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1 /* GLIB - Library of useful routines for C programming |
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2 * Copyright (C) 1995-1997 Peter Mattis, Spencer Kimball and Josh MacDonald |
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3 * |
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4 * GAsyncQueue: thread pool implementation. |
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5 * Copyright (C) 2000 Sebastian Wilhelmi; University of Karlsruhe |
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6 * Portions copyright (c) 2006 Nokia Corporation. All rights reserved. |
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7 * |
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8 * This library is free software; you can redistribute it and/or |
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9 * modify it under the terms of the GNU Lesser General Public |
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10 * License as published by the Free Software Foundation; either |
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11 * version 2 of the License, or (at your option) any later version. |
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12 * |
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13 * This library is distributed in the hope that it will be useful, |
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14 * but WITHOUT ANY WARRANTY; without even the implied warranty of |
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15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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16 * Lesser General Public License for more details. |
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17 * |
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18 * You should have received a copy of the GNU Lesser General Public |
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19 * License along with this library; if not, write to the |
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20 * Free Software Foundation, Inc., 59 Temple Place - Suite 330, |
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21 * Boston, MA 02111-1307, USA. |
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22 */ |
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23 |
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24 /* |
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25 * MT safe |
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26 */ |
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27 |
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28 #include "config.h" |
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29 |
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30 #include "glib.h" |
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31 #include "galias.h" |
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32 |
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33 #ifdef __SYMBIAN32__ |
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34 #include <glib_wsd.h> |
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35 #endif /* __SYMBIAN32__ */ |
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36 |
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37 #if EMULATOR |
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38 #define g_thread_functions_for_glib_use (*_g_thread_functions_for_glib_use()) |
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39 #define g_thread_use_default_impl (*_g_thread_use_default_impl()) |
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40 #endif /* EMULATOR */ |
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41 |
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42 #define DEBUG_MSG(x) |
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43 /* #define DEBUG_MSG(args) g_printerr args ; g_printerr ("\n"); */ |
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44 |
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45 |
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46 typedef struct _GRealThreadPool GRealThreadPool; |
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47 |
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48 struct _GRealThreadPool |
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49 { |
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50 GThreadPool pool; |
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51 GAsyncQueue* queue; |
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52 GCond* cond; |
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53 gint max_threads; |
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54 gint num_threads; |
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55 gboolean running; |
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56 gboolean immediate; |
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57 gboolean waiting; |
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58 GCompareDataFunc sort_func; |
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59 gpointer sort_user_data; |
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60 }; |
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61 |
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62 /* The following is just an address to mark the wakeup order for a |
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63 * thread, it could be any address (as long, as it isn't a valid |
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64 * GThreadPool address) */ |
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65 #if EMULATOR |
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66 |
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67 PLS(wakeup_thread_serial,gthreadpool,gint) |
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68 PLS(unused_thread_queue,gthreadpool,GAsyncQueue *) |
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69 PLS(unused_threads,gthreadpool,gint) |
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70 PLS(max_unused_threads,gthreadpool,gint) |
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71 PLS(kill_unused_threads,gthreadpool,gint) |
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72 PLS(max_idle_time,gthreadpool,guint) |
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73 |
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74 #define wakeup_thread_serial (*FUNCTION_NAME(wakeup_thread_serial,gthreadpool)()) |
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75 #define unused_thread_queue (*FUNCTION_NAME(unused_thread_queue,gthreadpool)()) |
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76 #define unused_threads (*FUNCTION_NAME(unused_threads,gthreadpool)()) |
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77 #define max_unused_threads (*FUNCTION_NAME(max_unused_threads,gthreadpool)()) |
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78 #define kill_unused_threads (*FUNCTION_NAME(kill_unused_threads,gthreadpool)()) |
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79 #define max_idle_time (*FUNCTION_NAME(max_idle_time,gthreadpool)()) |
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80 |
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81 #else |
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82 |
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83 static gint wakeup_thread_serial = 0; |
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84 |
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85 /* Here all unused threads are waiting */ |
