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src/hotspot/share/compiler/compileBroker.cpp
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rev 54112 : 8216314: SIGILL in CodeHeapState::print_names()
Reviewed-by: thartmann, kvn
@@ -1,7 +1,7 @@
/*
- * Copyright (c) 1999, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1999, 2019, 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.
@@ -2742,10 +2742,11 @@
// That's a tradeoff which keeps together important blocks of output.
// At the same time, continuous tty_lock hold time is kept in check,
// preventing concurrently printing threads from stalling a long time.
void CompileBroker::print_heapinfo(outputStream* out, const char* function, size_t granularity) {
TimeStamp ts_total;
+ TimeStamp ts_global;
TimeStamp ts;
bool allFun = !strcmp(function, "all");
bool aggregate = !strcmp(function, "aggregate") || !strcmp(function, "analyze") || allFun;
bool usedSpace = !strcmp(function, "UsedSpace") || allFun;
@@ -2771,48 +2772,62 @@
if (aggregate) {
print_info(out);
}
// We hold the CodeHeapStateAnalytics_lock all the time, from here until we leave this function.
- // That helps us getting a consistent view on the CodeHeap, at least for the "all" function.
+ // That prevents another thread from destroying our view on the CodeHeap.
// When we request individual parts of the analysis via the jcmd interface, it is possible
// that in between another thread (another jcmd user or the vm running into CodeCache OOM)
// updated the aggregated data. That's a tolerable tradeoff because we can't hold a lock
// across user interaction.
+ // Acquire this lock before acquiring the CodeCache_lock.
+ // CodeHeapStateAnalytics_lock could be held by a concurrent thread for a long time,
+ // leading to an unnecessarily long hold time of the CodeCache_lock.
ts.update(); // record starting point
MutexLockerEx mu1(CodeHeapStateAnalytics_lock, Mutex::_no_safepoint_check_flag);
- out->cr();
- out->print_cr("__ CodeHeapStateAnalytics lock wait took %10.3f seconds _________", ts.seconds());
- out->cr();
+ out->print_cr("\n__ CodeHeapStateAnalytics lock wait took %10.3f seconds _________\n", ts.seconds());
+
+ // If we serve an "allFun" call, it is beneficial to hold the CodeCache_lock
+ // for the entire duration of aggregation and printing. That makes sure
+ // we see a consistent picture and do not run into issues caused by
+ // the CodeHeap being altered concurrently.
+ Monitor* global_lock = allFun ? CodeCache_lock : NULL;
+ Monitor* function_lock = allFun ? NULL : CodeCache_lock;
+ ts_global.update(); // record starting point
+ MutexLockerEx mu2(global_lock, Mutex::_no_safepoint_check_flag);
+ if (global_lock != NULL) {
+ out->print_cr("\n__ CodeCache (global) lock wait took %10.3f seconds _________\n", ts_global.seconds());
+ ts_global.update(); // record starting point
+ }
if (aggregate) {
- // It is sufficient to hold the CodeCache_lock only for the aggregate step.
- // All other functions operate on aggregated data - except MethodNames, but that should be safe.
- // The separate CodeHeapStateAnalytics_lock protects the printing functions against
- // concurrent aggregate steps. Acquire this lock before acquiring the CodeCache_lock.
- // CodeHeapStateAnalytics_lock could be held by a concurrent thread for a long time,
- // leading to an unnecessarily long hold time of the CodeCache_lock.
ts.update(); // record starting point
- MutexLockerEx mu2(CodeCache_lock, Mutex::_no_safepoint_check_flag);
- out->cr();
- out->print_cr("__ CodeCache lock wait took %10.3f seconds _________", ts.seconds());
- out->cr();
+ MutexLockerEx mu3(function_lock, Mutex::_no_safepoint_check_flag);
+ if (function_lock != NULL) {
+ out->print_cr("\n__ CodeCache (function) lock wait took %10.3f seconds _________\n", ts.seconds());
+ }
ts.update(); // record starting point
CodeCache::aggregate(out, granularity);
- out->cr();
- out->print_cr("__ CodeCache lock hold took %10.3f seconds _________", ts.seconds());
- out->cr();
+ if (function_lock != NULL) {
+ out->print_cr("\n__ CodeCache (function) lock hold took %10.3f seconds _________\n", ts.seconds());
+ }
}
if (usedSpace) CodeCache::print_usedSpace(out);
if (freeSpace) CodeCache::print_freeSpace(out);
if (methodCount) CodeCache::print_count(out);
if (methodSpace) CodeCache::print_space(out);
if (methodAge) CodeCache::print_age(out);
- if (methodNames) CodeCache::print_names(out);
+ if (methodNames) {
+ // print_names() has shown to be sensitive to concurrent CodeHeap modifications.
+ // Therefore, request the CodeCache_lock before calling...
+ MutexLockerEx mu3(function_lock, Mutex::_no_safepoint_check_flag);
+ CodeCache::print_names(out);
+ }
if (discard) CodeCache::discard(out);
- out->cr();
- out->print_cr("__ CodeHeapStateAnalytics total duration %10.3f seconds _________", ts_total.seconds());
- out->cr();
+ if (global_lock != NULL) {
+ out->print_cr("\n__ CodeCache (global) lock hold took %10.3f seconds _________\n", ts_global.seconds());
+ }
+ out->print_cr("\n__ CodeHeapStateAnalytics total duration %10.3f seconds _________\n", ts_total.seconds());
}
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