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1 | office | 1 | /** |
2 | * @file depend.c |
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3 | * @author Ambroz Bizjak <ambrop7@gmail.com> |
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4 | * |
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5 | * @section LICENSE |
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6 | * |
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7 | * Redistribution and use in source and binary forms, with or without |
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8 | * modification, are permitted provided that the following conditions are met: |
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9 | * 1. Redistributions of source code must retain the above copyright |
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10 | * notice, this list of conditions and the following disclaimer. |
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11 | * 2. Redistributions in binary form must reproduce the above copyright |
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12 | * notice, this list of conditions and the following disclaimer in the |
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13 | * documentation and/or other materials provided with the distribution. |
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14 | * 3. Neither the name of the author nor the |
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15 | * names of its contributors may be used to endorse or promote products |
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16 | * derived from this software without specific prior written permission. |
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17 | * |
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18 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND |
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19 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED |
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20 | * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE |
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21 | * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY |
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22 | * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES |
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23 | * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; |
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24 | * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND |
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25 | * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
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26 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS |
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27 | * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
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28 | * |
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29 | * @section DESCRIPTION |
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30 | * |
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31 | * Dependencies module. |
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32 | * |
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33 | * Synopsis: provide(string name) |
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34 | * Description: Provides a resource. On initialization, transitions any depend()-s |
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35 | * waiting for this resource to UP state. On deinitialization, transitions |
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36 | * depend()-s using this resource to DOWN state, and waits for all of them to |
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37 | * receive the clean signal (i.e. wait for all of the statements following them in |
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38 | * their processes to terminate). Initialization fails if a provide() already |
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39 | * exists for this resource (including if it is being deinitialized). |
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40 | * |
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41 | * Synopsis: provide_event(string name) |
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42 | * Description: Like provide(), but if another provide() already exists for this |
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43 | * resource, initialization does not fail, and the request is queued to the active |
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44 | * provide() for this resource. When an active provide() disappears that has |
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45 | * queued provide()-s, one of them is promoted to be the active provide() for this |
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46 | * resource, and the remaining queue is transferred to it. |
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47 | * (mentions of provide() in this text also apply to provide_event()) |
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48 | * |
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49 | * Synopsis: depend(string name) |
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50 | * Description: Depends on a resource. Is in UP state when a provide() |
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51 | * for this resource is available, and in DOWN state when it is not (either |
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52 | * it does not exist or is being terminated). |
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53 | * Variables: Provides variables available from the corresponding provide, |
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54 | * ("modname.varname" or "modname"). |
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55 | */ |
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56 | |||
57 | #include <stdlib.h> |
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58 | #include <string.h> |
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59 | |||
60 | #include <misc/offset.h> |
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61 | #include <misc/debug.h> |
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62 | #include <misc/balloc.h> |
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63 | #include <structure/LinkedList1.h> |
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64 | #include <structure/LinkedList3.h> |
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65 | |||
66 | #include <ncd/module_common.h> |
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67 | |||
68 | #include <generated/blog_channel_ncd_depend.h> |
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69 | |||
70 | struct provide { |
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71 | NCDModuleInst *i; |
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72 | MemRef name; |
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73 | int is_queued; |
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74 | union { |
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75 | struct { |
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76 | LinkedList3Node queued_node; // node in list which begins with provide.queued_provides_firstnode |
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77 | }; |
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78 | struct { |
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79 | LinkedList1Node provides_node; // node in provides |
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80 | LinkedList1 depends; |
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81 | LinkedList3Node queued_provides_firstnode; |
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82 | int dying; |
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83 | }; |
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84 | }; |
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85 | }; |
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86 | |||
87 | struct depend { |
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88 | NCDModuleInst *i; |
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89 | MemRef name; |
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90 | struct provide *p; |
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91 | LinkedList1Node node; |
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92 | }; |
