oracle/graal · error · IOException

Invalid replay string definition index

Error message

Invalid replay string definition index

What it means

IOException thrown by BinaryReplayCodec.ReadState.defineString when a string-definition record's index does not equal the string table's current size. Definitions must append strictly sequentially (index == size) so lookups stay dense; a gap or repeat means the stream is malformed or out of sync with the codec that wrote it.

Source

Thrown at compiler/src/jdk.graal.compiler/src/jdk/graal/compiler/hotspot/replaycomp/BinaryReplayCodec.java:259

        @SuppressWarnings("unchecked") private final EconomicMap<Integer, Object>[] instanceProxies = (EconomicMap<Integer, Object>[]) new EconomicMap<?, ?>[registrations.length];

        private Architecture architecture = hostTarget.arch;

        private ReadState(CompilationProxies.ProxyFactory proxyFactory) {
            this.proxyFactory = proxyFactory;
            stringTable.add(null);
        }

        private String stringAt(int index) throws IOException {
            if (index < 0 || index >= stringTable.size()) {
                throw new IOException("Invalid replay string table index " + index);
            }
            return stringTable.get(index);
        }

        private void defineString(int index, String value) throws IOException {
            if (index != stringTable.size()) {
                throw new IOException("Invalid replay string definition index " + index);
            }
            stringTable.add(value);
        }

        private CompilationProxy.SymbolicMethod methodAt(int index) throws IOException {
            if (index < 0 || index >= methodTable.size()) {
                throw new IOException("Invalid replay symbolic method index " + index);
            }
            return methodTable.get(index);
        }

        private void defineMethod(int index, CompilationProxy.SymbolicMethod method) throws IOException {
            if (index != methodTable.size()) {
                throw new IOException("Invalid replay symbolic method definition index " + index);
            }
            methodTable.add(method);
        }

View on GitHub (pinned to a66e9ccd1d)

Solutions

  1. Re-record the replay data on the same build you replay with.
  2. Discard and re-transfer the file to rule out truncation/corruption.
  3. Keep replay artifacts pinned to the compiler version that produced them.
Defensive patterns

Strategy: validation

Try / catch

try {
    replayCodec.decode(input);
} catch (IOException e) {
    if (e.getMessage().startsWith("Invalid replay string definition index")) {
        // stream out of sync: regenerate with matching build
    }
    throw e;
}

Prevention

When it happens

Trigger: Decoding a replay stream whose next DEFINE_STRING record carries an index other than table.size() — e.g. after a truncated prefix (missing earlier definitions) or a codec-version mismatch that changed record ordering.

Common situations: Replay files recorded and replayed with different compiler builds; partially downloaded or appended-to files; concurrent/corrupted writes during profile capture.

Related errors

AI-assisted analysis of oracle/graal@a66e9ccd1d (2026-08-14). Data as JSON: /api/errors/e0aa814c2f77e913. Report an issue: GitHub.