/* GStreamer * Copyright (C) 1999,2000 Erik Walthinsen * 2000 Wim Taymans * * gstthread.c: Threaded container object * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Library General Public * License as published by the Free Software Foundation; either * version 2 of the License, or (at your option) any later version. * * This library 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 * Library General Public License for more details. * * You should have received a copy of the GNU Library General Public * License along with this library; if not, write to the * Free Software Foundation, Inc., 59 Temple Place - Suite 330, * Boston, MA 02111-1307, USA. */ #include /* #define GST_DEBUG_ENABLED */ #include "gst_private.h" #include "gst.h" #include "gstthread.h" #include "gstscheduler.h" #include "gstqueue.h" #define STACK_SIZE 0x200000 #define g_thread_equal(a,b) ((a) == (b)) GstElementDetails gst_thread_details = { "Threaded container", "Generic/Bin", "LGPL", "Container that creates/manages a thread", VERSION, "Erik Walthinsen ", "(C) 1999, 2000", }; /* Thread signals and args */ enum { SHUTDOWN, /* FILL ME */ LAST_SIGNAL }; enum { SPINUP=0, STATECHANGE, STARTUP }; enum { ARG_0, ARG_SCHEDPOLICY, ARG_PRIORITY, }; static void gst_thread_class_init (GstThreadClass *klass); static void gst_thread_init (GstThread *thread); static void gst_thread_dispose (GObject *object); static void gst_thread_set_property (GObject *object, guint prop_id, const GValue *value, GParamSpec *pspec); static void gst_thread_get_property (GObject *object, guint prop_id, GValue *value, GParamSpec *pspec); static GstElementStateReturn gst_thread_change_state (GstElement *element); #ifndef GST_DISABLE_LOADSAVE static xmlNodePtr gst_thread_save_thyself (GstObject *object, xmlNodePtr parent); static void gst_thread_restore_thyself (GstObject *object, xmlNodePtr self); #endif static void* gst_thread_main_loop (void *arg); #define GST_TYPE_THREAD_SCHEDPOLICY (gst_thread_schedpolicy_get_type()) static GType gst_thread_schedpolicy_get_type(void) { static GType thread_schedpolicy_type = 0; static GEnumValue thread_schedpolicy[] = { {G_THREAD_PRIORITY_LOW, "LOW", "Low Priority Scheduling"}, {G_THREAD_PRIORITY_NORMAL, "NORMAL", "Normal Scheduling"}, {G_THREAD_PRIORITY_HIGH, "HIGH", "High Priority Scheduling"}, {G_THREAD_PRIORITY_URGENT, "URGENT", "Urgent Scheduling"}, {0, NULL, NULL}, }; if (!thread_schedpolicy_type) { thread_schedpolicy_type = g_enum_register_static("GstThreadSchedPolicy", thread_schedpolicy); } return thread_schedpolicy_type; } static GstBinClass *parent_class = NULL; static guint gst_thread_signals[LAST_SIGNAL] = { 0 }; GType gst_thread_get_type(void) { static GType thread_type = 0; if (!thread_type) { static const GTypeInfo thread_info = { sizeof(GstThreadClass), NULL, NULL, (GClassInitFunc)gst_thread_class_init, NULL, NULL, sizeof(GstThread), 4, (GInstanceInitFunc)gst_thread_init, NULL }; thread_type = g_type_register_static(GST_TYPE_BIN, "GstThread", &thread_info, 0); } return thread_type; } static void gst_thread_class_init (GstThreadClass *klass) { GObjectClass *gobject_class; GstObjectClass *gstobject_class; GstElementClass *gstelement_class; GstBinClass *gstbin_class; gobject_class = (GObjectClass*)klass; gstobject_class = (GstObjectClass*)klass; gstelement_class = (GstElementClass*)klass; gstbin_class = (GstBinClass*)klass; parent_class = g_type_class_ref (GST_TYPE_BIN); g_object_class_install_property(G_OBJECT_CLASS (klass), ARG_SCHEDPOLICY, g_param_spec_enum("schedpolicy", "Scheduling