stream_get-line repeatedly calls php_stream_fill_read_buffer until
enough data is accumulated in buffer. However, when stream contains
filters attached to it, then each call to fill buffer essentially
resets buffer read/write pointers and new data is written over old.
This causes stream_get_line to skip parts of data from stream
This patch fixes such behavior, so fill buffer call will append.
There are two related changes here:
1. Also check for S_ISCHR/FILE_TYPE_CHAR when checking for pipes, so
that we detect ttys as well, which are also not seekable.
2. Always set position=-1 (i.e. ftell will return false) when a pipe
is detected. Previously position=0 was sometimes used, depending on
whether we're on Windows/Linux and whether the FD or FILE codepath
was used.
fcgi_accept_request function is supposed to call a FastCGI implementation's
on_accept hook when entering an "accepting" stage (that is right before
calling "accept"). This hook implementation (fpm_request_accepting) updates
a worker state to an "accepting" state which is effectively an "Idle" state,
and updates counters on the scoreboard of the corresponding pool (idle++,
active--).
But this is not done when listening for client connections on a named pipe on
Windows platform. In that case a combination of
ConnectNamedPipe/WaitForSingleObject is used (to be able to catch in_shutdown
as far as I understand), but it is nonetheless functionally equivalent to
"accept" call. Also by not calling on_hook neither a worker's state is updated
to "accepting" state nor scoreboard counters are updated.
There are a few parts here:
* opcache should not be blocking signals while invoking compile_file,
otherwise signals may remain blocked on a compile error. While at
it, also protect SHM memory during compile_file.
* We should deactivate Zend signals at the end of the request, to make
sure that we gracefully recover from a missing unblock and signals
don't remain blocked forever.
* We don't use a critical section in deactivation, because it should
not be necessary. Additionally we want to clean up the signal queue,
if it is non-empty.
* Enable SIGG(check) in debug builds so we notice issues in the future.
The php_stream_read() and php_stream_write() functions now return
an ssize_t value, with negative results indicating failure. Functions
like fread() and fwrite() will return false in that case.
As a special case, EWOULDBLOCK and EAGAIN on non-blocking streams
should not be regarded as error conditions, and be reported as
successful zero-length reads/writes instead. The handling of EINTR
remains unclear and is internally inconsistent (e.g. some code-paths
will automatically retry on EINTR, while some won't).
I'm landing this now to make sure the stream wrapper ops API changes
make it into 7.4 -- however, if the user-facing changes turn out to
be problematic we have the option of clamping negative returns to
zero in php_stream_read() and php_stream_write() to restore the
old behavior in a relatively non-intrusive manner.
