/*
- Copyright (C) 2012 Paul Davis
+ 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
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 <unistd.h>
#include <iostream>
+#include <algorithm>
#include "pbd/stacktrace.h"
#include "pbd/abstract_ui.h"
#include "pbd/failed_constructor.h"
#include "pbd/debug.h"
-#include "i18n.h"
+#include "pbd/i18n.h"
#ifdef COMPILER_MSVC
#include <ardourext/misc.h> // Needed for 'DECLARE_DEFAULT_COMPARISONS'. Objects in an STL container can be
using namespace std;
-template<typename RequestBuffer> void
+template<typename RequestBuffer> void
cleanup_request_buffer (void* ptr)
{
- RequestBuffer* rb = (RequestBuffer*) ptr;
-
+ RequestBuffer* rb = (RequestBuffer*) ptr;
+
/* this is called when the thread for which this request buffer was
* allocated dies. That could be before or after the end of the UI
* event loop for which this request buffer provides communication.
*
- * We are not modifying the UI's thread/buffer map, just marking it
+ * We are not modifying the UI's thread/buffer map, just marking it
* dead. If the UI is currently processing the buffers and misses
* this "dead" signal, it will find it the next time it receives
* a request. If the UI has finished processing requests, then
* we will leak this buffer object.
*/
-
+ DEBUG_TRACE (PBD::DEBUG::AbstractUI, string_compose ("thread \"%1\" exits: marking request buffer as dead @ %2\n", pthread_name(), rb));
rb->dead = true;
}
AbstractUI<RequestObject>::AbstractUI (const string& name)
: BaseUI (name)
{
- void (AbstractUI<RequestObject>::*pmf)(string,pthread_t,string,uint32_t) = &AbstractUI<RequestObject>::register_thread;
+ void (AbstractUI<RequestObject>::*pmf)(pthread_t,string,uint32_t) = &AbstractUI<RequestObject>::register_thread;
- /* better to make this connect a handler that runs in the UI event loop but the syntax seems hard, and
+ /* better to make this connect a handler that runs in the UI event loop but the syntax seems hard, and
register_thread() is thread safe anyway.
*/
- PBD::ThreadCreatedWithRequestSize.connect_same_thread (new_thread_connection, boost::bind (pmf, this, _1, _2, _3, _4));
+ PBD::ThreadCreatedWithRequestSize.connect_same_thread (new_thread_connection, boost::bind (pmf, this, _1, _2, _3));
+
+ /* find pre-registerer threads */
+
+ vector<EventLoop::ThreadBufferMapping> tbm = EventLoop::get_request_buffers_for_target_thread (event_loop_name());
+
+ {
+ Glib::Threads::Mutex::Lock rbml (request_buffer_map_lock);
+ for (vector<EventLoop::ThreadBufferMapping>::iterator t = tbm.begin(); t != tbm.end(); ++t) {
+ request_buffers[t->emitting_thread] = static_cast<RequestBuffer*> (t->request_buffer);
+ }
+ }
+}
+
+template <typename RequestObject>
+AbstractUI<RequestObject>::~AbstractUI ()
+{
+ for (RequestBufferMapIterator i = request_buffers.begin(); i != request_buffers.end(); ++i) {
+ if ((*i).second->dead) {
+ EventLoop::remove_request_buffer_from_map ((*i).second);
+ delete (*i).second;
+ }
+ }
}
template <typename RequestObject> void
-AbstractUI<RequestObject>::register_thread (string target_gui, pthread_t thread_id, string /*thread name*/, uint32_t num_requests)
+AbstractUI<RequestObject>::register_thread (pthread_t thread_id, string thread_name, uint32_t num_requests)
{
/* the calling thread wants to register with the thread that runs this
* UI's event loop, so that it will have its own per-thread queue of
* do so in a realtime-safe manner (no locks).
*/
- if (target_gui != name()) {
- /* this UI is not the UI that the calling thread is trying to
- register with
- */
- return;
- }
+ DEBUG_TRACE (PBD::DEBUG::AbstractUI, string_compose ("in %1 (thread name %4), %2 (%5) wants to register with UIs\n", event_loop_name(), thread_name, pthread_name(), DEBUG_THREAD_SELF));
/* the per_thread_request_buffer is a thread-private variable.
See pthreads documentation for more on these, but the key
thing is that it is a variable that as unique value for
- each thread, guaranteed.