Policy", "The scheduling policy of the thread", GST_TYPE_THREAD_SCHEDPOLICY, G_THREAD_PRIORITY_NORMAL, G_PARAM_READWRITE)); g_object_class_install_property(G_OBJECT_CLASS (klass), ARG_PRIORITY, g_param_spec_int("priority", "Scheduling Priority", "The scheduling priority of the thread", 0, 99, 0, G_PARAM_READWRITE)); gst_thread_signals[SHUTDOWN] = g_signal_new ("shutdown", G_TYPE_FROM_CLASS (klass), G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GstThreadClass, shutdown), NULL, NULL, gst_marshal_VOID__VOID, G_TYPE_NONE, 0); gobject_class->dispose = gst_thread_dispose; #ifndef GST_DISABLE_LOADSAVE gstobject_class->save_thyself = GST_DEBUG_FUNCPTR (gst_thread_save_thyself); gstobject_class->restore_thyself = GST_DEBUG_FUNCPTR (gst_thread_restore_thyself); #endif gstelement_class->change_state = GST_DEBUG_FUNCPTR (gst_thread_change_state); gobject_class->set_property = GST_DEBUG_FUNCPTR (gst_thread_set_property); gobject_class->get_property = GST_DEBUG_FUNCPTR (gst_thread_get_property); } static void gst_thread_init (GstThread *thread) { GstScheduler *scheduler; GST_DEBUG (GST_CAT_THREAD, "initializing thread"); /* threads are managing bins and iterate themselves */ /* CR1: the GstBin code checks these flags */ GST_FLAG_SET (thread, GST_BIN_FLAG_MANAGER); GST_FLAG_SET (thread, GST_BIN_SELF_SCHEDULABLE); scheduler = gst_scheduler_factory_make (NULL, GST_ELEMENT (thread)); thread->lock = g_mutex_new (); thread->cond = g_cond_new (); thread->ppid = getpid (); thread->thread_id = (GThread *) NULL; thread->sched_policy = G_THREAD_PRIORITY_NORMAL; thread->priority = 0; thread->stack = NULL; } static void gst_thread_dispose (GObject *object) { GstThread *thread = GST_THREAD (object); GST_DEBUG (GST_CAT_REFCOUNTING, "dispose"); g_mutex_lock (thread->lock); if (GST_STATE (thread) != GST_STATE_NULL) { GST_FLAG_UNSET (thread, GST_THREAD_STATE_SPINNING); } g_mutex_unlock (thread->lock); gst_element_set_state (GST_ELEMENT (thread), GST_STATE_NULL); g_mutex_free (thread->lock); g_cond_free (thread->cond); G_OBJECT_CLASS (parent_class)->dispose (object); if (GST_ELEMENT_SCHED (thread)) { gst_object_unref (GST_OBJECT (GST_ELEMENT_SCHED (thread))); } } static void gst_thread_set_property (GObject *object, guint prop_id, const GValue *value, GParamSpec *pspec) { GstThread *thread; /* it's not null if we got it, but it might not be ours */ g_return_if_fail (GST_IS_THREAD (object)); thread = GST_THREAD (object); switch (prop_id) { case ARG_SCHEDPOLICY: thread->sched_policy = g_value_get_enum (value); break; case ARG_PRIORITY: thread->priority = g_value_get_int (value); break; default: G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec); break; } } static void gst_thread_get_property (GObject *object, guint prop_id, GValue *value, GParamSpec *pspec) { GstThread *thread; /* it's not null if we got it, but it might not be ours */ g_return_if_fail (GST_IS_THREAD (object)); thread = GST_THREAD (object); switch (prop_id) { case ARG_SCHEDPOLICY: g_value_set_enum (value, thread->sched_policy); break; case ARG_PRIORITY: g_value_set_int (value, thread->priority); break; default: G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec); break; } } /** * gst_thread_new: * @name: the name of the thread * * Create a new thread with the given name. * * Returns: The new thread */ GstElement* gst_thread_new (const gchar *name) { return gst_element_factory_make ("thread", name); } /* these two macros are used for debug/info from the state_change