From d901b4f450bc709c26d2baeea9f0d2fccb2a841d Mon Sep 17 00:00:00 2001
From: Mark Olesen <Mark.Olesen@esi-group.com>
Date: Mon, 26 Mar 2018 21:38:47 +0200
Subject: [PATCH] ENH: reduce profiling overhead (issue #764)

- avoid clockTime in favour of clockValue.

- avoid allocations when profiling is not active.

- replace hashing with manual pointer lists
---
 src/OpenFOAM/db/Time/Time.C                   |  15 +-
 src/OpenFOAM/global/profiling/profiling.C     | 256 +++++++++---------
 src/OpenFOAM/global/profiling/profiling.H     |  96 +++----
 .../global/profiling/profilingInformation.C   |  51 +---
 .../global/profiling/profilingInformation.H   |  41 +--
 .../global/profiling/profilingSysInfo.C       |   2 +-
 .../global/profiling/profilingTrigger.C       |  21 +-
 .../global/profiling/profilingTrigger.H       |  35 +--
 8 files changed, 214 insertions(+), 303 deletions(-)

diff --git a/src/OpenFOAM/db/Time/Time.C b/src/OpenFOAM/db/Time/Time.C
index 73cc24f0d0..302ff14732 100644
--- a/src/OpenFOAM/db/Time/Time.C
+++ b/src/OpenFOAM/db/Time/Time.C
@@ -846,13 +846,14 @@ bool Foam::Time::run() const
         {
             // Ensure functionObjects execute on last time step
             // (and hence write uptodate functionObjectProperties)
-            addProfiling(foExec, "functionObjects.execute()");
-            functionObjects_.execute();
-            endProfiling(foExec);
-
-            addProfiling(foEnd, "functionObjects.end()");
-            functionObjects_.end();
-            endProfiling(foEnd);
+            {
+                addProfiling(fo, "functionObjects.execute()");
+                functionObjects_.execute();
+            }
+            {
+                addProfiling(fo, "functionObjects.end()");
+                functionObjects_.end();
+            }
         }
     }
 
diff --git a/src/OpenFOAM/global/profiling/profiling.C b/src/OpenFOAM/global/profiling/profiling.C
index 4ec25d5ba8..a8e23bf39d 100644
--- a/src/OpenFOAM/global/profiling/profiling.C
+++ b/src/OpenFOAM/global/profiling/profiling.C
@@ -3,7 +3,7 @@
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     |
     \\  /    A nd           | Copyright (C) 2009-2016 Bernhard Gschaider
-     \\/     M anipulation  | Copyright (C) 2016-2017 OpenCFD Ltd.
+     \\/     M anipulation  | Copyright (C) 2016-2018 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -33,47 +33,72 @@ License
 
 // * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
 
-int Foam::profiling::allowed
-(
-    Foam::debug::infoSwitch("allowProfiling", 1)
-);
-
-Foam::profiling* Foam::profiling::pool_(nullptr);
+int Foam::profiling::allowed(Foam::debug::infoSwitch("allowProfiling", 1));
+Foam::profiling* Foam::profiling::singleton_(nullptr);
 
 
 // * * * * * * * * * * * * Protected Member Functions  * * * * * * * * * * * //
 
-Foam::profilingInformation* Foam::profiling::find
-(
-    const string& descr,
-    const label parentId
-)
+Foam::profilingInformation* Foam::profiling::create(const zero)
 {
-    return hash_.lookup(Key(descr, parentId), nullptr);
-}
+    // Top-level entry: reset everything
+    pool_.clear();
+    children_.clear();
+    stack_.clear();
+    times_.clear();
 
+    Information* info = new Information();
+
+    pool_.append(info);
+    children_.resize(pool_.size());
+    children_.last().clear();  // safety
 
-Foam::profilingInformation* Foam::profiling::store(profilingInformation *info)
-{
-    // Profile information lookup is qualified by parent id
-    hash_.insert(Key(info->description(), info->parent().id()), info);
     return info;
 }
 