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86 static GAsyncQueue *unused_thread_queue = NULL; |
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87 static gint unused_threads = 0; |
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88 static gint max_unused_threads = 0; |
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89 static gint kill_unused_threads = 0; |
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90 static guint max_idle_time = 0; |
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91 |
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92 #endif /* EMULATOR */ |
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93 |
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94 static gconstpointer const wakeup_thread_marker = (gconstpointer) &g_thread_pool_new; |
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95 |
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96 static void g_thread_pool_queue_push_unlocked (GRealThreadPool *pool, |
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97 gpointer data); |
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98 static void g_thread_pool_free_internal (GRealThreadPool *pool); |
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99 static gpointer g_thread_pool_thread_proxy (gpointer data); |
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100 static void g_thread_pool_start_thread (GRealThreadPool *pool, |
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101 GError **error); |
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102 static void g_thread_pool_wakeup_and_stop_all (GRealThreadPool *pool); |
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103 static GRealThreadPool* g_thread_pool_wait_for_new_pool (void); |
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104 static gpointer g_thread_pool_wait_for_new_task (GRealThreadPool *pool); |
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105 |
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106 static void |
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107 g_thread_pool_queue_push_unlocked (GRealThreadPool *pool, |
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108 gpointer data) |
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109 { |
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110 if (pool->sort_func) |
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111 g_async_queue_push_sorted_unlocked (pool->queue, |
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112 data, |
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113 pool->sort_func, |
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114 pool->sort_user_data); |
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115 else |
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116 g_async_queue_push_unlocked (pool->queue, data); |
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117 } |
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118 |
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119 static GRealThreadPool* |
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120 g_thread_pool_wait_for_new_pool (void) |
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121 { |
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122 GRealThreadPool *pool; |
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123 gint local_wakeup_thread_serial; |
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124 guint local_max_unused_threads; |
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125 gint local_max_idle_time; |
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126 gint last_wakeup_thread_serial; |
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127 gboolean have_relayed_thread_marker = FALSE; |
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128 |
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129 local_max_unused_threads = g_atomic_int_get (&max_unused_threads); |
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130 local_max_idle_time = g_atomic_int_get (&max_idle_time); |
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131 last_wakeup_thread_serial = g_atomic_int_get (&wakeup_thread_serial); |
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132 |
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133 g_atomic_int_inc (&unused_threads); |
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134 |
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135 do |
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136 { |
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137 if (g_atomic_int_get (&unused_threads) >= local_max_unused_threads) |
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138 { |
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139 /* If this is a superfluous thread, stop it. */ |
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140 pool = NULL; |
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141 } |
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142 else if (local_max_idle_time > 0) |
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143 { |
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144 /* If a maximal idle time is given, wait for the given time. */ |
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145 GTimeVal end_time; |
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146 |
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147 g_get_current_time (&end_time); |
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148 g_time_val_add (&end_time, local_max_idle_time * 1000); |
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149 |
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150 DEBUG_MSG (("thread %p waiting in global pool for %f seconds.", |
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151 g_thread_self (), local_max_idle_time / 1000.0)); |
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152 |
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153 pool = g_async_queue_timed_pop (unused_thread_queue, &end_time); |
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154 } |
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155 else |
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156 { |
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157 /* If no maximal idle time is given, wait indefinitely. */ |
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158 DEBUG_MSG (("thread %p waiting in global pool.", |
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159 g_thread_self ())); |
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160 pool = g_async_queue_pop (unused_thread_queue); |
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161 } |
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162 |
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163 if (pool == wakeup_thread_marker) |
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164 { |
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165 local_wakeup_thread_serial = g_atomic_int_get (&wakeup_thread_serial); |
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166 if (last_wakeup_thread_serial == local_wakeup_thread_serial) |
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167 { |
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168 if (!have_relayed_thread_marker) |
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169 { |
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170 /* If this wakeup marker has been received for |
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171 * the second time, relay it. |