function */ #define THR_INFO(format,args...) \ GST_INFO_ELEMENT(GST_CAT_THREAD, thread, "sync(" GST_DEBUG_THREAD_FORMAT "): " format , \ GST_DEBUG_THREAD_ARGS(thread->pid) , ## args ) #define THR_DEBUG(format,args...) \ GST_DEBUG_ELEMENT(GST_CAT_THREAD, thread, "sync(" GST_DEBUG_THREAD_FORMAT "): " format , \ GST_DEBUG_THREAD_ARGS(thread->pid) , ## args ) /* these two macros are used for debug/info from the gst_thread_main_loop * function */ #define THR_INFO_MAIN(format,args...) \ GST_INFO_ELEMENT(GST_CAT_THREAD, thread, "sync-main(" GST_DEBUG_THREAD_FORMAT "): " format , \ GST_DEBUG_THREAD_ARGS(thread->ppid) , ## args ) #define THR_DEBUG_MAIN(format,args...) \ GST_DEBUG_ELEMENT(GST_CAT_THREAD, thread, "sync-main(" GST_DEBUG_THREAD_FORMAT "): " format , \ GST_DEBUG_THREAD_ARGS(thread->ppid) , ## args ) static GstElementStateReturn gst_thread_update_state (GstThread *thread) { GST_DEBUG_ELEMENT (GST_CAT_THREAD, thread, "updating state of thread"); /* check for state change */ if (GST_STATE_PENDING (thread) != GST_STATE_VOID_PENDING) { /* punt and change state on all the children */ if (GST_ELEMENT_CLASS (parent_class)->change_state) return GST_ELEMENT_CLASS (parent_class)->change_state (GST_ELEMENT (thread)); } /* FIXME: in the case of no change_state function in the parent's class, * shouldn't we actually change the thread's state ? */ g_warning ("thread's parent doesn't have change_state, returning success"); return GST_STATE_SUCCESS; } static GstElementStateReturn gst_thread_change_state (GstElement * element) { GstThread *thread; gboolean stateset = GST_STATE_SUCCESS; gint transition; GThread * self = g_thread_self (); GError * error = NULL; g_return_val_if_fail (GST_IS_THREAD (element), GST_STATE_FAILURE); g_return_val_if_fail (gst_has_threads (), GST_STATE_FAILURE); thread = GST_THREAD (element); transition = GST_STATE_TRANSITION (element); THR_INFO ("changing state from %s to %s", gst_element_state_get_name (GST_STATE (element)), gst_element_state_get_name (GST_STATE_PENDING (element))); if (g_thread_equal (self, thread->thread_id)) { GST_DEBUG (GST_CAT_THREAD, "no sync(" GST_DEBUG_THREAD_FORMAT "): setting own thread's state to spinning", GST_DEBUG_THREAD_ARGS (thread->pid)); return gst_thread_update_state (thread); } switch (transition) { case GST_STATE_NULL_TO_READY: /* set the state to idle */ GST_FLAG_UNSET (thread, GST_THREAD_STATE_SPINNING); THR_DEBUG ("creating thread \"%s\"", GST_ELEMENT_NAME (element)); /* this bit of code handles creation of GThreads * this is therefor tricky code * compare it with the block of code that handles the destruction * in GST_STATE_READY_TO_NULL below */ g_mutex_lock (thread->lock); /* create a new GThread * use the specified attributes * make it execute gst_thread_main_loop (thread) */ GST_DEBUG (GST_CAT_THREAD, "going to g_thread_create_full..."); thread->thread_id = g_thread_create_full(gst_thread_main_loop, thread, STACK_SIZE, TRUE, TRUE, G_THREAD_PRIORITY_NORMAL, &error); if (!thread->thread_id){ GST_DEBUG (GST_CAT_THREAD, "g_thread_create_full failed"); g_mutex_unlock (thread->lock); GST_DEBUG (GST_CAT_THREAD, "could not create thread \"%s\"", GST_ELEMENT_NAME (element)); return GST_STATE_FAILURE; } GST_DEBUG (GST_CAT_THREAD, "GThread created"); /* wait for it to 'spin up' */ THR_DEBUG ("waiting for child thread spinup"); g_cond_wait (thread->cond, thread->lock); THR_DEBUG ("thread claims to be up"); g_mutex_unlock (thread->lock); break; case GST_STATE_READY_TO_PAUSED: THR_INFO ("readying thread"); g_mutex_lock (thread->lock); THR_DEBUG ("signaling"); g_cond_signal (thread->cond); THR_DEBUG ("waiting for ack"); g_cond_wait (thread->cond, thread->lock); THR_DEBUG ("got ack"); g_mutex_unlock (thread->lock); break; case GST_STATE_PAUSED_TO_PLAYING: { /* fixme: recurse into sub-bins */ const GList *elements = gst_bin_get_list (GST_BIN (thread)); while (elements) { gst_element_enable_threadsafe_properties ((GstElement*)elements->data); elements = g_list_next (elements); } THR_DEBUG ("telling thread to start spinning"); g_mutex_lock (thread->lock); THR_DEBUG ("signaling"); g_cond_signal (thread->cond); THR_DEBUG ("waiting for ack"); g_cond_wait (thread->cond, thread->lock); THR_DEBUG ("got ack"); g_mutex_unlock (thread->lock); break; } case GST_STATE_PLAYING_TO_PAUSED: { const GList *elements = (GList *) gst_bin_get_list (GST_BIN (thread)); THR_INFO ("pausing thread"); /* the following code ensures that the bottom half of thread will run * to perform each elements' change_state() (by calling gstbin.c:: * change_state()). * + the pending state was already set by gstelement.c::set_state() * + unlock all elements so the bottom half can start the state change. */ g_mutex_lock (thread->lock); GST_FLAG_UNSET (thread, GST_THREAD_STATE_SPINNING); while (elements) { GstElement *element = GST_ELEMENT (elements->data); GList *pads; g_assert (element); THR_DEBUG (" waking element \"%s\"", GST_ELEMENT_NAME (element)); elements = g_list_next (elements); if (!gst_element_release_locks (element)) { g_warning ("element %s could not release locks", GST_ELEMENT_NAME (element)); } pads = GST_ELEMENT_PADS (element); while (pads) { GstRealPad *peer = NULL; GstElement *peerelement; if (GST_PAD_PEER (pads->data)) peer = GST_REAL_PAD (GST_PAD_PEER (pads->data)); pads = g_list_next (pads); if (!peer) continue; peerelement = GST_PAD_PARENT (peer); if (!peerelement) continue; /* deal with case where there's no peer */ if (!GST_FLAG_IS_SET (peerelement, GST_ELEMENT_DECOUPLED)) { GST_DEBUG (GST_CAT_THREAD, "peer element isn't DECOUPLED"); continue; } if (GST_ELEMENT_SCHED (peerelement) != GST_ELEMENT_SCHED (thread)) { THR_DEBUG (" element \"%s\" has pad cross sched boundary", GST_ELEMENT_NAME (element)); THR_DEBUG (" waking element \"%s\"", GST_ELEMENT_NAME (peerelement)); if (!gst_element_release_locks (peerelement)) { g_warning ("element %s could not release locks", GST_ELEMENT_NAME (peerelement)); } } } } THR_DEBUG ("telling thread to pause, signaling"); g_cond_signal (thread->cond); THR_DEBUG ("waiting for ack"); g_cond_wait (thread->cond, thread->lock); THR_DEBUG ("got ack"); g_mutex_unlock (thread->lock); elements = gst_bin_get_list (GST_BIN (thread)); while (elements) { gst_element_disable_threadsafe_properties ((GstElement*)elements->data); elements = g_list_next (elements); } break; } case GST_STATE_READY_TO_NULL: THR_DEBUG ("telling thread to pause (null) - and joining"); /* MattH FIXME revisit */ g_mutex_lock (thread->lock); THR_DEBUG ("signaling"); g_cond_signal (thread->cond); THR_DEBUG ("waiting for ack"); g_cond_wait (thread->cond, thread->lock); THR_DEBUG ("got ack"); /* this block of code is very tricky * basically, we try to clean up the whole thread and * everything related to it in the right order without * triggering segfaults * compare this block to the block */ GST_DEBUG (GST_CAT_THREAD, "joining GThread %p", thread->thread_id); g_thread_join (thread->thread_id); thread->thread_id = NULL; thread->stack = NULL; THR_DEBUG ("unlocking mutex"); g_mutex_unlock (thread->lock); GST_FLAG_UNSET (thread, GST_THREAD_STATE_REAPING); GST_FLAG_UNSET (thread, GST_THREAD_STATE_STARTED); GST_FLAG_UNSET (thread, GST_THREAD_STATE_SPINNING); break; case GST_STATE_PAUSED_TO_READY: THR_DEBUG ("telling thread to stop spinning"); g_mutex_lock (thread->lock); THR_DEBUG ("signaling"); g_cond_signal (thread->cond); THR_DEBUG ("waiting for ack"); g_cond_wait (thread->cond, thread->lock); THR_DEBUG ("got ack"); g_mutex_unlock (thread->lock); break; default: GST_DEBUG_ELEMENT (GST_CAT_THREAD, element, "UNHANDLED STATE CHANGE! %x", transition); break; } return stateset; } /** * gst_thread_main_loop: * @arg: the thread to start * * The main loop of the thread. The thread will iterate * while the state is GST_THREAD_STATE_SPINNING. */ static void * gst_thread_main_loop (void *arg) { GstThread *thread = NULL; gint stateset; glong page_size; gpointer stack_pointer; gulong stack_offset; GST_DEBUG (GST_CAT_THREAD, "gst_thread_main_loop started"); thread = GST_THREAD (arg); g_mutex_lock (thread->lock); /* set up the element's scheduler */ gst_scheduler_setup (GST_ELEMENT_SCHED (thread)); GST_FLAG_UNSET (thread, GST_THREAD_STATE_REAPING); thread->pid = getpid(); THR_INFO_MAIN ("thread is running"); page_size = sysconf(_SC_PAGESIZE); stack_pointer = (gpointer) &stack_pointer; if(((gulong)stack_pointer & (page_size-1)) < (page_size>>1)){ /* stack grows up, I think */ /* FIXME this is probably not true for the main thread */ stack_offset = (gulong)stack_pointer & (page_size - 1); }else{ /* stack grows down, I think */ stack_offset = STACK_SIZE - ((gulong)stack_pointer & (page_size - 1)); } /* note the subtlety with pointer arithmetic */ thread->stack = stack_pointer - stack_offset; thread->stack_size = STACK_SIZE; /* first we need to change the state of all the children */ if (GST_ELEMENT_CLASS (parent_class)->change_state) { stateset = GST_ELEMENT_CLASS (parent_class)->change_state (GST_ELEMENT(thread)); if (stateset != GST_STATE_SUCCESS) { THR_DEBUG_MAIN ("state change of children failed"); } } THR_DEBUG_MAIN ("indicating spinup"); g_cond_signal (thread->cond); /* don't unlock the mutex because we hold it into the top of the while loop */ THR_DEBUG_MAIN ("thread has indicated spinup to parent process"); /***** THREAD IS NOW IN READY STATE *****/ /* CR1: most of this code is handshaking */ /* do this while the thread lives */ while (!GST_FLAG_IS_SET (thread, GST_THREAD_STATE_REAPING)) { /* NOTE we hold the thread lock at this point */ /* what we do depends on what state we're in */ switch (GST_STATE (thread)) { /* NOTE: cannot be in NULL, we're not running in that state at all */ case GST_STATE_READY: /* wait to be set to either the NULL or PAUSED states */ THR_DEBUG_MAIN ("thread in %s state, waiting for either %s or %s", gst_element_state_get_name (GST_STATE_READY), gst_element_state_get_name (GST_STATE_NULL), gst_element_state_get_name (GST_STATE_PAUSED)); g_cond_wait (thread->cond, thread->lock); /* this must have happened by a state change in the thread context */ if (GST_STATE_PENDING (thread) != GST_STATE_NULL && GST_STATE_PENDING (thread) != GST_STATE_PAUSED) { g_cond_signal (thread->cond); continue; } /* been signaled, we need to state transition now and signal back */ gst_thread_update_state (thread); THR_DEBUG_MAIN ("done with state transition, " "signaling back to parent process"); g_cond_signal (thread->cond); /* now we decide what to do next */ if (GST_STATE (thread) == GST_STATE_NULL) { /* REAPING must be set, we can simply break