1 | // |
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2 | // Cforall Version 1.0.0 Copyright (C) 2021 University of Waterloo |
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3 | // |
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4 | // The contents of this file are covered under the licence agreement in the |
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5 | // file "LICENCE" distributed with Cforall. |
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6 | // |
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7 | // locks.hfa -- PUBLIC |
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8 | // Runtime locks that used with the runtime thread system. |
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9 | // |
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10 | // Author : Colby Alexander Parsons |
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11 | // Created On : Thu Jan 21 19:46:50 2021 |
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12 | // Last Modified By : |
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13 | // Last Modified On : |
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14 | // Update Count : |
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15 | // |
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16 | |
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17 | #pragma once |
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18 | |
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19 | #include <stdbool.h> |
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20 | #include <stdio.h> |
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21 | |
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22 | #include "bits/weakso_locks.hfa" |
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23 | #include "containers/lockfree.hfa" |
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24 | #include "containers/list.hfa" |
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25 | |
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26 | #include "limits.hfa" |
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27 | #include "thread.hfa" |
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28 | |
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29 | #include "time_t.hfa" |
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30 | #include "time.hfa" |
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31 | |
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32 | #include "select.hfa" |
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33 | |
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34 | // futex headers |
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35 | #include <linux/futex.h> /* Definition of FUTEX_* constants */ |
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36 | #include <sys/syscall.h> /* Definition of SYS_* constants */ |
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37 | #include <unistd.h> /* Definition of syscall routine */ |
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38 | |
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39 | typedef void (*__cfa_pre_park)( void * ); |
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40 | |
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41 | static inline void pre_park_noop( void * ) {} |
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42 | |
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43 | //----------------------------------------------------------------------------- |
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44 | // is_blocking_lock |
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45 | forall( L & | sized(L) ) |
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46 | trait is_blocking_lock { |
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47 | // For synchronization locks to use when acquiring |
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48 | void on_notify( L &, struct thread$ * ); |
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49 | |
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50 | // For synchronization locks to use when releasing |
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51 | size_t on_wait( L &, __cfa_pre_park pp_fn, void * pp_datum ); |
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52 | |
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53 | // to set recursion count after getting signalled; |
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54 | void on_wakeup( L &, size_t recursion ); |
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55 | }; |
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56 | |
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57 | static inline void pre_park_then_park( __cfa_pre_park pp_fn, void * pp_datum ) { |
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58 | pp_fn( pp_datum ); |
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59 | park(); |
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60 | } |
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61 | |
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62 | // macros for default routine impls for is_blocking_lock trait that do not wait-morph |
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63 | |
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64 | #define DEFAULT_ON_NOTIFY( lock_type ) \ |
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65 | static inline void on_notify( lock_type & this, thread$ * t ){ unpark(t); } |
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66 | |
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67 | #define DEFAULT_ON_WAIT( lock_type ) \ |
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68 | static inline size_t on_wait( lock_type & this, __cfa_pre_park pp_fn, void * pp_datum ) { \ |
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69 | unlock( this ); \ |
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70 | pre_park_then_park( pp_fn, pp_datum ); \ |
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71 | return 0; \ |
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72 | } |
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73 | |
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74 | // on_wakeup impl if lock should be reacquired after waking up |
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75 | #define DEFAULT_ON_WAKEUP_REACQ( lock_type ) \ |
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76 | static inline void on_wakeup( lock_type & this, size_t recursion ) { lock( this ); } |
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77 | |
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78 | // on_wakeup impl if lock will not be reacquired after waking up |
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79 | #define DEFAULT_ON_WAKEUP_NO_REACQ( lock_type ) \ |
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80 | static inline void on_wakeup( lock_type & this, size_t recursion ) {} |
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81 | |
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82 | |
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83 | |
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84 | //----------------------------------------------------------------------------- |
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85 | // Semaphore |
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86 | struct semaphore { |
