This is a simple example to learn something about threaded applications using boost::thread's in a C++ environment with a Tk front end. It's simple and not perfect. It is only a little showcase to get an idea how that works and what could be done better.
(Sources: [L1 ])
Sources:
//Tcl_Handling.h #include <tk.h> int Tk_AppInit(Tcl_Interp* interp); int startJob_ObjCmd(ClientData clientData, Tcl_Interp *interp, int objc, Tcl_Obj*CONST objv[]); int jobFinished_ObjCmd(ClientData clientData, Tcl_Interp *interp, int objc, Tcl_Obj*CONST objv[]); int getJobResult_ObjCmd(ClientData clientData, Tcl_Interp *interp, int objc, Tcl_Obj*CONST objv[]); int cancelJob_ObjCmd(ClientData clientData, Tcl_Interp *interp, int objc, Tcl_Obj*CONST objv[]); //Tcl_Handling.cxx #include <cassert> #include "Tcl_Handling.h" #include "Job_Handling.h" int Tk_AppInit(Tcl_Interp* interp) { if (Tcl_Init(interp) == TCL_ERROR) return TCL_ERROR; if (Tk_Init(interp) == TCL_ERROR) return TCL_ERROR; //define new commands here Tcl_CreateObjCommand(interp, "::tkmain::startJob", startJob_ObjCmd, &g_GetJobQueue(), (Tcl_CmdDeleteProc*)NULL); Tcl_CreateObjCommand(interp, "::tkmain::jobFinished", jobFinished_ObjCmd, &g_GetJobQueue(), (Tcl_CmdDeleteProc*)NULL); Tcl_CreateObjCommand(interp, "::tkmain::getJobResult", getJobResult_ObjCmd, &g_GetJobQueue(), (Tcl_CmdDeleteProc*)NULL); Tcl_CreateObjCommand(interp, "::tkmain::cancelJob", cancelJob_ObjCmd, &g_GetJobQueue(), (Tcl_CmdDeleteProc*)NULL); return TCL_OK; } int startJob_ObjCmd(ClientData clientData, Tcl_Interp *interp, int objc, Tcl_Obj*CONST objv[]) { if (objc != 3) { Tcl_WrongNumArgs(interp, 1, objv, "op n"); return TCL_ERROR; } std::string op_type = Tcl_GetStringFromObj(objv[1],NULL); int n; if (Tcl_GetIntFromObj(interp, objv[2], &n) != TCL_OK) return TCL_ERROR; JobQueue* _jobs = reinterpret_cast<JobQueue*>(clientData); if (!_jobs) return TCL_ERROR; jobID id = _jobs->AppendJob(op_type, JobArg(static_cast<double>(n))); Tcl_SetObjResult(interp,Tcl_NewIntObj(id)); return TCL_OK; } int jobFinished_ObjCmd(ClientData clientData, Tcl_Interp *interp, int objc, Tcl_Obj*CONST objv[]) { if (objc != 2) { Tcl_WrongNumArgs(interp, 1, objv, "id"); return TCL_ERROR; } jobID id; if (Tcl_GetIntFromObj(interp, objv[1], &id) != TCL_OK) return TCL_ERROR; JobQueue* _jobs = reinterpret_cast<JobQueue*>(clientData); if (!_jobs) return TCL_ERROR; if (_jobs->JobFinished(id)) Tcl_SetObjResult(interp,Tcl_NewBooleanObj(1)); else Tcl_SetObjResult(interp,Tcl_NewBooleanObj(0)); return TCL_OK; } int getJobResult_ObjCmd(ClientData clientData, Tcl_Interp *interp, int objc, Tcl_Obj*CONST objv[]) { if (objc != 2) { Tcl_WrongNumArgs(interp, 1, objv, "id"); return TCL_ERROR; } jobID id; if (Tcl_GetIntFromObj(interp, objv[1], &id) != TCL_OK) return TCL_ERROR; JobQueue* _jobs = reinterpret_cast<JobQueue*>(clientData); if (!_jobs) return TCL_ERROR; assert(_jobs->JobFinished(id)); const JobArg res = _jobs->GetJobResult(id); switch (res.GetType()) { case JobArg::BOOL: { if (res.GetBool()) Tcl_SetObjResult(interp,Tcl_NewBooleanObj(1)); else Tcl_SetObjResult(interp,Tcl_NewBooleanObj(0)); break; } case JobArg::DOUBLE: { Tcl_SetObjResult(interp,Tcl_NewDoubleObj(res.GetDouble())); break; } case JobArg::STRING: { Tcl_SetObjResult(interp,Tcl_NewStringObj(res.GetString().c_str(), -1)); break; } default: Tcl_SetObjResult(interp,Tcl_NewStringObj("error", -1)); } return TCL_OK; } int cancelJob_ObjCmd(ClientData clientData, Tcl_Interp *interp, int objc, Tcl_Obj*CONST objv[]) { if (objc != 2) { Tcl_WrongNumArgs(interp, 1, objv, "id"); return TCL_ERROR; } jobID id; if (Tcl_GetIntFromObj(interp, objv[1], &id) != TCL_OK) return TCL_ERROR; JobQueue* _jobs = reinterpret_cast<JobQueue*>(clientData); if (!