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Make run-tests.php check for tcp fwrite edge cases #9242

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Merged
merged 1 commit into from
Oct 8, 2022
Merged

Make run-tests.php check for tcp fwrite edge cases #9242

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38 changes: 37 additions & 1 deletion run-tests.php
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Original file line number Diff line number Diff line change
Expand Up @@ -1645,11 +1645,47 @@ function run_all_tests_parallel(array $test_files, array $env, $redir_tested): v
}
}

/**
* Calls fwrite and retries when network writes fail with errors such as "Resource temporarily unavailable"
*
* @param resource $stream the stream to fwrite to
* @param string $data
* @return int|false
*/
function safe_fwrite($stream, string $data)
{
// safe_fwrite was tested by adding $message['unused'] = str_repeat('a', 20_000_000); in send_message()
// fwrites on tcp sockets can return false or less than strlen if the recipient is busy.
// (e.g. fwrite(): Send of 577 bytes failed with errno=35 Resource temporarily unavailable)
$bytes_written = 0;
while ($bytes_written < strlen($data)) {
$n = @fwrite($stream, substr($data, $bytes_written));
if ($n === false) {
$write_streams = [$stream];
$read_streams = [];
$except_streams = [];
/* Wait for up to 10 seconds for the stream to be ready to write again. */
$result = stream_select($read_streams, $write_streams, $except_streams, 10);
if (!$result) {
echo "ERROR: send_message() stream_select() failed\n";
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Suggested change
echo "ERROR: send_message() stream_select() failed\n";
fwrite(STDERR, "ERROR: send_message() stream_select() failed\n");

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function error(string $message): void
{
    echo "ERROR: {$message}\n";
    exit(1);
}

Nothing else in run-tests.php is printing to STDERR or referencing STDERR yet - starting to do that would introduce an inconsistency with similar error logging.

For anything redirecting to a log file, the existing behavior of printing to stdout seems fine, especially since there's no machine-readable output format for run-tests.php as an option

return false;
}
$n = @fwrite($stream, substr($data, $bytes_written));
if ($n === false) {
echo "ERROR: send_message() Failed to write chunk after stream_select: " . error_get_last()['message'] . "\n";
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Suggested change
echo "ERROR: send_message() Failed to write chunk after stream_select: " . error_get_last()['message'] . "\n";
fwrite(STDERR, "ERROR: send_message() Failed to write chunk after stream_select: " . error_get_last()['message'] . "\n");

return false;
}
}
$bytes_written += $n;
}
return $bytes_written;
}

function send_message($stream, array $message): void
{
$blocking = stream_get_meta_data($stream)["blocked"];
stream_set_blocking($stream, true);
fwrite($stream, base64_encode(serialize($message)) . "\n");
safe_fwrite($stream, base64_encode(serialize($message)) . "\n");
stream_set_blocking($stream, $blocking);
}

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