I think everyone is in agreement now that preventing the double close
is the best way to handle this failure. If there are no further comments,
I'll push the attached patch on Thurs morning to the jdk/jdk repos.
I'll also close JDK-8223361 as a duplicate.
On 6/19/19, 2:36 AM, Langer, Christoph wrote:
Hi Gary,
I think overall it would be better to fix the InputStream to be tolerant to
multiple calls to close, as Ralf pointed out. Maybe someone else on some other
place runs into this again because he/she relies on the correct implementation
of Closeable.
However, as a quick fix I can also imagine to do use a single resource like
this:
try (InputStreamReader isr = new InputStreamReader(hvm.executeJCmd(line),
"UTF-8")) {
Then we'd also have a single close call per instance.
But if you do that, you should at least open a bug to track fixing of the
InputStream implementation...
Best regards
Christoph
-----Original Message-----
From: serviceability-dev<serviceability-dev-boun...@openjdk.java.net> On
Behalf Of gary.ad...@oracle.com
Sent: Dienstag, 18. Juni 2019 12:08
To: OpenJDK Serviceability<serviceability-dev@openjdk.java.net>
Subject: RFR: JDK-8224642: Test sun/tools/jcmd/TestJcmdSanity.java fails:
Bad file descriptor
The workaround below passed 1000 testruns on linux-x64-debug.
A more localized fix simply moves the stream reader out of the
try with resources, so only one close is applied to the underlying
socket. I'll run this test through 1000 testruns today.
Looking for a final review for this change.
diff --git a/src/jdk.jcmd/share/classes/sun/tools/jcmd/JCmd.java
b/src/jdk.jcmd/share/classes/sun/tools/jcmd/JCmd.java
--- a/src/jdk.jcmd/share/classes/sun/tools/jcmd/JCmd.java
+++ b/src/jdk.jcmd/share/classes/sun/tools/jcmd/JCmd.java
@@ -122,8 +122,8 @@
if (line.trim().equals("stop")) {
break;
}
- try (InputStream in = hvm.executeJCmd(line);
- InputStreamReader isr = new InputStreamReader(in,
"UTF-8")) {
+ try (InputStream in = hvm.executeJCmd(line)) {
+ InputStreamReader isr = new InputStreamReader(in, "UTF-8");
// read to EOF and just print output
char c[] = new char[256];
int n;
On 6/17/19 3:23 PM, Gary Adams wrote:
https://bugs.openjdk.java.net/browse/JDK-8224642
I may have a handle on what is going wrong with the
TestJcmdSanity test and the bad file descriptor.
A change made in April 2019 placed the input stream and reader
within the same try with resources block. This has the effect of
calling the
SocketInputStream close method twice for each command processed.
https://bugs.openjdk.java.net/browse/JDK-8222491
http://hg.openjdk.java.net/jdk/jdk/rev/4224f26b2e7f
The last set of tests in the TestJcmdSanity test attempts to process ~100
VM.version commands in a loop. Since the closes are handled
when the objects are collected it may come at an inopportune time.
I'm testing the fix below to ensure a second close becomes a noop.
It may be better to revisit the earlier change that set up the double
close calls.
diff --git
a/src/jdk.attach/linux/classes/sun/tools/attach/VirtualMachineImpl.java
b/src/jdk.attach/linux/classes/sun/tools/attach/VirtualMachineImpl.java
---
a/src/jdk.attach/linux/classes/sun/tools/attach/VirtualMachineImpl.java
+++
b/src/jdk.attach/linux/classes/sun/tools/attach/VirtualMachineImpl.java
@@ -233,7 +233,7 @@
* InputStream for the socket connection to get target VM
*/
private class SocketInputStream extends InputStream {
- int s;
+ int s = -1;
public SocketInputStream(int s) {
this.s = s;
@@ -261,7 +261,10 @@
}
public void close() throws IOException {
+ if (s != -1) {
VirtualMachineImpl.close(s);
+ s = -1;
+ }
}
}
# HG changeset patch
# User gadams
# Date 1560945060 14400
# Wed Jun 19 07:51:00 2019 -0400
# Node ID ff79eb44347a5aed75ddd8d536ffcf784384c126
# Parent e0be41293b41975cd8e20c5d63ad0e176e12df3c
8224642: Test sun/tools/jcmd/TestJcmdSanity.java fails: Bad file descriptor
Reviewed-by: cjplummer, rschmelter, clanger
diff --git
a/src/jdk.attach/linux/classes/sun/tools/attach/VirtualMachineImpl.java
b/src/jdk.attach/linux/classes/sun/tools/attach/VirtualMachineImpl.java
--- a/src/jdk.attach/linux/classes/sun/tools/attach/VirtualMachineImpl.java
+++ b/src/jdk.attach/linux/classes/sun/tools/attach/VirtualMachineImpl.java
@@ -233,7 +233,7 @@
* InputStream for the socket connection to get target VM
*/
private class SocketInputStream extends InputStream {
- int s;
+ int s = -1;
public SocketInputStream(int s) {
this.s = s;
@@ -261,7 +261,10 @@
}
public void close() throws IOException {
- VirtualMachineImpl.close(s);
+ if (s != -1) {
+ VirtualMachineImpl.close(s);
+ s = -1;
+ }
}
}