_jobs) return TCL_ERROR; _jobs->Cancel(id); return TCL_OK; } //Job_Handling.h #include <boost/noncopyable.hpp> #include <boost/thread/thread.hpp> #include <boost/thread/mutex.hpp> #include <cstdlib> #include <list> #include <string> #include <map> typedef int jobID; static jobID g_count = 0; jobID g_Count(); //quick and dirty class JobArg { public: enum type {DOUBLE, STRING, BOOL, NAN}; JobArg():_t(NAN) {} JobArg(std::string s):_s(s),_t(STRING) {} JobArg(double d):_d(d),_t(DOUBLE) {} JobArg(bool b):_b(b),_t(BOOL) {} inline type GetType() const {return _t;} inline std::string GetString() const {return _s;} inline double GetDouble() const {return _d;} inline bool GetBool() const {return _b;} private: type _t; double _d; std::string _s; bool _b; }; class JobItem { public: JobItem(JobArg arg):a(arg),id(g_Count()){ } void operator()(); virtual ~JobItem() {}; jobID GetJobID() const {return id;} protected: const JobArg& GetArg() const {return a;} virtual void run() = 0; JobArg a; jobID id; }; class approx_pi : public JobItem { public: approx_pi(JobArg arg):JobItem(arg){ } protected: void run(); }; class approx_exp : public JobItem { public: approx_exp(JobArg arg):JobItem(arg){ } protected: void run(); }; class JobQueue : private boost::noncopyable { public: JobQueue(){} enum JobType {APPOXPI}; jobID AppendJob(const std::string& type, JobArg data); void RunNextJob(); int Size(); void AppendResult(jobID id, JobArg res); bool JobFinished(jobID id) const; const JobArg GetJobResult(jobID id) const; void Cancel(jobID id); private: std::list<JobItem*> _jobs; std::map<jobID, JobArg> _results; boost::mutex monitor; boost::thread exe_thread; //dangerous }; void WorkHorse(); JobQueue& g_GetJobQueue(); //Job_Handling.cxx #include <tk.h> #include <boost/thread/xtime.hpp> #include <boost/math/special_functions/gamma.hpp> #include <iostream> #include <cassert> #include "Job_Handling.h" void JobItem::operator()() { try { run(); } catch(boost::thread_interrupted&) { g_GetJobQueue().AppendResult(GetJobID(),JobArg()); } } void approx_pi::run() { assert(GetArg().GetType() == JobArg::DOUBLE); int n = static_cast<int>(GetArg().GetDouble()); int c_count = 0; double Xd,Yd; for (int i = 0; i < n; ++i) { Xd = static_cast<double>(rand()); Yd = static_cast<double>(rand()); Xd/=static_cast<double>(RAND_MAX); Yd/=static_cast<double>(RAND_MAX); if ( sqrt(Xd*Xd + Yd*Yd) < 1.0 ) ++c_count; boost::this_thread::interruption_point(); } double res = 4.0 * static_cast<double>(c_count) / static_cast<double>(n); g_GetJobQueue().AppendResult(GetJobID(),res); } void approx_exp::run() { assert(GetArg().GetType() == JobArg::DOUBLE); double n = GetArg().GetDouble(); double e = 1.0; double plus = 0.0; for (double i = 1.0; i < n; ++i) { plus = 1.0/boost::math::tgamma(i); if (plus < 10e-15) break; e+=plus; boost::this_thread::interruption_point(); } g_GetJobQueue().AppendResult(GetJobID(),e); } jobID JobQueue::AppendJob(const std::string& type, JobArg data) { boost::mutex::scoped_lock lock(monitor); jobID id = -1; std::cout << "append a job" << std::endl; JobItem* job = 0; if (type == "pi") job = new approx_pi(data); else if (type == "exp") job = new approx_exp(data); if (job) { _jobs.push_back(job); id = job->GetJobID(); } assert(id != -1); return id; } void JobQueue::RunNextJob() { monitor.lock(); std::cout << "start a job" << std::endl; std::list<JobItem*>::iterator iter = _jobs.begin(); //temporary todo: inheritance behavior is difficult with boost?! approx_pi* j = dynamic_cast<approx_pi*>(*iter); if (j) { _jobs.pop_front(); monitor.unlock(); exe_thread = boost::thread(*j); exe_thread.join(); delete j; } else { approx_exp* j = dynamic_cast<approx_exp*>(*iter); _jobs.pop_front(); monitor.unlock(); exe_thread = boost::thread(*j); exe_thread.join(); delete j; } std::cout << "job finished" << std::endl; } int JobQueue::Size() { boost::mutex::scoped_lock lock(monitor); return