Transaction stuck after first step execution

[timemanx]

Hi,

I'm using the transaction API but it seems the transaction always gets stuck after executing the first step.
I'm using EdgeDB 5.6 on EdgeDB Cloud and Java client library version 0.3.0.

Here is a simple example using Kotlin.

package com.test.edgedbclient

import com.edgedb.driver.EdgeDBClient
import com.edgedb.driver.EdgeDBConnection
import kotlinx.coroutines.future.await

suspend fun main() {
    val client = EdgeDBClient(EdgeDBConnection.parse(null, null, true))
    val output = client.transaction { tx ->
        tx.query(String::class.java, "SELECT 'Hello, World 1!'")
            .thenCompose {
                println("Output0: $it")
                tx.query(String::class.java, "SELECT 'Hello, World 2!'")
            }
            .thenCompose {
                println("Output1: $it")
                tx.query(String::class.java, "SELECT 'Hello, World 3!'")
            }
    }.await()

    println("--- Completed ---")
    println("Final output: $output")
    client.close()
}

The output is Output0: [Hello, World 1!] from the first step and then it's stuck.

I believe this is happening due to the semaphore in TransactionImpl being acquired

edgedb-java/src/driver/src/main/java/com/edgedb/driver/internal/TransactionImpl.java

Lines 98 to 114 in 3ddbee1

	private <T, U> CompletionStage<U> executeTransaction(
	Class<T> cls,
	String query,
	@Nullable Map<String, Object> args,
	EnumSet<Capabilities> capabilities,
	@NotNull QueryDelegate<T, U> delegate
	) {
	final AtomicInteger attempts = new AtomicInteger();
	return CompletableFuture.runAsync(() -> {
	try {
	semaphore.acquire();
	} catch (InterruptedException e) {
	throw new CompletionException(e);
	}
	}).thenCompose((v) -> executeTransactionStep(cls, query, args, capabilities, attempts, delegate));
	}

but never being released in the executeTransactionStep method after completion of the step.

edgedb-java/src/driver/src/main/java/com/edgedb/driver/internal/TransactionImpl.java

Lines 71 to 96 in 3ddbee1

	private <T, U> CompletionStage<U> executeTransactionStep(
	Class<T> cls,
	String query,
	@Nullable Map<String, Object> args,
	EnumSet<Capabilities> capabilities,
	@NotNull AtomicInteger attempts,
	@NotNull QueryDelegate<T, U> delegate
	) {
	return CompletableFuture.completedFuture(null)
	.thenCompose((v) ->
	delegate.run(cls, query, args, capabilities)
	.thenApply(t -> (CompletionStage<U>)CompletableFuture.completedFuture(t))
	.exceptionally(e -> {
	if(e instanceof EdgeDBException) {
	if(((EdgeDBException) e).shouldRetry) {
	if(attempts.getAndIncrement() <= settings.getRetryAttempts()) {
	return executeTransactionStep(cls, query, args, capabilities, attempts, delegate);
	}
	}
	}
	return CompletableFuture.failedFuture(new TransactionException("Transaction failed after" + settings.getRetryAttempts() + "attempt(s)", e));
	})
	).thenCompose(v -> v);
	}

This issue could be the same as #21.

Please let me know if any other details are required.

Thanks

[timemanx]

I can get it to work by calling semaphore.release() in whenComplete().

-).thenCompose(v -> v);
+)
+.thenCompose(v -> v)
+.whenComplete((result, error) -> {
+    semaphore.release();  // Release in both success and failure cases
+});

on this line

edgedb-java/src/driver/src/main/java/com/edgedb/driver/internal/TransactionImpl.java

Line 95 in 3ddbee1

).thenCompose(v -> v);

Not sure whether it can cause any side-effects though.

[timemanx]

@quinchs Any possibility of a fix soon?

[KageRiyuu]

Facing same issue, by when it can be fixed?