Fix for Bug#74932 (20066806), ConnectionImp Doesn't Close Server Prep…

…ared Statement (PreparedStatement Leak).
fnet123 · Jul 3, 2017 · 05201b0 · 05201b0
1 parent 109e7a5
commit 05201b0
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diff --git a/CHANGES b/CHANGES
@@ -3,6 +3,8 @@
 
 Version 5.1.43
 
+  - Fix for Bug#74932 (20066806), ConnectionImp Doesn't Close Server Prepared Statement (PreparedStatement Leak).
+
   - WL#10536, Deprecating COM_SHUTDOWN.
 
   - Fix for Bug#25650305, GETDATE(),GETTIME() AND GETTIMESTAMP() CALL WITH NULL CALENDAR RETURNS NPE.

diff --git a/src/com/mysql/jdbc/ConnectionImpl.java b/src/com/mysql/jdbc/ConnectionImpl.java
@@ -4273,7 +4273,11 @@ public void recachePreparedStatement(ServerPreparedStatement pstmt) throws SQLEx
         synchronized (getConnectionMutex()) {
             if (getCachePreparedStatements() && pstmt.isPoolable()) {
                 synchronized (this.serverSideStatementCache) {
-                    this.serverSideStatementCache.put(makePreparedStatementCacheKey(pstmt.currentCatalog, pstmt.originalSql), pstmt);
+                    Object oldServerPrepStmt = this.serverSideStatementCache.put(makePreparedStatementCacheKey(pstmt.currentCatalog, pstmt.originalSql), pstmt);
+                    if (oldServerPrepStmt != null) {
+                        ((ServerPreparedStatement) oldServerPrepStmt).isCached = false;
+                        ((ServerPreparedStatement) oldServerPrepStmt).realClose(true, true);
+                    }
                 }
             }
         }

diff --git a/src/testsuite/regression/StatementRegressionTest.java b/src/testsuite/regression/StatementRegressionTest.java
@@ -8290,4 +8290,67 @@ public Void call() throws Exception {
             testConn.close();
         } while (useSPS = !useSPS);
     }
+
+    /**
+     * Tests fix for Bug#74932 - ConnectionImp Doesn't Close Server Prepared Statement (PreparedStatement Leak).
+     */
+    public void testBug74932() throws Exception {
+        createTable("testBug74932", "(c1 INT, c2 INT)");
+        this.stmt.executeUpdate("INSERT INTO testBug74932 VALUES (1, 1), (1, 2), (2, 1), (2, 2)");
+
+        String sql1 = "SELECT * FROM testBug74932 WHERE c1 = ?";
+        String sql2 = "SELECT * FROM testBug74932 WHERE c2 = ?";
+
+        // Prepare different statements.
+        Connection testConn = getConnectionWithProps("prepStmtCacheSize=10,cachePrepStmts=true,useServerPrepStmts=true");
+        for (int i = 0; i < 10; i++) {
+            testBug74932ExecuteStmts(testConn, sql1, sql2);
+
+            this.rs = testConn.createStatement().executeQuery("SHOW STATUS LIKE 'Prepared_stmt_count'");
+            assertTrue(this.rs.next());
+            assertEquals(2, this.rs.getInt(2));
+        }
+        testConn.close();
+
+        // Prepare same statement.
+        testConn = getConnectionWithProps("prepStmtCacheSize=10,cachePrepStmts=true,useServerPrepStmts=true");
+        for (int i = 0; i < 10; i++) {
+            testBug74932ExecuteStmts(testConn, sql1, sql1);
+            this.rs = testConn.createStatement().executeQuery("SHOW STATUS LIKE 'Prepared_stmt_count'");
+            assertTrue(this.rs.next());
+            assertEquals(1, this.rs.getInt(2));
+        }
+        testConn.close();
+    }
+
+    private void testBug74932ExecuteStmts(final Connection testConn, final String sqlOuter, final String sqlInner) throws SQLException {
+        PreparedStatement psOuter = null;
+        PreparedStatement psInner = null;
+        ResultSet rsOuter = null;
+        ResultSet rsInner = null;
+
+        psOuter = testConn.prepareStatement(sqlOuter);
+        psOuter.setInt(1, 1);
+        rsOuter = psOuter.executeQuery();
+        for (int i = 0; i < 2; i++) {
+            assertTrue(rsOuter.next());
+            try {
+                psInner = testConn.prepareStatement(sqlInner);
+                psInner.setInt(1, 2);
+                rsInner = psInner.executeQuery();
+                assertTrue(rsInner.next());
+                assertTrue(rsInner.next());
+                assertFalse(rsInner.next());
+            } finally {
+                if (rsInner != null) {
+                    rsInner.close();
+                }
+                psInner.close();
+            }
+        }
+        assertFalse(rsOuter.next());
+        rsOuter.close();
+        rsInner.close();
+        psOuter.close();
+    }
 }