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eventloop and abstractui debugging, lots more commenting on abstractui/eventloop implementation; minor tweaks elsewhere

git-svn-id: svn://localhost/ardour2/branches/3.0@12076 d708f5d6-7413-0410-9779-e7cbd77b26cf
This commit is contained in:
Paul Davis 2012-04-24 16:45:38 +00:00
parent 9b8fe0b09f
commit d5e14b3d91
16 changed files with 266 additions and 19 deletions

View File

@ -313,7 +313,6 @@ MidiTimeAxisView::model_changed()
for (std::list<std::string>::const_iterator i = device_modes.begin();
i != device_modes.end(); ++i) {
cerr << "found custom device mode " << *i << " thread_id: " << pthread_self() << endl;
_custom_device_mode_selector.append_text(*i);
}

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@ -5,6 +5,7 @@
#include "pbd/abstract_ui.h"
#include "pbd/signals.h"
#include "pbd/stacktrace.h"
namespace MIDI {
class Port;
@ -21,8 +22,8 @@ class Session;
struct MidiUIRequest : public BaseUI::BaseRequestObject {
public:
MidiUIRequest () {}
~MidiUIRequest() {}
MidiUIRequest () { }
~MidiUIRequest() { }
};
class MidiControlUI : public AbstractUI<MidiUIRequest>

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@ -134,6 +134,8 @@ MidiControlUI::reset_ports ()
for (MIDI::Manager::PortList::const_iterator i = plist->begin(); i != plist->end(); ++i) {
cerr << "MIDI UI looking at port " << (*i)->name() << endl;
if (!(*i)->centrally_parsed()) {
continue;
}

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@ -249,6 +249,7 @@ int
IPMIDIPort::write (byte* msg, size_t msglen, timestamp_t /* ignored */) {
if (sockout) {
Glib::Mutex::Lock lm (write_lock);
if (::sendto (sockout, (char *) msg, msglen, 0, (struct sockaddr *) &addrout, sizeof(struct sockaddr_in)) < 0) {
::perror("sendto");
return -1;

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@ -271,6 +271,7 @@ JackMIDIPort::write(byte * msg, size_t msglen, timestamp_t timestamp)
cerr << "write of " << msglen << " failed, port holds "
<< jack_midi_get_event_count (jack_port_get_buffer (_jack_port, _nframes_this_cycle))
<< endl;
// PBD::stacktrace (cerr, 20);
}
} else {
cerr << "write to JACK midi port failed: not currently in a process cycle." << endl;

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@ -28,6 +28,8 @@
#include <net/if.h>
#endif
#include <glibmm/thread.h>
#include <jack/types.h>
#include "pbd/xml++.h"
@ -64,7 +66,8 @@ private:
int sockin;
int sockout;
struct sockaddr_in addrout;
Glib::Mutex write_lock;
bool open_sockets (int base_port, const std::string& ifname);
void close_sockets ();

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@ -25,6 +25,7 @@
#include <cstring>
#include "pbd/base_ui.h"
#include "pbd/debug.h"
#include "pbd/pthread_utils.h"
#include "pbd/error.h"
#include "pbd/compose.h"
@ -72,6 +73,7 @@ BaseUI::new_request_type ()
void
BaseUI::main_thread ()
{
DEBUG_TRACE (DEBUG::EventLoop, string_compose ("%1: event loop running in thread %2\n", name(), pthread_self()));
set_event_loop_for_thread (this);
thread_init ();
_main_loop->run ();

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@ -36,6 +36,8 @@ uint64_t PBD::DEBUG::Stateful = PBD::new_debug_bit ("stateful");
uint64_t PBD::DEBUG::Properties = PBD::new_debug_bit ("properties");
uint64_t PBD::DEBUG::FileManager = PBD::new_debug_bit ("filemanager");
uint64_t PBD::DEBUG::Pool = PBD::new_debug_bit ("pool");
uint64_t PBD::DEBUG::EventLoop = PBD::new_debug_bit ("eventloop");
uint64_t PBD::DEBUG::AbstractUI = PBD::new_debug_bit ("abstractui");
uint64_t PBD::debug_bits = 0x0;