this iteration */ THR_DEBUG_MAIN ("set GST_THREAD_STATE_REAPING"); GST_FLAG_SET (thread, GST_THREAD_STATE_REAPING); } continue; case GST_STATE_PAUSED: /* wait to be set to either the READY or PLAYING states */ THR_DEBUG_MAIN ("thread in %s state, waiting for either %s or %s", gst_element_state_get_name (GST_STATE_PAUSED), gst_element_state_get_name (GST_STATE_READY), gst_element_state_get_name (GST_STATE_PLAYING)); g_cond_wait (thread->cond, thread->lock); /* this must have happened by a state change in the thread context */ if (GST_STATE_PENDING (thread) != GST_STATE_READY && GST_STATE_PENDING (thread) != GST_STATE_PLAYING) { g_cond_signal (thread->cond); continue; } /* been signaled, we need to state transition now and signal back */ gst_thread_update_state (thread); /* now we decide what to do next */ if (GST_STATE (thread) != GST_STATE_PLAYING) { /* either READY or the state change failed for some reason */ g_cond_signal (thread->cond); continue; } else { GST_FLAG_SET (thread, GST_THREAD_STATE_SPINNING); /* PLAYING is coming up, so we can now start spinning */ while (GST_FLAG_IS_SET (thread, GST_THREAD_STATE_SPINNING)) { gboolean status; g_cond_signal (thread->cond); g_mutex_unlock (thread->lock); status = gst_bin_iterate (GST_BIN (thread)); g_mutex_lock (thread->lock); /* g_cond_signal(thread->cond); */ if (!status || GST_STATE_PENDING (thread) != GST_STATE_VOID_PENDING) GST_FLAG_UNSET (thread, GST_THREAD_STATE_SPINNING); } /* looks like we were stopped because of a statechange */ if (GST_STATE_PENDING (thread) != GST_STATE_VOID_PENDING) { gst_thread_update_state (thread); } /* once we're here, SPINNING has stopped, we should signal that we're done */ THR_DEBUG_MAIN ("SPINNING stopped, signaling back to parent process"); g_cond_signal (thread->cond); /* now we can wait for PAUSED */ continue; } case GST_STATE_PLAYING: /* wait to be set to PAUSED */ THR_DEBUG_MAIN ("thread in %s state, waiting for %s", gst_element_state_get_name (GST_STATE_PLAYING), gst_element_state_get_name (GST_STATE_PAUSED)); g_cond_wait (thread->cond,thread->lock); /* been signaled, we need to state transition now and signal back */ gst_thread_update_state (thread); g_cond_signal (thread->cond); /* now we decide what to do next */ /* there's only PAUSED, we we just wait for it */ continue; case GST_STATE_NULL: THR_DEBUG_MAIN ("thread in %s state, preparing to die", gst_element_state_get_name (GST_STATE_NULL)); GST_FLAG_SET (thread, GST_THREAD_STATE_REAPING); break; default: g_assert_not_reached (); break; } } /* THREAD HAS STOPPED RUNNING */ /* we need to destroy the scheduler here because it has mapped it's * stack into the threads stack space */ gst_scheduler_reset (GST_ELEMENT_SCHED (thread)); /* since we don't unlock at the end of the while loop, do it here */ g_mutex_unlock (thread->lock); GST_INFO (GST_CAT_THREAD, "gstthread: thread \"%s\" is stopped", GST_ELEMENT_NAME (thread)); g_signal_emit (G_OBJECT (thread), gst_thread_signals[SHUTDOWN], 0); return NULL; } #ifndef GST_DISABLE_LOADSAVE static xmlNodePtr gst_thread_save_thyself (GstObject *object, xmlNodePtr self) { if (GST_OBJECT_CLASS (parent_class)->save_thyself) GST_OBJECT_CLASS (parent_class)->save_thyself (object, self); return NULL; } static void gst_thread_restore_thyself (GstObject *object, xmlNodePtr self) { GST_DEBUG (GST_CAT_THREAD,"gstthread: restore"); if (GST_OBJECT_CLASS (parent_class)->restore_thyself) GST_OBJECT_CLASS (parent_class)->restore_thyself (object, self); } #endif /* GST_DISABLE_LOADSAVE */