From c8b939093bed955edab0bb536e9b6a28b1a1625f Mon Sep 17 00:00:00 2001
From: stepan <stepan.sindelar@oracle.com>
Date: Tue, 17 Apr 2018 15:07:11 +0200
Subject: [PATCH] Fix issue when MAX_CONNECTIONS limit is reached
Remove broken ReferenceQueue with connections, just use WeakReferences. Unclosed connections may still leak resources.
---
.../r/runtime/conn/ConnectionSupport.java | 49 ++++++++-----------
1 file changed, 20 insertions(+), 29 deletions(-)
diff --git a/com.oracle.truffle.r.runtime/src/com/oracle/truffle/r/runtime/conn/ConnectionSupport.java b/com.oracle.truffle.r.runtime/src/com/oracle/truffle/r/runtime/conn/ConnectionSupport.java
index e9585217ee..dedb05d865 100644
--- a/com.oracle.truffle.r.runtime/src/com/oracle/truffle/r/runtime/conn/ConnectionSupport.java
+++ b/com.oracle.truffle.r.runtime/src/com/oracle/truffle/r/runtime/conn/ConnectionSupport.java
@@ -80,11 +80,6 @@ public class ConnectionSupport {
*/
private int hwm = 2;
- /**
- * Periodically we can poll the queue and close unused connections as per GnuR.
- */
- private final ReferenceQueue<BaseRConnection> refQueue = new ReferenceQueue<>();
-
private ContextStateImpl() {
for (int i = 0; i < MAX_CONNECTIONS; i++) {
allConnections.add(i, null);
@@ -112,8 +107,8 @@ public class ConnectionSupport {
}
private int setConnection(int index, BaseRConnection con) {
- assert allConnections.get(index) == null;
- allConnections.set(index, new WeakReference<>(con, refQueue));
+ assert allConnections.get(index) == null || allConnections.get(index).get() == null;
+ allConnections.set(index, new WeakReference<>(con));
return index;
}
@@ -141,16 +136,30 @@ public class ConnectionSupport {
}
private int setConnection(BaseRConnection con) {
- collectUnusedConnections();
+ int i = findEmptySlot(con);
+ if (i == -1) {
+ // TODO: rewrite to ReferenceQueue
+ // We have no way of reclaiming the connection slots than GC...
+ System.gc();
+ i = findEmptySlot(con);
+ }
+ if (i >= 0) {
+ return setConnection(i, con);
+ } else {
+ throw RError.error(RError.SHOW_CALLER2, RError.Message.ALL_CONNECTIONS_IN_USE);
+ }
+ }
+
+ private int findEmptySlot(BaseRConnection con) {
for (int i = 3; i < MAX_CONNECTIONS; i++) {
- if (allConnections.get(i) == null) {
+ if (allConnections.get(i) == null || allConnections.get(i).get() == null) {
if (i > hwm) {
hwm = i;
}
- return setConnection(i, con);
+ return i;
}
}
- throw RError.error(RError.SHOW_CALLER2, RError.Message.ALL_CONNECTIONS_IN_USE);
+ return -1;
}
@Override
@@ -168,24 +177,6 @@ public class ConnectionSupport {
}
}
- private void collectUnusedConnections() {
- while (true) {
- Reference<? extends BaseRConnection> ref = refQueue.poll();
- if (ref == null) {
- return;
- }
- BaseRConnection con = ref.get();
- if (con instanceof TextConnections.TextRConnection) {
- RError.warning(RError.SHOW_CALLER2, RError.Message.UNUSED_TEXTCONN, con.descriptor, ((TextConnections.TextRConnection) con).description);
- }
- if (con != null) {
- int index = con.descriptor;
- closeAndDestroy(con);
- allConnections.set(index, null);
- }
- }
- }
-
private static void closeAndDestroy(BaseRConnection con) {
if (!con.closed) {
try {
--
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