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172 */ |
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173 DEBUG_MSG (("thread %p relaying wakeup message to " |
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174 "waiting thread with lower serial.", |
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175 g_thread_self ())); |
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176 |
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177 g_async_queue_push (unused_thread_queue, FIX_CASTING(void *)wakeup_thread_marker); |
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178 have_relayed_thread_marker = TRUE; |
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179 |
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180 /* If a wakeup marker has been relayed, this thread |
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181 * will get out of the way for 100 microseconds to |
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182 * avoid receiving this marker again. */ |
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183 g_usleep (100); |
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184 } |
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185 } |
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186 else |
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187 { |
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188 if (g_atomic_int_exchange_and_add (&kill_unused_threads, -1) > 0) |
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189 { |
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190 pool = NULL; |
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191 break; |
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192 } |
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193 |
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194 DEBUG_MSG (("thread %p updating to new limits.", |
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195 g_thread_self ())); |
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196 |
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197 local_max_unused_threads = g_atomic_int_get (&max_unused_threads); |
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198 local_max_idle_time = g_atomic_int_get (&max_idle_time); |
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199 last_wakeup_thread_serial = local_wakeup_thread_serial; |
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200 |
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201 have_relayed_thread_marker = FALSE; |
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202 } |
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203 } |
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204 } |
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205 while (pool == wakeup_thread_marker); |
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206 |
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207 g_atomic_int_add (&unused_threads, -1); |
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208 |
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209 return pool; |
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210 } |
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211 |
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212 static gpointer |
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213 g_thread_pool_wait_for_new_task (GRealThreadPool *pool) |
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214 { |
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215 gpointer task = NULL; |
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216 |
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217 if (pool->running || (!pool->immediate && |
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218 g_async_queue_length_unlocked (pool->queue) > 0)) |
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219 { |
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220 /* This thread pool is still active. */ |
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221 if (pool->num_threads > pool->max_threads && pool->max_threads != -1) |
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222 { |
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223 /* This is a superfluous thread, so it goes to the global pool. */ |
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224 DEBUG_MSG (("superfluous thread %p in pool %p.", |
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225 g_thread_self (), pool)); |
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226 } |
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227 else if (pool->pool.exclusive) |
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228 { |
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229 /* Exclusive threads stay attached to the pool. */ |
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230 task = g_async_queue_pop_unlocked (pool->queue); |
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231 |
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232 DEBUG_MSG (("thread %p in exclusive pool %p waits for task " |
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233 "(%d running, %d unprocessed).", |
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234 g_thread_self (), pool, pool->num_threads, |
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235 g_async_queue_length_unlocked (pool->queue))); |
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236 } |
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237 else |
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238 { |
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239 /* A thread will wait for new tasks for at most 1/2 |
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240 * second before going to the global pool. |
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241 */ |
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242 GTimeVal end_time; |
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243 |
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244 g_get_current_time (&end_time); |
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245 g_time_val_add (&end_time, G_USEC_PER_SEC / 2); /* 1/2 second */ |
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246 |
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247 DEBUG_MSG (("thread %p in pool %p waits for up to a 1/2 second for task " |
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248 "(%d running, %d unprocessed).", |
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249 g_thread_self (), pool, pool->num_threads, |
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250 g_async_queue_length_unlocked (pool->queue))); |
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251 |
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252 task = g_async_queue_timed_pop_unlocked (pool->queue, &end_time); |
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253 } |
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254 } |
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255 else |
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256 { |
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257 /* This thread pool is inactive, it will no longer process tasks. */ |
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258 DEBUG_MSG (("pool %p not active, thread %p will go to global pool " |
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259 "(running: %s, immediate: %s, len: %d).", |
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260 pool, g_thread_self (), |