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87 | __spinlock_t lock; |
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88 | int count; |
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89 | __queue_t(thread$) waiting; |
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90 | }; |
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91 | |
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92 | void ?{}(semaphore & this, int count = 1); |
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93 | void ^?{}(semaphore & this); |
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94 | bool P (semaphore & this); |
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95 | bool V (semaphore & this); |
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96 | bool V (semaphore & this, unsigned count); |
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97 | thread$ * V (semaphore & this, bool ); |
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98 | |
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99 | //---------- |
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100 | struct single_acquisition_lock { |
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101 | inline blocking_lock; |
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102 | }; |
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103 | |
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104 | static inline void ?{}( single_acquisition_lock & this ) {((blocking_lock &)this){ false, false };} |
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105 | static inline void ^?{}( single_acquisition_lock & this ) {} |
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106 | static inline void lock ( single_acquisition_lock & this ) { lock ( (blocking_lock &)this ); } |
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107 | static inline bool try_lock ( single_acquisition_lock & this ) { return try_lock( (blocking_lock &)this ); } |
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108 | static inline void unlock ( single_acquisition_lock & this ) { unlock ( (blocking_lock &)this ); } |
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109 | static inline size_t on_wait ( single_acquisition_lock & this, __cfa_pre_park pp_fn, void * pp_datum ) { return on_wait ( (blocking_lock &)this, pp_fn, pp_datum ); } |
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110 | static inline void on_wakeup( single_acquisition_lock & this, size_t v ) { on_wakeup ( (blocking_lock &)this, v ); } |
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111 | static inline void on_notify( single_acquisition_lock & this, struct thread$ * t ) { on_notify( (blocking_lock &)this, t ); } |
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112 | static inline bool register_select( single_acquisition_lock & this, select_node & node ) { return register_select( (blocking_lock &)this, node ); } |
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113 | static inline bool unregister_select( single_acquisition_lock & this, select_node & node ) { return unregister_select( (blocking_lock &)this, node ); } |
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114 | static inline bool on_selected( single_acquisition_lock & this, select_node & node ) { return on_selected( (blocking_lock &)this, node ); } |
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115 | __CFA_SELECT_GET_TYPE( single_acquisition_lock ); |
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116 | |
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117 | //---------- |
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118 | struct owner_lock { |
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119 | inline blocking_lock; |
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120 | }; |
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121 | |
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122 | static inline void ?{}( owner_lock & this ) {((blocking_lock &)this){ true, true };} |
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123 | static inline void ^?{}( owner_lock & this ) {} |
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124 | static inline void lock ( owner_lock & this ) { lock ( (blocking_lock &)this ); } |
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125 | static inline bool try_lock ( owner_lock & this ) { return try_lock( (blocking_lock &)this ); } |
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126 | static inline void unlock ( owner_lock & this ) { unlock ( (blocking_lock &)this ); } |
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127 | static inline size_t on_wait ( owner_lock & this, __cfa_pre_park pp_fn, void * pp_datum ) { return on_wait ( (blocking_lock &)this, pp_fn, pp_datum ); } |
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128 | static inline void on_wakeup( owner_lock & this, size_t v ) { on_wakeup ( (blocking_lock &)this, v ); } |
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129 | static inline void on_notify( owner_lock & this, struct thread$ * t ) { on_notify( (blocking_lock &)this, t ); } |
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130 | static inline bool register_select( owner_lock & this, select_node & node ) { return register_select( (blocking_lock &)this, node ); } |
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131 | static inline bool unregister_select( owner_lock & this, select_node & node ) { return unregister_select( (blocking_lock &)this, node ); } |
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132 | static inline bool on_selected( owner_lock & this, select_node & node ) { return on_selected( (blocking_lock &)this, node ); } |
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133 | __CFA_SELECT_GET_TYPE( owner_lock ); |
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134 | |
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135 | //----------------------------------------------------------------------------- |
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136 | // MCS Lock |
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137 | struct mcs_node { |
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138 | mcs_node * volatile next; |
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139 | single_sem sem; |
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140 | }; |
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141 | |
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142 | static inline void ?{}( mcs_node & this ) { this.next = 0p; } |
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143 | |
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144 | static inline mcs_node * volatile & ?`next ( mcs_node * node ) { |
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145 | return node->next; |
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146 | } |
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147 | |
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148 | struct mcs_lock { |
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149 | mcs_queue(mcs_node) queue; |
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150 | }; |
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151 | |
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152 | static inline void lock( mcs_lock & l, mcs_node & n ) { |
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153 | if(push(l.queue, &n)) |
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154 | wait(n.sem); |
