else |
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418 | static inline void _SMP_lock_Initialize( |
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419 | #endif |
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420 | SMP_lock_Control *lock, |
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421 | const char *name |
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422 | ) |
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423 | { |
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424 | _SMP_ticket_lock_Initialize( &lock->Ticket_lock ); |
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425 | #if defined( RTEMS_PROFILING ) |
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426 | _SMP_lock_Stats_initialize( &lock->Stats, name ); |
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427 | #else |
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428 | (void) name; |
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429 | #endif |
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430 | } |
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431 | |
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432 | /** |
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433 | * @brief Destroys an SMP lock. |
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434 | * |
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435 | * Concurrent destruction leads to unpredictable results. |
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436 | * |
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437 | * @param[in] lock The SMP lock control. |
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438 | */ |
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439 | #if defined( RTEMS_SMP_LOCK_DO_NOT_INLINE ) |
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440 | void _SMP_lock_Destroy( SMP_lock_Control *lock ); |
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441 | |
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442 | static inline void _SMP_lock_Destroy_body( SMP_lock_Control *lock ) |
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443 | #else |
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444 | static inline void _SMP_lock_Destroy( SMP_lock_Control *lock ) |
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445 | #endif |
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446 | { |
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447 | _SMP_ticket_lock_Destroy( &lock->Ticket_lock ); |
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448 | _SMP_lock_Stats_destroy( &lock->Stats ); |
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449 | } |
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450 | |
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451 | /** |
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452 | * @brief Acquires an SMP lock. |
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453 | * |
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454 | * This function will not disable interrupts. The caller must ensure that the |
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455 | * current thread of execution is not interrupted indefinite once it obtained |
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456 | * the SMP lock. |
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457 | * |
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458 | * @param[in] lock The SMP lock control. |
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459 | * @param[in] context The local SMP lock context for an acquire and release |
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460 | * pair. |
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461 | */ |
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462 | #if defined( RTEMS_SMP_LOCK_DO_NOT_INLINE ) |
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463 | void _SMP_lock_Acquire( |
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464 | SMP_lock_Control *lock, |
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465 | SMP_lock_Context *context |
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466 | ); |
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467 | |
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468 | static inline void _SMP_lock_Acquire_body( |
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469 | #else |
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470 | static inline void _SMP_lock_Acquire( |
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471 | #endif |
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472 | SMP_lock_Control *lock, |
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473 | SMP_lock_Context *context |
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474 | ) |
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475 | { |
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476 | (void) context; |
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477 | _SMP_ticket_lock_Acquire( |
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478 | &lock->Ticket_lock, |
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479 | &lock->Stats, |
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480 | &context->Stats_context |
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481 | ); |
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482 | } |
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483 | |
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484 | /** |
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485 | * @brief Releases an SMP lock. |
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486 | * |
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487 | * @param[in] lock The SMP lock control. |
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488 | * @param[in] context The local SMP lock context for an acquire and release |
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489 | * pair. |
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490 | */ |
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491 | #if defined( RTEMS_SMP_LOCK_DO_NOT_INLINE ) |
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492 | void _SMP_lock_Release( |
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493 | SMP_lock_Control *lock, |
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494 | SMP_lock_Context *context |
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495 | ); |
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496 | |
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497 | static inline void _SMP_lock_Release_body( |
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498 | #else |
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499 | static inline void _SMP_lock_Release( |
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500 | #endif |
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501 | SMP_lock_Control *lock, |
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502 | SMP_lock_Context *context |
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503 | ) |
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504 | { |
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505 | (void) context; |
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506 | _SMP_ticket_lock_Release( |
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507 | &lock->Ticket_lock, |
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508 | &context->Stats_context |
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509 | ); |
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510 | } |
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511 | |
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512 | /** |
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513 | * @brief Disables interrupts and acquires the SMP lock. |
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514 | * |
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515 | * @param[in] lock The SMP lock control. |
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516 | * @param[in] context The local SMP lock context for an acquire and release |
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517 | * pair. |
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518 | */ |
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519 | #if defined( RTEMS_SMP_LOCK_DO_NOT_INLINE ) |
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520 | void _SMP_lock_ISR_disable_and_acquire( |
