From 3922a521b957a0acac87b1369e2dd8d277647ee7 Mon Sep 17 00:00:00 2001
From: Peter Hofer <peter.hofer@oracle.com>
Date: Thu, 29 Sep 2022 14:18:06 +0200
Subject: [PATCH] Fallback from PosixPerfMemoryProvider to
 CHeapPerfMemoryProvider.

(cherry picked from commit 62432ef3b318bf4eae3c50d3e612cca8208bd988)
---
 .../oracle/svm/core/jvmstat/PerfMemory.java   | 46 ++++++++++++-------
 1 file changed, 30 insertions(+), 16 deletions(-)

diff --git a/substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/jvmstat/PerfMemory.java b/substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/jvmstat/PerfMemory.java
index ba2e8eaf5f59..b2ed521f2df7 100644
--- a/substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/jvmstat/PerfMemory.java
+++ b/substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/jvmstat/PerfMemory.java
@@ -71,18 +71,10 @@ public PerfMemory() {
     }
 
     public boolean initialize() {
-        PerfMemoryProvider m = getPerfMemoryProvider();
-        ByteBuffer b = m.create();
-        if (b == null || b.capacity() < PerfMemoryPrologue.getPrologueSize()) {
+        if (!createBuffer()) {
             return false;
         }
 
-        memoryProvider = m;
-        buffer = b;
-        capacity = b.capacity();
-        rawMemory = WordFactory.pointer(SubstrateUtil.cast(b, Target_java_nio_Buffer.class).address);
-        assert verifyRawMemoryAccess();
-
         PerfMemoryPrologue.initialize(rawMemory, ByteOrder.nativeOrder().equals(ByteOrder.BIG_ENDIAN));
 
         used = PerfMemoryPrologue.getPrologueSize();
@@ -90,16 +82,38 @@ public boolean initialize() {
         return true;
     }
 
-    private static PerfMemoryProvider getPerfMemoryProvider() {
+    private boolean createBuffer() {
+        PerfMemoryProvider m = null;
+        ByteBuffer b = null;
         if (PerfDataMemoryMappedFile.getValue() && tryAcquirePerfDataFile()) {
-            return ImageSingletons.lookup(PerfMemoryProvider.class);
+            m = ImageSingletons.lookup(PerfMemoryProvider.class);
+            b = m.create();
+            if (b == null) {
+                releasePerfDataFile();
+            }
         }
 
-        /*
-         * Memory mapped file support is disabled or another isolate already owns the perf data
-         * file. Either way, this isolate needs to use C heap memory instead.
-         */
-        return new CHeapPerfMemoryProvider();
+        if (b == null) {
+            /*
+             * Memory mapped file support is disabled, another isolate already owns the perf data
+             * file, or the file or buffer could not be created. Either way, this isolate needs to
+             * use C heap memory instead.
+             */
+            m = new CHeapPerfMemoryProvider();
+            b = m.create();
+        }
+
+        if (b == null || b.capacity() < PerfMemoryPrologue.getPrologueSize()) {
+            return false;
+        }
+
+        memoryProvider = m;
+        buffer = b;
+        capacity = b.capacity();
+        rawMemory = WordFactory.pointer(SubstrateUtil.cast(b, Target_java_nio_Buffer.class).address);
+        assert verifyRawMemoryAccess();
+
+        return true;
     }
 
     private boolean verifyRawMemoryAccess() {