J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 2003-2005 Sun Microsystems, Inc. All Rights Reserved. |
| 3 | * |
| 4 | * Redistribution and use in source and binary forms, with or without |
| 5 | * modification, are permitted provided that the following conditions |
| 6 | * are met: |
| 7 | * |
| 8 | * - Redistributions of source code must retain the above copyright |
| 9 | * notice, this list of conditions and the following disclaimer. |
| 10 | * |
| 11 | * - Redistributions in binary form must reproduce the above copyright |
| 12 | * notice, this list of conditions and the following disclaimer in the |
| 13 | * documentation and/or other materials provided with the distribution. |
| 14 | * |
| 15 | * - Neither the name of Sun Microsystems nor the names of its |
| 16 | * contributors may be used to endorse or promote products derived |
| 17 | * from this software without specific prior written permission. |
| 18 | * |
| 19 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS |
| 20 | * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, |
| 21 | * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
| 22 | * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR |
| 23 | * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, |
| 24 | * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, |
| 25 | * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR |
| 26 | * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF |
| 27 | * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING |
| 28 | * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS |
| 29 | * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 30 | */ |
| 31 | |
| 32 | /* The Class Loader table. */ |
| 33 | |
| 34 | /* |
| 35 | * The Class Loader objects show up so early in the VM process that a |
| 36 | * separate table was designated for Class Loaders. |
| 37 | * |
| 38 | * The Class Loader is unique by way of it's jobject uniqueness, unfortunately |
| 39 | * use of JNI too early for jobject comparisons is problematic. |
| 40 | * It is assumed that the number of class loaders will be limited, and |
| 41 | * a simple linear search will be performed for now. |
| 42 | * That logic is isolated here and can be changed to use the standard |
| 43 | * table hash table search once we know JNI can be called safely. |
| 44 | * |
| 45 | * A weak global reference is created to keep tabs on loaders, and as |
| 46 | * each search for a loader happens, NULL weak global references will |
| 47 | * trigger the freedom of those entries. |
| 48 | * |
| 49 | */ |
| 50 | |
| 51 | #include "hprof.h" |
| 52 | |
| 53 | typedef struct { |
| 54 | jobject globalref; /* Weak Global reference for object */ |
| 55 | ObjectIndex object_index; |
| 56 | } LoaderInfo; |
| 57 | |
| 58 | static LoaderInfo * |
| 59 | get_info(LoaderIndex index) |
| 60 | { |
| 61 | return (LoaderInfo*)table_get_info(gdata->loader_table, index); |
| 62 | } |
| 63 | |
| 64 | static void |
| 65 | delete_globalref(JNIEnv *env, LoaderInfo *info) |
| 66 | { |
| 67 | jobject ref; |
| 68 | |
| 69 | HPROF_ASSERT(env!=NULL); |
| 70 | HPROF_ASSERT(info!=NULL); |
| 71 | ref = info->globalref; |
| 72 | info->globalref = NULL; |
| 73 | if ( ref != NULL ) { |
| 74 | deleteWeakGlobalReference(env, ref); |
| 75 | } |
| 76 | info->object_index = 0; |
| 77 | } |
| 78 | |
| 79 | static void |
| 80 | cleanup_item(TableIndex index, void *key_ptr, int key_len, |
| 81 | void *info_ptr, void *arg) |
| 82 | { |
| 83 | } |
| 84 | |
| 85 | static void |
| 86 | delete_ref_item(TableIndex index, void *key_ptr, int key_len, |
| 87 | void *info_ptr, void *arg) |
| 88 | { |
| 89 | delete_globalref((JNIEnv*)arg, (LoaderInfo*)info_ptr); |
| 90 | } |
| 91 | |
| 92 | static void |
| 93 | list_item(TableIndex index, void *key_ptr, int key_len, |
| 94 | void *info_ptr, void *arg) |
| 95 | { |
| 96 | LoaderInfo *info; |
| 97 | |
| 98 | HPROF_ASSERT(info_ptr!=NULL); |
| 99 | |
| 100 | info = (LoaderInfo*)info_ptr; |
| 101 | debug_message( "Loader 0x%08x: globalref=%p, object_index=%d\n", |
| 102 | index, (void*)info->globalref, info->object_index); |
| 103 | } |
| 104 | |
| 105 | static void |
| 106 | free_entry(JNIEnv *env, LoaderIndex index) |
| 107 | { |
| 108 | LoaderInfo *info; |
| 109 | |
| 110 | info = get_info(index); |
| 111 | delete_globalref(env, info); |
| 112 | table_free_entry(gdata->loader_table, index); |
| 113 | } |
| 114 | |
| 115 | typedef struct SearchData { |
| 116 | JNIEnv *env; |
| 117 | jobject loader; |
| 118 | LoaderIndex found; |
| 119 | } SearchData; |
| 120 | |
| 121 | static void |
