1 | /* |
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2 | * Event loop |
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3 | * Copyright (c) 2002-2006, Jouni Malinen <j@w1.fi> |
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4 | * |
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5 | * This software may be distributed under the terms of the BSD license. |
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6 | * See README for more details. |
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7 | * |
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8 | * This file defines an event loop interface that supports processing events |
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9 | * from registered timeouts (i.e., do something after N seconds), sockets |
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10 | * (e.g., a new packet available for reading), and signals. eloop.c is an |
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11 | * implementation of this interface using select() and sockets. This is |
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12 | * suitable for most UNIX/POSIX systems. When porting to other operating |
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13 | * systems, it may be necessary to replace that implementation with OS specific |
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14 | * mechanisms. |
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15 | */ |
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16 | |
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17 | #ifndef ELOOP_H |
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18 | #define ELOOP_H |
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19 | |
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20 | /** |
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21 | * ELOOP_ALL_CTX - eloop_cancel_timeout() magic number to match all timeouts |
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22 | */ |
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23 | #define ELOOP_ALL_CTX (void *) -1 |
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24 | |
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25 | /** |
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26 | * eloop_event_type - eloop socket event type for eloop_register_sock() |
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27 | * @EVENT_TYPE_READ: Socket has data available for reading |
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28 | * @EVENT_TYPE_WRITE: Socket has room for new data to be written |
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29 | * @EVENT_TYPE_EXCEPTION: An exception has been reported |
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30 | */ |
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31 | typedef enum { |
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32 | EVENT_TYPE_READ = 0, |
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33 | EVENT_TYPE_WRITE, |
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34 | EVENT_TYPE_EXCEPTION |
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35 | } eloop_event_type; |
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36 | |
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37 | /** |
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38 | * eloop_sock_handler - eloop socket event callback type |
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39 | * @sock: File descriptor number for the socket |
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40 | * @eloop_ctx: Registered callback context data (eloop_data) |
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41 | * @sock_ctx: Registered callback context data (user_data) |
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42 | */ |
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43 | typedef void (*eloop_sock_handler)(int sock, void *eloop_ctx, void *sock_ctx); |
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44 | |
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45 | /** |
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46 | * eloop_event_handler - eloop generic event callback type |
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47 | * @eloop_ctx: Registered callback context data (eloop_data) |
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48 | * @sock_ctx: Registered callback context data (user_data) |
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49 | */ |
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50 | typedef void (*eloop_event_handler)(void *eloop_data, void *user_ctx); |
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51 | |
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52 | /** |
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53 | * eloop_timeout_handler - eloop timeout event callback type |
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54 | * @eloop_ctx: Registered callback context data (eloop_data) |
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55 | * @sock_ctx: Registered callback context data (user_data) |
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56 | */ |
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57 | typedef void (*eloop_timeout_handler)(void *eloop_data, void *user_ctx); |
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58 | |
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59 | /** |
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60 | * eloop_signal_handler - eloop signal event callback type |
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61 | * @sig: Signal number |
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62 | * @signal_ctx: Registered callback context data (user_data from |
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63 | * eloop_register_signal(), eloop_register_signal_terminate(), or |
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64 | * eloop_register_signal_reconfig() call) |
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65 | */ |
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66 | typedef void (*eloop_signal_handler)(int sig, void *signal_ctx); |
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67 | |
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68 | /** |
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69 | * eloop_init() - Initialize global event loop data |
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70 | * Returns: 0 on success, -1 on failure |
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71 | * |
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72 | * This function must be called before any other eloop_* function. |
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73 | */ |
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74 | int eloop_init(void); |
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75 | |
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76 | /** |
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77 | * eloop_register_read_sock - Register handler for read events |
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78 | * @sock: File descriptor number for the socket |
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79 | * @handler: Callback function to be called when data is available for reading |
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80 | * @eloop_data: Callback context data (eloop_ctx) |
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81 | * @user_data: Callback context data (sock_ctx) |
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82 | * Returns: 0 on success, -1 on failure |
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83 | * |
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84 | * Register a read socket notifier for the given file descriptor. The handler |
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85 | * function will be called whenever data is available for reading from the |
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86 | * socket. The handler function is responsible for clearing the event after |
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87 | * having processed it in order to avoid eloop from calling the handler again |
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88 | * for the same event. |
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89 | */ |
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90 | int eloop_register_read_sock(int sock, eloop_sock_handler handler, |
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91 | void *eloop_data, void *user_data); |
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92 | |
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93 | /** |
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94 | * eloop_unregister_read_sock - Unregister handler for read events |
