> On 16 Feb 2018, at 17:40, Frediano Ziglio <fziglio@xxxxxxxxxx> wrote:
>
>>
>> From: Christophe de Dinechin <dinechin@xxxxxxxxxx>
>>
>> Get rid of C-style 'goto done' in do_capture.
>> Get rid of global streamfd, pass it around (cleaned up in later patch)
>> Fixes a race condition, make sure we only use stream after opening
>>
>> Signed-off-by: Christophe de Dinechin <dinechin@xxxxxxxxxx>
>> ---
>> src/spice-streaming-agent.cpp | 79
>> +++++++++++++++++++++++++------------------
>> 1 file changed, 47 insertions(+), 32 deletions(-)
>>
>> diff --git a/src/spice-streaming-agent.cpp b/src/spice-streaming-agent.cpp
>> index 646d15b..9b8fd45 100644
>> --- a/src/spice-streaming-agent.cpp
>> +++ b/src/spice-streaming-agent.cpp
>> @@ -53,14 +53,38 @@ struct SpiceStreamDataMessage
>> StreamMsgData msg;
>> };
>>
>> +struct SpiceStreamCursorMessage
>> +{
>> + StreamDevHeader hdr;
>> + StreamMsgCursorSet msg;
>> +};
>> +
>
> This is weird in this patch
Yes. I may have merged two patches. Will check.
>
>> +class Stream
>> +{
>> +public:
>> + Stream(const char *name)
>> + {
>> + fd = open(name, O_RDWR);
>> + if (fd < 0)
>> + throw std::runtime_error("failed to open streaming device");
>> + }
>> + ~Stream()
>> + {
>> + close(fd);
>
> You probably what to check for -1 to avoid calling close(-1)
I think this cannot happen, since in that case you’d have thrown from the ctor.
>
>> + }
>> + operator int() { return fd; }
>
> Sure you want this? I think is safer to avoid implicit cast
> also considering stuff like
>
> Stream s;
> if (s) …
It is removed in a later patch once it’s no longer needed. The objective here is to minimize noisy changes at each step.
>
>> +
>> +private:
>> + int fd = -1;
>
> So with a default constructor you want a class with
> an invalid state?
> Or just disable default constructor.
It’s disabled, there’s a ctor with args.
> I would disable also copy.
Also implicitly disabled.
>
>> +};
>> +
>> static bool streaming_requested = false;
>> static bool quit_requested = false;
>> static bool log_binary = false;
>> static std::set<SpiceVideoCodecType> client_codecs;
>> -static int streamfd = -1;
>> static std::mutex stream_mtx;
>>
>> -static int have_something_to_read(int timeout)
>> +static int have_something_to_read(int streamfd, int timeout)
>
> maybe would be better to use the "fd" name here, is no more
> bound to stream.
Kept to minimize changes
>> {
>> struct pollfd pollfd = {streamfd, POLLIN, 0};
>>
>> @@ -76,7 +100,7 @@ static int have_something_to_read(int timeout)
>> return 0;
>> }
>>
>> -static int read_command_from_device(void)
>> +static int read_command_from_device(int streamfd)
>
> Have you considered Stream::read_command?
For that specific case, I liked the “from_device”. But…
> Ok, mostly in a following patch
>
>> {
>> StreamDevHeader hdr;
>> uint8_t msg[64];
>> @@ -121,18 +145,18 @@ static int read_command_from_device(void)
>> return 1;
>> }
>>
>> -static int read_command(bool blocking)
>> +static int read_command(int streamfd, bool blocking)
>> {
>> int timeout = blocking?-1:0;
>> while (!quit_requested) {
>> - if (!have_something_to_read(timeout)) {
>> + if (!have_something_to_read(streamfd, timeout)) {
>> if (!blocking) {
>> return 0;
>> }
>> sleep(1);
>> continue;
>> }
>> - return read_command_from_device();
>> + return read_command_from_device(streamfd);
>> }
>>
>> return 1;
>> @@ -157,7 +181,7 @@ write_all(int fd, const void *buf, const size_t len)
>> return written;
>> }
>>
>> -static int spice_stream_send_format(unsigned w, unsigned h, unsigned c)
>> +static int spice_stream_send_format(int streamfd, unsigned w, unsigned h,
>> unsigned c)
>> {
>>
>> SpiceStreamFormatMessage msg;
>> @@ -178,7 +202,7 @@ static int spice_stream_send_format(unsigned w, unsigned
>> h, unsigned c)
>> return EXIT_SUCCESS;
>> }
>>
>> -static int spice_stream_send_frame(const void *buf, const unsigned size)
