# HG changeset patch
# User shade
# Date 1534752240 -7200
# Node ID cdffba164671a2620efc3e2eeccc4135a70c71b8
# Parent  703576fdd268138047de557f47af4ba08d4a1bae
8209573: [TESTBUG] gc/epsilon/TestMemoryMXBeans should retry on failure
Reviewed-by: kvn, pliden

diff -r 703576fdd268 -r cdffba164671 test/hotspot/jtreg/gc/epsilon/TestMemoryMXBeans.java
--- a/test/hotspot/jtreg/gc/epsilon/TestMemoryMXBeans.java	Sun Aug 19 22:41:49 2018 -0700
+++ b/test/hotspot/jtreg/gc/epsilon/TestMemoryMXBeans.java	Mon Aug 20 10:04:00 2018 +0200
@@ -67,28 +67,37 @@
         }
     }
 
-    public static void testAllocs() {
+    public static void testAllocs() throws Exception {
         MemoryMXBean memoryMXBean = ManagementFactory.getMemoryMXBean();
 
-        // Do lazy inits first:
-        long heapUsed1 = memoryMXBean.getHeapMemoryUsage().getUsed();
-        sink = new int[1024*1024];
-        long heapUsed2 = memoryMXBean.getHeapMemoryUsage().getUsed();
+        // Try multiple times, to capture either APIs we call allocate lazily, or the background threads allocating
+        int maxTries = 10;
+        int tries = 0;
 
-        // Compute how much we waste during the calls themselves:
-        heapUsed1 = memoryMXBean.getHeapMemoryUsage().getUsed();
-        heapUsed2 = memoryMXBean.getHeapMemoryUsage().getUsed();
-        long adj = heapUsed2 - heapUsed1;
+        while (true) {
+            // Compute how much we waste during the calls themselves:
+            long heapUsed1 = memoryMXBean.getHeapMemoryUsage().getUsed();
+            long heapUsed2 = memoryMXBean.getHeapMemoryUsage().getUsed();
+            long adj = heapUsed2 - heapUsed1;
+
+            heapUsed1 = memoryMXBean.getHeapMemoryUsage().getUsed();
+            sink = new int[1024*1024];
+            heapUsed2 = memoryMXBean.getHeapMemoryUsage().getUsed();
 
-        heapUsed1 = memoryMXBean.getHeapMemoryUsage().getUsed();
-        sink = new int[1024*1024];
-        heapUsed2 = memoryMXBean.getHeapMemoryUsage().getUsed();
+            long diff = heapUsed2 - heapUsed1 - adj;
+            long min =  8 + 4*1024*1024;
+            long max = 16 + 4*1024*1024;
+            if ((min <= diff && diff <= max)) {
+              // Success
+              return;
+            }
 
-        long diff = heapUsed2 - heapUsed1 - adj;
-        long min = 8 + 4*1024*1024;
-        long max = 16 + 4*1024*1024;
-        if (!(min <= diff && diff <= max)) {
-           throw new IllegalStateException("Allocation did not change used space right: " + diff + " should be in [" + min + ", " + max + "]");
+            if (tries++ > maxTries) {
+              throw new IllegalStateException("Allocation did not change used space right: " + diff + " should be in [" + min + ", " + max + "]");
+            }
+
+            // Wait and try again
+            Thread.sleep(1000);
         }
     }