new class PIThreadPoolLoop

libs/main/io_devices/pifile.h

@@ -85,6 +85,7 @@ public:
 	};
 	
 	//! Constructs a file with path "path" and open mode "mode"
+	//! If "path" is not empty then open file
 	explicit PIFile(const PIString & path, DeviceMode mode = ReadWrite);
 	
 

libs/main/thread/pithreadmodule.h

@@ -26,7 +26,8 @@
 #include "pitimer.h"
 #include "pipipelinethread.h"
 #include "pigrabberbase.h"
-#include "pithreadpoolexecutor.h"
 #include "piconditionvar.h"
+#include "pithreadpoolexecutor.h"
+#include "pithreadpoolloop.h"
 
 #endif // PITHREADMODULE_H

libs/main/thread/pithreadpoolloop.cpp

@@ -0,0 +1,130 @@
+/*
+	PIP - Platform Independent Primitives
+	Thread pool loop
+	Ivan Pelipenko peri4ko@yandex.ru
+
+	This program is free software: you can redistribute it and/or modify
+	it under the terms of the GNU Lesser General Public License as published by
+	the Free Software Foundation, either version 3 of the License, or
+	(at your option) any later version.
+
+	This program 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 Lesser General Public License for more details.
+
+	You should have received a copy of the GNU Lesser General Public License
+	along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "pithreadpoolloop.h"
+#include "pisysteminfo.h"
+#include "pithread.h"
+
+
+/*! \class PIThreadPoolLoop
+ * @brief Thread class
+ * \details This class allow you parallelize loop.
+ * 
+ * \section PIThreadPoolLoop_sec0 Usage
+ * This class designed to replace "for(;;)" statement in very simple way.
+ * In constructor several threads created, then by "setFunction()" method
+ * you should pass body of your loop, and then call "start()" or "exec()".
+ * Every thread take loop counter and execute your function until all
+ * counter range is passed.
+ *
+ * Example:
+\code{.cpp}
+PIVector<int> data(10, [](int i)->int{return i;});
+
+piCout << data; // {0, 1, 2, 3, 4, 5, 6, 7, 8, 9}
+
+PIThreadPoolLoop pool;
+pool.exec(0, data.size(), [&](int i){ // parallel analogue "for (int i = 0; i < data.size(); i++)"
+	data[i] = data[i] + 10;
+});
+
+piCout << data; // {10, 11, 12, 13, 14, 15, 16, 17, 18, 19}
+\endcode
+ *
+ * Equivalent to:
+\code{.cpp}
+PIVector<int> data(10, [](int i)->int{return i;});
+
+piCout << data; // {0, 1, 2, 3, 4, 5, 6, 7, 8, 9}
+
+pool.setFunction([&](int i){
+	data[i] = data[i] + 10;
+});
+pool.exec(0, data.size());
+
+piCout << data; // {10, 11, 12, 13, 14, 15, 16, 17, 18, 19}
+\endcode
+ *
+ * \section PIThreadPoolLoop_sec1 Important
+ * Due to multithreading it`s very important to protect output data of loop body, use mutex.
+ * Also remember that execution order is undefined and you shouldn`t use global variables in
+ * your function. Use local variables and lambda capture.
+ * 
+ */
+
+
+PIThreadPoolLoop::PIThreadPoolLoop(int thread_cnt) {
+	if (thread_cnt <= 0)
+		thread_cnt = piMaxi(1, PISystemInfo::instance()->processorsCount);
+	piForTimes (thread_cnt) {
+		auto * t = new PIThread();
+		threads << t;
+	}
+	//piCout << "PIThreadPoolLoop" << proc_cnt << "threads";
+}
+
+
+PIThreadPoolLoop::~PIThreadPoolLoop() {
+	for (auto * t: threads) {
+		t->stop(false);
+		if (!t->waitForFinish(100))
+			t->terminate();
+		delete t;
+	}
+}
+
+
+void PIThreadPoolLoop::setFunction(std::function<void (int)> f) {
+	func = f;
+}
+
+
+void PIThreadPoolLoop::start(int index_start, int index_count) {
+	counter = index_start;
+	int end = index_start + index_count;
+	for (auto * t: threads)
+		t->start([this,end,t](){
+			while (1) {
+				int cc = counter.fetch_add(1);
+				if (cc >= end) {
+					t->stop(false);
+					return;
+				}
+				func(cc);
+			}
+		});
+}
+
+
+void PIThreadPoolLoop::exec(int index_start, int index_count) {
+	start(index_start, index_count);
+	wait();
+}
+
+
+void PIThreadPoolLoop::exec(int index_start, int index_count, std::function<void (int)> f) {
+	setFunction(f);
+	exec(index_start, index_count);
+}
+
+
+void PIThreadPoolLoop::wait() {
+	for (auto * t: threads)
+		t->waitForFinish();
+}

libs/main/thread/pithreadpoolloop.h

@@ -0,0 +1,69 @@
+/*! @file pithreadpoolloop.h
+ * @brief Thread pool loop
+ * 
+ * This file declare thread class and some wait functions
+*/
+/*
+	PIP - Platform Independent Primitives
+	Thread pool loop
+	Ivan Pelipenko peri4ko@yandex.ru
+
+	This program is free software: you can redistribute it and/or modify
+	it under the terms of the GNU Lesser General Public License as published by
+	the Free Software Foundation, either version 3 of the License, or
+	(at your option) any later version.
+
+	This program 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 Lesser General Public License for more details.
+
+	You should have received a copy of the GNU Lesser General Public License
+	along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef PITHREADPOOLLOOP_H
+#define PITHREADPOOLLOOP_H
+
+#include "pivector.h"
+
+class PIThread;
+
+class PIP_EXPORT PIThreadPoolLoop {
+public:
+
+	//! Contructs thread pool with threads count "thread_cnt".
+	//! If "thread_cnt" = -1 then system processors count used
+	PIThreadPoolLoop(int thread_cnt = -1);
+
+	virtual ~PIThreadPoolLoop();
+
+	//! Set threads function to "f" with format [](int){...}
+	void setFunction(std::function<void(int)> f);
+
+	//! Wait for all threads stop
+	void wait();
+
+	//! Start functions execution with integer argument range
+	//! from "index_start" to "index_start + index_count - 1"
+	void start(int index_start, int index_count);
+
+	//! Start functions execution with integer argument range
+	//! from "index_start" to "index_start + index_count - 1"
+	//! and wait for finish
+	void exec(int index_start, int index_count);
+
+	//! Start functions "f" execution with integer argument range
+	//! from "index_start" to "index_start + index_count - 1"
+	//! and wait for finish
+	void exec(int index_start, int index_count, std::function<void(int)> f);
+
+private:
+	PIVector<PIThread * > threads;
+	std::function<void(int)> func;
+	std::atomic_int counter;
+
+};
+
+
+#endif