>> +static int spice_stream_send_frame(int streamfd, const void *buf, const
>> unsigned size)
>> {
>> SpiceStreamDataMessage msg;
>> const size_t msgsize = sizeof(msg);
>> @@ -254,7 +278,7 @@ static void usage(const char *progname)
>> }
>>
>> static void
>> -send_cursor(unsigned width, unsigned height, int hotspot_x, int hotspot_y,
>> +send_cursor(int streamfd, unsigned width, unsigned height, int hotspot_x,
>> int hotspot_y,
>> std::function<void(uint32_t *)> fill_cursor)
>> {
>> if (width >= STREAM_MSG_CURSOR_SET_MAX_WIDTH ||
>> @@ -288,7 +312,7 @@ send_cursor(unsigned width, unsigned height, int
>> hotspot_x, int hotspot_y,
>> write_all(streamfd, msg.get(), cursor_size);
>> }
>>
>> -static void cursor_changes(Display *display, int event_base)
>> +static void cursor_changes(int streamfd, Display *display, int event_base)
>> {
>> unsigned long last_serial = 0;
>>
>> @@ -310,25 +334,20 @@ static void cursor_changes(Display *display, int
>> event_base)
>> for (unsigned i = 0; i < cursor->width * cursor->height; ++i)
>> pixels[i] = cursor->pixels[i];
>> };
>> - send_cursor(cursor->width, cursor->height, cursor->xhot,
>> cursor->yhot, fill_cursor);
>> + send_cursor(streamfd,
>> + cursor->width, cursor->height, cursor->xhot,
>> cursor->yhot, fill_cursor);
>> }
>> }
>>
>> static void
>> -do_capture(const char *streamport, FILE *f_log)
>> +do_capture(int streamfd, const char *streamport, FILE *f_log)
>> {
>> - streamfd = open(streamport, O_RDWR);
>> - if (streamfd < 0)
>> - throw std::runtime_error("failed to open the streaming device (" +
>> - std::string(streamport) + "): "
>> - + strerror(errno));
>> -
>> unsigned int frame_count = 0;
>> while (!quit_requested) {
>> while (!quit_requested && !streaming_requested) {
>> - if (read_command(true) < 0) {
>> + if (read_command(streamfd, true) < 0) {
>> syslog(LOG_ERR, "FAILED to read command\n");
>> - goto done;
>> + return;
>> }
>> }
>>
>> @@ -370,7 +389,7 @@ do_capture(const char *streamport, FILE *f_log)
>>
>> syslog(LOG_DEBUG, "wXh %uX%u codec=%u\n", width, height,
>> codec);
>>
>> - if (spice_stream_send_format(width, height, codec) ==
>> EXIT_FAILURE)
>> + if (spice_stream_send_format(streamfd, width, height, codec)
>> == EXIT_FAILURE)
>> throw std::runtime_error("FAILED to send format
>> message");
>> }
>> if (f_log) {
>> @@ -382,23 +401,18 @@ do_capture(const char *streamport, FILE *f_log)
>> hexdump(frame.buffer, frame.buffer_size, f_log);
>> }
>> }
>> - if (spice_stream_send_frame(frame.buffer, frame.buffer_size) ==
>> EXIT_FAILURE) {
>> + if (spice_stream_send_frame(streamfd,
>> + frame.buffer, frame.buffer_size) ==
>> EXIT_FAILURE) {
>> syslog(LOG_ERR, "FAILED to send a frame\n");
>> break;
>> }
>> //usleep(1);
>> - if (read_command(false) < 0) {
>> + if (read_command(streamfd, false) < 0) {
>> syslog(LOG_ERR, "FAILED to read command\n");
>> - goto done;
>> + return;
>> }
>> }
>> }
>> -
>> -done:
>> - if (streamfd >= 0) {
>> - close(streamfd);
>> - streamfd = -1;
>> - }
>> }
>>
>> #define arg_error(...) syslog(LOG_ERR, ## __VA_ARGS__);
>> @@ -481,12 +495,13 @@ int main(int argc, char* argv[])
>> Window rootwindow = DefaultRootWindow(display);
>> XFixesSelectCursorInput(display, rootwindow,
>> XFixesDisplayCursorNotifyMask);
>>
>> - std::thread cursor_th(cursor_changes, display, event_base);
>> + Stream streamfd(streamport);
>> + std::thread cursor_th(cursor_changes, (int) streamfd, display,
>> event_base);
>> cursor_th.detach();
>>
>> int ret = EXIT_SUCCESS;
>> try {
>> - do_capture(streamport, f_log);
>> + do_capture(streamfd, streamport, f_log);
>
> Not a fun of this implicit conversion
Well, we can make it explicitl. But this is temporary, and is suppressed by the end of the series.
> .
>
>> }
>> catch (std::runtime_error &err) {
>> syslog(LOG_ERR, "%s\n", err.what());
>
> Frediano
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