-#include <iostream>
+/*
+ Copyright (C) 2012 Paul Davis
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, write to the Free Software
+ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+*/
+
+#include <cstring>
+
+#include <pthread.h>
+
+#include "pbd/compose.h"
+#include "pbd/debug.h"
#include "pbd/event_loop.h"
+#include "pbd/error.h"
#include "pbd/stacktrace.h"
+#include "pbd/i18n.h"
+
using namespace PBD;
using namespace std;
-Glib::StaticPrivate<EventLoop> EventLoop::thread_event_loop;
-
static void do_not_delete_the_loop_pointer (void*) { }
-EventLoop*
-EventLoop::get_event_loop_for_thread() {
+Glib::Threads::Private<EventLoop> EventLoop::thread_event_loop (do_not_delete_the_loop_pointer);
+
+Glib::Threads::RWLock EventLoop::thread_buffer_requests_lock;
+EventLoop::ThreadRequestBufferList EventLoop::thread_buffer_requests;
+EventLoop::RequestBufferSuppliers EventLoop::request_buffer_suppliers;
+
+EventLoop::EventLoop (string const& name)
+ : _name (name)
+{
+}
+
+EventLoop*
+EventLoop::get_event_loop_for_thread()
+{
return thread_event_loop.get ();
}
-void
-EventLoop::set_event_loop_for_thread (EventLoop* loop)
+void
+EventLoop::set_event_loop_for_thread (EventLoop* loop)
{
- thread_event_loop.set (loop, do_not_delete_the_loop_pointer);
+ thread_event_loop.set (loop);
}
-/** Called when a sigc::trackable that was connected to using the invalidator() macro
- * is destroyed.
- */
-void*
+void*
EventLoop::invalidate_request (void* data)
{
InvalidationRecord* ir = (InvalidationRecord*) data;
+ /* Some of the requests queued with an EventLoop may involve functors
+ * that make method calls to objects whose lifetime is shorter
+ * than the EventLoop's. We do not want to make those calls if the
+ * object involve has been destroyed. To prevent this, we
+ * provide a way to invalidate those requests when the object is
+ * destroyed.
+ *
+ * An object was passed to __invalidator() which added a callback to
+ * EventLoop::invalidate_request() to its "notify when destroyed"
+ * list. __invalidator() returned an InvalidationRecord that has been
+ * to passed to this function as data.
+ *
+ * The object is currently being destroyed and so we want to
+ * mark all requests involving this object that are queued with
+ * any EventLoop as invalid.
+ *
+ * As of April 2012, we are usign sigc::trackable as the base object
+ * used to queue calls to ::invalidate_request() to be made upon
+ * destruction, via its ::add_destroy_notify_callback() API. This is
+ * not necessarily ideal, but it is very close to precisely what we
+ * want, and many of the objects we want to do this with already
+ * inherit (indirectly) from sigc::trackable.
+ */
+
if (ir->event_loop) {
- Glib::Mutex::Lock lm (ir->event_loop->slot_invalidation_mutex());
+ Glib::Threads::Mutex::Lock lm (ir->event_loop->slot_invalidation_mutex());
for (list<BaseRequestObject*>::iterator i = ir->requests.begin(); i != ir->requests.end(); ++i) {
(*i)->valid = false;
(*i)->invalidation = 0;
return 0;
}
+vector<EventLoop::ThreadBufferMapping>
+EventLoop::get_request_buffers_for_target_thread (const std::string& target_thread)
+{
+ vector<ThreadBufferMapping> ret;
+ Glib::Threads::RWLock::WriterLock lm (thread_buffer_requests_lock);
+
+ for (ThreadRequestBufferList::const_iterator x = thread_buffer_requests.begin();
+ x != thread_buffer_requests.end(); ++x) {
+
+ if (x->second.target_thread_name == target_thread) {
+ ret.push_back (x->second);
+ }
+ }
+
+ DEBUG_TRACE (PBD::DEBUG::EventLoop, string_compose ("for thread \"%1\", found %2 request buffers\n", target_thread, ret.size()));
+
+ return ret;
+}
+
+void
+EventLoop::register_request_buffer_factory (const string& target_thread_name,
+ void* (*factory)(uint32_t))
+{
+
+ RequestBufferSupplier trs;
+ trs.name = target_thread_name;
+ trs.factory = factory;
+
+ {
+ Glib::Threads::RWLock::WriterLock lm (thread_buffer_requests_lock);
+ request_buffer_suppliers.push_back (trs);
+ }
+}
+
+void
+EventLoop::pre_register (const string& emitting_thread_name, uint32_t num_requests)
+{
+ /* Threads that need to emit signals "towards" other threads, but with
+ RT safe behavior may be created before the receiving threads
+ exist. This makes it impossible for them to use the
+ ThreadCreatedWithRequestSize signal to notify receiving threads of
+ their existence.