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521 | SMP_lock_Control *lock, |
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522 | SMP_lock_Context *context |
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523 | ); |
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524 | |
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525 | static inline void _SMP_lock_ISR_disable_and_acquire_body( |
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526 | #else |
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527 | static inline void _SMP_lock_ISR_disable_and_acquire( |
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528 | #endif |
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529 | SMP_lock_Control *lock, |
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530 | SMP_lock_Context *context |
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531 | ) |
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532 | { |
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533 | _ISR_Disable_without_giant( context->isr_level ); |
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534 | _SMP_lock_Acquire( lock, context ); |
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535 | } |
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536 | |
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537 | /** |
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538 | * @brief Releases the SMP lock and enables interrupts. |
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539 | * |
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540 | * @param[in] lock The SMP lock control. |
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541 | * @param[in] context The local SMP lock context for an acquire and release |
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542 | * pair. |
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543 | */ |
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544 | #if defined( RTEMS_SMP_LOCK_DO_NOT_INLINE ) |
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545 | void _SMP_lock_Release_and_ISR_enable( |
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546 | SMP_lock_Control *lock, |
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547 | SMP_lock_Context *context |
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548 | ); |
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549 | |
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550 | static inline void _SMP_lock_Release_and_ISR_enable_body( |
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551 | #else |
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552 | static inline void _SMP_lock_Release_and_ISR_enable( |
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553 | #endif |
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554 | SMP_lock_Control *lock, |
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555 | SMP_lock_Context *context |
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556 | ) |
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557 | { |
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558 | _SMP_lock_Release( lock, context ); |
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559 | _ISR_Enable_without_giant( context->isr_level ); |
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560 | } |
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561 | |
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562 | #if defined( RTEMS_PROFILING ) |
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563 | |
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564 | typedef struct { |
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565 | SMP_lock_Control Lock; |
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566 | Chain_Control Stats_chain; |
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567 | Chain_Control Iterator_chain; |
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568 | } SMP_lock_Stats_control; |
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569 | |
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570 | typedef struct { |
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571 | Chain_Node Node; |
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572 | SMP_lock_Stats *current; |
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573 | } SMP_lock_Stats_iteration_context; |
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574 | |
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575 | extern SMP_lock_Stats_control _SMP_lock_Stats_control; |
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576 | |
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577 | static inline void _SMP_lock_Stats_iteration_start( |
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578 | SMP_lock_Stats_iteration_context *iteration_context |
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579 | ) |
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580 | { |
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581 | SMP_lock_Stats_control *control = &_SMP_lock_Stats_control; |
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582 | SMP_lock_Context lock_context; |
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583 | |
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584 | _SMP_lock_ISR_disable_and_acquire( &control->Lock, &lock_context ); |
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585 | |
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586 | _Chain_Append_unprotected( |
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587 | &control->Iterator_chain, |
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588 | &iteration_context->Node |
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589 | ); |
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590 | iteration_context->current = |
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591 | (SMP_lock_Stats *) _Chain_First( &control->Stats_chain ); |
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592 | |
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593 | _SMP_lock_Release_and_ISR_enable( &control->Lock, &lock_context ); |
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594 | } |
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595 | |
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596 | static inline bool _SMP_lock_Stats_iteration_next( |
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597 | SMP_lock_Stats_iteration_context *iteration_context, |
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598 | SMP_lock_Stats *snapshot, |
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599 | char *name, |
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600 | size_t name_size |
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601 | ) |
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602 | { |
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603 | SMP_lock_Stats_control *control = &_SMP_lock_Stats_control; |
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604 | SMP_lock_Context lock_context; |
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605 | SMP_lock_Stats *current; |
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606 | bool valid; |
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607 | |
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608 | _SMP_lock_ISR_disable_and_acquire( &control->Lock, &lock_context ); |
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609 | |
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610 | current = iteration_context->current; |
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611 | if ( !_Chain_Is_tail( &control->Stats_chain, ¤t->Node ) ) { |
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612 | size_t name_len = current->name != NULL ? strlen(current->name) : 0; |
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613 | |
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614 | valid = true; |
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615 | |
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616 | iteration_context->current = (SMP_lock_Stats *) |
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617 | _Chain_Next( ¤t->Node ); |
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618 | |
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619 | *snapshot = *current; |
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620 | snapshot->name = name; |
