rollback to 3428, before the mysterious removal of libs/* at 3431/3432

git-svn-id: svn://localhost/ardour2/branches/3.0@3435 d708f5d6-7413-0410-9779-e7cbd77b26cf

1 files changed, 149 insertions, 0 deletions

diff --git a/libs/pbd/pbd/abstract_ui.cc b/libs/pbd/pbd/abstract_ui.cc
new file mode 100644
index 0000000000..97f19e1fe5
--- /dev/null
+++ b/libs/pbd/pbd/abstract_ui.cc
@@ -0,0 +1,149 @@
+#include <unistd.h>
+
+#include <pbd/abstract_ui.h>
+#include <pbd/pthread_utils.h>
+#include <pbd/failed_constructor.h>
+
+#include "i18n.h"
+
+using namespace std;
+
+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 ("no %1-UI request buffer found for thread %2", name(), pthread_name())
+		     << endl;
+		abort ();
+	}
+	
+	RequestBufferVector vec;
+	vec.buf[0] = 0;
+	vec.buf[1] = 0;
+	
+	rbuf->get_write_vector (&vec);
+
+	if (vec.len[0] == 0) {
+		if (vec.len[1] == 0) {
+			cerr << string_compose ("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_buffer_map_lock.unlock ();
+				do_request (vec.buf[0]);
+				request_buffer_map_lock.lock ();
+				i->second->increment_read_ptr (1);
+			} 
+		}
+	}
+
+	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 ("AbstractUI::send_request() called from %1 (%2), but no request buffer exists for that thread", name(), 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);
+		}
+	}
+}
+