diff options
Diffstat (limited to 'indra/llcommon/llevents.cpp')
| -rw-r--r-- | indra/llcommon/llevents.cpp | 265 |
1 files changed, 142 insertions, 123 deletions
diff --git a/indra/llcommon/llevents.cpp b/indra/llcommon/llevents.cpp index 645c29d770..e38fc5b2a6 100644 --- a/indra/llcommon/llevents.cpp +++ b/indra/llcommon/llevents.cpp @@ -275,6 +275,8 @@ LLEventPumps::~LLEventPumps() #pragma warning (push) #pragma warning (disable : 4355) // 'this' used in initializer list: yes, intentionally #endif +const std::string LLEventPump::ANONYMOUS = std::string(); + LLEventPump::LLEventPump(const std::string& name, bool tweak): // Register every new instance with LLEventPumps @@ -313,145 +315,162 @@ LLBoundListener LLEventPump::listen_impl(const std::string& name, const LLEventL const NameList& after, const NameList& before) { - // Check for duplicate name before connecting listener to mSignal - ConnectionMap::const_iterator found = mConnections.find(name); - // In some cases the user might disconnect a connection explicitly -- or - // might use LLEventTrackable to disconnect implicitly. Either way, we can - // end up retaining in mConnections a zombie connection object that's - // already been disconnected. Such a connection object can't be - // reconnected -- nor, in the case of LLEventTrackable, would we want to - // try, since disconnection happens with the destruction of the listener - // object. That means it's safe to overwrite a disconnected connection - // object with the new one we're attempting. The case we want to prevent - // is only when the existing connection object is still connected. - if (found != mConnections.end() && found->second.connected()) - { - throw DupListenerName(std::string("Attempt to register duplicate listener name '") + name + - "' on " + typeid(*this).name() + " '" + getName() + "'"); - } - // Okay, name is unique, try to reconcile its dependencies. Specify a new - // "node" value that we never use for an mSignal placement; we'll fix it - // later. - DependencyMap::node_type& newNode = mDeps.add(name, -1.0, after, before); - // What if this listener has been added, removed and re-added? In that - // case newNode already has a non-negative value because we never remove a - // listener from mDeps. But keep processing uniformly anyway in case the - // listener was added back with different dependencies. Then mDeps.sort() - // would put it in a different position, and the old newNode placement - // value would be wrong, so we'd have to reassign it anyway. Trust that - // re-adding a listener with the same dependencies is the trivial case for - // mDeps.sort(): it can just replay its cache. - DependencyMap::sorted_range sorted_range; - try - { - // Can we pick an order that works including this new entry? - sorted_range = mDeps.sort(); - } - catch (const DependencyMap::Cycle& e) - { - // No: the new node's after/before dependencies have made mDeps - // unsortable. If we leave the new node in mDeps, it will continue - // to screw up all future attempts to sort()! Pull it out. - mDeps.remove(name); - throw Cycle(std::string("New listener '") + name + "' on " + typeid(*this).name() + - " '" + getName() + "' would cause cycle: " + e.what()); - } - // Walk the list to verify that we haven't changed the order. - float previous = 0.0, myprev = 0.0; - DependencyMap::sorted_iterator mydmi = sorted_range.end(); // need this visible after loop - for (DependencyMap::sorted_iterator dmi = sorted_range.begin(); - dmi != sorted_range.end(); ++dmi) + float nodePosition = 1.0; + + // if the supplied name is empty we are not interested in the ordering mechanism + // and can bypass attempting to find the optimal location to insert the new + // listener. We'll just tack it on to the end. + if (!name.empty()) // should be the same as testing against ANONYMOUS { - // Since we've added the new entry with an invalid placement, - // recognize it and skip it. - if (dmi->first == name) + // Check for duplicate name before connecting listener to mSignal + ConnectionMap::const_iterator found = mConnections.find(name); + // In some cases the user might disconnect a connection explicitly -- or + // might use LLEventTrackable to disconnect implicitly. Either way, we can + // end up retaining in mConnections a zombie connection object that's + // already been disconnected. Such a connection object can't be + // reconnected -- nor, in the case of LLEventTrackable, would we