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