static_cast<int>(_jobs.size()); } void JobQueue::AppendResult(jobID id, JobArg res) { boost::mutex::scoped_lock lock(monitor); _results.insert(std::make_pair<jobID, JobArg>(id, res)); } bool JobQueue::JobFinished(jobID id) const { std::map<jobID, JobArg>::const_iterator iter = _results.find(id); return (iter != _results.end()); } const JobArg JobQueue::GetJobResult(jobID id) const { std::map<jobID, JobArg>::const_iterator iter = _results.find(id); if (iter != _results.end()) return iter->second; return JobArg(); } void JobQueue::Cancel(jobID id) { std::list<JobItem*>::iterator iter; for (iter = _jobs.begin(); iter != _jobs.end(); ++iter) { if ((*iter)->GetJobID() == id) { monitor.lock(); delete *iter; _jobs.erase(iter); monitor.unlock(); g_GetJobQueue().AppendResult(id,JobArg()); return; } } //current exe thread exe_thread.interrupt(); } JobQueue jobs; void WorkHorse() { while(1) { if(g_GetJobQueue().Size()) { g_GetJobQueue().RunNextJob(); } else { boost::xtime xt; boost::xtime_get(&xt, boost::TIME_UTC); xt.sec += 1; boost::thread::sleep(xt); std::cout << "wait for work " << std::endl; } } } JobQueue& g_GetJobQueue() { return jobs; } jobID g_Count() { return ++g_count; } //Tk_Main_Threaded.cpp // Tk_Main_Threaded.cpp : Defines the entry point for the console application. // #include <tk.h> #include <boost/thread/thread.hpp> #include "Job_Handling.h" #include "Tcl_Handling.h" class TclThread { public: TclThread(int aargc, char** aargv):argc(aargc),argv(aargv) { } void operator()() { init(); } private: void init() { Tk_Main(argc, argv, Tk_AppInit); } private: int argc; char** argv; }; int main(int argc, char* argv[]) { boost::thread_group threads; TclThread tcl(argc, argv); threads.create_thread(tcl); threads.create_thread(WorkHorse); threads.join_all(); return 0; } //main.tcl lappend auto_path . namespace eval ::tkmain { variable ns [namespace current] } proc ::tkmain::BuildGui {} { variable ns variable title "thread test : " set fStart [frame .fStart] set startJob [button $fStart.startJob -text "Start" -command ${ns}::start] variable op "pi" set radio [frame $fStart.radio] foreach item {pi exp dummy} { set radio${item} [radiobutton $radio.radio${item} \ -text $item \ -value $item \ -variable ${ns}::op] if {$item == "dummy"} { [set radio${item}] config -state disabled } pack [set radio${item}] -anchor w } variable textVar "100000000" set textField [entry $fStart.textField -textvariable ${ns}::textVar] variable opFrame [labelframe .opFrame -text "Jobs"] pack $startJob $radio $textField -side left -padx 5 -pady 5 pack $fStart -fill x -expand false -anchor n -padx 10 -pady 10 pack $opFrame -fill both -expand true -padx 10 -pady 10 wm geometry . 400x500 variable pending_jobs [list] UpdateGUI } proc ::tkmain::AddJobControl {id op arg} { variable ns variable opFrame set tFrame [frame $opFrame.tFrame${id}] set b [button $tFrame.b -text "Cancel" -command "${ns}::cancelJob $id"] set l [label $tFrame.l -text "$op\($arg\) = "] pack $b $l -side left pack $tFrame -fill x variable pending_jobs lappend pending_jobs $id } proc ::tkmain::AddResult {id res} { variable opFrame set f $opFrame.tFrame${id} $f.b config -state disabled $f.l config -text "[$f.l cget -text] $res" variable pending_jobs set i [lsearch $pending_jobs $id] if {$i != -1} { set pending_jobs [lreplace $pending_jobs $i $i] } } proc ::tkmain::start {} { variable textVar variable op set id [startJob $op $textVar] if {$id != -1} { AddJobControl $id $op $textVar } } proc ::tkmain::UpdateGUI {} { variable title wm title . "$title [clock format [clock seconds] -format %H:%M:%S]" UpdateJobs variable ns after 100 ${ns}::UpdateGUI } proc ::tkmain::UpdateJobs {} { variable pending_jobs foreach job $pending_jobs { if {[jobFinished $job]} { AddResult $job [getJobResult $job] } } } ::tkmain::BuildGui