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93 | |||
94 | struct global { |
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95 | LinkedList1 provides; |
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96 | LinkedList1 free_depends; |
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97 | }; |
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98 | |||
99 | static struct provide * find_provide (struct global *g, MemRef name) |
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100 | { |
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101 | for (LinkedList1Node *n = LinkedList1_GetFirst(&g->provides); n; n = LinkedList1Node_Next(n)) { |
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102 | struct provide *p = UPPER_OBJECT(n, struct provide, provides_node); |
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103 | ASSERT(!p->is_queued) |
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104 | |||
105 | if (MemRef_Equal(p->name, name)) { |
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106 | return p; |
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107 | } |
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108 | } |
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109 | |||
110 | return NULL; |
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111 | } |
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112 | |||
113 | static void provide_promote (struct provide *o) |
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114 | { |
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115 | struct global *g = ModuleGlobal(o->i); |
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116 | ASSERT(!find_provide(g, o->name)) |
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117 | |||
118 | // set not queued |
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119 | o->is_queued = 0; |
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120 | |||
121 | // insert to provides list |
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122 | LinkedList1_Append(&g->provides, &o->provides_node); |
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123 | |||
124 | // init depends list |
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125 | LinkedList1_Init(&o->depends); |
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126 | |||
127 | // set not dying |
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128 | o->dying = 0; |
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129 | |||
130 | // attach free depends with this name |
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131 | LinkedList1Node *n = LinkedList1_GetFirst(&g->free_depends); |
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132 | while (n) { |
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133 | LinkedList1Node *next = LinkedList1Node_Next(n); |
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134 | struct depend *d = UPPER_OBJECT(n, struct depend, node); |
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135 | ASSERT(!d->p) |
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136 | |||
137 | if (!MemRef_Equal(d->name, o->name)) { |
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138 | n = next; |
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139 | continue; |
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140 | } |
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141 | |||
142 | // remove from free depends list |
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143 | LinkedList1_Remove(&g->free_depends, &d->node); |
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144 | |||
145 | // insert to provide's list |
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146 | LinkedList1_Append(&o->depends, &d->node); |
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147 | |||
148 | // set provide |
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149 | d->p = o; |
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150 | |||
151 | // signal up |
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152 | NCDModuleInst_Backend_Up(d->i); |
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153 | |||
154 | n = next; |
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155 | } |
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156 | } |
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157 | |||
158 | static int func_globalinit (struct NCDInterpModuleGroup *group, const struct NCDModuleInst_iparams *params) |
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159 | { |
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160 | // allocate global state structure |
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161 | struct global *g = BAlloc(sizeof(*g)); |
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162 | if (!g) { |
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163 | BLog(BLOG_ERROR, "BAlloc failed"); |
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164 | return 0; |
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165 | } |
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166 | |||
167 | // set group state pointer |
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168 | group->group_state = g; |
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169 | |||
170 | // init provides list |
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171 | LinkedList1_Init(&g->provides); |
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172 | |||
173 | // init free depends list |
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174 | LinkedList1_Init(&g->free_depends); |
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175 | |||
176 | return 1; |
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177 | } |
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178 | |||
179 | static void func_globalfree (struct NCDInterpModuleGroup *group) |
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180 | { |
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181 | struct global *g = group->group_state; |
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182 | ASSERT(LinkedList1_IsEmpty(&g->free_depends)) |
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183 | ASSERT(LinkedList1_IsEmpty(&g->provides)) |
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184 | |||
185 | // free global state structure |
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186 | BFree(g); |
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187 | } |
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188 | |||
189 | static void provide_func_new_templ (void *vo, NCDModuleInst *i, const struct NCDModuleInst_new_params *params, int event) |
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190 | { |
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191 | struct global *g = ModuleGlobal(i); |
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192 | struct provide *o = vo; |
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193 | o->i = i; |
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194 | |||
195 | // read arguments |
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196 | NCDValRef name_arg; |
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197 | if (!NCDVal_ListRead(params->args, 1, &name_arg)) { |
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198 | ModuleLog(o->i, BLOG_ERROR, "wrong arity"); |
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199 | goto fail0; |
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200 | } |
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201 | if (!NCDVal_IsString(name_arg)) { |
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202 | ModuleLog(o->i, BLOG_ERROR, "wrong type"); |
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203 | goto fail0; |
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204 | } |
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205 | o->name = NCDVal_StringMemRef(name_arg); |
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206 | |||
207 | // signal up. |
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208 | // This comes above provide_promote(), so that effects on related depend statements are |
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209 | // computed before this process advances, avoiding problems like failed variable resolutions. |
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210 | NCDModuleInst_Backend_Up(o->i); |
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211 | |||
212 | // check for existing provide with this name |