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95 | * @sock: File descriptor number for the socket |
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96 | * |
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97 | * Unregister a read socket notifier that was previously registered with |
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98 | * eloop_register_read_sock(). |
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99 | */ |
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100 | void eloop_unregister_read_sock(int sock); |
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101 | |
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102 | /** |
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103 | * eloop_register_sock - Register handler for socket events |
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104 | * @sock: File descriptor number for the socket |
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105 | * @type: Type of event to wait for |
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106 | * @handler: Callback function to be called when the event is triggered |
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107 | * @eloop_data: Callback context data (eloop_ctx) |
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108 | * @user_data: Callback context data (sock_ctx) |
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109 | * Returns: 0 on success, -1 on failure |
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110 | * |
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111 | * Register an event notifier for the given socket's file descriptor. The |
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112 | * handler function will be called whenever the that event is triggered for the |
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113 | * socket. The handler function is responsible for clearing the event after |
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114 | * having processed it in order to avoid eloop from calling the handler again |
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115 | * for the same event. |
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116 | */ |
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117 | int eloop_register_sock(int sock, eloop_event_type type, |
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118 | eloop_sock_handler handler, |
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119 | void *eloop_data, void *user_data); |
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120 | |
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121 | /** |
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122 | * eloop_unregister_sock - Unregister handler for socket events |
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123 | * @sock: File descriptor number for the socket |
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124 | * @type: Type of event for which sock was registered |
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125 | * |
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126 | * Unregister a socket event notifier that was previously registered with |
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127 | * eloop_register_sock(). |
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128 | */ |
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129 | void eloop_unregister_sock(int sock, eloop_event_type type); |
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130 | |
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131 | /** |
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132 | * eloop_register_event - Register handler for generic events |
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133 | * @event: Event to wait (eloop implementation specific) |
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134 | * @event_size: Size of event data |
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135 | * @handler: Callback function to be called when event is triggered |
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136 | * @eloop_data: Callback context data (eloop_data) |
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137 | * @user_data: Callback context data (user_data) |
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138 | * Returns: 0 on success, -1 on failure |
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139 | * |
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140 | * Register an event handler for the given event. This function is used to |
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141 | * register eloop implementation specific events which are mainly targeted for |
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142 | * operating system specific code (driver interface and l2_packet) since the |
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143 | * portable code will not be able to use such an OS-specific call. The handler |
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144 | * function will be called whenever the event is triggered. The handler |
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145 | * function is responsible for clearing the event after having processed it in |
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146 | * order to avoid eloop from calling the handler again for the same event. |
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147 | * |
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148 | * In case of Windows implementation (eloop_win.c), event pointer is of HANDLE |
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149 | * type, i.e., void*. The callers are likely to have 'HANDLE h' type variable, |
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150 | * and they would call this function with eloop_register_event(h, sizeof(h), |
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151 | * ...). |
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152 | */ |
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153 | int eloop_register_event(void *event, size_t event_size, |
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154 | eloop_event_handler handler, |
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155 | void *eloop_data, void *user_data); |
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156 | |
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157 | /** |
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158 | * eloop_unregister_event - Unregister handler for a generic event |
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159 | * @event: Event to cancel (eloop implementation specific) |
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160 | * @event_size: Size of event data |
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161 | * |
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162 | * Unregister a generic event notifier that was previously registered with |
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163 | * eloop_register_event(). |
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164 | */ |
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165 | void eloop_unregister_event(void *event, size_t event_size); |
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166 | |
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167 | /** |
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168 | * eloop_register_timeout - Register timeout |
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169 | * @secs: Number of seconds to the timeout |
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170 | * @usecs: Number of microseconds to the timeout |
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171 | * @handler: Callback function to be called when timeout occurs |
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172 | * @eloop_data: Callback context data (eloop_ctx) |
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173 | * @user_data: Callback context data (sock_ctx) |
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174 | * Returns: 0 on success, -1 on failure |
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175 | * |
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176 | * Register a timeout that will cause the handler function to be called after |
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177 | * given time. |
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178 | */ |
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179 | int eloop_register_timeout(unsigned int secs, unsigned int usecs, |
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180 | eloop_timeout_handler handler, |
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181 | void *eloop_data, void *user_data); |
