Bug Summary

File:jdk/src/hotspot/share/gc/shenandoah/shenandoahEvacOOMHandler.inline.hpp
Warning:line 35, column 8
Value stored to 'threads_in_evac' during its initialization is never read

Annotated Source Code

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clang -cc1 -triple x86_64-pc-linux-gnu -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name shenandoahPassiveMode.cpp -analyzer-store=region -analyzer-opt-analyze-nested-blocks -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=cplusplus -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -setup-static-analyzer -mrelocation-model pic -pic-level 2 -mthread-model posix -fno-delete-null-pointer-checks -mframe-pointer=all -relaxed-aliasing -fmath-errno -fno-rounding-math -masm-verbose -mconstructor-aliases -munwind-tables -target-cpu x86-64 -dwarf-column-info -fno-split-dwarf-inlining -debugger-tuning=gdb -resource-dir /usr/lib/llvm-10/lib/clang/10.0.0 -I /home/daniel/Projects/java/jdk/build/linux-x86_64-server-fastdebug/hotspot/variant-server/libjvm/objs/precompiled -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -D __STDC_CONSTANT_MACROS -D _GNU_SOURCE -D _REENTRANT -D LIBC=gnu -D LINUX -D VM_LITTLE_ENDIAN -D _LP64=1 -D ASSERT -D CHECK_UNHANDLED_OOPS -D TARGET_ARCH_x86 -D INCLUDE_SUFFIX_OS=_linux -D INCLUDE_SUFFIX_CPU=_x86 -D INCLUDE_SUFFIX_COMPILER=_gcc -D TARGET_COMPILER_gcc -D AMD64 -D HOTSPOT_LIB_ARCH="amd64" -D COMPILER1 -D COMPILER2 -I /home/daniel/Projects/java/jdk/build/linux-x86_64-server-fastdebug/hotspot/variant-server/gensrc/adfiles -I /home/daniel/Projects/java/jdk/src/hotspot/share -I /home/daniel/Projects/java/jdk/src/hotspot/os/linux -I /home/daniel/Projects/java/jdk/src/hotspot/os/posix -I /home/daniel/Projects/java/jdk/src/hotspot/cpu/x86 -I /home/daniel/Projects/java/jdk/src/hotspot/os_cpu/linux_x86 -I /home/daniel/Projects/java/jdk/build/linux-x86_64-server-fastdebug/hotspot/variant-server/gensrc -I /home/daniel/Projects/java/jdk/src/hotspot/share/precompiled -I /home/daniel/Projects/java/jdk/src/hotspot/share/include -I /home/daniel/Projects/java/jdk/src/hotspot/os/posix/include -I /home/daniel/Projects/java/jdk/build/linux-x86_64-server-fastdebug/support/modules_include/java.base -I /home/daniel/Projects/java/jdk/build/linux-x86_64-server-fastdebug/support/modules_include/java.base/linux -I /home/daniel/Projects/java/jdk/src/java.base/share/native/libjimage -I /home/daniel/Projects/java/jdk/build/linux-x86_64-server-fastdebug/hotspot/variant-server/gensrc/adfiles -I /home/daniel/Projects/java/jdk/src/hotspot/share -I /home/daniel/Projects/java/jdk/src/hotspot/os/linux -I /home/daniel/Projects/java/jdk/src/hotspot/os/posix -I /home/daniel/Projects/java/jdk/src/hotspot/cpu/x86 -I /home/daniel/Projects/java/jdk/src/hotspot/os_cpu/linux_x86 -I /home/daniel/Projects/java/jdk/build/linux-x86_64-server-fastdebug/hotspot/variant-server/gensrc -D _FORTIFY_SOURCE=2 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/7.5.0/../../../../include/c++/7.5.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/7.5.0/../../../../include/x86_64-linux-gnu/c++/7.5.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/7.5.0/../../../../include/x86_64-linux-gnu/c++/7.5.