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155 | } |
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156 | |
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157 | static inline void unlock(mcs_lock & l, mcs_node & n) { |
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158 | mcs_node * next = advance(l.queue, &n); |
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159 | if(next) post(next->sem); |
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160 | } |
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161 | |
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162 | //----------------------------------------------------------------------------- |
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163 | // MCS Spin Lock |
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164 | // - No recursive acquisition |
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165 | // - Needs to be released by owner |
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166 | |
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167 | struct mcs_spin_node { |
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168 | mcs_spin_node * volatile next; |
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169 | volatile bool locked; |
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170 | }; |
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171 | |
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172 | struct mcs_spin_queue { |
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173 | mcs_spin_node * volatile tail; |
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174 | }; |
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175 | |
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176 | static inline void ?{}( mcs_spin_node & this ) { this.next = 0p; this.locked = true; } |
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177 | |
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178 | struct mcs_spin_lock { |
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179 | mcs_spin_queue queue; |
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180 | }; |
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181 | |
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182 | static inline void lock( mcs_spin_lock & l, mcs_spin_node & n ) { |
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183 | n.locked = true; |
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184 | mcs_spin_node * prev = __atomic_exchange_n(&l.queue.tail, &n, __ATOMIC_SEQ_CST); |
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185 | if( prev == 0p ) return; |
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186 | prev->next = &n; |
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187 | while( __atomic_load_n(&n.locked, __ATOMIC_RELAXED) ) Pause(); |
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188 | } |
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189 | |
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190 | static inline void unlock(mcs_spin_lock & l, mcs_spin_node & n) { |
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191 | mcs_spin_node * n_ptr = &n; |
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192 | if (__atomic_compare_exchange_n(&l.queue.tail, &n_ptr, 0p, false, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST)) return; |
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193 | while (__atomic_load_n(&n.next, __ATOMIC_RELAXED) == 0p) Pause(); |
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194 | n.next->locked = false; |
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195 | } |
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196 | |
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197 | //----------------------------------------------------------------------------- |
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198 | // futex_mutex |
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199 | |
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200 | // - Kernel thd blocking alternative to the spinlock |
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201 | // - No ownership (will deadlock on reacq) |
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202 | // - no reacq on wakeup |
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203 | struct futex_mutex { |
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204 | // lock state any state other than UNLOCKED is locked |
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205 | // enum LockState { UNLOCKED = 0, UNCONTENDED = 1, CONTENDED = 2 }; |
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206 | |
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207 | // stores a lock state |
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208 | int val; |
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209 | }; |
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210 | |
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211 | // to use for FUTEX_WAKE and FUTEX_WAIT (other futex calls will need more params) |
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212 | static inline int futex(int *uaddr, int futex_op, int val) { |
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213 | return syscall(SYS_futex, uaddr, futex_op, val, NULL, NULL, 0); |
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214 | } |
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215 | |
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216 | static inline void ?{}( futex_mutex & this ) with(this) { val = 0; } |
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217 | |
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218 | static inline bool internal_try_lock( futex_mutex & this, int & compare_val) with(this) { |
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219 | return __atomic_compare_exchange_n((int*)&val, (int*)&compare_val, 1, false, __ATOMIC_ACQUIRE, __ATOMIC_ACQUIRE); |
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220 | } |
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221 | |
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222 | static inline int internal_exchange( futex_mutex & this ) with(this) { |
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223 | return __atomic_exchange_n((int*)&val, 2, __ATOMIC_ACQUIRE); |
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224 | } |
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225 | |
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226 | // if this is called recursively IT WILL DEADLOCK!!!!! |
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227 | static inline void lock( futex_mutex & this ) with(this) { |
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228 | int state; |
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229 | |
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230 | for( int spin = 4; spin < 1024; spin += spin) { |
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231 | state = 0; |
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232 | // if unlocked, lock and return |
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233 | if (internal_try_lock(this, state)) return; |
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234 | if (2 == state) break; |
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235 | for (int i = 0; i < spin; i++) Pause(); |
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236 | } |