 
-void Foam::profiling::push(profilingInformation *info, clockTime& timer)
+Foam::profilingInformation* Foam::profiling::create
+(
+    profilingInformation *parent,
+    const string& descr
+)
 {
-    stack_.push(info);
-    timers_.set(info->id(), &timer);
-    info->push();                       // mark as on stack
+    const label parentId = parent->id();
+
+    for (Information* child : children_[parentId])
+    {
+        if (descr == child->description())
+        {
+            return child;  // Found existing
+        }
+    }
+
+    Information* info = new Information(parent, descr, pool_.size());
+
+    pool_.append(info);
+    children_.resize(pool_.size());
+    children_.last().clear();  // safety
+    children_[parentId].append(info);
+
+    return info;
 }
 
 
-Foam::profilingInformation* Foam::profiling::pop()
+void Foam::profiling::beginTimer(profilingInformation *info)
 {
-    profilingInformation *info = stack_.pop();
-    timers_.erase(info->id());
-    info->pop();                        // mark as off stack
+    stack_.append(info);
+    times_.append(clockValue::now());
+    info->setActive(true);              // Mark as on stack
+}
+
+
+Foam::profilingInformation* Foam::profiling::endTimer()
+{
+    Information *info = stack_.remove();
+    clockValue clockval = times_.remove();
+
+    info->update(clockval.elapsed());   // Update elapsed time
+    info->setActive(false);             // Mark as off stack
 
     return info;
 }
@@ -83,7 +108,7 @@ Foam::profilingInformation* Foam::profiling::pop()
 
 bool Foam::profiling::active()
 {
-    return allowed && pool_;
+    return allowed && singleton_;
 }
 
 
@@ -97,7 +122,7 @@ bool Foam::profiling::print(Ostream& os)
 {
     if (active())
     {
-        return pool_->writeData(os);
+        return singleton_->writeData(os);
     }
 
     return false;
@@ -108,7 +133,7 @@ bool Foam::profiling::writeNow()
 {
     if (active())
     {
-        return pool_->regIOobject::write();
+        return singleton_->regIOobject::write();
     }
 
     return false;
@@ -121,24 +146,10 @@ void Foam::profiling::initialize
     const Time& owner
 )
 {
-    if (allowed && !pool_)
+    if (allowed && !singleton_)
     {
-        pool_ = new profiling(ioObj, owner);
-
-        profilingInformation *info = pool_->store
-        (
-            new profilingInformation()
-        );
-
-        pool_->push(info, pool_->clockTime_);
-        if (argList::bannerEnabled())
-        {
-            Info<< "profiling initialized" << nl;
-        }
+        singleton_ = new profiling(ioObj, owner);
     }
-
-    // silently ignore multiple initializations
-    // eg, decomposePar uses multiple simultaneous Times
 }
 
 
@@ -149,63 +160,40 @@ void Foam::profiling::initialize
     const Time& owner
 )
 {
-    if (allowed && !pool_)
+    if (allowed && !singleton_)
     {
-        pool_ = new profiling(dict, ioObj, owner);
-
-        profilingInformation *info = pool_->store
-        (
-            new profilingInformation()
-        );
-
-        pool_->push(info, pool_->clockTime_);
-        if (argList::bannerEnabled())
-        {
-            Info<< "profiling initialized" << nl;
-        }
+        singleton_ = new profiling(dict, ioObj, owner);
     }
-
-    // silently ignore multiple initializations
-    // eg, decomposePar uses multiple simultaneous Times
 }
 
 
 void Foam::profiling::stop(const Time& owner)
 {
-    if (pool_ && &owner == &(pool_->owner_))
+    if (singleton_ && &owner == &(singleton_->owner_))
     {
-        delete pool_;
-        pool_ = nullptr;
+        delete singleton_;
+        singleton_ = nullptr;
     }
 }
 
 
-Foam::profilingInformation* Foam::profiling::New
-(
-    const string& descr,
-    clockTime& timer
-)
+Foam::profilingInformation* Foam::profiling::New(const string& descr)
 {
-    profilingInformation *info = nullptr;
+    Information *info = nullptr;
 
     if (active())
     {
-        profilingInformation *parent = pool_->stack_.top();
+        Information *parent = singleton_->stack_.last();
 
-        info = pool_->find(descr, parent->id());
-        if (!info)
-        {
-            info = pool_->store(new profilingInformation(descr, parent));
-        }
+        info = singleton_->create(parent, descr);
+        singleton_->beginTimer(info);
 