want to + // try, since disconnection happens with the destruction of the listener + // object. That means it's safe to overwrite a disconnected connection + // object with the new one we're attempting. The case we want to prevent + // is only when the existing connection object is still connected. + if (found != mConnections.end() && found->second.connected()) { - // Remember the iterator belonging to our new node, and which - // placement value was 'previous' at that point. - mydmi = dmi; - myprev = previous; - continue; + throw DupListenerName(std::string("Attempt to register duplicate listener name '") + name + + "' on " + typeid(*this).name() + " '" + getName() + "'"); } - // If the new node has rearranged the existing nodes, we'll find - // that their placement values are no longer in increasing order. - if (dmi->second < previous) + // Okay, name is unique, try to reconcile its dependencies. Specify a new + // "node" value that we never use for an mSignal placement; we'll fix it + // later. + DependencyMap::node_type& newNode = mDeps.add(name, -1.0, after, before); + // What if this listener has been added, removed and re-added? In that + // case newNode already has a non-negative value because we never remove a + // listener from mDeps. But keep processing uniformly anyway in case the + // listener was added back with different dependencies. Then mDeps.sort() + // would put it in a different position, and the old newNode placement + // value would be wrong, so we'd have to reassign it anyway. Trust that + // re-adding a listener with the same dependencies is the trivial case for + // mDeps.sort(): it can just replay its cache. + DependencyMap::sorted_range sorted_range; + try { - // This is another scenario in which we'd better back out the - // newly-added node from mDeps -- but don't do it yet, we want to - // traverse the existing mDeps to report on it! - // Describe the change to the order of our listeners. Copy - // everything but the newest listener to a vector we can sort to - // obtain the old order. - typedef std::vector< std::pair<float, std::string> > SortNameList; - SortNameList sortnames; - for (DependencyMap::sorted_iterator cdmi(sorted_range.begin()), cdmend(sorted_range.end()); - cdmi != cdmend; ++cdmi) + // Can we pick an order that works including this new entry? + sorted_range = mDeps.sort(); + } + catch (const DependencyMap::Cycle& e) + { + // No: the new node's after/before dependencies have made mDeps + // unsortable. If we leave the new node in mDeps, it will continue + // to screw up all future attempts to sort()! Pull it out. + mDeps.remove(name); + throw Cycle(std::string("New listener '") + name + "' on " + typeid(*this).name() + + " '" + getName() + "' would cause cycle: " + e.what()); + } + // Walk the list to verify that we haven't changed the order. + float previous = 0.0, myprev = 0.0; + DependencyMap::sorted_iterator mydmi = sorted_range.end(); // need this visible after loop + for (DependencyMap::sorted_iterator dmi = sorted_range.begin(); + dmi != sorted_range.end(); ++dmi) + { + // Since we've added the new entry with an invalid placement, + // recognize it and skip it. + if (dmi->first == name) { - if (cdmi->first != name) - { - sortnames.push_back(SortNameList::value_type(cdmi->second, cdmi->first)); - } + // Remember the iterator belonging to our new node, and which + // placement value was 'previous' at that point. + mydmi = dmi; + myprev = previous; + continue; } - std::sort(sortnames.begin(), sortnames.end()); - std::ostringstream out; - out << "New listener '" << name << "' on " << typeid(*this).name() << " '" << getName() - << "' would move previous listener '" << dmi->first << "'\nwas: "; - SortNameList::const_iterator sni(sortnames.begin()), snend(sortnames.end()); - if (sni != snend) + // If the new node has rearranged the existing nodes, we'll find + // that their placement values are no longer in increasing order. + if (dmi->second < previous) { - out << sni->second; - while (++sni != snend) + // This is another scenario in which we'd better back out the + // newly-added node from mDeps -- but don't do it yet, we want to + // traverse the existing mDeps to report on it! + // Describe the change to the order of our listeners. Copy + // everything but the newest listener to a vector we can sort to + // obtain the old order. + typedef std::vector< std::pair<float, std::string> > SortNameList; + SortNameList