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621 | |
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622 | if ( name_len >= name_size ) { |
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623 | name_len = name_size - 1; |
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624 | } |
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625 | |
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626 | name[name_len] = '\0'; |
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627 | memcpy(name, current->name, name_len); |
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628 | } else { |
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629 | valid = false; |
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630 | } |
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631 | |
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632 | _SMP_lock_Release_and_ISR_enable( &control->Lock, &lock_context ); |
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633 | |
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634 | return valid; |
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635 | } |
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636 | |
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637 | static inline void _SMP_lock_Stats_iteration_stop( |
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638 | SMP_lock_Stats_iteration_context *iteration_context |
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639 | ) |
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640 | { |
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641 | SMP_lock_Stats_control *control = &_SMP_lock_Stats_control; |
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642 | SMP_lock_Context lock_context; |
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643 | |
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644 | _SMP_lock_ISR_disable_and_acquire( &control->Lock, &lock_context ); |
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645 | _Chain_Extract_unprotected( &iteration_context->Node ); |
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646 | _SMP_lock_Release_and_ISR_enable( &control->Lock, &lock_context ); |
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647 | } |
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648 | |
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649 | static inline void _SMP_lock_Stats_destroy( SMP_lock_Stats *stats ) |
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650 | { |
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651 | if ( !_Chain_Is_node_off_chain( &stats->Node ) ) { |
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652 | SMP_lock_Stats_control *control = &_SMP_lock_Stats_control; |
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653 | SMP_lock_Context lock_context; |
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654 | SMP_lock_Stats_iteration_context *iteration_context; |
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655 | SMP_lock_Stats_iteration_context *iteration_context_tail; |
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656 | SMP_lock_Stats *next_stats; |
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657 | |
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658 | _SMP_lock_ISR_disable_and_acquire( &control->Lock, &lock_context ); |
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659 | |
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660 | next_stats = (SMP_lock_Stats *) _Chain_Next( &stats->Node ); |
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661 | _Chain_Extract_unprotected( &stats->Node ); |
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662 | |
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663 | iteration_context = (SMP_lock_Stats_iteration_context *) |
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664 | _Chain_First( &control->Iterator_chain ); |
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665 | iteration_context_tail = (SMP_lock_Stats_iteration_context *) |
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666 | _Chain_Tail( &control->Iterator_chain ); |
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667 | |
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668 | while ( iteration_context != iteration_context_tail ) { |
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669 | if ( iteration_context->current == stats ) { |
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670 | iteration_context->current = next_stats; |
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671 | } |
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672 | |
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673 | iteration_context = (SMP_lock_Stats_iteration_context *) |
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674 | _Chain_Next( &iteration_context->Node ); |
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675 | } |
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676 | |
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677 | _SMP_lock_Release_and_ISR_enable( &control->Lock, &lock_context ); |
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678 | } |
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679 | } |
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680 | |
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681 | static inline void _SMP_lock_Stats_release_update( |
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682 | const SMP_lock_Stats_context *stats_context |
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683 | ) |
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684 | { |
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685 | SMP_lock_Stats *stats = stats_context->stats; |
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686 | CPU_Counter_ticks first = stats_context->acquire_instant; |
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687 | CPU_Counter_ticks second = _CPU_Counter_read(); |
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688 | CPU_Counter_ticks delta = _CPU_Counter_difference( second, first ); |
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689 | |
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690 | stats->total_section_time += delta; |
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691 | |
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692 | if ( stats->max_section_time < delta ) { |
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693 | stats->max_section_time = delta; |
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694 | |
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695 | if ( _Chain_Is_node_off_chain( &stats->Node ) ) { |
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696 | SMP_lock_Stats_control *control = &_SMP_lock_Stats_control; |
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697 | SMP_lock_Context lock_context; |
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698 | |
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699 | _SMP_lock_ISR_disable_and_acquire( &control->Lock, &lock_context ); |
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700 | _Chain_Append_unprotected( &control->Stats_chain, &stats->Node ); |
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701 | _SMP_lock_Release_and_ISR_enable( &control->Lock, &lock_context ); |
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702 | } |
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703 | } |
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704 | } |
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705 | |
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706 | #endif /* RTEMS_PROFILING */ |
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707 | |
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708 | /**@}*/ |
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709 | |
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710 | #ifdef __cplusplus |
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711 | } |
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712 | #endif /* __cplusplus */ |
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713 | |
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714 | #endif /* defined( RTEMS_SMP ) */ |
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715 | |
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716 | #endif /* _RTEMS_SCORE_SMPLOCK_H */ |
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