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@ -20,14 +20,35 @@ EventLoop::set_event_loop_for_thread (EventLoop* loop)
thread_event_loop.set (loop, do_not_delete_the_loop_pointer);
}
/** Called when a sigc::trackable that was connected to using the invalidator() macro
* is destroyed.
*/
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());
for (list<BaseRequestObject*>::iterator i = ir->requests.begin(); i != ir->requests.end(); ++i) {

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@ -5,6 +5,7 @@
#include "pbd/abstract_ui.h"
#include "pbd/pthread_utils.h"
#include "pbd/failed_constructor.h"
#include "pbd/debug.h"
#include "i18n.h"
@ -17,6 +18,14 @@ template<typename RequestBuffer> void
cleanup_request_buffer (void* ptr)
{
RequestBuffer* rb = (RequestBuffer*) ptr;
/* there is the question of why we don't simply erase the request
* buffer and delete it right here, since we have to take the lock
* anyway.
*
* as of april 24th 2012, i don't have a good answer to that.
*/
{
Glib::Mutex::Lock lm (rb->ui.request_buffer_map_lock);
@ -40,10 +49,25 @@ AbstractUI<RequestObject>::AbstractUI (const string& name)
template <typename RequestObject> void
AbstractUI<RequestObject>::register_thread (string target_gui, 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
* requests. this means that when it makes a request to this UI it can
* 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;
}
/* 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.
*/
RequestBuffer* b = per_thread_request_buffer.get();
if (b) {
@ -52,13 +76,30 @@ AbstractUI<RequestObject>::register_thread (string target_gui, pthread_t thread_
return;
}
/* create a new request queue/ringbuffer */
b = new RequestBuffer (num_requests, *this);
{
/* 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,
and so this is of little consequence.
*/
Glib::Mutex::Lock lm (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, cleanup_request_buffer<RequestBuffer>);
}
@ -68,20 +109,38 @@ AbstractUI<RequestObject>::get_request (RequestType rt)
RequestBuffer* rbuf = per_thread_request_buffer.get ();
RequestBufferVector vec;
/* see comments in ::register_thread() above for an explanation of
the per_thread_request_buffer variable
*/
if (rbuf != 0) {
/* we have a per-thread FIFO, use it */
/* the calling thread has registered with this UI and therefore
* we have a per-thread request queue/ringbuffer. use it. this
* "allocation" of a request is RT-safe.
*/
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));
return 0;
}
DEBUG_TRACE (PBD::DEBUG::AbstractUI, string_compose ("%1: allocated per-thread request of type %2, caller %3\n", name(), rt, pthread_self()));
vec.buf[0]->type = rt;
vec.buf[0]->valid = true;
return vec.buf[0];
}
/* calling thread has not registered, so just allocate a new request on
* the heap. the lack of registration implies that realtime constraints
* 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_self()));
RequestObject* req = new RequestObject;
req->type = rt;
@ -94,7 +153,7 @@ AbstractUI<RequestObject>::handle_ui_requests ()
RequestBufferMapIterator i;
RequestBufferVector vec;
/* per-thread buffers first */
/* check all registered per-thread buffers first */
request_buffer_map_lock.lock ();
@ -134,6 +193,8 @@ AbstractUI<RequestObject>::handle_ui_requests ()
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_self(), i->first, i->second));
delete (*i).second;
RequestBufferMapIterator tmp = i;
++tmp;
@ -156,11 +217,12 @@ AbstractUI<RequestObject>::handle_ui_requests ()
/* We need to use this lock, because its the one
returned by slot_invalidation_mutex() and protects
against request invalidation.
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_self(), req->type));
delete req;
request_buffer_map_lock.unlock ();
continue;
@ -172,17 +234,48 @@ AbstractUI<RequestObject>::handle_ui_requests ()
*/
if (req->invalidation) {
DEBUG_TRACE (PBD::DEBUG::AbstractUI, string_compose ("%1/%2 remove request from its invalidation list\n", name(), pthread_self()));
/* after this call, if the object referenced by the
* invalidation record is deleted, it will no longer
* try to mark the request as invalid.
*/
req->invalidation->requests.remove (req);
}
/* 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.
*
* 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
* threads since they have their own queue) from making requests.
*/
lm.release ();
DEBUG_TRACE (PBD::DEBUG::AbstractUI, string_compose ("%1/%2 execute request type %3\n", name(), pthread_self(), 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
* some kind of central request type registration logic
*/
do_request (req);
DEBUG_TRACE (PBD::DEBUG::AbstractUI, string_compose ("%1/%2 delete heap request type %3\n", name(), pthread_self(), req->type));
delete req;
/* re-acquire the list lock so that we check again */
lm.acquire();
}
}
@ -190,25 +283,53 @@ AbstractUI<RequestObject>::handle_ui_requests ()
template <typename RequestObject> void
AbstractUI<RequestObject>::send_request (RequestObject *req)
{
/* This is called to ask a given UI to carry out a request. It may be
* called from the same thread that runs the UI's event loop (see the
* caller_is_self() case below), or from any other thread.
*/
if (base_instance() == 0) {
return; /* XXX is this the right thing to do ? */
}
if (caller_is_self ()) {
/* 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_self(), req->type));
do_request (req);
} else {
/* If called from a different thread, we first check to see if
* the calling thread is registered with this UI. If so, there
* is a per-thread ringbuffer of requests that ::get_request()
* just set up a new request in. If so, all we need do here is
* to advance the write ptr in that ringbuffer so that the next
* request by this calling thread will use the next slot in
* the ringbuffer. The ringbuffer has
* single-reader/single-writer semantics because the calling
* thread is the only writer, and the UI event loop is the only
* reader.
*/
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_self(), req->type));
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_self(), req->type));
Glib::Mutex::Lock lm (request_list_lock);
request_list.push_back (req);
}
/* send the UI event loop thread a wakeup so that it will look
at the per-thread and generic request lists.
*/
request_channel.wakeup ();
}
}
@ -217,6 +338,7 @@ template<typename RequestObject> void
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_self(), &f, invalidation));
f ();
return;
}
@ -227,7 +349,20 @@ AbstractUI<RequestObject>::call_slot (InvalidationRecord* invalidation, const bo
return;
}
DEBUG_TRACE (PBD::DEBUG::AbstractUI, string_compose ("%1/%2 queue call-slot using functor @ %3, invalidation %4\n", name(), pthread_self(), &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
* 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) {

