1 files changed, 173 insertions, 0 deletions
diff --git a/src/build.cc b/src/build.cc
new file mode 100644
index 0000000..445979e
--- /dev/null
+++ b/src/build.cc
@@ -0,0 +1,173 @@
+#include "build.h"
+
+#include <future>
+#include <vector>
+#include <iostream>
+#include <chrono>
+#include <set>
+#include <thread>
+
+#include "tasks.h"
+
+using namespace std::chrono_literals;
+
+int build(const Settings& settings,
+          const std::string& name,
+          const std::list<std::shared_ptr<Task>>& tasks,
+          const std::list<std::shared_ptr<Task>>& all_tasks)
+{
+	if(settings.verbose > 1)
+	{
+		std::cout << "Building '" << name << "'\n";
+	}
+
+	std::list<std::shared_ptr<Task>> dirtyTasks;
+	for(auto task : tasks)
+	{
+		if(task->dirty())
+		{
+			dirtyTasks.push_back(task);
+		}
+	}
+
+	if(dirtyTasks.empty())
+	{
+		std::cout << "Nothing to be done for '"<< name << "'\n";
+		return 0;
+	}
+
+	std::list<std::future<int>> processes;
+
+	// Start all tasks
+	bool done{false};
+	while(!done)
+	{
+		bool started_one{false};
+		while(processes.size() < settings.parallel_processes)
+		{
+			if(dirtyTasks.empty())
+			{
+				done = true;
+				break;
+			}
+
+			auto task = getNextTask(all_tasks, dirtyTasks);
+			if(task == nullptr)
+			{
+				if(processes.empty() && !dirtyTasks.empty())
+				{
+					// No running processes, yet no process to run. This is a dead-lock...
+					std::cout << "Dead-lock detected.\n";
+					return 1;
+				}
+				break;
+			}
+
+			processes.emplace_back(
+				std::async(std::launch::async,
+				           [task]()
+				           {
+					           return task->run();
+				           }));
+			started_one = true;
+			std::this_thread::sleep_for(2ms);
+		}
+
+		for(auto process = processes.begin();
+		    process != processes.end();
+		    ++process)
+		{
+			if(process->valid())
+			{
+				if(process->get() != 0)
+				{
+					// TODO: Wait for other processes to finish before returning
+					return 1;
+				}
+				processes.erase(process);
+				break;
+			}
+		}
+
+		if(started_one)
+		{
+			std::this_thread::sleep_for(2ms);
+		}
+		else
+		{
+			std::this_thread::sleep_for(200ms);
+		}
+	}
+
+	for(auto process = processes.begin();
+	    process != processes.end();
+	    ++process)
+	{
+		process->wait();
+		auto ret = process->get();
+		if(ret != 0)
+		{
+			return 1;
+		}
+	}
+
+	return 0;
+}
+
+namespace
+{
+std::set<std::shared_ptr<Task>> getDepTasks(std::shared_ptr<Task> task)
+{
+	std::set<std::shared_ptr<Task>> tasks;
+	tasks.insert(task);
+
+	auto deps = task->getDependsTasks();
+	for(const auto& dep : deps)
+	{
+		auto depSet = getDepTasks(dep);
+		for(const auto& dep : depSet)
+		{
+			tasks.insert(dep);
+		}
+	}
+
+	return tasks;
+}
+}
+
+int build(const Settings& settings,
+          const std::string& name,
+          const std::list<std::shared_ptr<Task>>& all_tasks)
+{
+	bool task_found{false};
+	for(auto task : all_tasks)
+	{
+		if(task->name() == name || task->target() == name)
+		{
+			std::cout << name << "\n";
+			task_found = true;
+
+			auto depSet = getDepTasks(task);
+			std::list<std::shared_ptr<Task>> ts;
+			for(const auto& task : depSet)
+			{
+				ts.push_back(task);
+			}
+			auto ret = build(settings, name, ts, all_tasks);
+			if(ret != 0)
+			{
+				return ret;
+			}
+
+			break;
+		}
+	}
+
+	if(!task_found)
+	{
+		std::cerr << "*** No rule to make target '" << name << "'.  Stop.\n";
+		return 1;
+	}
+
+	return 0;
+}