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237 | |
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238 | // if not in contended state, set to be in contended state |
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239 | if (state != 2) state = internal_exchange(this); |
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240 | |
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241 | // block and spin until we win the lock |
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242 | while (state != 0) { |
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243 | futex((int*)&val, FUTEX_WAIT, 2); // if val is not 2 this returns with EWOULDBLOCK |
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244 | state = internal_exchange(this); |
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245 | } |
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246 | } |
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247 | |
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248 | static inline void unlock(futex_mutex & this) with(this) { |
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249 | // if uncontended do atomic unlock and then return |
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250 | if (__atomic_exchange_n(&val, 0, __ATOMIC_RELEASE) == 1) return; |
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251 | |
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252 | // otherwise threads are blocked so we must wake one |
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253 | futex((int *)&val, FUTEX_WAKE, 1); |
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254 | } |
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255 | |
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256 | DEFAULT_ON_NOTIFY( futex_mutex ) |
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257 | DEFAULT_ON_WAIT( futex_mutex ) |
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258 | DEFAULT_ON_WAKEUP_NO_REACQ( futex_mutex ) |
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259 | |
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260 | //----------------------------------------------------------------------------- |
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261 | // go_mutex |
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262 | |
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263 | // - Kernel thd blocking alternative to the spinlock |
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264 | // - No ownership (will deadlock on reacq) |
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265 | // - Golang's flavour of mutex |
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266 | // - Impl taken from Golang: src/runtime/lock_futex.go |
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267 | struct go_mutex { |
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268 | // lock state any state other than UNLOCKED is locked |
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269 | // enum LockState { UNLOCKED = 0, LOCKED = 1, SLEEPING = 2 }; |
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270 | |
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271 | // stores a lock state |
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272 | int val; |
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273 | }; |
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274 | static inline void ?{}( go_mutex & this ) with(this) { val = 0; } |
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275 | static inline void ?{}( go_mutex & this, go_mutex this2 ) = void; |
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276 | static inline void ?=?( go_mutex & this, go_mutex this2 ) = void; |
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277 | |
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278 | static inline bool internal_try_lock(go_mutex & this, int & compare_val, int new_val ) with(this) { |
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279 | return __atomic_compare_exchange_n((int*)&val, (int*)&compare_val, new_val, false, __ATOMIC_ACQUIRE, __ATOMIC_ACQUIRE); |
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280 | } |
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281 | |
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282 | static inline int internal_exchange(go_mutex & this, int swap ) with(this) { |
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283 | return __atomic_exchange_n((int*)&val, swap, __ATOMIC_ACQUIRE); |
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284 | } |
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285 | |
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286 | // if this is called recursively IT WILL DEADLOCK!!!!! |
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287 | static inline void lock( go_mutex & this ) with( this ) { |
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288 | int state, init_state; |
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289 | |
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290 | // speculative grab |
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291 | state = internal_exchange(this, 1); |
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292 | if ( !state ) return; // state == 0 |
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293 | init_state = state; |
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294 | for (;;) { |
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295 | for( int i = 0; i < 4; i++ ) { |
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296 | while( !val ) { // lock unlocked |
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297 | state = 0; |
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298 | if ( internal_try_lock( this, state, init_state ) ) return; |
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299 | } |
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300 | for (int i = 0; i < 30; i++) Pause(); |
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301 | } |
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302 | |
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303 | while( !val ) { // lock unlocked |
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304 | state = 0; |
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305 | if ( internal_try_lock( this, state, init_state ) ) return; |
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306 | } |
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307 | sched_yield(); |
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308 | |
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309 | // if not in contended state, set to be in contended state |
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310 | state = internal_exchange( this, 2 ); |
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311 | if ( !state ) return; // state == 0 |
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312 | init_state = 2; |
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313 | futex( (int*)&val, FUTEX_WAIT, 2 ); // if val is not 2 this returns with EWOULDBLOCK |
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314 | } |
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315 | } |
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316 | |
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317 | static inline void unlock( go_mutex & this ) with(this) { |
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318 | // if uncontended do atomic unlock and then return |