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261 pool->running ? "true" : "false", |
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262 pool->immediate ? "true" : "false", |
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263 g_async_queue_length_unlocked (pool->queue))); |
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264 } |
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265 |
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266 return task; |
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267 } |
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268 |
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269 |
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270 static gpointer |
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271 g_thread_pool_thread_proxy (gpointer data) |
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272 { |
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273 GRealThreadPool *pool; |
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274 |
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275 pool = data; |
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276 |
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277 DEBUG_MSG (("thread %p started for pool %p.", |
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278 g_thread_self (), pool)); |
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279 |
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280 g_async_queue_lock (pool->queue); |
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281 |
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282 while (TRUE) |
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283 { |
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284 gpointer task; |
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285 |
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286 task = g_thread_pool_wait_for_new_task (pool); |
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287 if (task) |
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288 { |
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289 if (pool->running || !pool->immediate) |
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290 { |
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291 /* A task was received and the thread pool is active, so |
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292 * execute the function. |
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293 */ |
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294 g_async_queue_unlock (pool->queue); |
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295 DEBUG_MSG (("thread %p in pool %p calling func.", |
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296 g_thread_self (), pool)); |
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297 pool->pool.func (task, pool->pool.user_data); |
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298 g_async_queue_lock (pool->queue); |
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299 } |
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300 } |
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301 else |
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302 { |
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303 /* No task was received, so this thread goes to the global |
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304 * pool. |
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305 */ |
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306 gboolean free_pool = FALSE; |
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307 |
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308 DEBUG_MSG (("thread %p leaving pool %p for global pool.", |
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309 g_thread_self (), pool)); |
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310 pool->num_threads--; |
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311 |
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312 if (!pool->running) |
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313 { |
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314 if (!pool->waiting) |
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315 { |
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316 if (pool->num_threads == 0) |
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317 { |
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318 /* If the pool is not running and no other |
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319 * thread is waiting for this thread pool to |
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320 * finish and this is the last thread of this |
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321 * pool, free the pool. |
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322 */ |
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323 free_pool = TRUE; |
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324 } |
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325 else |
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326 { |
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327 /* If the pool is not running and no other |
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328 * thread is waiting for this thread pool to |
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329 * finish and this is not the last thread of |
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330 * this pool and there are no tasks left in the |
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331 * queue, wakeup the remaining threads. |
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332 */ |
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333 if (g_async_queue_length_unlocked (pool->queue) == |
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334 - pool->num_threads) |
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335 g_thread_pool_wakeup_and_stop_all (pool); |
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336 } |
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337 } |
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338 else if (pool->immediate || |
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339 g_async_queue_length_unlocked (pool->queue) <= 0) |
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340 { |
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341 /* If the pool is not running and another thread is |
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342 * waiting for this thread pool to finish and there |
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343 * are either no tasks left or the pool shall stop |
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344 * immediatly, inform the waiting thread of a change |
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345 * of the thread pool state. |
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346 */ |
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347 g_cond_broadcast (pool->cond); |
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348 } |
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349 } |
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350 |
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351 g_async_queue_unlock (pool->queue); |
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352 |
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353 if (free_pool) |
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354 g_thread_pool_free_internal (pool); |
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355 |