+ each thread, guaranteed. Note that the thread in question
+ is the caller of this function, which is assumed to be the
+ thread from which signals will be emitted that this UI's
+ event loop will catch.
*/
RequestBuffer* b = per_thread_request_buffer.get();
- if (b) {
- /* thread already registered with this UI
- */
- return;
- }
+ if (!b) {
+
+ /* create a new request queue/ringbuffer */
+
+ DEBUG_TRACE (PBD::DEBUG::AbstractUI, string_compose ("create new request buffer for %1 in %2\n", thread_name, event_loop_name()));
- /* create a new request queue/ringbuffer */
+ b = new RequestBuffer (num_requests); // XXX leaks
+ /* set this thread's per_thread_request_buffer to this new
+ queue/ringbuffer. remember that only this thread will
+ get this queue when it calls per_thread_request_buffer.get()
- b = new RequestBuffer (num_requests, *this);
+ the second argument is a function that will be called
+ when the thread exits, and ensures that the buffer is marked
+ dead. it will then be deleted during a call to handle_ui_requests()
+ */
+
+ per_thread_request_buffer.set (b);
+ } else {
+ DEBUG_TRACE (PBD::DEBUG::AbstractUI, string_compose ("%1 : %2 is already registered\n", event_loop_name(), thread_name));
+ }
{
/* add the new request queue (ringbuffer) to our map
so that we can iterate over it when the time is right.
This step is not RT-safe, but is assumed to be called
- only at thread initialization time, not repeatedly,
+ only at thread initialization time, not repeatedly,
and so this is of little consequence.
*/
- Glib::Threads::Mutex::Lock lm (request_buffer_map_lock);
+ Glib::Threads::Mutex::Lock rbml (request_buffer_map_lock);
request_buffers[thread_id] = b;
}
- /* set this thread's per_thread_request_buffer to this new
- queue/ringbuffer. remember that only this thread will
- get this queue when it calls per_thread_request_buffer.get()
-
- the second argument is a function that will be called
- when the thread exits, and ensures that the buffer is marked
- dead. it will then be deleted during a call to handle_ui_requests()
- */
-
- per_thread_request_buffer.set (b);
}
template <typename RequestObject> RequestObject*
rbuf->get_write_vector (&vec);
if (vec.len[0] == 0) {
- DEBUG_TRACE (PBD::DEBUG::AbstractUI, string_compose ("%1: no space in per thread pool for request of type %2\n", name(), rt));
+ DEBUG_TRACE (PBD::DEBUG::AbstractUI, string_compose ("%1: no space in per thread pool for request of type %2\n", event_loop_name(), rt));
return 0;
}
- DEBUG_TRACE (PBD::DEBUG::AbstractUI, string_compose ("%1: allocated per-thread request of type %2, caller %3\n", name(), rt, pthread_name()));
+ DEBUG_TRACE (PBD::DEBUG::AbstractUI, string_compose ("%1: allocated per-thread request of type %2, caller %3\n", event_loop_name(), rt, pthread_name()));
vec.buf[0]->type = rt;
- vec.buf[0]->valid = true;
return vec.buf[0];
}
* are not at work.