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319 | if ( __atomic_exchange_n(&val, 0, __ATOMIC_RELEASE) == 1 ) return; |
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320 | |
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321 | // otherwise threads are blocked so we must wake one |
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322 | futex( (int *)&val, FUTEX_WAKE, 1 ); |
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323 | } |
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324 | |
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325 | DEFAULT_ON_NOTIFY( go_mutex ) |
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326 | DEFAULT_ON_WAIT( go_mutex ) |
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327 | DEFAULT_ON_WAKEUP_NO_REACQ( go_mutex ) |
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328 | |
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329 | //----------------------------------------------------------------------------- |
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330 | // Exponential backoff then block lock |
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331 | struct exp_backoff_then_block_lock { |
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332 | // Spin lock used for mutual exclusion |
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333 | __spinlock_t spinlock; |
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334 | |
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335 | // List of blocked threads |
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336 | dlist( thread$ ) blocked_threads; |
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337 | |
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338 | // Used for comparing and exchanging |
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339 | volatile size_t lock_value; |
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340 | }; |
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341 | |
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342 | static inline void ?{}( exp_backoff_then_block_lock & this ) { |
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343 | this.spinlock{}; |
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344 | this.blocked_threads{}; |
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345 | this.lock_value = 0; |
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346 | } |
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347 | static inline void ?{}( exp_backoff_then_block_lock & this, exp_backoff_then_block_lock this2 ) = void; |
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348 | static inline void ?=?( exp_backoff_then_block_lock & this, exp_backoff_then_block_lock this2 ) = void; |
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349 | |
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350 | static inline void ^?{}( exp_backoff_then_block_lock & this ){} |
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351 | |
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352 | static inline bool internal_try_lock( exp_backoff_then_block_lock & this, size_t & compare_val ) with(this) { |
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353 | return __atomic_compare_exchange_n(&lock_value, &compare_val, 1, false, __ATOMIC_ACQUIRE, __ATOMIC_RELAXED); |
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354 | } |
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355 | |
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356 | static inline bool try_lock( exp_backoff_then_block_lock & this ) { size_t compare_val = 0; return internal_try_lock( this, compare_val ); } |
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357 | |
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358 | static inline bool try_lock_contention( exp_backoff_then_block_lock & this ) with(this) { |
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359 | return !__atomic_exchange_n( &lock_value, 2, __ATOMIC_ACQUIRE ); |
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360 | } |
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361 | |
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362 | static inline bool block( exp_backoff_then_block_lock & this ) with(this) { |
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363 | lock( spinlock __cfaabi_dbg_ctx2 ); |
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364 | if (__atomic_load_n( &lock_value, __ATOMIC_SEQ_CST) != 2) { |
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365 | unlock( spinlock ); |
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366 | return true; |
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367 | } |
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368 | insert_last( blocked_threads, *active_thread() ); |
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369 | unlock( spinlock ); |
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370 | park( ); |
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371 | return true; |
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372 | } |
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373 | |
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374 | static inline void lock( exp_backoff_then_block_lock & this ) with(this) { |
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375 | size_t compare_val = 0; |
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376 | int spin = 4; |
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377 | |
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378 | // linear backoff |
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379 | for( ;; ) { |
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380 | compare_val = 0; |
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381 | if (internal_try_lock(this, compare_val)) return; |
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382 | if (2 == compare_val) break; |
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383 | for (int i = 0; i < spin; i++) Pause(); |
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384 | if (spin >= 1024) break; |
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385 | spin += spin; |
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386 | } |
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387 | |
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388 | if(2 != compare_val && try_lock_contention(this)) return; |
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389 | // block until signalled |
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390 | while (block(this)) if(try_lock_contention(this)) return; |
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391 | } |
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392 | |
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393 | static inline void unlock( exp_backoff_then_block_lock & this ) with(this) { |
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394 | if (__atomic_exchange_n(&lock_value, 0, __ATOMIC_RELEASE) == 1) return; |
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395 | lock( spinlock __cfaabi_dbg_ctx2 ); |
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396 | thread$ * t = &try_pop_front( blocked_threads ); |
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397 | unlock( spinlock ); |
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398 | unpark( t ); |
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399 | } |