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356 if ((pool = g_thread_pool_wait_for_new_pool ()) == NULL) |
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357 break; |
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358 |
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359 g_async_queue_lock (pool->queue); |
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360 |
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361 DEBUG_MSG (("thread %p entering pool %p from global pool.", |
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362 g_thread_self (), pool)); |
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363 |
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364 /* pool->num_threads++ is not done here, but in |
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365 * g_thread_pool_start_thread to make the new started thread |
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366 * known to the pool, before itself can do it. |
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367 */ |
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368 } |
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369 } |
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370 |
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371 return NULL; |
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372 } |
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373 |
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374 static void |
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375 g_thread_pool_start_thread (GRealThreadPool *pool, |
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376 GError **error) |
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377 { |
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378 gboolean success = FALSE; |
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379 |
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380 if (pool->num_threads >= pool->max_threads && pool->max_threads != -1) |
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381 /* Enough threads are already running */ |
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382 return; |
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383 |
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384 g_async_queue_lock (unused_thread_queue); |
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385 |
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386 if (g_async_queue_length_unlocked (unused_thread_queue) < 0) |
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387 { |
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388 g_async_queue_push_unlocked (unused_thread_queue, pool); |
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389 success = TRUE; |
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390 } |
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391 |
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392 g_async_queue_unlock (unused_thread_queue); |
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393 |
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394 if (!success) |
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395 { |
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396 GError *local_error = NULL; |
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397 /* No thread was found, we have to start a new one */ |
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398 g_thread_create (g_thread_pool_thread_proxy, pool, FALSE, &local_error); |
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399 |
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400 if (local_error) |
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401 { |
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402 g_propagate_error (error, local_error); |
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403 return; |
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404 } |
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405 } |
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406 |
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407 /* See comment in g_thread_pool_thread_proxy as to why this is done |
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408 * here and not there |
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409 */ |
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410 pool->num_threads++; |
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411 } |
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412 |
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413 /** |
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414 * g_thread_pool_new: |
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415 * @func: a function to execute in the threads of the new thread pool |
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416 * @user_data: user data that is handed over to @func every time it |
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417 * is called |
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418 * @max_threads: the maximal number of threads to execute concurrently in |
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419 * the new thread pool, -1 means no limit |
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420 * @exclusive: should this thread pool be exclusive? |
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421 * @error: return location for error |
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422 * |
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423 * This function creates a new thread pool. |
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424 * |
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425 * Whenever you call g_thread_pool_push(), either a new thread is |
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426 * created or an unused one is reused. At most @max_threads threads |
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427 * are running concurrently for this thread pool. @max_threads = -1 |
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428 * allows unlimited threads to be created for this thread pool. The |
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429 * newly created or reused thread now executes the function @func with |
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430 * the two arguments. The first one is the parameter to |
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431 * g_thread_pool_push() and the second one is @user_data. |
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432 * |
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433 * The parameter @exclusive determines, whether the thread pool owns |
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434 * all threads exclusive or whether the threads are shared |
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435 * globally. If @exclusive is %TRUE, @max_threads threads are started |
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436 * immediately and they will run exclusively for this thread pool until |
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437 * it is destroyed by g_thread_pool_free(). If @exclusive is %FALSE, |
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438 * threads are created, when needed and shared between all |
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439 * non-exclusive thread pools. This implies that @max_threads may not |
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440 * be -1 for exclusive thread pools. |
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441 * |