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/7.5.0/../../../../include/c++/7.5.0/backward -internal-isystem /usr/local/include -internal-isystem /usr/lib/llvm-10/lib/clang/10.0.0/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -O3 -Wno-format-zero-length -Wno-unused-parameter -Wno-unused -Wno-parentheses -Wno-comment -Wno-unknown-pragmas -Wno-address -Wno-delete-non-virtual-dtor -Wno-char-subscripts -Wno-array-bounds -Wno-int-in-bool-context -Wno-ignored-qualifiers -Wno-missing-field-initializers -Wno-implicit-fallthrough -Wno-empty-body -Wno-strict-overflow -Wno-sequence-point -Wno-maybe-uninitialized -Wno-misleading-indentation -Wno-cast-function-type -Wno-shift-negative-value -std=c++14 -fdeprecated-macro -fdebug-compilation-dir /home/daniel/Projects/java/jdk/make/hotspot -ferror-limit 19 -fmessage-length 0 -fvisibility hidden -stack-protector 1 -fno-rtti -fgnuc-version=4.2.1 -fobjc-runtime=gcc -fdiagnostics-show-option -vectorize-loops -vectorize-slp -analyzer-output=html -faddrsig -o /home/daniel/Projects/java/scan/2021-12-21-193737-8510-1 -x c++ /home/daniel/Projects/java/jdk/src/hotspot/share/gc/shenandoah/mode/shenandoahPassiveMode.cpp
1/*
2 * Copyright (c) 2020, Red Hat, Inc. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25#ifndef SHARE_GC_SHENANDOAH_SHENANDOAHEVACOOMHANDLER_INLINE_HPP
26#define SHARE_GC_SHENANDOAH_SHENANDOAHEVACOOMHANDLER_INLINE_HPP
27
28#include "gc/shenandoah/shenandoahEvacOOMHandler.hpp"
29
30#include "gc/shenandoah/shenandoahHeap.inline.hpp"
31#include "gc/shenandoah/shenandoahThreadLocalData.hpp"
32#include "runtime/atomic.hpp"
33
34void ShenandoahEvacOOMHandler::enter_evacuation(Thread* thr) {
35 jint threads_in_evac = Atomic::load_acquire(&_threads_in_evac);
Value stored to 'threads_in_evac' during its initialization is never read
36
37 uint8_t level = ShenandoahThreadLocalData::push_evac_oom_scope(thr);
38 if (level == 0) {
39 // Entering top level scope, register this thread.
40 register_thread(thr);
41 } else if (!ShenandoahThreadLocalData::is_oom_during_evac(thr)) {
42 jint threads_in_evac = Atomic::load_acquire(&_threads_in_evac);
43 // If OOM is in progress, handle it.
44 if ((threads_in_evac & OOM_MARKER_MASK) != 0) {
45 assert((threads_in_evac & ~OOM_MARKER_MASK) > 0, "sanity")do { if (!((threads_in_evac & ~OOM_MARKER_MASK) > 0)) {
(*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/gc/shenandoah/shenandoahEvacOOMHandler.inline.hpp"
, 45, "assert(" "(threads_in_evac & ~OOM_MARKER_MASK) > 0"
") failed", "sanity"); ::breakpoint(); } } while (0)
;
46 Atomic::dec(&_threads_in_evac);
47 wait_for_no_evac_threads();
48 }
49 }
50}
51
52void ShenandoahEvacOOMHandler::leave_evacuation(Thread* thr) {
53 uint8_t level = ShenandoahThreadLocalData::pop_evac_oom_scope(thr);
54 // Not top level, just return
55 if (level > 1) {
56 return;
57 }
58
59 // Leaving top level scope, unregister this thread.
60 unregister_thread(thr);
61}
62
63ShenandoahEvacOOMScope::ShenandoahEvacOOMScope() :
64 _thread(Thread::current()) {
65 ShenandoahHeap::heap()->enter_evacuation(_thread);
66}
67
68ShenandoahEvacOOMScope::ShenandoahEvacOOMScope(Thread* t) :
69 _thread(t) {
70 ShenandoahHeap::heap()->enter_evacuation(_thread);
71}
72
73ShenandoahEvacOOMScope::~ShenandoahEvacOOMScope() {
74 ShenandoahHeap::heap()->leave_evacuation(_thread);
75}
76
77#endif // SHARE_GC_SHENANDOAH_SHENANDOAHEVACOOMHANDLER_INLINE_HPP