*/
- DEBUG_TRACE (PBD::DEBUG::AbstractUI, string_compose ("%1: allocated normal heap request of type %2, caller %3\n", name(), rt, pthread_name()));
+ DEBUG_TRACE (PBD::DEBUG::AbstractUI, string_compose ("%1: allocated normal heap request of type %2, caller %3\n", event_loop_name(), rt, pthread_name()));
RequestObject* req = new RequestObject;
req->type = rt;
RequestBufferVector vec;
/* check all registered per-thread buffers first */
+ Glib::Threads::Mutex::Lock rbml (request_buffer_map_lock);
+
+ /* clean up any dead invalidation records (object was deleted) */
+ trash.sort();
+ trash.unique();
+ for (std::list<InvalidationRecord*>::iterator r = trash.begin(); r != trash.end();) {
+ if (!(*r)->in_use ()) {
+ assert (!(*r)->valid ());
+ DEBUG_TRACE (PBD::DEBUG::AbstractUI, string_compose ("%1 drop invalidation trash %2\n", event_loop_name(), *r));
+ std::list<InvalidationRecord*>::iterator tmp = r;
+ ++tmp;
+ delete *r;
+ trash.erase (r);
+ r = tmp;
+ } else {
+ ++r;
+ }
+ }
+#ifndef NDEBUG
+ if (trash.size() > 0) {
+ DEBUG_TRACE (PBD::DEBUG::AbstractUI, string_compose ("%1 items in trash: %2\n", event_loop_name(), trash.size()));
+ }
+#endif
- request_buffer_map_lock.lock ();
+ DEBUG_TRACE (PBD::DEBUG::AbstractUI, string_compose ("%1 check %2 request buffers for requests\n", event_loop_name(), request_buffers.size()));
for (i = request_buffers.begin(); i != request_buffers.end(); ++i) {
- 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 {
- if (vec.buf[0]->valid) {
- request_buffer_map_lock.unlock ();
- do_request (vec.buf[0]);
- request_buffer_map_lock.lock ();
- if (vec.buf[0]->invalidation) {
- vec.buf[0]->invalidation->requests.remove (vec.buf[0]);
- }
- delete vec.buf[0];
- i->second->increment_read_ptr (1);
- }
- }
- }
- }
-
- /* clean up any dead request buffers (their thread has exited) */
+ while (!(*i).second->dead) {
+ /* 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);
+
+ DEBUG_TRACE (PBD::DEBUG::AbstractUI, string_compose ("%1 reading requests from RB[%2] @ %5, requests = %3 + %4\n",
+ event_loop_name(), std::distance (request_buffers.begin(), i), vec.len[0], vec.len[1], i->second));
+
+ if (vec.len[0] == 0) {
+ break;
+ } else {
+ if (vec.buf[0]->invalidation && !vec.buf[0]->invalidation->valid ()) {
+ DEBUG_TRACE (PBD::DEBUG::AbstractUI, string_compose ("%1: skipping invalidated request\n", event_loop_name()));
+ rbml.release ();
+ } else {
+
+ DEBUG_TRACE (PBD::DEBUG::AbstractUI, string_compose ("%1: valid request, unlocking before calling\n", event_loop_name()));
+ rbml.release ();
+
+ DEBUG_TRACE (PBD::DEBUG::AbstractUI, string_compose ("%1: valid request, calling ::do_request()\n", event_loop_name()));
+ do_request (vec.buf[0]);
+ }
+
+ /* if the request was CallSlot, then we need to ensure that we reset the functor in the request, in case it
+ * held a shared_ptr<>. Failure to do so can lead to dangling references to objects passed to PBD::Signals.
+ *
+ * Note that this method (::handle_ui_requests()) is by definition called from the event loop thread, so
+ * caller_is_self() is true, which means that the execution of the functor has definitely happened after
+ * do_request() returns and we no longer need the functor for any reason.
+ */
+
+ if (vec.buf[0]->type == CallSlot) {
+ vec.buf[0]->the_slot = 0;
+ }
+
+ rbml.acquire ();
+ if (vec.buf[0]->invalidation) {
+ vec.buf[0]->invalidation->unref ();
+ }
+ vec.buf[0]->invalidation = NULL;
+ i->second->increment_read_ptr (1);
+ }
+ }
+ }
+
+ assert (rbml.locked ());
for (i = request_buffers.begin(); i != request_buffers.end(); ) {
- if ((*i).second->dead) {
- DEBUG_TRACE (PBD::DEBUG::AbstractUI, string_compose ("%1/%2 deleting dead per-thread request buffer for %3 @ %4\n",
- name(), pthread_name(), i->second));
- delete (*i).second;
- RequestBufferMapIterator tmp = i;
- ++tmp;
- request_buffers.erase (i);
- i = tmp;
- } else {
- ++i;
- }
- }
-
- request_buffer_map_lock.unlock ();
+ if ((*i).second->dead) {
+ DEBUG_TRACE (PBD::DEBUG::AbstractUI, string_compose ("%1/%2 deleting dead per-thread request buffer for %3 @ %4 (%5 requests)\n", event_loop_name(), pthread_name(), i->second, (*i).second->read_space()));
+ RequestBufferMapIterator tmp = i;
+ ++tmp;
+ /* remove it from the EventLoop static map of all request buffers */
+ EventLoop::remove_request_buffer_from_map ((*i).second);
+ /* delete it
+ *
+ * Deleting the ringbuffer destroys all RequestObjects
+ * and thereby drops any InvalidationRecord references of
+ * requests that have not been processed.
