Executing a member function of a class

Question

I am trying to experiment the C++11 threads in a way that it accepts a member function of a class as a parameter into the thread constructor as shown in the first code snippet below on line 20 that is marked . The class definition is given in the 2nd code snippet. When this code is compiled, I am getting a bunch of errors shown in the 3rd snippet. Can anyone tell me what I am doing wrong? Thanks.

SNIPPET 1: Thread initialization (main_app.cpp)

#include <thread> #include "ServiceRegistrar.hpp" #define SERVER_TYPE 100065 #define SERVER_INST_LOWER 1 #define SERVER_INST_UPPER 2 #define TIMEOUT 500000 int main() { ServiceRegistrar sr1(SERVER_TYPE, TIMEOUT, SERVER_INST_LOWER, SERVER_INST_LOWER); /*LINE 20 is the following*/ std::thread t(&ServiceRegistrar::subscribe2TopologyServer, sr1); t.join(); sr1.publishForSRs(); }

SNIPPET 2: Class definition

class ServiceRegistrar { public: ServiceRegistrar(int serverType, int serverTimeOut, int serverInstanceLower, int serverInstanceUpper) : mServerType(serverType), mServerTimeOut(serverTimeOut), mServerInstanceLower(serverInstanceLower), mServerInstanceUpper(serverInstanceUpper) { } void subscribe2TopologyServer(); void publishForSRs(); void publishForServices(); private: int mServerType; int mServerTimeOut; int mServerInstanceLower; int mServerInstanceUpper; };

SNIPPET 3: Compilation output

 $ g++ -g -c -Wall -std=c++11 main_app.cpp -pthread In file included from /usr/include/c++/4.7/ratio:38:0, from /usr/include/c++/4.7/chrono:38, from /usr/include/c++/4.7/thread:38, from main_app.cpp:8: /usr/include/c++/4.7/type_traits: In instantiation of ‘struct std::_Result_of_impl<false, false, std::_Mem_fn<void (ServiceRegistrar::*)()>, ServiceRegistrar>’: /usr/include/c++/4.7/type_traits:1857:12: required from ‘class std::result_of<std::_Mem_fn<void (ServiceRegistrar::*)()>(ServiceRegistrar)>’ /usr/include/c++/4.7/functional:1563:61: required from ‘struct std::_Bind_simple<std::_Mem_fn<void (ServiceRegistrar::*)()>(ServiceRegistrar)>’ /usr/include/c++/4.7/thread:133:9: required from ‘std::thread::thread(_Callable&&, _Args&& ...) [with _Callable = void (ServiceRegistrar::*)(); _Args = {ServiceRegistrar&}]’ main_app.cpp:20:64: required from here /usr/include/c++/4.7/type_traits:1834:9: error: no match for call to ‘ (std::_Mem_fn<void (ServiceRegistrar::*)()>) (ServiceRegistrar)’

ewwww very unnecessary macros.

Puppy
– Puppy

2013-02-28 19:00:39 +00:00
Commented Feb 28, 2013 at 19:00 — Puppy
– Puppy, Commented Feb 28, 2013 at 19:00

Community · Accepted Answer · 2017-05-23 11:57:40Z

4

Apparently it's a gcc 4.7 bug...use

std::thread t(&ServiceRegistrar::subscribe2TopologyServer, &sr1);

instead.

EDIT: actually, you probably don't want to be copying sr1 to the thread-local-storage of t, so this is better anyway.

edited May 23, 2017 at 11:57

CommunityBot

11 silver badge

answered Feb 28, 2013 at 18:40

Stephen Lin

5,57028 silver badges48 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

Mike Seymour Over a year ago

Bug or not, you almost certainly want to bind to a pointer or reference here anyway.

Stephen Lin Over a year ago

@MikeSeymour yep, just added that

zzk · Accepted Answer · 2013-02-28 18:41:41Z

0

Try:

std::thread t(std::bind(&ServiceRegistrar::subscribe2TopologyServer, sr1));

Hope it helps.

answered Feb 28, 2013 at 18:41

zzk

1,3679 silver badges15 bronze badges

1 Comment

Mike Seymour Over a year ago

That masks the problem, since bind doesn't share the same bug as thread. But binding to a copy of sr1 is almost certainly the wrong thing to do.

Collectives™ on Stack Overflow

Executing a member function of a class

2 Answers 2

2 Comments

1 Comment

Linked

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

2 Comments

1 Comment

Linked

Related