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400 | |
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401 | DEFAULT_ON_NOTIFY( exp_backoff_then_block_lock ) |
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402 | DEFAULT_ON_WAIT( exp_backoff_then_block_lock ) |
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403 | DEFAULT_ON_WAKEUP_REACQ( exp_backoff_then_block_lock ) |
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404 | |
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405 | //----------------------------------------------------------------------------- |
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406 | // Fast Block Lock |
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407 | |
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408 | // minimal blocking lock |
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409 | // - No reacquire for cond var |
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410 | // - No recursive acquisition |
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411 | // - No ownership |
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412 | struct fast_block_lock { |
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413 | // List of blocked threads |
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414 | dlist( thread$ ) blocked_threads; |
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415 | |
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416 | // Spin lock used for mutual exclusion |
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417 | __spinlock_t lock; |
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418 | |
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419 | // flag showing if lock is held |
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420 | bool held:1; |
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421 | }; |
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422 | |
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423 | static inline void ?{}( fast_block_lock & this ) with(this) { |
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424 | lock{}; |
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425 | blocked_threads{}; |
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426 | held = false; |
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427 | } |
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428 | static inline void ^?{}( fast_block_lock & this ) {} |
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429 | static inline void ?{}( fast_block_lock & this, fast_block_lock this2 ) = void; |
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430 | static inline void ?=?( fast_block_lock & this, fast_block_lock this2 ) = void; |
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431 | |
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432 | // if this is called recursively IT WILL DEADLOCK!!!!! |
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433 | static inline void lock( fast_block_lock & this ) with(this) { |
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434 | lock( lock __cfaabi_dbg_ctx2 ); |
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435 | if ( held ) { |
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436 | insert_last( blocked_threads, *active_thread() ); |
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437 | unlock( lock ); |
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438 | park( ); |
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439 | return; |
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440 | } |
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441 | held = true; |
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442 | unlock( lock ); |
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443 | } |
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444 | |
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445 | static inline void unlock( fast_block_lock & this ) with(this) { |
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446 | lock( lock __cfaabi_dbg_ctx2 ); |
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447 | /* paranoid */ verifyf( held != false, "Attempt to release lock %p that isn't held", &this ); |
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448 | thread$ * t = &try_pop_front( blocked_threads ); |
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449 | held = ( t ? true : false ); |
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450 | unpark( t ); |
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451 | unlock( lock ); |
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452 | } |
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453 | |
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454 | static inline void on_notify( fast_block_lock & this, struct thread$ * t ) with(this) { |
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455 | lock( lock __cfaabi_dbg_ctx2 ); |
---|
456 | insert_last( blocked_threads, *t ); |
---|
457 | unlock( lock ); |
---|
458 | } |
---|
459 | DEFAULT_ON_WAIT( fast_block_lock ) |
---|
460 | DEFAULT_ON_WAKEUP_NO_REACQ( fast_block_lock ) |
---|
461 | |
---|
462 | //----------------------------------------------------------------------------- |
---|
463 | // simple_owner_lock |
---|
464 | |
---|
465 | // pthread owner lock |
---|
466 | // - reacquire for cond var |
---|
467 | // - recursive acquisition |
---|
468 | // - ownership |
---|
469 | struct simple_owner_lock { |
---|
470 | // List of blocked threads |
---|
471 | dlist( select_node ) blocked_threads; |
---|
472 | |
---|
473 | // Spin lock used for mutual exclusion |
---|
474 | __spinlock_t lock; |
---|
475 | |
---|
476 | // owner showing if lock is held |
---|
477 | struct thread$ * owner; |
---|
478 | |
---|
479 | size_t recursion_count; |
---|
480 | }; |
---|
481 | |
---|
482 | static inline void ?{}( simple_owner_lock & this ) with(this) { |
---|
483 | lock{}; |
---|
484 | blocked_threads{}; |
---|
485 | owner = 0p; |
---|
486 | recursion_count = 0; |
---|
487 | } |
---|
488 | static inline void ^?{}( simple_owner_lock & this ) {} |
---|
489 | static inline void ?{}( simple_owner_lock & this, simple_owner_lock this2 ) = void; |
---|
490 | static inline void ?=?( simple_owner_lock & this, simple_owner_lock this2 ) = void; |
---|
491 | |
---|
492 | static inline void lock( simple_owner_lock & this ) with(this) { |
---|
493 | if ( owner == active_thread() ) { |
---|
494 | recursion_count++; |
---|
495 | return; |
---|
496 | } |
---|
497 | lock( lock __cfaabi_dbg_ctx2 ); |
---|
498 | |
---|
499 | if ( owner != 0p ) { |
---|
500 | select_node node; |
---|
501 | insert_last( blocked_threads, node ); |
---|
502 | unlock( lock ); |
---|
503 | park( ); |
---|
504 | return; |
---|
505 | } |
---|
506 | owner = active_thread(); |
---|
507 | recursion_count = 1; |
---|
508 | unlock( lock ); |
---|
509 | } |
---|
510 | |
---|
511 | static inline void pop_node( simple_owner_lock & this ) with(this) { |
---|
512 | __handle_waituntil_OR( blocked_threads ); |
---|
513 | select_node * node = &try_pop_front( blocked_threads ); |
---|
514 | if ( node ) { |
---|
515 | owner = node->blocked_thread; |
---|
516 | recursion_count = 1; |
---|
517 | // if ( !node->clause_status || __make_select_node_available( *node ) ) unpark( node->blocked_thread ); |
---|
518 | wake_one( blocked_threads, *node ); |
---|
519 | } else { |
---|
520 | owner = 0p; |
---|
521 | recursion_count = 0; |
---|
522 | } |
---|