-        pool_->push(info, timer);
-
-        if (pool_->memInfo_)
+        if (singleton_->memInfo_)
         {
             info->maxMem_ = Foam::max
             (
                 info->maxMem_,
-                pool_->memInfo_->update().size()
+                singleton_->memInfo_->update().size()
             );
         }
     }
@@ -218,7 +206,7 @@ void Foam::profiling::unstack(const profilingInformation *info)
 {
     if (active() && info)
     {
-        profilingInformation *top = pool_->pop();
+        Information *top = singleton_->endTimer();
 
         if (info->id() != top->id())
         {
@@ -245,14 +233,22 @@ Foam::profiling::profiling
 :
     IOdictionary(io),
     owner_(owner),
-    clockTime_(),
-    hash_(),
+    pool_(),
+    children_(),
     stack_(),
-    timers_(),
+    times_(),
     sysInfo_(new profilingSysInfo()),
     cpuInfo_(new cpuInfo()),
     memInfo_(new memInfo())
-{}
+{
+    Information *info = this->create(Zero);
+    this->beginTimer(info);
+
+    if (argList::bannerEnabled())
+    {
+        Info<< "profiling initialized" << nl;
+    }
+}
 
 
 Foam::profiling::profiling
@@ -264,10 +260,10 @@ Foam::profiling::profiling
 :
     IOdictionary(io),
     owner_(owner),
-    clockTime_(),
-    hash_(),
+    pool_(),
+    children_(),
     stack_(),
-    timers_(),
+    times_(),
     sysInfo_
     (
         dict.lookupOrDefault("sysInfo", false)
@@ -283,7 +279,15 @@ Foam::profiling::profiling
         dict.lookupOrDefault("memInfo", false)
       ? new memInfo() : nullptr
     )
-{}
+{
+    Information *info = this->create(Zero);
+    this->beginTimer(info);
+
+    if (argList::bannerEnabled())
+    {
+        Info<< "profiling initialized" << nl;
+    }
+}
 
 
 // * * * * * * * * * * * * * * * * Destructor  * * * * * * * * * * * * * * * //
@@ -294,10 +298,9 @@ Foam::profiling::~profiling()
     deleteDemandDrivenData(cpuInfo_);
     deleteDemandDrivenData(memInfo_);
 
-    if (pool_ == this)
+    if (singleton_ == this)
     {
-        pool_ = nullptr;
-        profilingInformation::nextId_ = 0;
+        singleton_ = nullptr;
     }
 }
 
@@ -318,54 +321,43 @@ Foam::label Foam::profiling::size() const
 
 bool Foam::profiling::writeData(Ostream& os) const
 {
+    static DynamicList<scalar> elapsed;
+
+    const clockValue now(clockValue::now());
+
+    const label nstack = stack_.size();
+
+    elapsed.resize(nstack+1);   // extend for last entry, which has no child.
+
+    for (label stacki=0; stacki < nstack; ++stacki)
+    {
+        elapsed[stacki] = (now - times_[stacki]);
+    }
+    elapsed.last() = 0;
+
     os.beginBlock("profiling");
 
-    // Add extra new line between entries
-    label nTrigger = 0;
-
-    // write on-stack items
-    // newest is first on the stack, top-level is at the end
-    // this is how the child times are summed
+    // Active items
+    for (label stacki=0; stacki < nstack; ++stacki)
     {
-        scalar oldElapsed = 0;
-        forAllConstIter(StackContainer, stack_, iter)
-        {
-            const profilingInformation *info = *iter;
-            scalar elapsed = timers_[info->id()]->elapsedTime();
+        if (stacki) os << nl;   // Extra line between entries
 
-            if (nTrigger++)
-            {
-                os << nl;
-            }
-            info->write(os, true, elapsed, oldElapsed);
-            oldElapsed = elapsed;
-        }
+        stack_[stacki]->write
+        (
+            os,
+            true,
+            elapsed[stacki],    // elapsedTime
+            elapsed[stacki+1]   // childTimes
+        );
     }
 