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213 | struct provide *ep = find_provide(g, o->name); |
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214 | if (ep) { |
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215 | ASSERT(!ep->is_queued) |
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216 | |||
217 | if (!event) { |
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218 | ModuleLog(o->i, BLOG_ERROR, "a provide with this name already exists"); |
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219 | goto fail0; |
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220 | } |
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221 | |||
222 | // set queued |
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223 | o->is_queued = 1; |
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224 | |||
225 | // insert to existing provide's queued provides list |
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226 | LinkedList3Node_InitAfter(&o->queued_node, &ep->queued_provides_firstnode); |
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227 | } else { |
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228 | // init first node for queued provides list |
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229 | LinkedList3Node_InitLonely(&o->queued_provides_firstnode); |
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230 | |||
231 | // promote provide |
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232 | provide_promote(o); |
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233 | } |
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234 | |||
235 | return; |
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236 | |||
237 | fail0: |
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238 | NCDModuleInst_Backend_DeadError(i); |
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239 | } |
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240 | |||
241 | static void provide_func_new (void *vo, NCDModuleInst *i, const struct NCDModuleInst_new_params *params) |
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242 | { |
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243 | provide_func_new_templ(vo, i, params, 0); |
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244 | } |
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245 | |||
246 | static void provide_event_func_new (void *vo, NCDModuleInst *i, const struct NCDModuleInst_new_params *params) |
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247 | { |
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248 | provide_func_new_templ(vo, i, params, 1); |
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249 | } |
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250 | |||
251 | static void provide_free (struct provide *o) |
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252 | { |
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253 | struct global *g = ModuleGlobal(o->i); |
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254 | ASSERT(o->is_queued || LinkedList1_IsEmpty(&o->depends)) |
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255 | |||
256 | if (o->is_queued) { |
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257 | // remove from existing provide's queued provides list |
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258 | LinkedList3Node_Free(&o->queued_node); |
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259 | } else { |
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260 | // remove from provides list |
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261 | LinkedList1_Remove(&g->provides, &o->provides_node); |
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262 | |||
263 | // if we have provides queued, promote the first one |
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264 | if (LinkedList3Node_Next(&o->queued_provides_firstnode)) { |
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265 | // get first queued provide |
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266 | struct provide *qp = UPPER_OBJECT(LinkedList3Node_Next(&o->queued_provides_firstnode), struct provide, queued_node); |
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267 | ASSERT(qp->is_queued) |
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268 | |||
269 | // make it the head of the queued provides list |
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270 | LinkedList3Node_Free(&qp->queued_node); |
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271 | LinkedList3Node_InitAfter(&qp->queued_provides_firstnode, &o->queued_provides_firstnode); |
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272 | LinkedList3Node_Free(&o->queued_provides_firstnode); |
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273 | |||
274 | // promote provide |
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275 | provide_promote(qp); |
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276 | } |
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277 | } |
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278 | |||
279 | NCDModuleInst_Backend_Dead(o->i); |
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280 | } |
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281 | |||
282 | static void provide_func_die (void *vo) |
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283 | { |
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284 | struct provide *o = vo; |
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285 | ASSERT(o->is_queued || !o->dying) |
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286 | |||
287 | // if we are queued or have no depends, die immediately |
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288 | if (o->is_queued || LinkedList1_IsEmpty(&o->depends)) { |
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289 | provide_free(o); |
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290 | return; |
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291 | } |
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292 | |||
293 | // set dying |
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294 | o->dying = 1; |
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295 | |||
296 | // signal our depends down |
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297 | for (LinkedList1Node *n = LinkedList1_GetFirst(&o->depends); n; n = LinkedList1Node_Next(n)) { |
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298 | struct depend *d = UPPER_OBJECT(n, struct depend, node); |
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299 | ASSERT(d->p == o) |
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300 | |||
301 | // signal down |
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302 | NCDModuleInst_Backend_Down(d->i); |
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303 | } |
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304 | } |
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305 | |||
306 | static void depend_func_new (void *vo, NCDModuleInst *i, const struct NCDModuleInst_new_params *params) |
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307 | { |
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308 | struct global *g = ModuleGlobal(i); |
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309 | struct depend *o = vo; |
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310 | o->i = i; |
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311 | |||
312 | // read arguments |
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313 | NCDValRef name_arg; |
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314 | if (!NCDVal_ListRead(params->args, 1, &name_arg)) { |
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315 | ModuleLog(o->i, BLOG_ERROR, "wrong arity"); |
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316 | goto fail0; |
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317 | } |
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318 | if (!NCDVal_IsString(name_arg)) { |
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319 | ModuleLog(o->i, BLOG_ERROR, "wrong type"); |
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320 | goto fail0; |
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321 | } |
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322 | o->name = NCDVal_StringMemRef(name_arg); |
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323 | |||
324 | // find a provide with our name |