| 122 | search_item(TableIndex index, void *key_ptr, int key_len, void *info_ptr, void *arg) |
| 123 | { |
| 124 | LoaderInfo *info; |
| 125 | SearchData *data; |
| 126 | |
| 127 | HPROF_ASSERT(info_ptr!=NULL); |
| 128 | HPROF_ASSERT(arg!=NULL); |
| 129 | info = (LoaderInfo*)info_ptr; |
| 130 | data = (SearchData*)arg; |
| 131 | if ( data->loader == info->globalref ) { |
| 132 | /* Covers when looking for NULL too. */ |
| 133 | HPROF_ASSERT(data->found==0); /* Did we find more than one? */ |
| 134 | data->found = index; |
| 135 | } else if ( data->env != NULL && data->loader != NULL && |
| 136 | info->globalref != NULL ) { |
| 137 | jobject lref; |
| 138 | |
| 139 | lref = newLocalReference(data->env, info->globalref); |
| 140 | if ( lref == NULL ) { |
| 141 | /* Object went away, free reference and entry */ |
| 142 | free_entry(data->env, index); |
| 143 | } else if ( isSameObject(data->env, data->loader, lref) ) { |
| 144 | HPROF_ASSERT(data->found==0); /* Did we find more than one? */ |
| 145 | data->found = index; |
| 146 | } |
| 147 | if ( lref != NULL ) { |
| 148 | deleteLocalReference(data->env, lref); |
| 149 | } |
| 150 | } |
| 151 | |
| 152 | } |
| 153 | |
| 154 | static LoaderIndex |
| 155 | search(JNIEnv *env, jobject loader) |
| 156 | { |
| 157 | SearchData data; |
| 158 | |
| 159 | data.env = env; |
| 160 | data.loader = loader; |
| 161 | data.found = 0; |
| 162 | table_walk_items(gdata->loader_table, &search_item, (void*)&data); |
| 163 | return data.found; |
| 164 | } |
| 165 | |
| 166 | LoaderIndex |
| 167 | loader_find_or_create(JNIEnv *env, jobject loader) |
| 168 | { |
| 169 | LoaderIndex index; |
| 170 | |
| 171 | /* See if we remembered the system loader */ |
| 172 | if ( loader==NULL && gdata->system_loader != 0 ) { |
| 173 | return gdata->system_loader; |
| 174 | } |
| 175 | if ( loader==NULL ) { |
| 176 | env = NULL; |
| 177 | } |
| 178 | index = search(env, loader); |
| 179 | if ( index == 0 ) { |
| 180 | static LoaderInfo empty_info; |
| 181 | LoaderInfo info; |
| 182 | |
| 183 | info = empty_info; |
| 184 | if ( loader != NULL ) { |
| 185 | HPROF_ASSERT(env!=NULL); |
| 186 | info.globalref = newWeakGlobalReference(env, loader); |
| 187 | info.object_index = 0; |
| 188 | } |
| 189 | index = table_create_entry(gdata->loader_table, NULL, 0, (void*)&info); |
| 190 | } |
| 191 | HPROF_ASSERT(search(env,loader)==index); |
| 192 | /* Remember the system loader */ |
| 193 | if ( loader==NULL && gdata->system_loader == 0 ) { |
| 194 | gdata->system_loader = index; |
| 195 | } |
| 196 | return index; |
| 197 | } |
| 198 | |
| 199 | void |
| 200 | loader_init(void) |
| 201 | { |
| 202 | gdata->loader_table = table_initialize("Loader", |
| 203 | 16, 16, 0, (int)sizeof(LoaderInfo)); |
| 204 | } |
| 205 | |
| 206 | void |
| 207 | loader_list(void) |
| 208 | { |
| 209 | debug_message( |
| 210 | "--------------------- Loader Table ------------------------\n"); |
| 211 | table_walk_items(gdata->loader_table, &list_item, NULL); |
| 212 | debug_message( |
| 213 | "----------------------------------------------------------\n"); |
| 214 | } |
| 215 | |
| 216 | void |
| 217 | loader_cleanup(void) |
| 218 | { |
| 219 | table_cleanup(gdata->loader_table, &cleanup_item, NULL); |
| 220 | gdata->loader_table = NULL; |
| 221 | } |
| 222 | |
| 223 | void |
| 224 | loader_delete_global_references(JNIEnv *env) |
| 225 | { |
| 226 | table_walk_items(gdata->loader_table, &delete_ref_item, (void*)env); |
| 227 | } |
| 228 | |
| 229 | /* Get the object index for a class loader */ |
| 230 | ObjectIndex |
| 231 | loader_object_index(JNIEnv *env, LoaderIndex index) |
| 232 | { |
| 233 | LoaderInfo *info; |
| 234 | ObjectIndex object_index; |
| 235 | jobject wref; |
| 236 | |
| 237 | /* Assume no object index at first (default class loader) */ |
| 238 | info = get_info(index); |
| 239 | object_index = info->object_index; |
| 240 | wref = info->globalref; |
| 241 | if ( wref != NULL && object_index == 0 ) { |
| 242 | jobject lref; |
| 243 | |
| 244 | object_index = 0; |
| 245 | lref = newLocalReference(env, wref); |
| 246 | if ( lref != NULL && !isSameObject(env, lref, NULL) ) { |
| 247 | jlong tag; |
| 248 | |
| 249 | /* Get the tag on the object and extract the object_index */ |
| 250 | tag = getTag(lref); |
| 251 | if ( tag != (jlong)0 ) { |
| 252 | object_index = tag_extract(tag); |
| 253 | } |
| 254 | } |
| 255 | if ( lref != NULL ) { |
| 256 | deleteLocalReference(env, lref); |
| 257 | } |
| 258 | info->object_index = object_index; |
| 259 | } |
| 260 | return object_index; |
| 261 | } |