Changeset 17243 for trunk/Mars/mcore

Timestamp:

10/17/13 16:49:25 (11 years ago)

Author:

tbretz

Message:

Encapsulated the header with a guard (I don't understand why this was not yet done); reworked the static setup functions to avoid the need for a source file if included in multiple targets; simplified SetNumThreads... a good documentation is enough.

File:

• trunk/Mars/mcore/zofits.h (modified) (7 diffs)

trunk/Mars/mcore/zofits.h

@@ +1 @@
+#ifndef FACT_zofits
+#define FACT_zofits
+
 /*
  * zofits.h
@@ -57 +60 @@
 
 public:
+        /// static setter for the default number of threads to use. -1 means all available physical cores
+        static uint32_t DefaultNumThreads(const uint32_t &_n=-2) { static uint32_t n=0; if (int32_t(_n)<-1) n=_n; return n; }
+        static uint32_t DefaultMaxMemory(const uint32_t &_n=0) { static uint32_t n=1000000; if (_n>0) n=_n; return n; }
+        static uint32_t DefaultMaxNumTiles(const uint32_t &_n=0) { static uint32_t n=1000; if (_n>0) n=_n; return n; }
+        static uint32_t DefaultNumRowsPerTile(const uint32_t &_n=0) { static uint32_t n=100; if (_n>0) n=_n; return n; }
+
         /// constructors
         /// @param numTiles how many data groups should be pre-reserved ?
         /// @param rowPerTile how many rows will be grouped together in a single tile
         /// @param maxUsableMem how many bytes of memory can be used by the compression buffers
-        zofits(uint32_t numTiles    = fgNumTiles,
-               uint32_t rowPerTile  = fgRowPerTile,
-               uint64_t maxUsableMem= fgMaxUsableMem) : ofits(),
-                                                        fMemPool(0, maxUsableMem),
+        zofits(uint32_t numTiles    = DefaultMaxNumTiles(),
+               uint32_t rowPerTile  = DefaultNumRowsPerTile(),
+               uint32_t maxUsableMem= DefaultMaxMemory()) : ofits(),
+                                                        fMemPool(0, maxUsableMem*1000),
                                                         fWriteToDiskQueue(bind(&zofits::WriteBufferToDisk, this, placeholders::_1), false)
         {
-            InitMemberVariables(numTiles, rowPerTile, maxUsableMem);
-            SetNumThreads(fgNumQueues);
+            InitMemberVariables(numTiles, rowPerTile, maxUsableMem*1000);
+            SetNumThreads(DefaultNumThreads());
         }
 
@@ -76 +85 @@
         /// @param maxUsableMem how many bytes of memory can be used by the compression buffers
         zofits(const char* fname,
-               uint32_t numTiles    = fgNumTiles,
-               uint32_t rowPerTile  = fgRowPerTile,
-               uint64_t maxUsableMem= fgMaxUsableMem) : ofits(fname),
-                                                        fMemPool(0, maxUsableMem),
+               uint32_t numTiles    = DefaultMaxNumTiles(),
+               uint32_t rowPerTile  = DefaultNumRowsPerTile(),
+               uint32_t maxUsableMem= DefaultMaxMemory()) : ofits(fname),
+                                                        fMemPool(0, maxUsableMem*1000),
                                                         fWriteToDiskQueue(bind(&zofits::WriteBufferToDisk, this, placeholders::_1), false)
         {
-            InitMemberVariables(numTiles, rowPerTile, maxUsableMem);
-            SetNumThreads(fgNumQueues);
-        }
-
-        /// destructors
-        virtual ~zofits()
-        {
+            InitMemberVariables(numTiles, rowPerTile, maxUsableMem*1000);
+            SetNumThreads(DefaultNumThreads());
         }
 
