[GR-65615] TruffleStrings: fix cacheInsertFirstBeforePublished optimization.

PullRequest: graal/21024

Author: djoooooe

truffle/src/com.oracle.truffle.api.strings/src/com/oracle/truffle/api/strings/TStringInternalNodes.java

@@ -2010,13 +2010,14 @@ static TruffleString doNonEmpty(Node node, String javaString, int charOffset, in
                 }
             }
             int hash = TStringUnsafe.getJavaStringHashMasked(javaString);
-            TruffleString ret = TruffleString.createFromByteArray(array, offset, length, stride, Encoding.UTF_16, codePointLength, codeRange, hash, true);
+            final TruffleString cacheEntry;
             if (length == javaString.length()) {
                 assert charOffset == 0;
-                TruffleString wrapped = TruffleString.createWrapJavaString(javaString, codePointLength, codeRange);
-                ret.cacheInsertFirstBeforePublished(wrapped);
+                cacheEntry = TruffleString.createWrapJavaString(javaString, codePointLength, codeRange);
+            } else {
+                cacheEntry = null;
             }
-            return ret;
+            return TruffleString.createFromByteArrayWithCacheEntry(array, offset, length, stride, Encoding.UTF_16, codePointLength, codeRange, hash, cacheEntry);
         }
     }
 

truffle/src/com.oracle.truffle.api.strings/src/com/oracle/truffle/api/strings/TruffleString.java

@@ -148,6 +148,18 @@ private TruffleString(Object data, int offset, int length, int stride, Encoding
         super(data, offset, length, stride, encoding, isCacheHead ? FLAG_CACHE_HEAD : 0, codePointLength, codeRange, hashCode);
     }
 
+    private TruffleString(Object data, int offset, int length, int stride, Encoding encoding, int codePointLength, int codeRange, int hashCode, boolean isCacheHead, TruffleString cacheEntry) {
+        this(data, offset, length, stride, encoding, codePointLength, codeRange, hashCode, isCacheHead);
+        if (cacheEntry != null) {
+            assert !cacheEntry.isCacheHead();
+            assert isCacheHead();
+            assert next == null;
+            TruffleString cacheHead = this;
+            cacheEntry.next = cacheHead;
+            cacheHead.next = cacheEntry;
+        }
+    }
+
     private static TruffleString create(Object data, int offset, int length, int stride, Encoding encoding, int codePointLength, int codeRange, int hashCode, boolean isCacheHead) {
         TruffleString string = new TruffleString(data, offset, length, stride, encoding, codePointLength, codeRange, hashCode, isCacheHead);
         if (AbstractTruffleString.DEBUG_ALWAYS_CREATE_JAVA_STRING) {
@@ -156,6 +168,14 @@ private static TruffleString create(Object data, int offset, int length, int str
         return string;
     }
 
+    private static TruffleString createWithCacheEntry(Object data, int offset, int length, int stride, Encoding encoding, int codePointLength, int codeRange, int hashCode, TruffleString cacheEntry) {
+        TruffleString string = new TruffleString(data, offset, length, stride, encoding, codePointLength, codeRange, hashCode, true, cacheEntry);
+        if (AbstractTruffleString.DEBUG_ALWAYS_CREATE_JAVA_STRING) {
+            string.toJavaStringUncached();
+        }
+        return string;
+    }
+
     static TruffleString createFromByteArray(byte[] bytes, int length, int stride, Encoding encoding, int codePointLength, int codeRange) {
         return createFromByteArray(bytes, 0, length, stride, encoding, codePointLength, codeRange, true);
     }
@@ -196,6 +216,14 @@ static TruffleString createFromArray(Object bytes, int offset, int length, int s
         return TruffleString.create(bytes, offset, length, stride, encoding, codePointLength, codeRange, hashCode, isCacheHead);
     }
 
+    static TruffleString createFromByteArrayWithCacheEntry(byte[] bytes, int offset, int length, int stride, Encoding encoding, int codePointLength, int codeRange, int hashCode,
+                    TruffleString cacheEntry) {
+        assert offset >= 0;
+        assert offset + ((long) length << stride) <= bytes.length;
+        assert attrsAreCorrect(bytes, encoding, offset, length, codePointLength, codeRange, stride);
+        return TruffleString.createWithCacheEntry(bytes, offset, length, stride, encoding, codePointLength, codeRange, hashCode, cacheEntry);
+    }
+
     static TruffleString createConstant(byte[] bytes, int length, int stride, Encoding encoding, int codePointLength, int codeRange) {
         return createConstant(bytes, length, stride, encoding, codePointLength, codeRange, true);
     }
@@ -298,20 +326,6 @@ void cacheInsert(TruffleString entry) {
         } while (!setNextAtomic(cacheHead, cacheHeadNext, entry));
     }
 
-    /*
-     * Simpler and faster insertion for the case `this` and `entry` were just allocated together and
-     * before they are published. The CAS is not needed in that case since we know nobody could
-     * write to `next` fields before us.
-     */
-    void cacheInsertFirstBeforePublished(TruffleString entry) {
-        assert !entry.isCacheHead();
-        assert isCacheHead();
-        assert next == null;
-        TruffleString cacheHead = this;
-        entry.next = cacheHead;
-        cacheHead.next = entry;
-    }
-
     private static boolean hasDuplicateEncoding(TruffleString cacheHead, TruffleString start, TruffleString insertEntry) {
         if (start == null) {
             return false;