blocking call in Http1xServerResponse.doSendFile()

[lllxin037]

Questions

file blocking call in async sendFile(). Can sendFile() be executed in worker thread executeBlocking()? I searched and found the answer is no.

Version

4.4.9

Context

Http1xServerResponse.sendFile() should be an async call and executed in event loop thread. However, I observed it calls raf = new RandomAccessFile(file, "r"); inside doSendFile():

vert.x/src/main/java/io/vertx/core/http/impl/Http1xServerResponse.java

Line 574 in 23e921c

raf = new RandomAccessFile(file, "r");

new RandomAccessFile() internally calls RandomAccessFile.open() which is a blocking IO operation.

Why sendFile() behave in such way ? In a high pressure workload, I saw thread has been blocked due to this.

Should I call sendFile() in executeBlocking() or not ? If not, what I can do ?

Do you have a reproducer?

No

Extra

Linux + JDK 17.

[vietj]

we will support in 5.0.1 a sendFile version that accepts a FileChannel leaving you the ability to avoid this and handle yourself the creation of the FileChannel

[olivierayache]

Hello @lllxin037, I am currently working on a PR that might fix that (#5558)

This PR is in progress but the idea is to give the possibility to have a new version of sendFile that accept a FileChannel for HttpServerResponse

This will let you manage the FileChannel on your own and pass it to HttpServerResponse. The ownership of FileChannel closing will be on the caller side