+ */
+ delete (*i).second;
+ /* remove it from this thread's list of request buffers */
+ request_buffers.erase (i);
+ i = tmp;
+ } else {
+ ++i;
+ }
+ }
/* and now, the generic request buffer. same rules as above apply */
- Glib::Threads::Mutex::Lock lm (request_list_lock);
-
while (!request_list.empty()) {
+ assert (rbml.locked ());
RequestObject* req = request_list.front ();
request_list.pop_front ();
- /* We need to use this lock, because its the one
- returned by slot_invalidation_mutex() and protects
- against request invalidation.
- */
-
- request_buffer_map_lock.lock ();
- if (!req->valid) {
- DEBUG_TRACE (PBD::DEBUG::AbstractUI, string_compose ("%1/%2 handling invalid heap request, type %3, deleting\n", name(), pthread_name(), req->type));
- delete req;
- request_buffer_map_lock.unlock ();
- continue;
- }
-
- /* we're about to execute this request, so its
- too late for any invalidation. mark
- the request as "done" before we start.
- */
-
- if (req->invalidation) {
- DEBUG_TRACE (PBD::DEBUG::AbstractUI, string_compose ("%1/%2 remove request from its invalidation list\n", name(), pthread_name()));
-
- /* after this call, if the object referenced by the
- * invalidation record is deleted, it will no longer
- * try to mark the request as invalid.
- */
+ /* we're about to execute this request, so its
+ * too late for any invalidation. mark
+ * the request as "done" before we start.
+ */
- req->invalidation->requests.remove (req);
- }
+ if (req->invalidation && !req->invalidation->valid()) {
+ DEBUG_TRACE (PBD::DEBUG::AbstractUI, string_compose ("%1/%2 handling invalid heap request, type %3, deleting\n", event_loop_name(), pthread_name(), req->type));
+ delete req;
+ continue;
+ }
/* at this point, an object involved in a functor could be
* deleted before we actually execute the functor. so there is
* a race condition that makes the invalidation architecture
- * somewhat pointless.
+ * somewhat pointless.
*
* really, we should only allow functors containing shared_ptr
* references to objects to enter into the request queue.
*/
- request_buffer_map_lock.unlock ();
-
/* unlock the request lock while we execute the request, so
- * that we don't needlessly block other threads (note: not RT
+ * that we don't needlessly block other threads (note: not RT
* threads since they have their own queue) from making requests.
*/
- lm.release ();
+ /* also the request may destroy the object itself resulting in a direct
+ * path to EventLoop::invalidate_request () from here
+ * which takes the lock */
- DEBUG_TRACE (PBD::DEBUG::AbstractUI, string_compose ("%1/%2 execute request type %3\n", name(), pthread_name(), req->type));
+ rbml.release ();
+
+ DEBUG_TRACE (PBD::DEBUG::AbstractUI, string_compose ("%1/%2 execute request type %3\n", event_loop_name(), pthread_name(), req->type));
/* and lets do it ... this is a virtual call so that each
* specific type of UI can have its own set of requests without
do_request (req);
- DEBUG_TRACE (PBD::DEBUG::AbstractUI, string_compose ("%1/%2 delete heap request type %3\n", name(), pthread_name(), req->type));
+ DEBUG_TRACE (PBD::DEBUG::AbstractUI, string_compose ("%1/%2 delete heap request type %3\n", event_loop_name(), pthread_name(), req->type));
delete req;
/* re-acquire the list lock so that we check again */
- lm.acquire();
+ rbml.acquire();
}
+
+ rbml.release ();
}
template <typename RequestObject> void
*/
if (base_instance() == 0) {
+ delete req;
return; /* XXX is this the right thing to do ? */
}
/* the thread that runs this UI's event loop is sending itself
a request: we dispatch it immediately and inline.