523 | } |
---|
524 | |
---|
525 | static inline void unlock( simple_owner_lock & this ) with(this) { |
---|
526 | lock( lock __cfaabi_dbg_ctx2 ); |
---|
527 | /* paranoid */ verifyf( owner != 0p, "Attempt to release lock %p that isn't held", &this ); |
---|
528 | /* paranoid */ verifyf( owner == active_thread(), "Thread %p other than the owner %p attempted to release owner lock %p", owner, active_thread(), &this ); |
---|
529 | // if recursion count is zero release lock and set new owner if one is waiting |
---|
530 | recursion_count--; |
---|
531 | if ( recursion_count == 0 ) { |
---|
532 | pop_node( this ); |
---|
533 | } |
---|
534 | unlock( lock ); |
---|
535 | } |
---|
536 | |
---|
537 | static inline void on_notify( simple_owner_lock & this, thread$ * t ) with(this) { |
---|
538 | lock( lock __cfaabi_dbg_ctx2 ); |
---|
539 | // lock held |
---|
540 | if ( owner != 0p ) { |
---|
541 | insert_last( blocked_threads, *(select_node *)t->link_node ); |
---|
542 | } |
---|
543 | // lock not held |
---|
544 | else { |
---|
545 | owner = t; |
---|
546 | recursion_count = 1; |
---|
547 | unpark( t ); |
---|
548 | } |
---|
549 | unlock( lock ); |
---|
550 | } |
---|
551 | |
---|
552 | static inline size_t on_wait( simple_owner_lock & this, __cfa_pre_park pp_fn, void * pp_datum ) with(this) { |
---|
553 | lock( lock __cfaabi_dbg_ctx2 ); |
---|
554 | /* paranoid */ verifyf( owner != 0p, "Attempt to release lock %p that isn't held", &this ); |
---|
555 | /* paranoid */ verifyf( owner == active_thread(), "Thread %p other than the owner %p attempted to release owner lock %p", owner, active_thread(), &this ); |
---|
556 | |
---|
557 | size_t ret = recursion_count; |
---|
558 | |
---|
559 | pop_node( this ); |
---|
560 | |
---|
561 | select_node node; |
---|
562 | active_thread()->link_node = (void *)&node; |
---|
563 | unlock( lock ); |
---|
564 | |
---|
565 | pre_park_then_park( pp_fn, pp_datum ); |
---|
566 | |
---|
567 | return ret; |
---|
568 | } |
---|
569 | |
---|
570 | static inline void on_wakeup( simple_owner_lock & this, size_t recursion ) with(this) { recursion_count = recursion; } |
---|
571 | |
---|
572 | // waituntil() support |
---|
573 | static inline bool register_select( simple_owner_lock & this, select_node & node ) with(this) { |
---|
574 | lock( lock __cfaabi_dbg_ctx2 ); |
---|
575 | |
---|
576 | // check if we can complete operation. If so race to establish winner in special OR case |
---|
577 | if ( !node.park_counter && ( owner == active_thread() || owner == 0p ) ) { |
---|
578 | if ( !__make_select_node_available( node ) ) { // we didn't win the race so give up on registering |
---|
579 | unlock( lock ); |
---|
580 | return false; |
---|
581 | } |
---|
582 | } |
---|
583 | |
---|
584 | if ( owner == active_thread() ) { |
---|
585 | recursion_count++; |
---|
586 | if ( node.park_counter ) __make_select_node_available( node ); |
---|
587 | unlock( lock ); |
---|
588 | return true; |
---|
589 | } |
---|
590 | |
---|
591 | if ( owner != 0p ) { |
---|
592 | insert_last( blocked_threads, node ); |
---|
593 | unlock( lock ); |
---|
594 | return false; |
---|
595 | } |
---|
596 | |
---|
597 | owner = active_thread(); |
---|
598 | recursion_count = 1; |
---|
599 | |
---|
600 | if ( node.park_counter ) __make_select_node_available( node ); |
---|
601 | unlock( lock ); |
---|
602 | return true; |
---|
603 | } |
---|
604 | |
---|
605 | static inline bool unregister_select( simple_owner_lock & this, select_node & node ) with(this) { |
---|
606 | lock( lock __cfaabi_dbg_ctx2 ); |
---|
607 | if ( node`isListed ) { |
---|
608 | remove( node ); |
---|
609 | unlock( lock ); |
---|
610 | return false; |
---|
611 | } |
---|
612 | |
---|
613 | if ( owner == active_thread() ) { |
---|
614 | recursion_count--; |
---|
615 | if ( recursion_count == 0 ) { |
---|
616 | pop_node( this ); |
---|
617 | } |
---|
618 | } |
---|
619 | unlock( lock ); |
---|
620 | return false; |
---|
621 | } |
---|
622 | |
---|
623 | static inline bool on_selected( simple_owner_lock & this, select_node & node ) { return true; } |
---|
624 | __CFA_SELECT_GET_TYPE( simple_owner_lock ); |
---|
625 | |
---|
626 | //----------------------------------------------------------------------------- |
---|
627 | // Spin Queue Lock |
---|
628 | |
---|
629 | // - No reacquire for cond var |
---|
630 | // - No recursive acquisition |
---|
631 | // - No ownership |
---|
632 | // - spin lock with no locking/atomics in unlock |
---|
633 | struct spin_queue_lock { |
---|
634 | // Spin lock used for mutual exclusion |
---|
635 | mcs_spin_lock lock; |
---|
636 | |
---|
637 | // flag showing if lock is held |
---|
638 | volatile bool held; |
---|
639 | }; |
---|
640 | |
---|
641 | static inline void ?{}( spin_queue_lock & this ) with(this) { |
---|
642 | lock{}; |
---|
643 | held = false; |
---|
644 | } |
---|
645 | static inline void ^?{}( spin_queue_lock & this ) {} |
---|
646 | static inline void ?{}( spin_queue_lock & this, spin_queue_lock this2 ) = void; |
---|
647 | static inline void ?=?( spin_queue_lock & this, spin_queue_lock this2 ) = void; |
---|
648 | |
---|
649 | // if this is called recursively IT WILL DEADLOCK! |
---|
650 | static inline void lock( spin_queue_lock & this ) with(this) { |
---|
651 | mcs_spin_node node; |
---|
652 | lock( lock, node ); |
---|
653 | while(__atomic_load_n(&held, __ATOMIC_SEQ_CST)) Pause(); |
---|
654 | __atomic_store_n(&held, true, __ATOMIC_SEQ_CST); |
---|
655 | unlock( lock, node ); |
---|
656 | } |
---|
657 | |
---|
658 | static inline void unlock( spin_queue_lock & this ) with(this) { |
---|
659 | __atomic_store_n(&held, false, __ATOMIC_RELEASE); |
---|
660 | } |
---|
661 | |
---|
662 | DEFAULT_ON_NOTIFY( spin_queue_lock ) |
---|
663 | DEFAULT_ON_WAIT( spin_queue_lock ) |
---|
664 | DEFAULT_ON_WAKEUP_REACQ( spin_queue_lock ) |
---|
665 | |
---|
666 | //----------------------------------------------------------------------------- |
---|
667 | // MCS Block Spin Lock |
---|
668 | |
---|
669 | // - No reacquire for cond var |
---|
670 | // - No recursive acquisition |
---|
671 | // - No ownership |
---|
672 | // - Blocks but first node spins (like spin queue but blocking for not first thd) |
---|
673 | struct mcs_block_spin_lock { |
---|
674 | // Spin lock used for mutual exclusion |
---|
675 | mcs_lock lock; |
---|
676 | |
---|
677 | // flag showing if lock is held |
---|
678 | volatile bool held; |
---|
679 | }; |
---|
680 | |
---|
681 | static inline void ?{}( mcs_block_spin_lock & this ) with(this) { |
---|
682 | lock{}; |
---|
683 | held = false; |
---|
684 | } |
---|
685 | static inline void ^?{}( mcs_block_spin_lock & this ) {} |
---|
686 | static inline void ?{}( mcs_block_spin_lock & this, mcs_block_spin_lock this2 ) = void; |
---|
687 | static inline void ?=?( mcs_block_spin_lock & this, mcs_block_spin_lock this2 ) = void; |
---|
688 | |
---|
689 | // if this is called recursively IT WILL DEADLOCK!!!!! |
---|
690 | static inline void lock( mcs_block_spin_lock & this ) with(this) { |
---|
691 | mcs_node node; |
---|
692 | lock( lock, node ); |
---|
693 | while(__atomic_load_n(&held, __ATOMIC_SEQ_CST)) Pause(); |
---|
694 | __atomic_store_n(&held, true, __ATOMIC_SEQ_CST); |
---|
695 | unlock( lock, node ); |
---|
696 | } |
---|
697 | |
---|
698 | static inline void unlock(mcs_block_spin_lock & this) with(this) { |
---|
699 | __atomic_store_n(&held, false, __ATOMIC_SEQ_CST); |
---|
700 | } |
---|
701 | |
---|
702 | DEFAULT_ON_NOTIFY( mcs_block_spin_lock ) |
---|
703 | DEFAULT_ON_WAIT( mcs_block_spin_lock ) |
