| /* |
| * Copyright (c) 2003, 2008, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| /* |
| * Copyright 2003 Wily Technology, Inc. |
| */ |
| |
| #include <jni.h> |
| #include <jvmti.h> |
| |
| #include "JPLISAssert.h" |
| #include "Reentrancy.h" |
| #include "JPLISAgent.h" |
| |
| /* |
| * This module provides some utility functions to support the "same thread" re-entrancy management. |
| * Uses JVMTI TLS to store a single bit per thread. |
| * Non-zero means the thread is already inside; zero means the thread is not inside. |
| */ |
| |
| /* |
| * Local prototypes |
| */ |
| |
| /* Wrapper around set that does the set then re-fetches to make sure it worked. |
| * Degenerates to a simple set when assertions are disabled. |
| * This routine is only here because of a bug in the JVMTI where set to 0 fails. |
| */ |
| jvmtiError |
| confirmingTLSSet( jvmtiEnv * jvmtienv, |
| jthread thread, |
| const void * newValue); |
| |
| /* Confirmation routine only; used to assure that the TLS slot holds the value we expect it to. */ |
| void |
| assertTLSValue( jvmtiEnv * jvmtienv, |
| jthread thread, |
| const void * expected); |
| |
| |
| #define JPLIS_CURRENTLY_INSIDE_TOKEN ((void *) 0x7EFFC0BB) |
| #define JPLIS_CURRENTLY_OUTSIDE_TOKEN ((void *) 0) |
| |
| |
| jvmtiError |
| confirmingTLSSet( jvmtiEnv * jvmtienv, |
| jthread thread, |
| const void * newValue) { |
| jvmtiError error; |
| |
| error = (*jvmtienv)->SetThreadLocalStorage( |
| jvmtienv, |
| thread, |
| newValue); |
| check_phase_ret_blob(error, error); |
| |
| #if JPLISASSERT_ENABLEASSERTIONS |
| assertTLSValue( jvmtienv, |
| thread, |
| newValue); |
| #endif |
| |
| return error; |
| } |
| |
| void |
| assertTLSValue( jvmtiEnv * jvmtienv, |
| jthread thread, |
| const void * expected) { |
| jvmtiError error; |
| void * test = (void *) 0x99999999; |
| |
| /* now check if we do a fetch we get what we wrote */ |
| error = (*jvmtienv)->GetThreadLocalStorage( |
| jvmtienv, |
| thread, |
| &test); |
| check_phase_ret(error); |
| jplis_assert(error == JVMTI_ERROR_NONE); |
| jplis_assert(test == expected); |
| } |
| |
| jboolean |
| tryToAcquireReentrancyToken( jvmtiEnv * jvmtienv, |
| jthread thread) { |
| jboolean result = JNI_FALSE; |
| jvmtiError error = JVMTI_ERROR_NONE; |
| void * storedValue = NULL; |
| |
| error = (*jvmtienv)->GetThreadLocalStorage( |
| jvmtienv, |
| thread, |
| &storedValue); |
| check_phase_ret_false(error); |
| jplis_assert(error == JVMTI_ERROR_NONE); |
| if ( error == JVMTI_ERROR_NONE ) { |
| /* if this thread is already inside, just return false and short-circuit */ |
| if ( storedValue == JPLIS_CURRENTLY_INSIDE_TOKEN ) { |
| result = JNI_FALSE; |
| } |
| else { |
| /* stuff in the sentinel and return true */ |
| #if JPLISASSERT_ENABLEASSERTIONS |
| assertTLSValue( jvmtienv, |
| thread, |
| JPLIS_CURRENTLY_OUTSIDE_TOKEN); |
| #endif |
| error = confirmingTLSSet ( jvmtienv, |
| thread, |
| JPLIS_CURRENTLY_INSIDE_TOKEN); |
| check_phase_ret_false(error); |
| jplis_assert(error == JVMTI_ERROR_NONE); |
| if ( error != JVMTI_ERROR_NONE ) { |
| result = JNI_FALSE; |
| } |
| else { |
| result = JNI_TRUE; |
| } |
| } |
| } |
| return result; |
| } |
| |
| |
| void |
| releaseReentrancyToken( jvmtiEnv * jvmtienv, |
| jthread thread) { |
| jvmtiError error = JVMTI_ERROR_NONE; |
| |
| /* assert we hold the token */ |
| #if JPLISASSERT_ENABLEASSERTIONS |
| assertTLSValue( jvmtienv, |
| thread, |
| JPLIS_CURRENTLY_INSIDE_TOKEN); |
| #endif |
| |
| error = confirmingTLSSet( jvmtienv, |
| thread, |
| JPLIS_CURRENTLY_OUTSIDE_TOKEN); |
| check_phase_ret(error); |
| jplis_assert(error == JVMTI_ERROR_NONE); |
| |
| } |