-
-    // write off-stack items
-    // using an additional Map to sort by Id
+    // Non-active items
+    for (const Information& info : pool_)
     {
-        typedef Map<const Information*> LookupContainer;
-        LookupContainer lookup;
-
-        forAllConstIter(StorageContainer, hash_, iter)
+        if (!info.active())
         {
-            const profilingInformation *info = iter();
-
-            if (!info->onStack())
-            {
-                lookup.set(info->id(), info);
-            }
-        }
-
-        forAllConstIter(LookupContainer, lookup, iter)
-        {
-            if (nTrigger++)
-            {
-                os << nl;
-            }
-            iter()->write(os);
+            os << nl;
+            info.write(os);
         }
     }
 
diff --git a/src/OpenFOAM/global/profiling/profiling.H b/src/OpenFOAM/global/profiling/profiling.H
index 1c50844b3a..db7aa681ef 100644
--- a/src/OpenFOAM/global/profiling/profiling.H
+++ b/src/OpenFOAM/global/profiling/profiling.H
@@ -3,7 +3,7 @@
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     |
     \\  /    A nd           | Copyright (C) 2009-2016 Bernhard Gschaider
-     \\/     M anipulation  | Copyright (C) 2016-2107 OpenCFD Ltd.
+     \\/     M anipulation  | Copyright (C) 2016-2018 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -54,10 +54,8 @@ SourceFiles
 
 #include "profilingTrigger.H"
 #include "IOdictionary.H"
-#include "HashPtrTable.H"
-#include "Tuple2.H"
-#include "LIFOStack.H"
-#include "Map.H"
+#include "DynamicList.H"
+#include "PtrDynList.H"
 #include "Time.H"
 #include "clockTime.H"
 
@@ -82,7 +80,7 @@ class profiling
 {
 public:
 
-    // Public typedefs
+    // Public Typedefs
 
         typedef profilingInformation Information;
         typedef profilingTrigger Trigger;
@@ -98,38 +96,11 @@ private:
 
         typedef profilingSysInfo sysInfo;
 
-        //- Profile information lookup is qualified by parent id
-        typedef Tuple2<string, label> Key;
-
-        //- Hashing for information lookup
-        class HashKey
-        :
-            public Hash<Key>
-        {
-        public:
-
-            HashKey()
-            {}
-
-            //- Hash qualified by the parent id to avoid collisions
-            unsigned operator()(const Key& key) const
-            {
-                return
-                (
-                    Hash<string>()(key.first())
-                  + Hash<label>()(key.second())
-                );
-            }
-        };
-
-        typedef HashPtrTable<Information, Key, HashKey> StorageContainer;
-        typedef LIFOStack<Information*> StackContainer;
-
 
     // Private Static Data Members
 
-        //- Only one global pool object is possible
-        static profiling* pool_;
+        //- Only one global object is possible
+        static profiling* singleton_;
 
 
     // Private Data Members
@@ -137,17 +108,17 @@ private:
         //- The owner of the profiling
         const Time& owner_;
 
-        //- A global timer for the profiling
-        clockTime clockTime_;
-
         //- Storage of profiling information
-        StorageContainer hash_;
+        PtrDynList<Information> pool_;
 
-        //- Local stack of profiling information
-        StackContainer stack_;
+        //- Parent/child relationships for lookup purposes
+        DynamicList<DynamicList<Information*,16>> children_;
 
-        //- Note the timers (by Id) for the correct stack-output
-        Map<clockTime*> timers_;
+        //- LIFO stack of profiling information
+        DynamicList<Information*> stack_;
+
+        //- LIFO stack of clock values
+        DynamicList<clockValue> times_;
 
         //- General system information (optional)
         sysInfo* sysInfo_;
@@ -161,10 +132,10 @@ private:
 
     // Private Member Functions
 
-        //- Disallow default bitwise copy construct
+        //- Disallow copy construct
         profiling(const profiling&) = delete;
 
-        //- Disallow default bitwise assignment
+        //- Disallow copy assignment
         void operator=(const profiling&) = delete;
 
 
@@ -196,20 +167,25 @@ protected:
 
     // Protected Member Functions
 
-        //- Find named profiling information element with specified parent.
-        //  Return nullptr on failure.
-        profilingInformation* find(const string& descr, const label parentId);
+        //- Clear all profiling and restart with new profiling
+        //  \return pointer to stored information element
+        Information* create(const zero);
 