---|
704 | DEFAULT_ON_WAKEUP_REACQ( mcs_block_spin_lock ) |
---|
705 | |
---|
706 | //----------------------------------------------------------------------------- |
---|
707 | // Block Spin Lock |
---|
708 | |
---|
709 | // - No reacquire for cond var |
---|
710 | // - No recursive acquisition |
---|
711 | // - No ownership |
---|
712 | // - Blocks but first node spins (like spin queue but blocking for not first thd) |
---|
713 | struct block_spin_lock { |
---|
714 | // Spin lock used for mutual exclusion |
---|
715 | fast_block_lock lock; |
---|
716 | |
---|
717 | // flag showing if lock is held |
---|
718 | volatile bool held; |
---|
719 | }; |
---|
720 | |
---|
721 | static inline void ?{}( block_spin_lock & this ) with(this) { |
---|
722 | lock{}; |
---|
723 | held = false; |
---|
724 | } |
---|
725 | static inline void ^?{}( block_spin_lock & this ) {} |
---|
726 | static inline void ?{}( block_spin_lock & this, block_spin_lock this2 ) = void; |
---|
727 | static inline void ?=?( block_spin_lock & this, block_spin_lock this2 ) = void; |
---|
728 | |
---|
729 | // if this is called recursively IT WILL DEADLOCK!!!!! |
---|
730 | static inline void lock( block_spin_lock & this ) with(this) { |
---|
731 | lock( lock ); |
---|
732 | while(__atomic_load_n(&held, __ATOMIC_SEQ_CST)) Pause(); |
---|
733 | __atomic_store_n(&held, true, __ATOMIC_RELEASE); |
---|
734 | unlock( lock ); |
---|
735 | } |
---|
736 | |
---|
737 | static inline void unlock( block_spin_lock & this ) with(this) { |
---|
738 | __atomic_store_n(&held, false, __ATOMIC_RELEASE); |
---|
739 | } |
---|
740 | |
---|
741 | static inline void on_notify( block_spin_lock & this, struct thread$ * t ) with(this.lock) { |
---|
742 | // first we acquire internal fast_block_lock |
---|
743 | lock( lock __cfaabi_dbg_ctx2 ); |
---|
744 | if ( held ) { // if internal fast_block_lock is held |
---|
745 | insert_last( blocked_threads, *t ); |
---|
746 | unlock( lock ); |
---|
747 | return; |
---|
748 | } |
---|
749 | // if internal fast_block_lock is not held |
---|
750 | held = true; |
---|
751 | unlock( lock ); |
---|
752 | |
---|
753 | unpark(t); |
---|
754 | } |
---|
755 | DEFAULT_ON_WAIT( block_spin_lock ) |
---|
756 | static inline void on_wakeup( block_spin_lock & this, size_t recursion ) with(this) { |
---|
757 | // now we acquire the entire block_spin_lock upon waking up |
---|
758 | while(__atomic_load_n(&held, __ATOMIC_SEQ_CST)) Pause(); |
---|
759 | __atomic_store_n(&held, true, __ATOMIC_RELEASE); |
---|
760 | unlock( lock ); // Now we release the internal fast_spin_lock |
---|
761 | } |
---|
762 | |
---|
763 | //----------------------------------------------------------------------------- |
---|
764 | // // info_thread |
---|
765 | // // the info thread is a wrapper around a thread used |
---|
766 | // // to store extra data for use in the condition variable |
---|
767 | forall(L & | is_blocking_lock(L)) { |
---|
768 | struct info_thread; |
---|
769 | } |
---|
770 | |
---|
771 | //----------------------------------------------------------------------------- |
---|
772 | // Synchronization Locks |
---|
773 | forall(L & | is_blocking_lock(L)) { |
---|
774 | |
---|
775 | //----------------------------------------------------------------------------- |
---|
776 | // condition_variable |
---|
777 | |
---|
778 | // The multi-tool condition variable |
---|
779 | // - can pass timeouts to wait for either a signal or timeout |
---|
780 | // - can wait without passing a lock |
---|
781 | // - can have waiters reacquire different locks while waiting on the same cond var |
---|
782 | // - has shadow queue |
---|
783 | // - can be signalled outside of critical sections with no locks held |
---|
784 | struct condition_variable { |
---|
785 | // Spin lock used for mutual exclusion |
---|
786 | __spinlock_t lock; |
---|
787 | |
---|
788 | // List of blocked threads |
---|
789 | dlist( info_thread(L) ) blocked_threads; |
---|
790 | |
---|
791 | // Count of current blocked threads |
---|
792 | int count; |
---|
793 | }; |
---|
794 | |
---|
795 | |
---|
796 | void ?{}( condition_variable(L) & this ); |
---|
797 | void ^?{}( condition_variable(L) & this ); |
---|
798 | |
---|
799 | bool notify_one( condition_variable(L) & this ); |
---|
800 | bool notify_all( condition_variable(L) & this ); |
---|
801 | |
---|
802 | uintptr_t front( condition_variable(L) & this ); |
---|
803 | |
---|
804 | bool empty ( condition_variable(L) & this ); |
---|
805 | int counter( condition_variable(L) & this ); |
---|
806 | |
---|
807 | void wait( condition_variable(L) & this ); |
---|
808 | void wait( condition_variable(L) & this, uintptr_t info ); |
---|
809 | bool wait( condition_variable(L) & this, Duration duration ); |
---|
810 | bool wait( condition_variable(L) & this, uintptr_t info, Duration duration ); |
---|
811 | |
---|
812 | void wait( condition_variable(L) & this, L & l ); |
---|
813 | void wait( condition_variable(L) & this, L & l, uintptr_t info ); |
---|
814 | bool wait( condition_variable(L) & this, L & l, Duration duration ); |
---|
815 | bool wait( condition_variable(L) & this, L & l, uintptr_t info, Duration duration ); |
---|
816 | |
---|
817 | //----------------------------------------------------------------------------- |
---|
818 | // fast_cond_var |
---|
819 | |
---|
820 | // The trimmed and slim condition variable |
---|
821 | // - no internal lock so you must hold a lock while using this cond var |
---|
822 | // - signalling without holding branded lock is UNSAFE! |
---|
823 | // - only allows usage of one lock, cond var is branded after usage |
---|
824 | |
---|
825 | struct fast_cond_var { |
---|
826 | // List of blocked threads |
---|
827 | dlist( info_thread(L) ) blocked_threads; |
---|
828 | #ifdef __CFA_DEBUG__ |
---|
829 | L * lock_used; |
---|
830 | #endif |
---|
831 | }; |
---|
832 | |
---|
833 | void ?{}( fast_cond_var(L) & this ); |
---|
834 | void ^?{}( fast_cond_var(L) & this ); |
---|
835 | |
---|
836 | bool notify_one( fast_cond_var(L) & this ); |
---|
837 | bool notify_all( fast_cond_var(L) & this ); |
---|
838 | |
---|
839 | uintptr_t front( fast_cond_var(L) & this ); |
---|
840 | bool empty ( fast_cond_var(L) & this ); |
---|
841 | |
---|
842 | void wait( fast_cond_var(L) & this, L & l ); |
---|
843 | void wait( fast_cond_var(L) & this, L & l, uintptr_t info ); |
---|
844 | |
---|
845 | |
---|
846 | //----------------------------------------------------------------------------- |
---|
847 | // pthread_cond_var |
---|
848 | // |
---|
849 | // - cond var with minimal footprint |
---|
850 | // - supports operations needed for phthread cond |
---|
851 | |
---|
852 | struct pthread_cond_var { |
---|
853 | dlist( info_thread(L) ) blocked_threads; |
---|
854 | __spinlock_t lock; |
---|
855 | }; |
---|
856 | |
---|
857 | void ?{}( pthread_cond_var(L) & this ); |
---|
858 | void ^?{}( pthread_cond_var(L) & this ); |
---|
859 | |
---|
860 | bool notify_one( pthread_cond_var(L) & this ); |
---|
861 | bool notify_all( pthread_cond_var(L) & this ); |
---|
862 | |
---|
863 | uintptr_t front( pthread_cond_var(L) & this ); |
---|
864 | bool empty ( pthread_cond_var(L) & this ); |
---|
865 | |
---|
866 | void wait( pthread_cond_var(L) & this, L & l ); |
---|
867 | void wait( pthread_cond_var(L) & this, L & l, uintptr_t info ); |
---|
868 | bool wait( pthread_cond_var(L) & this, L & l, timespec t ); |
---|
869 | bool wait( pthread_cond_var(L) & this, L & l, uintptr_t info, timespec t ); |
---|
870 | } |
---|