+
+ This function creates a request buffer for them to use with
+ the (not yet) created threads, and stores it where the receiving
+ thread can find it later.
+ */
+
+ ThreadBufferMapping mapping;
+ Glib::Threads::RWLock::WriterLock lm (thread_buffer_requests_lock);
+
+ for (RequestBufferSuppliers::iterator trs = request_buffer_suppliers.begin(); trs != request_buffer_suppliers.end(); ++trs) {
+
+ if (!trs->factory) {
+ /* no factory - no request buffer required or expected */
+ continue;
+ }
+
+ if (emitting_thread_name == trs->name) {
+ /* no need to register an emitter with itself */
+ continue;
+ }
+
+ mapping.emitting_thread = pthread_self();
+ mapping.target_thread_name = trs->name;
+
+ /* Allocate a suitably sized request buffer. This will set the
+ * thread-local variable that holds a pointer to this request
+ * buffer.
+ */
+ mapping.request_buffer = trs->factory (num_requests);
+
+ /* now store it where the receiving thread (trs->name) can find
+ it if and when it is created. (Discovery happens in the
+ AbstractUI constructor. Note that if
+ */
+
+ const string key = string_compose ("%1/%2", emitting_thread_name, mapping.target_thread_name);
+
+ /* management of the thread_request_buffers map works as
+ * follows:
+ *
+ * when the factory method was called above, the pointer to the
+ * created buffer is set as a thread-local-storage (TLS) value
+ * for this (the emitting) thread.
+ *
+ * The TLS value is set up with a destructor that marks the
+ * request buffer as "dead" when the emitting thread exits.
+ *
+ * An entry will remain in the map after the thread exits.
+ *
+ * The receiving thread may (if it receives requests from other
+ * threads) notice the dead buffer. If it does, it will delete
+ * the request buffer, and call
+ * ::remove_request_buffer_from_map() to get rid of it from the map.
+ *
+ * This does mean that the lifetime of the request buffer is
+ * indeterminate: if the receiving thread were to receive no
+ * further requests, the request buffer will live on
+ * forever. But this is OK, because if there are no requests
+ * arriving, the receiving thread is not attempting to use the
+ * request buffer(s) in any way.
+ *
+ * Note, however, that *if* an emitting thread is recreated
+ * with the same name (e.g. when a control surface is
+ * enabled/disabled/enabled), then the request buffer for the
+ * new thread will replace the map entry for the key, because
+ * of the matching thread names. This does mean that
+ * potentially the request buffer can leak in this case, but
+ * (a) these buffers are not really that large anyway (b) the
+ * scenario is not particularly common (c) the buffers would
+ * typically last across a session instance if not program
+ * lifetime anyway.
+ */
+
+ thread_buffer_requests[key] = mapping;
+ DEBUG_TRACE (PBD::DEBUG::EventLoop, string_compose ("pre-registered request buffer for \"%1\" to send to \"%2\", buffer @ %3 (key was %4)\n",
+ emitting_thread_name, trs->name, mapping.request_buffer, key));
+ }
+}
+
+void
+EventLoop::remove_request_buffer_from_map (void* ptr)
+{
+ Glib::Threads::RWLock::WriterLock lm (thread_buffer_requests_lock);
+
+ for (ThreadRequestBufferList::iterator x = thread_buffer_requests.begin(); x != thread_buffer_requests.end(); ++x) {
+ if (x->second.request_buffer == ptr) {
+ thread_buffer_requests.erase (x);
+ break;
+ }
+ }
+}
projects / ardour.git / blobdiff