@@ -577 +581 @@
         }
 
-        /// static setter for the default number of threads to use. -1 means all available physical cores
-        static void SetDefaultNumThreads   (int32_t num)   { fgNumQueues = num;}
-        static void SetDefaultNumTiles     (uint32_t num)  { fgNumTiles = num;}
-        static void SetDefaultNumRowPerTile(uint32_t num)  { fgRowPerTile = num;}
-        static void SetDefaultMaxUsableMem (uint64_t size) { fgMaxUsableMem = size;}
-
-        static int32_t GetDefaultNumThreads()     { return fgNumQueues;}
-        static uint32_t GetDefaultNumTiles()      { return fgNumTiles;}
-        static uint32_t GetDefaultNumRowPerTile() { return fgRowPerTile;}
-        static uint64_t GetDefaulMaxUsableMem()   { return fgMaxUsableMem;}
-
         /// Get and set the actual number of threads for this object
         int32_t GetNumThreads() const { return fNumQueues;}
-        bool SetNumThreads(int32_t num)
+        bool SetNumThreads(uint32_t num)
         {
             if (is_open())
@@ -604 +597 @@
             //get number of physically available threads
 #ifdef USE_BOOST_THREADS
-            int32_t num_available_cores = boost::thread::hardware_concurrency();
+            unsigned int num_available_cores = boost::thread::hardware_concurrency();
 #else
-            int32_t num_available_cores = thread::hardware_concurrency();
-#endif
-
+            unsigned int num_available_cores = thread::hardware_concurrency();
+#endif
             // could not detect number of available cores from system properties...
-            // assume that 5 cores are available (4 compression, 1 write)
             if (num_available_cores == 0)
-                num_available_cores = 5;
-
-            // Throw an exception if too many cores are requested
+                num_available_cores = 1;
+
+            // leave one core for the main thread and one for the writing
             if (num > num_available_cores)
-            {
-                ostringstream str;
-                str << "You will be using more threads(" << num << ") than available cores(" << num_available_cores << "). Expect sub-optimal performances";
-#ifdef __EXCEPTIONS
-                throw runtime_error(str.str());
-#else
-                gLog << ___err___ << "WARNING - " << str.str() << endl;
-#endif
-            }
-
-            if (num == -1)
-                num = num_available_cores-2; // 1 for writing, 1 for the main thread
-
-            if (fCompressionQueues.size() == (uint32_t)num)
-                return true;
-
-            //cannot be const, as resize does not want it that way
-            Queue<CompressionTarget> queue(bind(&zofits::CompressBuffer, this, placeholders::_1), false);
-
-            //shrink if required
-            if ((uint32_t)num < fCompressionQueues.size())
-            {
-                fCompressionQueues.resize(num, queue);
-                return true;
-            }
-
-            //grow if required
-            fCompressionQueues.resize(num, queue);
-
-            fNumQueues = num;
+                num = num_available_cores>2 ? num_available_cores-2 : 1;
+
+            if (fCompressionQueues.size() != uint32_t(num))
+            {
+                fCompressionQueues.resize(num, Queue<CompressionTarget>(bind(&zofits::CompressBuffer, this, placeholders::_1), false));
+                fNumQueues = num;
+            }
 
             return true;
@@ -991 +959 @@
 
         //thread related stuff
-        MemoryManager   fMemPool;                  ///< Actual memory manager, providing memory for the compression buffers
-        static int32_t  fgNumQueues;              ///<  Default number of threads to be used by the objects
-        static uint32_t fgNumTiles;              ///< Default number of reserved tiles
-        static uint32_t fgRowPerTile;           ///< Default number of rows per tile
-        static uint64_t fgMaxUsableMem;        ///< Default usable memory PER OBJECT
-        int32_t         fNumQueues;           ///<   Current number of threads that will be used by this object
-        uint64_t        fMaxUsableMem;       ///<    Maximum number of bytes that can be allocated by the memory manager
-        int32_t         fLatestWrittenTile; ///<     Index of the last tile written to disk (for correct ordering while using several threads)
+        MemoryManager   fMemPool;           ///< Actual memory manager, providing memory for the compression buffers
+        int32_t         fNumQueues;         ///< Current number of threads that will be used by this object
+        uint64_t        fMaxUsableMem;      ///< Maximum number of bytes that can be allocated by the memory manager
+        int32_t         fLatestWrittenTile; ///< Index of the last tile written to disk (for correct ordering while using several threads)
 
         vector<Queue<CompressionTarget>>          fCompressionQueues;  ///< Processing queues (=threads)
@@ -1047 +1011 @@
 };
 
-int32_t  zofits::fgNumQueues = 0;
-uint32_t zofits::fgNumTiles = 1000;
-uint32_t zofits::fgRowPerTile = 100;
-uint64_t zofits::fgMaxUsableMem = 1073741824; // one gigabyte
-
 #ifndef __MARS__
 }; //namespace std
 #endif
+
+#endif