-        //- Add to hashed storage,
-        //  \return pointer to newly stored element for chaining
-        profilingInformation* store(profilingInformation* info);
+        //- Get or create named profiling information element with the
+        //- specified parent.
+        //  \return pointer to stored information element
+        Information* create
+        (
+            Information* parent,
+            const string& descr
+        );
 
-        //- Add to stack and set timer lookup (based on Id)
-        void push(profilingInformation* info, clockTime& timer);
+        //- Add to stack of active information and begin timer datum
+        void beginTimer(Information* info);
 
-        //- Remove from stack and remove timer lookup (based on Id).
-        //  \return pointer to profiling information element
-        profilingInformation* pop();
+        //- Remove from stack of active information and update elapsed time
+        //  \return pointer to profiling information element (for reference)
+        Information* endTimer();
 
 
     // Static control elements
@@ -233,12 +209,8 @@ protected:
         static void stop(const Time& owner);
 
         //- Existing or new element on pool, add to stack.
-        //  Returns null if profiling has not been initialized
-        static profilingInformation* New
-        (
-            const string& descr,
-            clockTime& timer
-        );
+        //  Returns nullptr if profiling has not been initialized
+        static profilingInformation* New(const string& descr);
 
         //- Remove the information from the top of the stack
         static void unstack(const profilingInformation* info);
diff --git a/src/OpenFOAM/global/profiling/profilingInformation.C b/src/OpenFOAM/global/profiling/profilingInformation.C
index 38181ece74..a63e1ac556 100644
--- a/src/OpenFOAM/global/profiling/profilingInformation.C
+++ b/src/OpenFOAM/global/profiling/profilingInformation.C
@@ -3,7 +3,7 @@
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     |
     \\  /    A nd           | Copyright (C) 2009-2016 Bernhard Gschaider
-     \\/     M anipulation  | Copyright (C) 2016 OpenCFD Ltd.
+     \\/     M anipulation  | Copyright (C) 2016-2018 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -27,57 +27,36 @@ License
 #include "Switch.H"
 #include "IOstreams.H"
 
-// * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
-
-Foam::label Foam::profilingInformation::nextId_(0);
-
-
-// * * * * * * * * * * * * * Static Member Functions * * * * * * * * * * * * //
-
-Foam::label Foam::profilingInformation::getNextId()
-{
-    return nextId_++;
-}
-
-
-void Foam::profilingInformation::raiseId(label maxVal)
-{
-    if (nextId_ < maxVal)
-    {
-        nextId_ = maxVal;
-    }
-}
-
-
 // * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
 
 Foam::profilingInformation::profilingInformation()
 :
-    id_(getNextId()),
+    id_(0),
     description_("application::main"),
     parent_(this),
     calls_(0),
     totalTime_(0),
     childTime_(0),
     maxMem_(0),
-    onStack_(false)
+    active_(false)
 {}
 
 
 Foam::profilingInformation::profilingInformation
 (
+    profilingInformation *parent,
     const string& descr,
-    profilingInformation *parent
+    const label id
 )
 :
-    id_(getNextId()),
+    id_(id),
     description_(descr),
     parent_(parent),
     calls_(0),
     totalTime_(0),
     childTime_(0),
     maxMem_(0),
-    onStack_(false)
+    active_(false)
 {}
 
 
@@ -88,24 +67,18 @@ void Foam::profilingInformation::update(const scalar elapsed)
     ++calls_;
     totalTime_ += elapsed;
 
-    if (id_ != parent().id())
+    if (id_ != parent_->id())
     {
-        parent().childTime_ += elapsed;
+        parent_->childTime_ += elapsed;
     }
 }
 
 
 // * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
 
-void Foam::profilingInformation::push() const
+void Foam::profilingInformation::setActive(bool state) const
 {
-    onStack_ = true;
-}
-
-
-void Foam::profilingInformation::pop() const
-{
-    onStack_ = false;
+    active_ = state;
 }
 
