Skip to content

Fix drain event of ThroughStream to handle potential race condition #171

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
WyriHaximus merged 1 commit into from
Sep 25, 2023
Merged

Fix drain event of ThroughStream to handle potential race condition #171

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
19 changes: 12 additions & 7 deletions src/ThroughStream.php
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -93,16 +93,19 @@ public function __construct($callback = null)

public function pause()
{
$this->paused = true;
// only allow pause if still readable, false otherwise
$this->paused = $this->readable;
}

public function resume()
{
$this->paused = false;

// emit drain event if previous write was paused (throttled)
if ($this->drain) {
$this->drain = false;
$this->emit('drain');
}
$this->paused = false;
}

public function pipe(WritableStreamInterface $dest, array $options = array())
Expand Down Expand Up @@ -139,12 +142,13 @@ public function write($data)

$this->emit('data', array($data));

// emit drain event on next resume if currently paused (throttled)
if ($this->paused) {
$this->drain = true;
return false;
}

return true;
// continue writing if still writable and not paused (throttled), false otherwise
return $this->writable && !$this->paused;
}

public function end($data = null)
Expand All @@ -164,7 +168,7 @@ public function end($data = null)

$this->readable = false;
$this->writable = false;
$this->paused = true;
$this->paused = false;
$this->drain = false;

$this->emit('end');
Expand All @@ -179,9 +183,10 @@ public function close()

$this->readable = false;
$this->writable = false;
$this->closed = true;
$this->paused = true;
$this->paused = false;
$this->drain = false;

$this->closed = true;
$this->callback = null;

$this->emit('close');
Expand Down
58 changes: 58 additions & 0 deletions tests/ThroughStreamTest.php
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -95,6 +95,30 @@ public function itShouldReturnFalseForAnyDataWrittenToItWhenPaused()
$this->assertFalse($ret);
}

/** @test */
public function itShouldReturnFalseForAnyDataWrittenToItWhenDataEventEndsStream()
{
$through = new ThroughStream();
$through->on('data', function () use ($through) {
$through->end();
});
$ret = $through->write('foo');

$this->assertFalse($ret);
}

/** @test */
public function itShouldReturnFalseForAnyDataWrittenToItWhenDataEventClosesStream()
{
$through = new ThroughStream();
$through->on('data', function () use ($through) {
$through->close();
});
$ret = $through->write('foo');

$this->assertFalse($ret);
}

/** @test */
public function itShouldEmitDrainOnResumeAfterReturnFalseForAnyDataWrittenToItWhenPaused()
{
Expand All @@ -106,6 +130,40 @@ public function itShouldEmitDrainOnResumeAfterReturnFalseForAnyDataWrittenToItWh
$through->resume();
}

/** @test */
public function itShouldNotEmitDrainOnResumeAfterClose()
{
$through = new ThroughStream();
$through->close();

$through->on('drain', $this->expectCallableNever());
$through->resume();
}

/** @test */
public function itShouldNotEmitDrainOnResumeAfterReturnFalseForAnyDataWrittenThatCausesStreamToClose()
{
$through = new ThroughStream();
$through->on('data', function () use ($through) { $through->close(); });
$through->write('foo');

$through->on('drain', $this->expectCallableNever());
$through->resume();
}

/** @test */
public function itShouldReturnFalseForAnyDataWrittenToItAfterPausingFromDrainEvent()
{
$through = new ThroughStream();
$through->pause();
$through->write('foo');

$through->on('drain', function () use ($through) { $through->pause(); });
$through->resume();

$this->assertFalse($through->write('bar'));
}

/** @test */
public function itShouldReturnTrueForAnyDataWrittenToItWhenResumedAfterPause()
{
Expand Down