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182 | |
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183 | /** |
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184 | * eloop_cancel_timeout - Cancel timeouts |
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185 | * @handler: Matching callback function |
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186 | * @eloop_data: Matching eloop_data or %ELOOP_ALL_CTX to match all |
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187 | * @user_data: Matching user_data or %ELOOP_ALL_CTX to match all |
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188 | * Returns: Number of cancelled timeouts |
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189 | * |
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190 | * Cancel matching <handler,eloop_data,user_data> timeouts registered with |
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191 | * eloop_register_timeout(). ELOOP_ALL_CTX can be used as a wildcard for |
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192 | * cancelling all timeouts regardless of eloop_data/user_data. |
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193 | */ |
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194 | int eloop_cancel_timeout(eloop_timeout_handler handler, |
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195 | void *eloop_data, void *user_data); |
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196 | |
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197 | /** |
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198 | * eloop_cancel_timeout_one - Cancel a single timeout |
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199 | * @handler: Matching callback function |
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200 | * @eloop_data: Matching eloop_data |
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201 | * @user_data: Matching user_data |
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202 | * @remaining: Time left on the cancelled timer |
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203 | * Returns: Number of cancelled timeouts |
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204 | * |
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205 | * Cancel matching <handler,eloop_data,user_data> timeout registered with |
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206 | * eloop_register_timeout() and return the remaining time left. |
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207 | */ |
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208 | int eloop_cancel_timeout_one(eloop_timeout_handler handler, |
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209 | void *eloop_data, void *user_data, |
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210 | struct os_reltime *remaining); |
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211 | |
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212 | /** |
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213 | * eloop_is_timeout_registered - Check if a timeout is already registered |
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214 | * @handler: Matching callback function |
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215 | * @eloop_data: Matching eloop_data |
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216 | * @user_data: Matching user_data |
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217 | * Returns: 1 if the timeout is registered, 0 if the timeout is not registered |
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218 | * |
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219 | * Determine if a matching <handler,eloop_data,user_data> timeout is registered |
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220 | * with eloop_register_timeout(). |
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221 | */ |
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222 | int eloop_is_timeout_registered(eloop_timeout_handler handler, |
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223 | void *eloop_data, void *user_data); |
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224 | |
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225 | /** |
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226 | * eloop_deplete_timeout - Deplete a timeout that is already registered |
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227 | * @req_secs: Requested number of seconds to the timeout |
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228 | * @req_usecs: Requested number of microseconds to the timeout |
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229 | * @handler: Matching callback function |
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230 | * @eloop_data: Matching eloop_data |
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231 | * @user_data: Matching user_data |
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232 | * Returns: 1 if the timeout is depleted, 0 if no change is made, -1 if no |
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233 | * timeout matched |
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234 | * |
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235 | * Find a registered matching <handler,eloop_data,user_data> timeout. If found, |
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236 | * deplete the timeout if remaining time is more than the requested time. |
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237 | */ |
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238 | int eloop_deplete_timeout(unsigned int req_secs, unsigned int req_usecs, |
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239 | eloop_timeout_handler handler, void *eloop_data, |
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240 | void *user_data); |
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241 | |
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242 | /** |
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243 | * eloop_replenish_timeout - Replenish a timeout that is already registered |
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244 | * @req_secs: Requested number of seconds to the timeout |
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245 | * @req_usecs: Requested number of microseconds to the timeout |
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246 | * @handler: Matching callback function |
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247 | * @eloop_data: Matching eloop_data |
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248 | * @user_data: Matching user_data |
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249 | * Returns: 1 if the timeout is replenished, 0 if no change is made, -1 if no |
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250 | * timeout matched |
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251 | * |
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252 | * Find a registered matching <handler,eloop_data,user_data> timeout. If found, |
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253 | * replenish the timeout if remaining time is less than the requested time. |
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254 | */ |
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255 | int eloop_replenish_timeout(unsigned int req_secs, unsigned int req_usecs, |
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256 | eloop_timeout_handler handler, void *eloop_data, |
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257 | void *user_data); |
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258 | |
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259 | /** |
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260 | * eloop_register_signal - Register handler for signals |
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261 | * @sig: Signal number (e.g., SIGHUP) |
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262 | * @handler: Callback function to be called when the signal is received |
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263 | * @user_data: Callback context data (signal_ctx) |
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264 | * Returns: 0 on success, -1 on failure |
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265 | * |
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266 | * Register a callback function that will be called when a signal is received. |
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267 | * The callback function is actually called only after the system signal |
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268 | * handler has returned. This means that the normal limits for sighandlers |
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269 | * (i.e., only "safe functions" allowed) do not apply for the registered |