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442 * @error can be %NULL to ignore errors, or non-%NULL to report |
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443 * errors. An error can only occur when @exclusive is set to %TRUE and |
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444 * not all @max_threads threads could be created. |
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445 * |
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446 * Return value: the new #GThreadPool |
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447 **/ |
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448 |
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449 #if EMULATOR |
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450 |
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451 PLS_MACRO(init,g_thread_pool_new,GStaticMutex) |
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452 #define g__init_lock (*FUNCTION_NAME_MACRO(init,g_thread_pool_new)()) |
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453 |
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454 #endif /* EMULATOR */ |
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455 |
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456 EXPORT_C GThreadPool* |
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457 g_thread_pool_new (GFunc func, |
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458 gpointer user_data, |
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459 gint max_threads, |
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460 gboolean exclusive, |
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461 GError **error) |
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462 { |
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463 GRealThreadPool *retval; |
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464 |
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465 #if !(EMULATOR) |
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466 G_LOCK_DEFINE_STATIC (init); |
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467 #endif /* !(EMULATOR) */ |
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468 |
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469 g_return_val_if_fail (func, NULL); |
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470 g_return_val_if_fail (!exclusive || max_threads != -1, NULL); |
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471 g_return_val_if_fail (max_threads >= -1, NULL); |
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472 g_return_val_if_fail (g_thread_supported (), NULL); |
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473 retval = g_new (GRealThreadPool, 1); |
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474 |
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475 retval->pool.func = func; |
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476 retval->pool.user_data = user_data; |
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477 retval->pool.exclusive = exclusive; |
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478 retval->queue = g_async_queue_new (); |
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479 retval->cond = NULL; |
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480 retval->max_threads = max_threads; |
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481 retval->num_threads = 0; |
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482 retval->running = TRUE; |
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483 retval->sort_func = NULL; |
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484 retval->sort_user_data = NULL; |
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485 |
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486 G_LOCK (init); |
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487 if (!unused_thread_queue) |
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488 unused_thread_queue = g_async_queue_new (); |
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489 G_UNLOCK (init); |
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490 |
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491 if (retval->pool.exclusive) |
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492 { |
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493 g_async_queue_lock (retval->queue); |
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494 |
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495 while (retval->num_threads < retval->max_threads) |
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496 { |
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497 GError *local_error = NULL; |
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498 g_thread_pool_start_thread (retval, &local_error); |
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499 if (local_error) |
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500 { |
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501 g_propagate_error (error, local_error); |
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502 break; |
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503 } |
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504 } |
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505 |
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506 g_async_queue_unlock (retval->queue); |
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507 } |
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508 |
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509 return (GThreadPool*) retval; |
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510 } |
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511 |
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512 #if EMULATOR |
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513 #undef init |
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514 #endif /* EMULATOR */ |
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515 |
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516 /** |
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517 * g_thread_pool_push: |
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518 * @pool: a #GThreadPool |
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519 * @data: a new task for @pool |
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520 * @error: return location for error |
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521 * |
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522 * Inserts @data into the list of tasks to be executed by @pool. When |
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523 * the number of currently running threads is lower than the maximal |
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524 * allowed number of threads, a new thread is started (or reused) with |
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525 * the properties given to g_thread_pool_new (). Otherwise @data stays |
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526 * in the queue until a thread in this pool finishes its previous task |
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527 * and processes @data. |
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528 * |
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529 * @error can be %NULL to ignore errors, or non-%NULL to report |
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530 * errors. An error can only occur when a new thread couldn't be |
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531 * created. In that case @data is simply appended to the queue of work |
