1 | // |
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2 | // C++ Interface: concurrent |
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3 | // |
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4 | // Description: |
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5 | // |
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6 | // |
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7 | // Author: Kohji Nakamura <k.nakamura@nao.ac.jp>, (C) 2012 |
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8 | // |
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9 | // Copyright: See COPYING file that comes with this distribution |
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10 | // |
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11 | // |
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12 | #ifndef CONCURRENT_H |
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13 | #define CONCURRENT_H |
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14 | |
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15 | #include <assert.h> |
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16 | #include <pthread.h> |
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17 | |
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18 | namespace concurrent { |
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19 | class PCException { |
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20 | public: |
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21 | virtual void raise() /*throw(PCException)*/ { throw *this; } |
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22 | virtual ~PCException() {} |
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23 | }; |
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24 | |
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25 | //typedef void (*produce_t)(void *context) throw(PCException); |
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26 | //typedef void (*consume_t)(void *context) throw(PCException); |
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27 | |
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28 | class Mutex { |
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29 | pthread_mutex_t mutex; |
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30 | public: |
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31 | Mutex() throw(int); |
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32 | virtual ~Mutex(); |
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33 | void lock() throw(int); |
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34 | /** |
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35 | * Returns true if this thread could lock. |
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36 | * Returns false if already locked. |
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37 | */ |
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38 | bool try_lock() throw(int); |
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39 | void unlock() throw(int); |
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40 | private: |
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41 | Mutex(Mutex const &other); |
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42 | Mutex &operator =(Mutex const &other); |
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43 | }; |
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44 | |
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45 | class Semaphore { |
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46 | pthread_mutex_t mutex; |
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47 | pthread_cond_t cond; |
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48 | unsigned sem; |
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49 | public: |
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50 | explicit Semaphore(unsigned initial = 0U) throw(int); |
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51 | void up(unsigned amount = 1U) throw(int); |
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52 | void down(unsigned amount = 1U) throw(int); |
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53 | virtual ~Semaphore(); |
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54 | private: |
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55 | Semaphore(Semaphore const &other); |
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56 | Semaphore &operator =(Semaphore const &other); |
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57 | }; |
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58 | |
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59 | class FIFOException { |
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60 | public: |
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61 | virtual void raise() { throw *this; } |
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62 | virtual ~FIFOException() {} |
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63 | }; |
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64 | |
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65 | class EmptyException { |
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66 | public: |
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67 | virtual void raise() { throw *this; } |
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68 | virtual ~EmptyException() {} |
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69 | }; |
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70 | |
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71 | class FullException { |
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72 | public: |
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73 | virtual void raise() { throw *this; } |
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74 | virtual ~FullException() {} |
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75 | }; |
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76 | |
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77 | template <class T, size_t N> |
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78 | class FIFO { |
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79 | T elements[N + 1]; // +1 to make an implementation simple. |
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80 | Mutex mutex; |
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81 | size_t head; |
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82 | size_t tail; |
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83 | |
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84 | size_t wrap(size_t n) { |
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85 | return n % (N + 1); |
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86 | } |
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87 | |
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88 | void reset() { |
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89 | head = tail = 0; |
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90 | } |
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91 | |
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92 | public: |
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93 | FIFO() { |
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94 | assert(N > 0); |
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95 | reset(); |
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96 | } |
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97 | virtual ~FIFO() { |
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98 | mutex.lock(); // wait until current lock is released. |
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99 | mutex.unlock(); |
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100 | } |
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101 | |
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102 | virtual void lock() { |
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103 | mutex.lock(); |
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104 | } |
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105 | |
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106 | /** |
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107 | * Returns true if this thread could lock. |
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108 | * Returns false if already locked. |
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109 | */ |
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110 | virtual bool try_lock() { |
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111 | return mutex.try_lock(); |
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112 | } |
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113 | |
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114 | virtual void unlock() { |
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115 | mutex.unlock(); |
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116 | } |
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117 | |
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118 | virtual void clear() { |
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119 | reset(); |
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120 | } |
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121 | |
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122 | virtual void put(T const &value) throw(FullException) { |
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123 | size_t new_tail = wrap(tail + 1); |
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124 | if (head == new_tail) { |
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125 | throw FullException(); |
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126 | } |
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127 | elements[tail] = value; |
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128 | tail = new_tail; |
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129 | } |
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130 | |
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131 | virtual T get() throw(EmptyException) { |