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270 | * callback. |
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271 | */ |
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272 | int eloop_register_signal(int sig, eloop_signal_handler handler, |
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273 | void *user_data); |
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274 | |
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275 | /** |
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276 | * eloop_register_signal_terminate - Register handler for terminate signals |
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277 | * @handler: Callback function to be called when the signal is received |
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278 | * @user_data: Callback context data (signal_ctx) |
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279 | * Returns: 0 on success, -1 on failure |
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280 | * |
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281 | * Register a callback function that will be called when a process termination |
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282 | * signal is received. The callback function is actually called only after the |
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283 | * system signal handler has returned. This means that the normal limits for |
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284 | * sighandlers (i.e., only "safe functions" allowed) do not apply for the |
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285 | * registered callback. |
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286 | * |
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287 | * This function is a more portable version of eloop_register_signal() since |
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288 | * the knowledge of exact details of the signals is hidden in eloop |
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289 | * implementation. In case of operating systems using signal(), this function |
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290 | * registers handlers for SIGINT and SIGTERM. |
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291 | */ |
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292 | int eloop_register_signal_terminate(eloop_signal_handler handler, |
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293 | void *user_data); |
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294 | |
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295 | /** |
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296 | * eloop_register_signal_reconfig - Register handler for reconfig signals |
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297 | * @handler: Callback function to be called when the signal is received |
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298 | * @user_data: Callback context data (signal_ctx) |
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299 | * Returns: 0 on success, -1 on failure |
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300 | * |
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301 | * Register a callback function that will be called when a reconfiguration / |
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302 | * hangup signal is received. The callback function is actually called only |
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303 | * after the system signal handler has returned. This means that the normal |
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304 | * limits for sighandlers (i.e., only "safe functions" allowed) do not apply |
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305 | * for the registered callback. |
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306 | * |
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307 | * This function is a more portable version of eloop_register_signal() since |
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308 | * the knowledge of exact details of the signals is hidden in eloop |
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309 | * implementation. In case of operating systems using signal(), this function |
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310 | * registers a handler for SIGHUP. |
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311 | */ |
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312 | int eloop_register_signal_reconfig(eloop_signal_handler handler, |
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313 | void *user_data); |
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314 | |
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315 | /** |
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316 | * eloop_run - Start the event loop |
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317 | * |
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318 | * Start the event loop and continue running as long as there are any |
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319 | * registered event handlers. This function is run after event loop has been |
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320 | * initialized with event_init() and one or more events have been registered. |
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321 | */ |
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322 | void eloop_run(void); |
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323 | |
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324 | /** |
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325 | * eloop_terminate - Terminate event loop |
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326 | * |
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327 | * Terminate event loop even if there are registered events. This can be used |
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328 | * to request the program to be terminated cleanly. |
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329 | */ |
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330 | void eloop_terminate(void); |
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331 | |
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332 | /** |
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333 | * eloop_destroy - Free any resources allocated for the event loop |
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334 | * |
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335 | * After calling eloop_destroy(), other eloop_* functions must not be called |
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336 | * before re-running eloop_init(). |
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337 | */ |
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338 | void eloop_destroy(void); |
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339 | |
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340 | /** |
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341 | * eloop_terminated - Check whether event loop has been terminated |
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342 | * Returns: 1 = event loop terminate, 0 = event loop still running |
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343 | * |
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344 | * This function can be used to check whether eloop_terminate() has been called |
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345 | * to request termination of the event loop. This is normally used to abort |
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346 | * operations that may still be queued to be run when eloop_terminate() was |
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347 | * called. |
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348 | */ |
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349 | int eloop_terminated(void); |
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350 | |
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351 | /** |
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352 | * eloop_wait_for_read_sock - Wait for a single reader |
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353 | * @sock: File descriptor number for the socket |
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354 | * |
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355 | * Do a blocking wait for a single read socket. |
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356 | */ |
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357 | void eloop_wait_for_read_sock(int sock); |
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358 | |
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359 | #endif /* ELOOP_H */ |
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