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325 | struct provide *p = find_provide(g, o->name); |
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326 | ASSERT(!p || !p->is_queued) |
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327 | |||
328 | if (p && !p->dying) { |
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329 | // insert to provide's list |
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330 | LinkedList1_Append(&p->depends, &o->node); |
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331 | |||
332 | // set provide |
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333 | o->p = p; |
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334 | |||
335 | // signal up |
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336 | NCDModuleInst_Backend_Up(o->i); |
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337 | } else { |
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338 | // insert to free depends list |
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339 | LinkedList1_Append(&g->free_depends, &o->node); |
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340 | |||
341 | // set no provide |
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342 | o->p = NULL; |
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343 | } |
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344 | |||
345 | return; |
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346 | |||
347 | fail0: |
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348 | NCDModuleInst_Backend_DeadError(i); |
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349 | } |
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350 | |||
351 | static void depend_free (struct depend *o) |
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352 | { |
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353 | struct global *g = ModuleGlobal(o->i); |
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354 | ASSERT(!o->p || !o->p->is_queued) |
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355 | |||
356 | if (o->p) { |
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357 | // remove from provide's list |
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358 | LinkedList1_Remove(&o->p->depends, &o->node); |
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359 | |||
360 | // if provide is dying and is empty, let it die |
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361 | if (o->p->dying && LinkedList1_IsEmpty(&o->p->depends)) { |
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362 | provide_free(o->p); |
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363 | } |
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364 | } else { |
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365 | // remove free depends list |
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366 | LinkedList1_Remove(&g->free_depends, &o->node); |
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367 | } |
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368 | |||
369 | NCDModuleInst_Backend_Dead(o->i); |
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370 | } |
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371 | |||
372 | static void depend_func_die (void *vo) |
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373 | { |
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374 | struct depend *o = vo; |
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375 | |||
376 | depend_free(o); |
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377 | } |
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378 | |||
379 | static void depend_func_clean (void *vo) |
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380 | { |
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381 | struct depend *o = vo; |
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382 | struct global *g = ModuleGlobal(o->i); |
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383 | ASSERT(!o->p || !o->p->is_queued) |
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384 | |||
385 | if (!(o->p && o->p->dying)) { |
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386 | return; |
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387 | } |
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388 | |||
389 | struct provide *p = o->p; |
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390 | |||
391 | // remove from provide's list |
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392 | LinkedList1_Remove(&p->depends, &o->node); |
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393 | |||
394 | // insert to free depends list |
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395 | LinkedList1_Append(&g->free_depends, &o->node); |
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396 | |||
397 | // set no provide |
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398 | o->p = NULL; |
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399 | |||
400 | // if provide is empty, let it die |
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401 | if (LinkedList1_IsEmpty(&p->depends)) { |
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402 | provide_free(p); |
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403 | } |
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404 | } |
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405 | |||
406 | static int depend_func_getobj (void *vo, NCD_string_id_t objname, NCDObject *out_object) |
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407 | { |
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408 | struct depend *o = vo; |
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409 | ASSERT(!o->p || !o->p->is_queued) |
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410 | |||
411 | if (!o->p) { |
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412 | return 0; |
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413 | } |
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414 | |||
415 | return NCDModuleInst_Backend_GetObj(o->p->i, objname, out_object); |
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416 | } |
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417 | |||
418 | static struct NCDModule modules[] = { |
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419 | { |
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420 | .type = "provide", |
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421 | .func_new2 = provide_func_new, |
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422 | .func_die = provide_func_die, |
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423 | .alloc_size = sizeof(struct provide) |
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424 | }, { |
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425 | .type = "provide_event", |
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426 | .func_new2 = provide_event_func_new, |
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427 | .func_die = provide_func_die, |
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428 | .alloc_size = sizeof(struct provide) |
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429 | }, { |
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430 | .type = "depend", |
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431 | .func_new2 = depend_func_new, |
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432 | .func_die = depend_func_die, |
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433 | .func_clean = depend_func_clean, |
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434 | .func_getobj = depend_func_getobj, |
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435 | .flags = NCDMODULE_FLAG_CAN_RESOLVE_WHEN_DOWN, |
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436 | .alloc_size = sizeof(struct depend) |
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437 | }, { |
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438 | .type = NULL |
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439 | } |
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440 | }; |
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441 | |||
442 | const struct NCDModuleGroup ncdmodule_depend = { |
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443 | .func_globalinit = func_globalinit, |
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444 | .func_globalfree = func_globalfree, |
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445 | .modules = modules |
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446 | }; |