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132 | if (head == tail) { |
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133 | throw EmptyException(); |
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134 | } |
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135 | T result = elements[head]; |
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136 | head = wrap(head + 1); |
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137 | return result; |
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138 | } |
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139 | |
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140 | /** |
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141 | * Returns capacity size. |
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142 | */ |
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143 | virtual size_t size() const { |
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144 | return N; |
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145 | } |
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146 | |
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147 | /** |
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148 | * Returns number of elements in this FIFO. |
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149 | */ |
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150 | virtual size_t length() const { |
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151 | size_t result = tail - head; |
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152 | if (head > tail) { |
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153 | result = N + 1 - (head - tail); |
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154 | } |
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155 | return result; |
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156 | } |
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157 | private: |
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158 | FIFO(FIFO const &other); |
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159 | FIFO &operator =(FIFO const &other); |
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160 | }; |
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161 | |
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162 | class Broker { |
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163 | protected: |
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164 | enum ThreadSpec { |
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165 | ProdAsMaster, ConsAsMaster, Unspecified |
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166 | }; |
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167 | bool (*producer)(void *context) throw(PCException); |
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168 | void (*consumer)(void *context) throw(PCException); |
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169 | virtual void _run(void *context, unsigned do_ahead, ThreadSpec threadSpec) throw(PCException); |
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170 | public: |
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171 | Broker(bool (*producer)(void *context) throw(PCException), |
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172 | void (*consumer)(void *context) throw(PCException)); |
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173 | virtual ~Broker(); |
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174 | static void enableNested(); |
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175 | static void disableNested(); |
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176 | static void setNestedState(bool nested); |
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177 | static bool getNestedState(); |
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178 | |
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179 | virtual void run(void *context, unsigned do_ahead=1) throw(PCException); |
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180 | virtual void runProducerAsMasterThread(void *context, unsigned do_ahead=1) throw(PCException); |
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181 | virtual void runConsumerAsMasterThread(void *context, unsigned do_ahead=1) throw(PCException); |
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182 | virtual void runSequential(void *context) throw(PCException); |
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183 | }; |
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184 | |
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185 | #if 0 |
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186 | template <class Context, class Product> |
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187 | class Producer { |
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188 | public: |
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189 | virtual Product produce(Context &ctx) throw(PCException) = 0; |
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190 | virtual ~Producer() {} |
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191 | }; |
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192 | |
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193 | template <class Context, class Product> |
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194 | class Consumer { |
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195 | public: |
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196 | virtual void consume(Context &ctx, Product const&product) throw(PCException) = 0; |
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197 | virtual ~Consumer() {} |
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198 | }; |
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199 | |
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200 | class ProdCons { |
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201 | public: |
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202 | virtual ~ProdCons() {} |
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203 | |
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204 | virtual void runProducerAsMasterThread(void *context) throw(PCException) = 0; |
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205 | virtual void runConsumerAsMasterThread(void *context) throw(PCException) = 0; |
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206 | virtual void produce(void *context) throw(PCException) = 0; |
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207 | virtual void consume(void *context) throw(PCException) = 0; |
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208 | |
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209 | /** |
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210 | * <src>produce()</src> should call this method to |
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211 | * let consumer to know it is ready. |
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212 | */ |
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213 | virtual void ready() = 0; |
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214 | |
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215 | /** |
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216 | * Returns true if ready, |
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217 | * otherwise, finished or there was an error, returns false. |
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218 | * |
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219 | * <src>consume()</src> should call this method |
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220 | * to check if it is ready or not. |
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221 | * If false is returned, <src>isError()</src> or/and |
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222 | * <src>isFinished()</src> should be called to see the reason. |
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223 | */ |
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224 | virtual bool waitForReady() = 0; |
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225 | |
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226 | /** |
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227 | * Returns true if <src>produce()</src> was finished, |
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228 | * otherwise returns false. |
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229 | */ |
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230 | virtual bool isFinished() = 0; |
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231 | |
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232 | /** |
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233 | * <src>produce()</src>/<src>consume()</src> should call this method |
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234 | * to report error to <src>consume()</src>/<src>produce()</src>. |
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235 | */ |
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236 | virtual void reportError(void *errorInfo) = 0; |
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237 | |
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238 | /** |
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239 | * Returns true and set errorInfo if <src>reportError()</src> is called, |
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240 | * otherwise returns false and set errorInfo to NULL. |
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241 | */ |
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242 | virtual bool isError(void &*errorInfo) = 0; |
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243 | }; |
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244 | #endif |
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245 | |
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246 | } |
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247 | |
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248 | |
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249 | #endif |
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