*/
- DEBUG_TRACE (PBD::DEBUG::AbstractUI, string_compose ("%1/%2 direct dispatch of request type %3\n", name(), pthread_name(), req->type));
+ DEBUG_TRACE (PBD::DEBUG::AbstractUI, string_compose ("%1/%2 direct dispatch of request type %3\n", event_loop_name(), pthread_name(), req->type));
do_request (req);
delete req;
- } else {
+ } else {
/* If called from a different thread, we first check to see if
* the calling thread is registered with this UI. If so, there
RequestBuffer* rbuf = per_thread_request_buffer.get ();
if (rbuf != 0) {
- DEBUG_TRACE (PBD::DEBUG::AbstractUI, string_compose ("%1/%2 send per-thread request type %3\n", name(), pthread_name(), req->type));
+ DEBUG_TRACE (PBD::DEBUG::AbstractUI, string_compose ("%1/%2 send per-thread request type %3 using ringbuffer @ %4 IR: %5\n", event_loop_name(), pthread_name(), req->type, rbuf, req->invalidation));
rbuf->increment_write_ptr (1);
} else {
/* no per-thread buffer, so just use a list with a lock so that it remains
- single-reader/single-writer semantics
- */
- DEBUG_TRACE (PBD::DEBUG::AbstractUI, string_compose ("%1/%2 send heap request type %3\n", name(), pthread_name(), req->type));
- Glib::Threads::Mutex::Lock lm (request_list_lock);
+ * single-reader/single-writer semantics
+ */
+ DEBUG_TRACE (PBD::DEBUG::AbstractUI, string_compose ("%1/%2 send heap request type %3 IR %4\n", event_loop_name(), pthread_name(), req->type, req->invalidation));
+ Glib::Threads::Mutex::Lock lm (request_buffer_map_lock);
request_list.push_back (req);
}
AbstractUI<RequestObject>::call_slot (InvalidationRecord* invalidation, const boost::function<void()>& f)
{
if (caller_is_self()) {
- DEBUG_TRACE (PBD::DEBUG::AbstractUI, string_compose ("%1/%2 direct dispatch of call slot via functor @ %3, invalidation %4\n", name(), pthread_name(), &f, invalidation));
+ DEBUG_TRACE (PBD::DEBUG::AbstractUI, string_compose ("%1/%2 direct dispatch of call slot via functor @ %3, invalidation %4\n", event_loop_name(), pthread_name(), &f, invalidation));
f ();
return;
}
+ /* object destruction may race with realtime signal emission.
+ *
+ * There may be a concurrent event-loop in progress of deleting
+ * the slot-object. That's perfectly fine. But we need to mark
+ * the invalidation record itself as being used by the request.
+ *
+ * The IR needs to be kept around until the last signal using
+ * it is disconnected and then it can be deleted in the event-loop
+ * (GUI thread).
+ */
+ if (invalidation) {
+ if (!invalidation->valid()) {
+ DEBUG_TRACE (PBD::DEBUG::AbstractUI, string_compose ("%1/%2 ignoring call-slot using functor @ %3, dead invalidation %4\n", event_loop_name(), pthread_name(), &f, invalidation));
+ return;
+ }
+ invalidation->ref ();
+ invalidation->event_loop = this;
+ }
+
RequestObject *req = get_request (BaseUI::CallSlot);
-
+
if (req == 0) {
+ if (invalidation) {
+ invalidation->unref ();
+ }
return;
}
- DEBUG_TRACE (PBD::DEBUG::AbstractUI, string_compose ("%1/%2 queue call-slot using functor @ %3, invalidation %4\n", name(), pthread_name(), &f, invalidation));
+ DEBUG_TRACE (PBD::DEBUG::AbstractUI, string_compose ("%1/%2 queue call-slot using functor @ %3, invalidation %4\n", event_loop_name(), pthread_name(), &f, invalidation));
/* copy semantics: copy the functor into the request object */
req->the_slot = f;
-
+
/* the invalidation record is an object which will carry out
- * invalidation of any requests associated with it when it is
+ * invalidation of any requests associated with it when it is
* destroyed. it can be null. if its not null, associate this
* request with the invalidation record. this allows us to
* "cancel" requests submitted to the UI because they involved
* a functor that uses an object that is being deleted.
*/
- req->invalidation = invalidation;
-
- if (invalidation) {
- invalidation->requests.push_back (req);
- invalidation->event_loop = this;
- }
+ req->invalidation = invalidation;
send_request (req);
-}
+}
+template<typename RequestObject> void*
+AbstractUI<RequestObject>::request_buffer_factory (uint32_t num_requests)
+{
+ RequestBuffer* mcr = new RequestBuffer (num_requests); // XXX leaks
+ per_thread_request_buffer.set (mcr);
+ return mcr;
+}