Hi Martin,
Yep, there are number of other ways stack could have been handled.
Another one might be to not "commit" all the stack memory until it is
needed.
So it takes up address space, but not memory; still not a perfect way.
I haven't looked to see if the 64k network stack buffer that is reserved
can be done another way; but that's a different idea.
In continued testing, I had another SOE with the 8k stack proposed.
I need to do another round with 16k.
Thanks, Roger
On 7/8/20 6:17 PM, Martin Buchholz wrote:
Approved.
As author of the small stack size for the reaper thread, I'm sorry
it's caused so much trouble.
But as always, the proper solution is to fix the java runtime so that
fixed allocations like this are unnecessary.
hard: stack size should not include native overhead like shadow pages.
Switching to a debug build should not cause SOE.
harder: banish SOE in pure java code entirely by loomishly moving
continuations to a larger stack.
On Wed, Jul 8, 2020 at 1:54 PM Roger Riggs <roger.ri...@oracle.com> wrote:
Please reveiw a change to increase the size of the Process Reaper stack
for debug builds.
This intermittent issue can be traced to the stack shadow page size
being larger
in debug builds than in release builds. The problem has only been
spotted in debug builds.
diff a/src/java.base/share/classes/java/lang/ProcessHandleImpl.java
b/src/java.base/share/classes/java/lang/ProcessHandleImpl.java
--- a/src/java.base/share/classes/java/lang/ProcessHandleImpl.java
+++ b/src/java.base/share/classes/java/lang/ProcessHandleImpl.java
@@ -85,12 +85,16 @@
doPrivileged((PrivilegedAction<Executor>) () -> {
ThreadGroup tg = Thread.currentThread().getThreadGroup();
while (tg.getParent() != null) tg = tg.getParent();
ThreadGroup systemThreadGroup = tg;
+
+ // For a debug build, the stack shadow zone is larger;
+ // Increase the total stack size to avoid potential stack
overflow.
+ int debugDelta =
"release".equals(System.getProperty("jdk.debug")) ? 0 : 8192;
final long stackSize =
Boolean.getBoolean("jdk.lang.processReaperUseDefaultStackSize")
- ? 0 : REAPER_DEFAULT_STACKSIZE;
+ ? 0 : REAPER_DEFAULT_STACKSIZE + debugDelta;
ThreadFactory threadFactory = grimReaper -> {
Thread t = new Thread(systemThreadGroup, grimReaper,
"process reaper", stackSize, false);
t.setDaemon(true);
Webrev:
http://cr.openjdk.java.net/~rriggs/webrev-process-stackoverflow-8217475/
Issue:
https://bugs.openjdk.java.net/browse/JDK-8217475
Thanks, Roger
