curlhttpsrc uses a single thread running the
gst_curl_http_src_curl_multi_loop() function to handle receiving
data and messages from libcurl. Each instance of curlhttpsrc adds
an entry into a queue in GstCurlHttpSrcMultiTaskContext and waits
for the multi_loop to perform the HTTP request.
Valgrind has shown up race conditions and memory leaks:
1. gst_curl_http_src_change_state() does not wait for the multi_loop
to complete before going to the NULL state, which means that
an instance of GstCurlHttpSrc can be released while
gst_curl_http_src_curl_multi_loop() still has a reference to it.
2. if multiple elements try to be removed from the queue at once,
only the last one is deleted.
3. source->caps is leaked
4. curl multi_handle is leaked
5. leak of curl_handle if URI not set
6. leak of http_headers when reusing element
7. null pointer dereference in negotiate caps
8. double-free of the default user-agent string
9. leak of multi_task_context.task
This commit changes the logic so that each element has a connection
status, which is used by the multi_loop to decide when to remove an
element from its queue. An instance of curlhttpsrc will not enter
the NULL state until its reference has been removed from the queue.
When shutting down the curl multi loop, the memory allocated from the
call to curl_multi_init() is now released.
When gstadaptivedemux uses a URI source element, it will re-use
it for multiple requests, moving it between READY and PLAYING
between each request. curlhttpsrc was leaking the http_headers
structure in this use case.
The gst_curl_http_src_negotiate_caps() function extracts the
"response-headers" field from the http_headers, but did not check
that this field might be NULL.
If the user-agent property is set, the global user-agent string
was freed. This caused a double-free error if the user-agent is
ever set a second time during the execution of the process.
There are situations within curlhttpsrc where the code needs
both the global multi_task_context mutex and the per-element
buffer_mutex. To avoid deadlocks, it is vital that the order in
which these are requested is always the same. This commit modifies
the locking order to always be in the order:
1. multi_task_context.task_rec_mutex
2. buffer_mutex
Fixes#876
gst_curl_http_src_remove_queue_item() can free qelement and then
we get an invalid memory reference when we do qelement->next a
couple of lines below. Take the next pointer earlier so that we can
safely free.
If the version of the curl library is recent enough to allow support
for HTTP2 (i.e. CURL_VERSION_HTTP2 is defined) but does not actually
have that feature enabled, the call to
g_object_class_install_property() uses an incorrect default value for
the "http-version" property. The default should be 1.1 if HTTP2 is
not supported by libcurl or if not enabled by libcurl.
https://bugzilla.gnome.org/show_bug.cgi?id=786049
https://github.com/mesonbuild/meson
With contributions from:
Tim-Philipp Müller <tim@centricular.com>
Matej Knopp <matej.knopp@gmail.com>
Jussi Pakkanen <jpakkane@gmail.com> (original port)
Highlights of the features provided are:
* Faster builds on Linux (~40-50% faster)
* The ability to build with MSVC on Windows
* Generate Visual Studio project files
* Generate XCode project files
* Much faster builds on Windows (on-par with Linux)
* Seriously fast configure and building on embedded
... and many more. For more details see:
http://blog.nirbheek.in/2016/05/gstreamer-and-meson-new-hope.htmlhttp://blog.nirbheek.in/2016/07/building-and-developing-gstreamer-using.html
Building with Meson should work on both Linux and Windows, but may
need a few more tweaks on other operating systems.
Previously GstCurlSmtpSink could cause the pipeline thread to end up
waiting for a stopped thread to perform work.
The scenario was that the sink could be rendering a buffer and waiting
for the curl transfer thread to have sent the data. As soon as the
transfer thread has copied all data to curl's data buffer in
gst_curl_base_sink_transfer_read_cb() then the render call would stop
waiting and return GST_FLOW_OK. While this takes place the transfer
thread may suffer from an error e.g. due gst_poll_wait() timing out.
This causes the transfer thread to record the error, claim (it is not
really true since there was an error) that the data has been sent and
that a response has been received by trying to signal the pipeline
thread (but this has already stopped waiting). Finally the transfer
thread stops itself. A short while later the pipeline thread may attempt
to push an EOS event into GstCurlSmtpSink. Since there is no check in
gst_curl_smtp_sink_event() to check if the sink has suffered from any
error it may attempt to add a final boundary and ask the, now deceased,
transfer thread to transfer the new data. Next the sink element would
have waited for the transfer to complete (using a different mechanism
than normal transfers through GstCurlBaseSink). In this case there was
an error check to avoid waiting if an error had already been seen.
Finally GstCurlSmtpSink would chain up to GstCurlBaseSink which would
then block waiting for a response (normally this would be prevented by
the transfer thread suffering the error claiming that it had been
received, but GstCurlSmtpSink clobbered this flag after the fact).
Now GstCurlSmtpSink avoids this by locking over the entire event handing
(preventing simultaneous changes to flags by the two threads) and also
by avoiding to initiate transfer of final boundary if an error has
already been seen.
Also add GST_FIXME() for remaining similar issue where the pipeline
thread may block indefinitely waiting for transfer thread to transfer
data but the transfer thread errors out and fails to notify the pipeline
thread that the transfer failed.
https://bugzilla.gnome.org/show_bug.cgi?id=767501
In this case the socket callback has not been called
by libcurl and the curlsink has not been notified about any
connection problems by libcurl.
This indicates that it's a bug in libcurl so catch it as
an unknown error.
https://bugzilla.gnome.org/show_bug.cgi?id=754432
rename gst-launch --> gst-launch-1.0
replace old elements with new elements(ffmpegcolorspace -> videoconvert, ffenc_** -> avenc_**)
fix caps in examples
https://bugzilla.gnome.org/show_bug.cgi?id=759432
Corrected the final boundary mechanism so that a final boundary is
added to each mail with multipart content that is sent,
not just to the last one.
https://bugzilla.gnome.org/show_bug.cgi?id=741553
