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livetrax/libs/pbd3/pbd/abstract_ui.cc

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#include <unistd.h>
#include <pbd/abstract_ui.h>
#include <pbd/pthread_utils.h>
#include <pbd/failed_constructor.h>
template <typename RequestObject>
AbstractUI<RequestObject>::AbstractUI (string name, bool with_signal_pipes)
: BaseUI (name, with_signal_pipes)
{
if (pthread_key_create (&thread_request_buffer_key, 0)) {
cerr << _("cannot create thread request buffer key") << endl;
throw failed_constructor();
}
PBD::ThreadCreated.connect (mem_fun (*this, &AbstractUI<RequestObject>::register_thread));
PBD::ThreadCreatedWithRequestSize.connect (mem_fun (*this, &AbstractUI<RequestObject>::register_thread_with_request_count));
}
template <typename RequestObject> void
AbstractUI<RequestObject>::register_thread (pthread_t thread_id, string name)
{
register_thread_with_request_count (thread_id, name, 256);
}
template <typename RequestObject> void
AbstractUI<RequestObject>::register_thread_with_request_count (pthread_t thread_id, string thread_name, uint32_t num_requests)
{
RequestBuffer* b = new RequestBuffer (num_requests);
{
Glib::Mutex::Lock lm (request_buffer_map_lock);
request_buffers[thread_id] = b;
}
pthread_setspecific (thread_request_buffer_key, b);
}
template <typename RequestObject> RequestObject*
AbstractUI<RequestObject>::get_request (RequestType rt)
{
RequestBuffer* rbuf = static_cast<RequestBuffer*>(pthread_getspecific (thread_request_buffer_key));
if (rbuf == 0) {
/* Cannot happen, but if it does we can't use the error reporting mechanism */
cerr << _("programming error: ")
<< string_compose (X_("no %1-UI request buffer found for thread %2"), name(), pthread_name())
<< endl;
abort ();
}
RequestBufferVector vec;
rbuf->get_write_vector (&vec);
if (vec.len[0] == 0) {
if (vec.len[1] == 0) {
cerr << string_compose (X_("no space in %1-UI request buffer for thread %2"), name(), pthread_name())
<< endl;
return 0;
} else {
vec.buf[1]->type = rt;
return vec.buf[1];
}
} else {
vec.buf[0]->type = rt;
return vec.buf[0];
}
}
template <typename RequestObject> void
AbstractUI<RequestObject>::handle_ui_requests ()
{
RequestBufferMapIterator i;
request_buffer_map_lock.lock ();
for (i = request_buffers.begin(); i != request_buffers.end(); ++i) {
RequestBufferVector vec;
while (true) {
/* we must process requests 1 by 1 because
the request may run a recursive main
event loop that will itself call
handle_ui_requests. when we return
from the request handler, we cannot
expect that the state of queued requests
is even remotely consistent with
the condition before we called it.
*/
i->second->get_read_vector (&vec);
if (vec.len[0] == 0) {
break;
} else {
/* request_factory/copy constructor does a deep
copy of the Request object,
unlike Ringbuffer::read()
*/
RequestObject req (*vec.buf[0]);
i->second->increment_read_ptr (1);
request_buffer_map_lock.unlock ();
do_request (&req);
request_buffer_map_lock.lock ();
}
}
}
request_buffer_map_lock.unlock ();
}
template <typename RequestObject> void
AbstractUI<RequestObject>::send_request (RequestObject *req)
{
if (base_instance() == 0) {
return; /* XXX is this the right thing to do ? */
}
if (caller_is_ui_thread()) {
// cerr << "GUI thread sent request " << req << " type = " << req->type << endl;
do_request (req);
} else {
RequestBuffer* rbuf = static_cast<RequestBuffer*> (pthread_getspecific (thread_request_buffer_key));
if (rbuf == 0) {
/* can't use the error system to report this, because this
thread isn't registered!
*/
cerr << _("programming error: ")
<< string_compose (X_("AbstractUI::send_request() called from %1, but no request buffer exists for that thread"), pthread_name())
<< endl;
abort ();
}
// cerr << "thread " << pthread_self() << " sent request " << req << " type = " << req->type << endl;
rbuf->increment_write_ptr (1);
if (signal_pipe[1] >= 0) {
const char c = 0;
write (signal_pipe[1], &c, 1);
}
}
}