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532 * to do. |
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533 **/ |
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534 EXPORT_C void |
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535 g_thread_pool_push (GThreadPool *pool, |
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536 gpointer data, |
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537 GError **error) |
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538 { |
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539 GRealThreadPool *real; |
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540 |
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541 real = (GRealThreadPool*) pool; |
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542 |
|
543 g_return_if_fail (real); |
|
544 g_return_if_fail (real->running); |
|
545 |
|
546 g_async_queue_lock (real->queue); |
|
547 |
|
548 if (g_async_queue_length_unlocked (real->queue) >= 0) |
|
549 /* No thread is waiting in the queue */ |
|
550 g_thread_pool_start_thread (real, error); |
|
551 |
|
552 g_thread_pool_queue_push_unlocked (real, data); |
|
553 g_async_queue_unlock (real->queue); |
|
554 } |
|
555 |
|
556 /** |
|
557 * g_thread_pool_set_max_threads: |
|
558 * @pool: a #GThreadPool |
|
559 * @max_threads: a new maximal number of threads for @pool |
|
560 * @error: return location for error |
|
561 * |
|
562 * Sets the maximal allowed number of threads for @pool. A value of -1 |
|
563 * means, that the maximal number of threads is unlimited. |
|
564 * |
|
565 * Setting @max_threads to 0 means stopping all work for @pool. It is |
|
566 * effectively frozen until @max_threads is set to a non-zero value |
|
567 * again. |
|
568 * |
|
569 * A thread is never terminated while calling @func, as supplied by |
|
570 * g_thread_pool_new (). Instead the maximal number of threads only |
|
571 * has effect for the allocation of new threads in g_thread_pool_push(). |
|
572 * A new thread is allocated, whenever the number of currently |
|
573 * running threads in @pool is smaller than the maximal number. |
|
574 * |
|
575 * @error can be %NULL to ignore errors, or non-%NULL to report |
|
576 * errors. An error can only occur when a new thread couldn't be |
|
577 * created. |
|
578 **/ |
|
579 EXPORT_C void |
|
580 g_thread_pool_set_max_threads (GThreadPool *pool, |
|
581 gint max_threads, |
|
582 GError **error) |
|
583 { |
|
584 GRealThreadPool *real; |
|
585 gint to_start; |
|
586 |
|
587 real = (GRealThreadPool*) pool; |
|
588 |
|
589 g_return_if_fail (real); |
|
590 g_return_if_fail (real->running); |
|
591 g_return_if_fail (!real->pool.exclusive || max_threads != -1); |
|
592 g_return_if_fail (max_threads >= -1); |
|
593 |
|
594 g_async_queue_lock (real->queue); |
|
595 |
|
596 real->max_threads = max_threads; |
|
597 |
|
598 if (pool->exclusive) |
|
599 to_start = real->max_threads - real->num_threads; |
|
600 else |
|
601 to_start = g_async_queue_length_unlocked (real->queue); |
|
602 |
|
603 for ( ; to_start > 0; to_start--) |
|
604 { |
|
605 GError *local_error = NULL; |
|
606 |
|
607 g_thread_pool_start_thread (real, &local_error); |
|
608 if (local_error) |
|
609 { |
|
610 g_propagate_error (error, local_error); |
|
611 break; |
|
612 } |
|
613 } |
|
614 |
|
615 g_async_queue_unlock (real->queue); |
|
616 } |
|
617 |
|
618 /** |
|
619 * g_thread_pool_get_max_threads: |
|
620 * @pool: a #GThreadPool |
|
621 * |
|
622 * Returns the maximal number of threads for @pool. |
|
623 * |
|
624 * Return value: the maximal number of threads |
|
625 **/ |
|
626 EXPORT_C gint |
|
627 g_thread_pool_get_max_threads (GThreadPool *pool) |
|
628 { |
|
629 GRealThreadPool *real; |
|
630 gint retval; |
|
631 |
|
632 real = (GRealThreadPool*) pool; |
|
633 |
|
634 g_return_val_if_fail (real, 0); |
|
635 g_return_val_if_fail (real->running, 0); |
|
636 |
|
637 g_async_queue_lock (real->queue); |
|
638 retval = real->max_threads; |
|
639 g_async_queue_unlock (real->queue); |
|
640 |
|
641 return retval; |
|
642 } |
|
643 |
|
644 /** |
|
645 * g_thread_pool_get_num_threads: |
|
646 * @pool: a #GThreadPool |
|
647 * |
|
648 * Returns the number of threads currently running in @pool. |
|
649 * |
|
650 * Return value: the number of threads currently running |
|
651 **/ |
|
652 EXPORT_C guint |
|
653 g_thread_pool_get_num_threads (GThreadPool *pool) |
|
654 { |
|
655 GRealThreadPool *real; |
|
656 guint retval; |
|
657 |
|
658 real = (GRealThreadPool*) pool; |
|
659 |
|
660 g_return_val_if_fail (real, 0); |
|
661 g_return_val_if_fail (real->running, 0); |
|
662 |
|
663 g_async_queue_lock (real->queue); |
|
664 retval = real->num_threads; |
|
665 g_async_queue_unlock (real->queue); |
|
666 |
|
667 return retval; |
|
668 } |
|
669 |
|
670 /** |
|
671 * g_thread_pool_unprocessed: |
|
672 * @pool: a #GThreadPool |
|
673 * |
|
674 * Returns the number of tasks still unprocessed in @pool. |
|
675 * |
|
676 * Return value: the number of unprocessed tasks |
|
677 **/ |
|
678 EXPORT_C guint |
|
679 g_thread_pool_unprocessed (GThreadPool *pool) |
|
680 { |
|
681 GRealThreadPool *real; |
|
682 gint unprocessed; |
|
683 |
|
684 real = (GRealThreadPool*) pool; |
|
685 |
|
686 g_return_val_if_fail (real, 0); |
|
687 g_return_val_if_fail (real->running, 0); |
|
688 |
|
689 unprocessed = g_async_queue_length (real->queue); |
|
690 |
|
691 return MAX (unprocessed, 0); |
|
692 } |
|
693 |
|
694 /** |
|
695 * g_thread_pool_free: |
|
696 * @pool: a #GThreadPool |
|
697 * @immediate: should @pool shut down immediately? |
|
698 * @wait: should the function wait for all tasks to be finished? |
|
699 * |
|
700 * Frees all resources allocated for @pool. |
|
701 * |
|
702 * If @immediate is %TRUE, no new task is processed for |
|
703 * @pool. Otherwise @pool is not freed before the last task is |
|
704 * processed. Note however, that no thread of this pool is |
|
705 * interrupted, while processing a task. Instead at least all still |
|
706 * running threads can finish their tasks before the @pool is freed. |
|
707 * |
|
708 * If @wait is %TRUE, the functions does not return before all tasks |
|
709 * to be processed (dependent on @immediate, whether all or only the |
|
710 * currently running) are ready. Otherwise the function returns immediately. |
|
711 * |
|
712 * After calling this function @pool must not be used anymore. |
|
713 **/ |
|
714 EXPORT_C void |
|
715 g_thread_pool_free (GThreadPool *pool, |
|
716 gboolean immediate, |
|
717 gboolean wait) |
|
718 { |
|
719 GRealThreadPool *real; |
|
720 |
|
721 real = (GRealThreadPool*) pool; |
|
722 |
|
723 g_return_if_fail (real); |
|
724 g_return_if_fail (real->running); |
|
725 |
|
726 /* If there's no thread allowed here, there is not much sense in |
|
727 * not stopping this pool immediately, when it's not empty |
|
728 */ |
|
729 g_return_if_fail (immediate || |
|
730 real->max_threads != 0 || |
|
731 g_async_queue_length (real->queue) == 0); |
|
732 |
|
733 g_async_queue_lock (real->queue); |
|
734 |
|
735 real->running = FALSE; |
|
736 real->immediate = immediate; |
|
737 real->waiting = wait; |
|
738 |
|
739 if (wait) |
|
740 { |
|
741 real->cond = g_cond_new (); |
|
742 |
|
743 while (g_async_queue_length_unlocked (real->queue) != -real->num_threads && |
|
744 !(immediate && real->num_threads == 0)) |
|
745 g_cond_wait (real->cond, _g_async_queue_get_mutex (real->queue)); |
|
746 } |
|
747 |
|
748 if (immediate || g_async_queue_length_unlocked (real->queue) == -real->num_threads) |
|
749 { |
|
750 /* No thread is currently doing something (and nothing is left |