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@ -32,6 +32,15 @@
#include "pbd/crossthread.h"
#include "pbd/event_loop.h"
/** A BaseUI is an abstraction designed to be used with any "user
* interface" (not necessarily graphical) that needs to wait on
* events/requests and dispatch/process them as they arrive.
*
* This implementation starts up a thread that runs a Glib main loop
* to wait on events/requests etc.
*/
class BaseUI : virtual public sigc::trackable, public PBD::EventLoop
{
public:
@ -52,7 +61,13 @@ class BaseUI : virtual public sigc::trackable, public PBD::EventLoop
static RequestType CallSlot;
static RequestType Quit;
/** start up a thread to run the main loop
*/
void run ();
/** stop the thread running the main loop (and block
* until it exits)
*/
void quit ();
protected:
@ -62,9 +77,21 @@ class BaseUI : virtual public sigc::trackable, public PBD::EventLoop
Glib::RefPtr<Glib::MainLoop> _main_loop;
Glib::Thread* run_loop_thread;
/** Derived UI objects can implement thread_init()
* which will be called by the event loop thread
* immediately before it enters the event loop.
*/
virtual void thread_init () {};
/** Called when there input ready on the request_channel
*/
bool request_handler (Glib::IOCondition);
/** Derived UI objects must implement this method,
* which will be called whenever there are requests
* to be dealt with.
*/
virtual void handle_ui_requests () = 0;
private:

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@ -26,20 +26,60 @@
#include <glibmm/main.h>
/** A simple abstraction of a mechanism of signalling one thread from another.
* The signaller calls ::wakeup() to tell the signalled thread to check for
* work to be done.
*
* This implementation provides both ::selectable() for use in direct
* poll/select-based event loops, and a Glib::IOSource via ::ios() for use
* in Glib main loop based situations.
*/
class CrossThreadChannel {
public:
CrossThreadChannel(bool);
/** if @a non_blocking is true, the channel will not cause blocking
* when used in an event loop based on poll/select or the glib main
* loop.
*/
CrossThreadChannel(bool non_blocking);
~CrossThreadChannel();
/** Tell the listening thread that is has work to do.
*/
void wakeup();
int selectable() const { return fds[0]; }
/* if the listening thread cares about the precise message
* it is being sent, then ::deliver() can be used to send
* a single byte message rather than a simple wakeup. These
* two mechanisms should not be used on the same CrossThreadChannel
* because there is no way to know which byte value will be used
* for ::wakeup()
*/
int deliver (char msg);
/** if using ::deliver() to wakeup the listening thread, then
* the listener should call ::receive() to fetch the message
* type from the channel.
*/
int receive (char& msg);
/** empty the channel of all requests.
* Typically this is done as soon as input
* is noticed on the channel, because the
* handler will look at a separately managed work
* queue. The actual number of queued "wakeups"
* in the channel will not be important.
*/
void drain ();
static void drain (int fd);
/** File descriptor that can be used with poll/select to
* detect when wakeup() has been called on this channel.
* It be marked as readable/input-ready when this condition
* is true. It has already been marked non-blocking.
*/
int selectable() const { return fds[0]; }
/* glibmm 2.22 and earlier has a terrifying bug that will
cause crashes whenever a Source is removed from
a MainContext (including the destruction of the MainContext),
@ -47,15 +87,17 @@ class CrossThreadChannel {
the RefPtr. I (Paul) have fixed this (https://bugzilla.gnome.org/show_bug.cgi?id=561885)
but in the meantime, we need a hack to get around the issue.
*/
Glib::RefPtr<Glib::IOSource> ios();
void drop_ios ();
/** returns true if the CrossThreadChannel was
* correctly constructed.
*/
bool ok() const { return fds[0] >= 0 && fds[1] >= 0; }
private:
Glib::RefPtr<Glib::IOSource>* _ios; // lazily constructed
int fds[2];
int fds[2]; // current implementation uses a pipe/fifo
};
#endif /* __pbd__crossthread_h__ */

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@ -41,6 +41,8 @@ namespace PBD {
extern uint64_t Properties;
extern uint64_t FileManager;
extern uint64_t Pool;
extern uint64_t EventLoop;
extern uint64_t AbstractUI;
}
}

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@ -27,6 +27,15 @@
namespace PBD
{
/** An EventLoop is as basic abstraction designed to be used with any "user
* interface" (not necessarily graphical) that needs to wait on
* events/requests and dispatch/process them as they arrive.
*
* This is a very basic class that doesn't by itself provide an actual
* event loop or thread. See BaseUI for the "real" object to be used
* when something like this is needed (it inherits from EventLoop).
*/
class EventLoop
{
public:

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@ -1081,7 +1081,7 @@ MackieControlProtocol::handle_button_event (Surface& surface, Button& button, Bu
bool
MackieControlProtocol::midi_input_handler (IOCondition ioc, MIDI::Port* port)
{
DEBUG_TRACE (DEBUG::MidiIO, string_compose ("something happend on %1\n", port->name()));
DEBUG_TRACE (DEBUG::MackieControl, string_compose ("something happend on %1\n", port->name()));
if (ioc & ~IO_IN) {
return false;
@ -1089,7 +1089,7 @@ MackieControlProtocol::midi_input_handler (IOCondition ioc, MIDI::Port* port)
if (ioc & IO_IN) {
DEBUG_TRACE (DEBUG::MidiIO, string_compose ("data available on %1\n", port->name()));
DEBUG_TRACE (DEBUG::MackieControl, string_compose ("data available on %1\n", port->name()));
framepos_t now = session->engine().frame_time();
port->parse (now);
}

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@ -585,7 +585,7 @@ Surface::zero_controls ()
if (_number == 0 && _mcp.device_info().has_two_character_display()) {
// any hardware-specific stuff
// clear 2-char display
show_two_char_display ("aa");
show_two_char_display (" ");
}
// and the led ring for the master strip