# Background Tasks

You can define background tasks to be run *after* returning a response.

This is useful for operations that need to happen after a request, but that the client doesn't really have to be waiting for the operation to complete before receiving the response.

This includes, for example:

* Email notifications sent after performing an action:

A secondary goal was to enable a smoother on-ramp from "Zero" to "Getting some value".
Historically, Istio had to really be consumed all-or-nothing for things to work as expected.
In particular, an easy answer to "I just want to have mTLS everywhere, then I can think about adopting the rest of service mesh" was desired.

Other documents include:

import com.google.common.annotations.J2ktIncompatible;
import java.io.IOException;
import java.io.Reader;
import java.nio.CharBuffer;
import javax.annotation.CheckForNull;

/**
 * A {@link Reader} that reads the characters in a {@link CharSequence}. Like {@code StringReader},
 * but works with any {@link CharSequence}.
 *
 * @author Colin Decker
 */
// TODO(cgdecker): make this public? as a type, or a method in CharStreams?

import com.google.common.annotations.J2ktIncompatible;
import java.io.IOException;
import java.io.Reader;
import java.nio.CharBuffer;
import javax.annotation.CheckForNull;

/**
 * A {@link Reader} that reads the characters in a {@link CharSequence}. Like {@code StringReader},
 * but works with any {@link CharSequence}.
 *
 * @author Colin Decker
 */
// TODO(cgdecker): make this public? as a type, or a method in CharStreams?

      /*
       * Since reflection can't tell the difference between <T> and <T extends Object>, it doesn't
       * make a ton of sense to have a separate tests for each. But having tests for each doesn't
       * really hurt anything, and maybe it will serve a purpose in a future in which Java has a
       * built-in nullness feature?
       */
      "ExtendsObject",
    })
    <T extends Object> void withObjectBound(List<T> list) {}

      /*
       * Since reflection can't tell the difference between <T> and <T extends Object>, it doesn't
       * make a ton of sense to have a separate tests for each. But having tests for each doesn't
       * really hurt anything, and maybe it will serve a purpose in a future in which Java has a
       * built-in nullness feature?
       */
      "ExtendsObject",
    })
    <T extends Object> void withObjectBound(List<T> list) {}

  }

  @J2ktIncompatible
  @GwtIncompatible // threads
  public void testOverflowTimeout() throws Exception {
    // First, sanity check that naive multiplication would really overflow to a negative number:
    long nanosPerSecond = NANOSECONDS.convert(1, SECONDS);
    assertThat(nanosPerSecond * Long.MAX_VALUE).isLessThan(0L);

            <multiplicity>*</multiplicity>
          </association>
          <comment><![CDATA[ This may be removed or relocated in the near
            future. It is undecided whether plugins really need a remote
            repository set of their own. ]]></comment>
        </field>
      </fields>
    </class>
    <class>
      <name>Activation</name>
      <version>1.0.0</version>

}

// NewReader returns a new Reader that wraps src and computes
// MD5 checksum of everything it reads as ETag.
//
// It also computes the SHA256 checksum of everything it reads
// if sha256Hex is not the empty string.
//
// If size resp. actualSize is unknown at the time of calling
// NewReader then it should be set to -1.

		internal32KByteBuffer.Put(&b)
		return
	}
	if cap(b) >= minBufferSize && cap(b) < biggerBufMin {
		internalByteBuffer.Put(&b)
		return
	}
}

// readAllInto reads from r and appends to b until an error or EOF and returns the data it read.
// A successful call returns err == nil, not err == EOF. Because readAllInto is
// defined to read from src until EOF, it does not treat an EOF from Read