|
751 * to process in the queue) |
|
752 */ |
|
753 if (real->num_threads == 0) |
|
754 { |
|
755 /* No threads left, we clean up */ |
|
756 g_async_queue_unlock (real->queue); |
|
757 g_thread_pool_free_internal (real); |
|
758 return; |
|
759 } |
|
760 |
|
761 g_thread_pool_wakeup_and_stop_all (real); |
|
762 } |
|
763 |
|
764 /* The last thread should cleanup the pool */ |
|
765 real->waiting = FALSE; |
|
766 g_async_queue_unlock (real->queue); |
|
767 } |
|
768 |
|
769 static void |
|
770 g_thread_pool_free_internal (GRealThreadPool* pool) |
|
771 { |
|
772 g_return_if_fail (pool); |
|
773 g_return_if_fail (pool->running == FALSE); |
|
774 g_return_if_fail (pool->num_threads == 0); |
|
775 |
|
776 g_async_queue_unref (pool->queue); |
|
777 |
|
778 if (pool->cond) |
|
779 g_cond_free (pool->cond); |
|
780 |
|
781 g_free (pool); |
|
782 } |
|
783 |
|
784 static void |
|
785 g_thread_pool_wakeup_and_stop_all (GRealThreadPool* pool) |
|
786 { |
|
787 guint i; |
|
788 |
|
789 g_return_if_fail (pool); |
|
790 g_return_if_fail (pool->running == FALSE); |
|
791 g_return_if_fail (pool->num_threads != 0); |
|
792 |
|
793 pool->immediate = TRUE; |
|
794 |
|
795 for (i = 0; i < pool->num_threads; i++) |
|
796 g_thread_pool_queue_push_unlocked (pool, GUINT_TO_POINTER (1)); |
|
797 } |
|
798 |
|
799 /** |
|
800 * g_thread_pool_set_max_unused_threads: |
|
801 * @max_threads: maximal number of unused threads |
|
802 * |
|
803 * Sets the maximal number of unused threads to @max_threads. If |
|
804 * @max_threads is -1, no limit is imposed on the number of unused |
|
805 * threads. |
|
806 **/ |
|
807 EXPORT_C void |
|
808 g_thread_pool_set_max_unused_threads (gint max_threads) |
|
809 { |
|
810 g_return_if_fail (max_threads >= -1); |
|
811 |
|
812 g_atomic_int_set (&max_unused_threads, max_threads); |
|
813 |
|
814 if (max_threads != -1) |
|
815 { |
|
816 max_threads -= g_atomic_int_get (&unused_threads); |
|
817 if (max_threads < 0) |
|
818 { |
|
819 g_atomic_int_set (&kill_unused_threads, -max_threads); |
|
820 g_atomic_int_inc (&wakeup_thread_serial); |
|
821 |
|
822 g_async_queue_lock (unused_thread_queue); |
|
823 |
|
824 do |
|
825 { |
|
826 g_async_queue_push_unlocked (unused_thread_queue, |
|
827 FIX_CASTING(void *)wakeup_thread_marker); |
|
828 } |
|
829 while (++max_threads); |
|
830 |
|
831 g_async_queue_unlock (unused_thread_queue); |
|
832 } |
|
833 } |
|
834 } |
|
835 |
|
836 /** |
|
837 * g_thread_pool_get_max_unused_threads: |
|
838 * |
|
839 * Returns the maximal allowed number of unused threads. |
|
840 * |
|
841 * Return value: the maximal number of unused threads |
|
842 **/ |
|
843 EXPORT_C gint |
|
844 g_thread_pool_get_max_unused_threads (void) |
|
845 { |
|
846 return g_atomic_int_get (&max_unused_threads); |
|
847 } |
|
848 |
|
849 /** |
|
850 * g_thread_pool_get_num_unused_threads: |
|
851 * |
|
852 * Returns the number of currently unused threads. |
|
853 * |
|
854 * Return value: the number of currently unused threads |
|
855 **/ |
|
856 EXPORT_C guint |
|
857 g_thread_pool_get_num_unused_threads (void) |
|
858 { |
|
859 return g_atomic_int_get (&unused_threads); |
|
860 } |
|
861 |
|
862 /** |
|
863 * g_thread_pool_stop_unused_threads: |
|
864 * |
|
865 * Stops all currently unused threads. This does not change the |
|
866 * maximal number of unused threads. This function can be used to |
|
867 * regularly stop all unused threads e.g. from g_timeout_add(). |
|
868 **/ |
|
869 EXPORT_C void |
|
870 g_thread_pool_stop_unused_threads (void) |
|
871 { |
|
872 guint oldval; |
|
873 |
|
874 oldval = g_thread_pool_get_max_unused_threads (); |
|
875 |
|
876 g_thread_pool_set_max_unused_threads (0); |
|
877 g_thread_pool_set_max_unused_threads (oldval); |
|
878 } |
|
879 |
|
880 /** |
|
881 * g_thread_pool_set_sort_function: |
|
882 * @pool: a #GThreadPool |
|
883 * @func: the #GCompareDataFunc used to sort the list of tasks. |
|
884 * This function is passed two tasks. It should return |
|
885 * 0 if the order in which they are handled does not matter, |
|
886 * a negative value if the first task should be processed before |
|
887 * the second or a positive value if the second task should be |
|
888 * processed first. |
|
889 * @user_data: user data passed to @func. |
|
890 * |
|
891 * Sets the function used to sort the list of tasks. This allows the |
|
892 * tasks to be processed by a priority determined by @func, and not |
|
893 * just in the order in which they were added to the pool. |
|
894 * |
|
895 * Note, if the maximum number of threads is more than 1, the order |
|
896 * that threads are executed can not be guranteed 100%. Threads are |
|
897 * scheduled by the operating system and are executed at random. It |
|
898 * cannot be assumed that threads are executed in the order they are |
|
899 * created. |
|
900 * |
|
901 * Since: 2.10 |
|
902 **/ |
|
903 EXPORT_C void |
|
904 g_thread_pool_set_sort_function (GThreadPool *pool, |
|
905 GCompareDataFunc func, |
|
906 gpointer user_data) |
|
907 { |
|
908 GRealThreadPool *real; |
|
909 |
|
910 real = (GRealThreadPool*) pool; |
|
911 |
|
912 g_return_if_fail (real); |
|
913 g_return_if_fail (real->running); |
|
914 |
|
915 g_async_queue_lock (real->queue); |
|
916 |
|
917 real->sort_func = func; |
|
918 real->sort_user_data = user_data; |
|
919 |
|
920 if (func) |
|
921 g_async_queue_sort_unlocked (real->queue, |
|
922 real->sort_func, |
|
923 real->sort_user_data); |
|
924 |
|
925 g_async_queue_unlock (real->queue); |
|
926 } |
|
927 |
|
928 /** |
|
929 * g_thread_pool_set_max_idle_time: |
|
930 * @interval: the maximum @interval (1/1000ths of a second) a thread |
|
931 * can be idle. |
|
932 * |
|
933 * This function will set the maximum @interval that a thread waiting |
|
934 * in the pool for new tasks can be idle for before being |
|
935 * stopped. This function is similar to calling |
|
936 * g_thread_pool_stop_unused_threads() on a regular timeout, except, |
|
937 * this is done on a per thread basis. |
|
938 * |
|
939 * By setting @interval to 0, idle threads will not be stopped. |
|
940 * |
|
941 * This function makes use of g_async_queue_timed_pop () using |
|
942 * @interval. |
|
943 * |
|
944 * Since: 2.10 |
|
945 **/ |
|
946 EXPORT_C void |
|
947 g_thread_pool_set_max_idle_time (guint interval) |
|
948 { |
|
949 guint i; |
|
950 |
|
951 g_atomic_int_set (&max_idle_time, interval); |
|
952 |
|
953 i = g_atomic_int_get (&unused_threads); |
|
954 if (i > 0) |
|
955 { |
|
956 g_atomic_int_inc (&wakeup_thread_serial); |
|
957 g_async_queue_lock (unused_thread_queue); |
|
958 |
|
959 do |
|
960 { |
|
961 g_async_queue_push_unlocked (unused_thread_queue, |
|
962 FIX_CASTING(void *)wakeup_thread_marker); |
|
963 } |
|
964 while (--i); |
|
965 |
|
966 g_async_queue_unlock (unused_thread_queue); |
|
967 } |
|
968 } |
|
969 |
|
970 /** |
|
971 * g_thread_pool_get_max_idle_time: |
|
972 * |
|
973 * This function will return the maximum @interval that a thread will |
|
974 * wait in the thread pool for new tasks before being stopped. |
|
975 * |
|
976 * If this function returns 0, threads waiting in the thread pool for |
|
977 * new work are not stopped. |
|
978 * |
|
979 * Return value: the maximum @interval to wait for new tasks in the |
|
980 * thread pool before stopping the thread (1/1000ths of a second). |
|
981 * |
|
982 * Since: 2.10 |
|
983 **/ |
|
984 EXPORT_C guint |
|
985 g_thread_pool_get_max_idle_time (void) |
|
986 { |
|
987 return g_atomic_int_get (&max_idle_time); |
|
988 } |
|
989 |
|
990 #define __G_THREADPOOL_C__ |
|
991 #include "galiasdef.c" |