 
@@ -128,7 +101,7 @@ Foam::Ostream& Foam::profilingInformation::write
     os.writeEntry("totalTime",      totalTime() + elapsedTime);
     os.writeEntry("childTime",      childTime() + childTimes);
     os.writeEntryIfDifferent<int>("maxMem", 0, maxMem_);
-    os.writeEntry("onStack",        Switch(onStack()));
+    os.writeEntry("active",         Switch(active()));
 
     os.endBlock();
 
diff --git a/src/OpenFOAM/global/profiling/profilingInformation.H b/src/OpenFOAM/global/profiling/profilingInformation.H
index 943260b86b..6a8ee2a7ab 100644
--- a/src/OpenFOAM/global/profiling/profilingInformation.H
+++ b/src/OpenFOAM/global/profiling/profilingInformation.H
@@ -58,18 +58,6 @@ Ostream& operator<<(Ostream& os, const profilingInformation& info);
 
 class profilingInformation
 {
-    // Private Static Data Members
-
-        //- Counter to generate the ids
-        static label nextId_;
-
-        //- Get a new ID and update the counter
-        static label getNextId();
-
-        //- Raise the next possible ID (to avoid ID-clashes during reading)
-        static void raiseId(label maxVal);
-
-
     // Private Data Members
 
         //- Unique id to identify it
@@ -81,7 +69,7 @@ class profilingInformation
         //- Pointer to the parent object (or self for top-level)
         profilingInformation* parent_;
 
-        //- Nr of times this was called
+        //- Number of times this was called
         long calls_;
 
         //- Total time spent
@@ -94,16 +82,16 @@ class profilingInformation
         //  Only valid when the calling profiling has memInfo active.
         mutable int maxMem_;
 
-        //- Is this information currently on the stack?
-        mutable bool onStack_;
+        //- Is this information active or passive (ie, on the stack)?
+        mutable bool active_;
 
 
     // Private Member Functions
 
-        //- Disallow default bitwise copy construct
+        //- No copy construct
         profilingInformation(const profilingInformation&) = delete;
 
-        //- Disallow default bitwise assignment
+        //- No copy assignment
         void operator=(const profilingInformation&) = delete;
 
 
@@ -122,12 +110,8 @@ protected:
 
     // Member Functions
 
-        //- Mark as being on the stack
-        void push() const;
-
-        //- Mark as being off the stack
-        void pop() const;
-
+        //- Mark as being active or passive)
+        void setActive(bool state) const;
 
         //- Write the profiling times, optionally with additional values
         //  Use dictionary format.
@@ -147,8 +131,9 @@ public:
         //- Construct from components
         profilingInformation
         (
+            profilingInformation* parent,
             const string& descr,
-            profilingInformation* parent
+            const label id
         );
 
 
@@ -158,7 +143,7 @@ public:
 
     // Member Functions
 
-      // Access
+    // Access
 
         inline label id() const
         {
@@ -202,13 +187,13 @@ public:
         }
 
 
-        inline bool onStack() const
+        inline bool active() const
         {
-            return onStack_;
+            return active_;
         }
 
 
-      // Edit
+    // Edit
 
         //- Update it with a new timing information
         void update(const scalar elapsedTime);
diff --git a/src/OpenFOAM/global/profiling/profilingSysInfo.C b/src/OpenFOAM/global/profiling/profilingSysInfo.C
index 12a5305a29..166f23e813 100644
--- a/src/OpenFOAM/global/profiling/profilingSysInfo.C
+++ b/src/OpenFOAM/global/profiling/profilingSysInfo.C
@@ -40,7 +40,7 @@ inline static void printEnv
     const std::string& envName
 )
 {
-    const std::string value = Foam::getEnv(envName);
+    const std::string value(Foam::getEnv(envName));
     if (!value.empty())
     {
         os.writeEntry(key, value);
diff --git a/src/OpenFOAM/global/profiling/profilingTrigger.C b/src/OpenFOAM/global/profiling/profilingTrigger.C
index f02f4ee1ca..617cc246e8 100644
--- a/src/OpenFOAM/global/profiling/profilingTrigger.C
+++ b/src/OpenFOAM/global/profiling/profilingTrigger.C
@@ -3,7 +3,7 @@
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     |
     \\  /    A nd           | Copyright (C) 2009-2016 Bernhard Gschaider
-     \\/     M anipulation  | Copyright (C) 2016-2017 OpenCFD Ltd.
+     \\/     M anipulation  | Copyright (C) 2016-2018 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -24,23 +24,26 @@ License
 \*---------------------------------------------------------------------------*/
 
 #include "profiling.H"
-#include "profilingInformation.H"
 #include "profilingTrigger.H"
-
+#include "profilingInformation.H"
 
 // * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
 
+Foam::profilingTrigger::profilingTrigger()
+:
+    ptr_(nullptr)
+{}
+
+
 Foam::profilingTrigger::profilingTrigger(const char* name)
 :
-    clock_(),
-    ptr_(profiling::New(name, clock_))
+    ptr_(profiling::New(name))
 {}
 
 
 Foam::profilingTrigger::profilingTrigger(const string& name)
 :
-    clock_(),
-    ptr_(profiling::New(name, clock_))
+    ptr_(profiling::New(name))
 {}
 
 
@@ -64,10 +67,10 @@ void Foam::profilingTrigger::stop()
 {
     if (ptr_)
     {
-        ptr_->update(clock_.elapsedTime());
+        // profiling info pointer managed by pool storage, so no delete here
         profiling::unstack(ptr_);
-        // pointer is managed by pool storage -> thus no delete here
     }
+
     ptr_ = nullptr;
 }
 
diff --git a/src/OpenFOAM/global/profiling/profilingTrigger.H b/src/OpenFOAM/global/profiling/profilingTrigger.H
index f459f46970..133c252a1b 100644
--- a/src/OpenFOAM/global/profiling/profilingTrigger.H
+++ b/src/OpenFOAM/global/profiling/profilingTrigger.H
@@ -3,7 +3,7 @@
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     |
     \\  /    A nd           | Copyright (C) 2009-2016 Bernhard Gschaider
-     \\/     M anipulation  | Copyright (C) 2016-2107 OpenCFD Ltd.
+     \\/     M anipulation  | Copyright (C) 2016-2018 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -35,7 +35,6 @@ SourceFiles
 #ifndef profilingTrigger_H
 #define profilingTrigger_H
 
-#include "clockTime.H"
 #include "string.H"
 
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
@@ -43,7 +42,7 @@ SourceFiles
 namespace Foam
 {
 
-// Forward declaration of classes
+// Forward declarations
 class profilingInformation;
 
 /*---------------------------------------------------------------------------*\
@@ -54,19 +53,16 @@ class profilingTrigger
 {
     // Private Data Members
 
-        //- The timer for the profiling information
-        clockTime clock_;
-
         //- The profiling information
         profilingInformation *ptr_;
 
 
     // Private Member Functions
 
-        //- Disallow default bitwise copy construct
+        //- No copy construct
         profilingTrigger(const profilingTrigger&) = delete;
 
-        //- Disallow default bitwise assignment
+        //- No copy assignment
         void operator=(const profilingTrigger&) = delete;
 
 
@@ -74,6 +70,9 @@ public:
 
     // Constructors
 
+        //- Construct null, no profiling trigger
+        profilingTrigger();
+
         //- Construct profiling with given description.
         //  Descriptions beginning with 'application::' are reserved for
         //  internal use.
@@ -91,14 +90,9 @@ public:
 
     // Member Functions
 
-      // Access
-
         //- True if the triggered profiling is active
         bool running() const;
 
-
-      // Edit
-
         //- Stop triggered profiling
         void stop();
 
@@ -113,21 +107,13 @@ public:
 
 // Macros
 
-//- Define profiling with specified name and description string
-//  This is required if the description contains space, colons etc.
-//  \sa addProfiling0
+//- Define profiling trigger with specified name and description string
 //  \sa endProfiling
 #define addProfiling(name,descr)                                               \
     ::Foam::profilingTrigger  profilingTriggerFor##name(descr)
 
-//- Define profiling with specified name and description correspond to the name
-//  \sa addProfiling
-//  \sa endProfiling
-#define addProfiling0(name)                                                    \
-    ::Foam::profilingTrigger  profilingTriggerFor##name(#name)
-
-//- Define profiling with specified name and description correspond to the
-//  compiler-defined function name string:
+//- Define profiling trigger with specified name and description
+//- corresponding to the compiler-defined function name string
 //  \sa addProfiling
 //  \sa endProfiling
 #ifdef __GNUC__
@@ -140,7 +126,6 @@ public:
 
 //- Remove profiling with specified name
 //  \sa addProfiling
-//  \sa addProfiling0
 #define endProfiling(name)    profilingTriggerFor##name.stop()