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/*
* Copyright (c) 2003, 2005, Oracle and/or its affiliates. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* - Neither the name of Oracle nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
* IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/* The Class Loader table. */
/*
* The Class Loader objects show up so early in the VM process that a
* separate table was designated for Class Loaders.
*
* The Class Loader is unique by way of it's jobject uniqueness, unfortunately
* use of JNI too early for jobject comparisons is problematic.
* It is assumed that the number of class loaders will be limited, and
* a simple linear search will be performed for now.
* That logic is isolated here and can be changed to use the standard
* table hash table search once we know JNI can be called safely.
*
* A weak global reference is created to keep tabs on loaders, and as
* each search for a loader happens, NULL weak global references will
* trigger the freedom of those entries.
*
*/
#include "hprof.h"
typedef struct {
jobject globalref; /* Weak Global reference for object */
ObjectIndex object_index;
} LoaderInfo;
static LoaderInfo *
get_info(LoaderIndex index)
{
return (LoaderInfo*)table_get_info(gdata->loader_table, index);
}
static void
delete_globalref(JNIEnv *env, LoaderInfo *info)
{
jobject ref;
HPROF_ASSERT(env!=NULL);
HPROF_ASSERT(info!=NULL);
ref = info->globalref;
info->globalref = NULL;
if ( ref != NULL ) {
deleteWeakGlobalReference(env, ref);
}
info->object_index = 0;
}
static void
cleanup_item(TableIndex index, void *key_ptr, int key_len,
void *info_ptr, void *arg)
{
}
static void
delete_ref_item(TableIndex index, void *key_ptr, int key_len,
void *info_ptr, void *arg)
{
delete_globalref((JNIEnv*)arg, (LoaderInfo*)info_ptr);
}
static void
list_item(TableIndex index, void *key_ptr, int key_len,
void *info_ptr, void *arg)
{
LoaderInfo *info;
HPROF_ASSERT(info_ptr!=NULL);
info = (LoaderInfo*)info_ptr;
debug_message( "Loader 0x%08x: globalref=%p, object_index=%d\n",
index, (void*)info->globalref, info->object_index);
}
static void
free_entry(JNIEnv *env, LoaderIndex index)
{
LoaderInfo *info;
info = get_info(index);
delete_globalref(env, info);
table_free_entry(gdata->loader_table, index);
}
typedef struct SearchData {
JNIEnv *env;
jobject loader;
LoaderIndex found;
} SearchData;
static void
search_item(TableIndex index, void *key_ptr, int key_len, void *info_ptr, void *arg)
{
LoaderInfo *info;
SearchData *data;
HPROF_ASSERT(info_ptr!=NULL);
HPROF_ASSERT(arg!=NULL);
info = (LoaderInfo*)info_ptr;
data = (SearchData*)arg;
if ( data->loader == info->globalref ) {
/* Covers when looking for NULL too. */
HPROF_ASSERT(data->found==0); /* Did we find more than one? */
data->found = index;
} else if ( data->env != NULL && data->loader != NULL &&
info->globalref != NULL ) {
jobject lref;
lref = newLocalReference(data->env, info->globalref);
if ( lref == NULL ) {
/* Object went away, free reference and entry */
free_entry(data->env, index);
} else if ( isSameObject(data->env, data->loader, lref) ) {
HPROF_ASSERT(data->found==0); /* Did we find more than one? */
data->found = index;
}
if ( lref != NULL ) {
deleteLocalReference(data->env, lref);
}
}
}
static LoaderIndex
search(JNIEnv *env, jobject loader)
{
SearchData data;
data.env = env;
data.loader = loader;
data.found = 0;
table_walk_items(gdata->loader_table, &search_item, (void*)&data);
return data.found;
}
LoaderIndex
loader_find_or_create(JNIEnv *env, jobject loader)
{
LoaderIndex index;
/* See if we remembered the system loader */
if ( loader==NULL && gdata->system_loader != 0 ) {
return gdata->system_loader;
}
if ( loader==NULL ) {
env = NULL;
}
index = search(env, loader);
if ( index == 0 ) {
static LoaderInfo empty_info;
LoaderInfo info;
info = empty_info;
if ( loader != NULL ) {
HPROF_ASSERT(env!=NULL);
info.globalref = newWeakGlobalReference(env, loader);
info.object_index = 0;
}
index = table_create_entry(gdata->loader_table, NULL, 0, (void*)&info);
}
HPROF_ASSERT(search(env,loader)==index);
/* Remember the system loader */
if ( loader==NULL && gdata->system_loader == 0 ) {
gdata->system_loader = index;
}
return index;
}
void
loader_init(void)
{
gdata->loader_table = table_initialize("Loader",
16, 16, 0, (int)sizeof(LoaderInfo));
}
void
loader_list(void)
{
debug_message(
"--------------------- Loader Table ------------------------\n");
table_walk_items(gdata->loader_table, &list_item, NULL);
debug_message(
"----------------------------------------------------------\n");
}
void
loader_cleanup(void)
{
table_cleanup(gdata->loader_table, &cleanup_item, NULL);
gdata->loader_table = NULL;
}
void
loader_delete_global_references(JNIEnv *env)
{
table_walk_items(gdata->loader_table, &delete_ref_item, (void*)env);
}
/* Get the object index for a class loader */
ObjectIndex
loader_object_index(JNIEnv *env, LoaderIndex index)
{
LoaderInfo *info;
ObjectIndex object_index;
jobject wref;
/* Assume no object index at first (default class loader) */
info = get_info(index);
object_index = info->object_index;
wref = info->globalref;
if ( wref != NULL && object_index == 0 ) {
jobject lref;
object_index = 0;
lref = newLocalReference(env, wref);
if ( lref != NULL && !isSameObject(env, lref, NULL) ) {
jlong tag;
/* Get the tag on the object and extract the object_index */
tag = getTag(lref);
if ( tag != (jlong)0 ) {
object_index = tag_extract(tag);
}
}
if ( lref != NULL ) {
deleteLocalReference(env, lref);
}
info->object_index = object_index;
}
return object_index;
}
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