sortnames; + for (DependencyMap::sorted_iterator cdmi(sorted_range.begin()), cdmend(sorted_range.end()); + cdmi != cdmend; ++cdmi) { - out << ", " << sni->second; + if (cdmi->first != name) + { + sortnames.push_back(SortNameList::value_type(cdmi->second, cdmi->first)); + } } - } - out << "\nnow: "; - DependencyMap::sorted_iterator ddmi(sorted_range.begin()), ddmend(sorted_range.end()); - if (ddmi != ddmend) - { - out << ddmi->first; - while (++ddmi != ddmend) + std::sort(sortnames.begin(), sortnames.end()); + std::ostringstream out; + out << "New listener '" << name << "' on " << typeid(*this).name() << " '" << getName() + << "' would move previous listener '" << dmi->first << "'\nwas: "; + SortNameList::const_iterator sni(sortnames.begin()), snend(sortnames.end()); + if (sni != snend) { - out << ", " << ddmi->first; + out << sni->second; + while (++sni != snend) + { + out << ", " << sni->second; + } } + out << "\nnow: "; + DependencyMap::sorted_iterator ddmi(sorted_range.begin()), ddmend(sorted_range.end()); + if (ddmi != ddmend) + { + out << ddmi->first; + while (++ddmi != ddmend) + { + out << ", " << ddmi->first; + } + } + // NOW remove the offending listener node. + mDeps.remove(name); + // Having constructed a description of the order change, inform caller. + throw OrderChange(out.str()); } - // NOW remove the offending listener node. - mDeps.remove(name); - // Having constructed a description of the order change, inform caller. - throw OrderChange(out.str()); + // This node becomes the previous one. + previous = dmi->second; } - // This node becomes the previous one. - previous = dmi->second; - } - // We just got done with a successful mDeps.add(name, ...) call. We'd - // better have found 'name' somewhere in that sorted list! - assert(mydmi != sorted_range.end()); - // Four cases: - // 0. name is the only entry: placement 1.0 - // 1. name is the first of several entries: placement (next placement)/2 - // 2. name is between two other entries: placement (myprev + (next placement))/2 - // 3. name is the last entry: placement ceil(myprev) + 1.0 - // Since we've cleverly arranged for myprev to be 0.0 if name is the - // first entry, this folds down to two cases. Case 1 is subsumed by - // case 2, and case 0 is subsumed by case 3. So we need only handle - // cases 2 and 3, which means we need only detect whether name is the - // last entry. Increment mydmi to see if there's anything beyond. - if (++mydmi != sorted_range.end()) - { - // The new node isn't last. Place it between the previous node and - // the successor. - newNode = (myprev + mydmi->second)/2.f; - } - else - { - // The new node is last. Bump myprev up to the next integer, add - // 1.0 and use that. - newNode = std::ceil(myprev) + 1.f; + // We just got done with a successful mDeps.add(name, ...) call. We'd + // better have found 'name' somewhere in that sorted list! + assert(mydmi != sorted_range.end()); + // Four cases: + // 0. name is the only entry: placement 1.0 + // 1. name is the first of several entries: placement (next placement)/2 + // 2. name is between two other entries: placement (myprev + (next placement))/2 + // 3. name is the last entry: placement ceil(myprev) + 1.0 + // Since we've cleverly arranged for myprev to be 0.0 if name is the + // first entry, this folds down to two cases. Case 1 is subsumed by + // case 2, and case 0 is subsumed by case 3. So we need only handle + // cases 2 and 3, which means we need only detect whether name is the + // last entry. Increment mydmi to see if there's anything beyond. + if (++mydmi != sorted_range.end()) + { + // The new node isn't last. Place it between the previous node and + // the successor. + newNode = (myprev + mydmi->second) / 2.f; + } + else + { + // The new node is last. Bump myprev up to the next integer, add + // 1.0 and use that. + newNode = std::ceil(myprev) + 1.f; + } + + nodePosition = newNode; } // Now that newNode has a value that places it appropriately in mSignal, // connect it. - LLBoundListener bound = mSignal->connect(newNode, listener); - mConnections[name] = bound; + LLBoundListener bound = mSignal->connect(nodePosition, listener); + + if (!name.empty()) + { // note that we are not tracking anonymous listeners here either. + // This means that it is the caller's responsibility to either assign + // to a TempBoundListerer (scoped_connection) or manually disconnect + // when done. + mConnections[name] = bound; + } return bound; } |