Allow canceling timers

Use MutexLocks for more robustness
Add get_next_timeout function

diff --git a/source/time/timer.cpp b/source/time/timer.cpp
index 9fc82f57e872bf0b0c1f1dcc3ee8f974003eafd5..efe22cc39d94b032e99c58032a7a8819364f7dfe 100644 (file)
--- a/source/time/timer.cpp
+++ b/source/time/timer.cpp
@@ -12,24 +12,17 @@ using namespace std;
 namespace Msp {
 namespace Time {
 
-Timer::Timer():
-       slots(slot_compare)
-{ }
-
 Timer::~Timer()
 {
-       while(!slots.empty())
-       {
-               delete slots.top();
-               slots.pop();
-       }
+       for(set<SlotProxy>::iterator i=slots.begin(); i!=slots.end(); ++i)
+               delete i->slot;
 }
 
 Timer::Slot &Timer::add(const TimeDelta &td)
 {
        Slot *s=new Slot(td);
        mutex.lock();
-       slots.push(s);
+       slots.insert(s);
        mutex.unlock();
        sem.signal();
        return *s;
@@ -38,41 +31,54 @@ Timer::Slot &Timer::add(const TimeDelta &td)
 Timer::Slot &Timer::add(const TimeStamp &ts)
 {
        Slot *s=new Slot(ts);
-       mutex.lock();
-       slots.push(s);
-       mutex.unlock();
+       {
+               MutexLock l(mutex);
+               slots.insert(s);
+       }
        sem.signal();
        return *s;
 }
 
+void Timer::cancel(Slot &slot)
+{
+       MutexLock l(mutex);
+       if(slots.erase(&slot))
+               delete &slot;
+}
+
 void Timer::tick(bool block)
 {
        if(slots.empty())
        {
                if(block)
                        sem.wait();
-               return;
+               else
+                       return;
        }
 
-       mutex.lock();
-       Slot *next=slots.top();
-       mutex.unlock();
+       Slot *next;
+       {
+               MutexLock l(mutex);
+               next=slots.begin()->slot;
+       }
 
        const TimeStamp &stamp=next->get_timeout();
        const TimeStamp t=now();
        if(stamp<=t || (block && sem.wait(stamp-t)==1))
        {
-               slots.pop();
+               slots.erase(slots.begin());
                if(next->signal_timeout.emit() && next->increment())
-                       slots.push(next);
+                       slots.insert(next);
                else
                        delete next;
        }
 }
 
-bool Timer::slot_compare(Slot *a, Slot *b)
+TimeStamp Timer::get_next_timeout() const
 {
-       return *a<*b;
+       if(slots.empty())
+               return TimeStamp();
+       return slots.begin()->slot->get_timeout();
 }
 
 
@@ -93,9 +99,14 @@ bool Timer::Slot::increment()
        return true;
 }
 
-bool Timer::Slot::operator<(const Slot &other) const
+
+Timer::SlotProxy::SlotProxy(Slot *s):
+       slot(s)
+{ }
+
+bool Timer::SlotProxy::operator<(const SlotProxy &sp) const
 {
-       return timeout<other.timeout;
+       return slot->get_timeout()<sp.slot->get_timeout();
 }
 
 } // namespace Time

diff --git a/source/time/timer.h b/source/time/timer.h
index cfa00bb0d1511f42f09591b04dbc5527ee8deb91..8b4e5957ebd17257e55bf8a5e2979dc99f75868f 100644 (file)
--- a/source/time/timer.h
+++ b/source/time/timer.h
@@ -7,7 +7,7 @@ Distributed under the LGPL
 #ifndef MSP_TIME_TIMER_H_
 #define MSP_TIME_TIMER_H_
 
-#include <queue>
+#include <set>
 #include <sigc++/sigc++.h>
 #include "../core/mutex.h"
 #include "../core/semaphore.h"
@@ -41,18 +41,22 @@ public:
                Slot(const TimeStamp &);
                const TimeStamp &get_timeout() const { return timeout; }
                bool increment();
-               bool operator<(const Slot &) const;
        };
 
 private:
-       typedef bool (*fSlotCompare)(Slot *, Slot *);
+       struct SlotProxy
+       {
+               Slot *slot;
+
+               SlotProxy(Slot *);
+               bool operator<(const SlotProxy &) const;
+       };
 
-       std::priority_queue<Slot *, std::vector<Slot *>, fSlotCompare> slots;
+       std::set<SlotProxy> slots;
        Semaphore sem;
        Mutex mutex;
 
 public:
-       Timer();
        ~Timer();
 
        /**
@@ -67,6 +71,11 @@ public:
        */
        Slot &add(const TimeStamp &);
 
+       /**
+       Cancels a previously added timer.
+       */
+       void cancel(Slot &);
+
        /**
        Checks all timers, executing any that have timed out.  If block is true,
        waits until one times out.
@@ -75,8 +84,8 @@ public:
        won't return until a timer is added from another thread.
        */
        void tick(bool block=true);
-private:
-       static bool slot_compare(Slot *, Slot *);
+
+       TimeStamp get_next_timeout() const;
 };
 
 } // namespace Time