--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/jdk.hprof.agent/share/native/libhprof/hprof_loader.c Tue Aug 26 07:55:08 2014 +0200
@@ -0,0 +1,270 @@
+/*
+ * Copyright (c) 2003, 2011, 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.
+ */
+
+/*
+ * This source code is provided to illustrate the usage of a given feature
+ * or technique and has been deliberately simplified. Additional steps
+ * required for a production-quality application, such as security checks,
+ * input validation and proper error handling, might not be present in
+ * this sample code.
+ */
+
+
+/* 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;
+}