wrapper: add release_GIL_and_enable_signal option.

- Add to the wrapper generator (add_method) the release_GIL_and_enable_signal option which :

   - release the GIL
   - save the python signal handler
   - enable the C++ triqs signal handler instead.
   - undo all of this after the code runs, or in a case of exception.
   - used python include, ceval.h, line 72 comments and below.

- reworked the triqs::signal_handler.
  simple C like function, no object (no need).
  start, stop, received, cf header file.

- clean the call_back.cpp : only place using the signal directly
  (qmc uses the callback).
  in particular, remove the old BOOST CHRONO, since
  the std::chrono works fine on platforms we use now.

pytriqs/wrap_generator/wrap_generator.py

@@ -42,8 +42,16 @@ class cfunction :
               auto result = self_c.method_name(a,b,c).
               INCOMPATIBLE with c_name.
               If c_name is given, the default calling_pattern is made.
+        - release_GIL_and_enable_signal [expert only] :
+          For long functions in pure C++.
+          If true the GIL is released in the call of the C++ function and restored after the call.
+          It also saves the signal handler of python and restore it after the call,
+          and enable the C++ triqs signal_handler.
+          This allows e.g. to intercept Ctrl-C during the long C++ function.
+          The requirement is that the function wrapped must be pure C++, i.e.
+          no call whatsoever to the python C API, directly or indirectly.
     """
-    def __init__(self, doc = '', is_method = False, no_self_c = False, is_static = False, **kw) :
+    def __init__(self, doc = '', is_method = False, no_self_c = False, is_static = False, release_GIL_and_enable_signal = False, **kw) :
       """ Use keywords to build, from the data. Cf doc of class"""
       self.c_name = kw.pop("c_name", None)
       self._calling_pattern = kw.pop("calling_pattern", None)
@@ -54,6 +62,7 @@ class cfunction :
       self.doc = doc
       self.is_method = is_method
       self.is_static = is_static
+      self.release_GIL_and_enable_signal = release_GIL_and_enable_signal
       self.args = []
       if 'signature' in kw :
         assert 'rtype' not in kw and 'args' not in kw, "signature and rtype/args are not compatible"
@@ -511,7 +520,6 @@ class module_ :
                the wrapped_type list
         """
         f = None
-        print "argv", sys.argv
         for path in module_path_list : 
           hppfile = path + '/' +  modulename + '.hpp'
           if os.path.exists(hppfile) : 

pytriqs/wrap_generator/wrapper.mako.cpp

@@ -16,6 +16,7 @@ using ${ns};
 %endfor
 
 #include <triqs/python_tools/wrapper_tools.hpp>
+#include <triqs/utility/signal_handler.hpp>
 using namespace triqs::py_tools;
 
 //--------------------- a dict of python function used in the module but not exposed to user (cf init function) ----------------
@@ -547,7 +548,26 @@ template<typename T>
        using self_class = ${self_c_type};
       %endif
       try {
+        %if overload.release_GIL_and_enable_signal :
+         PyOS_sighandler_t sig = PyOS_getsig(SIGINT);
+         triqs::signal_handler::start(); // start the C++ signal handler
+         Py_BEGIN_ALLOW_THREADS;
+	 try {
+        %endif
         ${overload.calling_pattern()}; // the call is here. It sets up "result" : sets up in the python layer.
+        %if overload.release_GIL_and_enable_signal :
+	 }
+	 catch(...) {
+	   // an error has occurred : clean GIL, handler and rethrow
+           Py_BLOCK_THREADS; // cf python include, ceval.h, line 72 comments and below.
+           triqs::signal_handler::stop(); // stop the C++ signal handler
+           PyOS_setsig(SIGINT, sig);
+           throw; //
+	 }
+         Py_END_ALLOW_THREADS;
+         triqs::signal_handler::stop();
+         PyOS_setsig(SIGINT, sig);
+        %endif
         %if not overload.is_constructor :
  	 %if overload.rtype != "void" :
          py_result = convert_to_python(std::move(result));

pytriqs/wrap_test/a.hpp

@@ -4,7 +4,7 @@
 #include <ostream>
 #include <triqs/arrays.hpp>
 //#include <triqs/h5.hpp>
-
+#include <triqs/utility/signal_handler.hpp>
 namespace triqs { namespace py_tools { 
  class reductor;
  class reconstructor;
@@ -44,21 +44,13 @@ struct A {
 
   void long_fnt() {
 
-   PyOS_sighandler_t sig = PyOS_getsig(SIGINT);
-   Py_BEGIN_ALLOW_THREADS;
    for (int u = 0; u < 101; u +=10) {
     sleep(1);
-    if (!triqs::signal_handler().empty()) goto _end;
+    if (triqs::signal_handler::received(true)) TRIQS_KEYBOARD_INTERRUPT;
     count = u;
     std::cout << " inner count " << count << std::endl;
    }
    std::cout << " completed" << std::endl;
-  _end:
-
-   Py_END_ALLOW_THREADS;
-   PyOS_setsig(SIGINT, sig);
-
-   // PyErr_SetString(PyExc_KeyboardInterrupt, " ended long_fnt");
   }
 
   double m1(int u) const {

pytriqs/wrap_test/g.hpp

@@ -44,3 +44,7 @@ void pass_sgf(gf_view<imfreq,scalar_valued> g) {
   h5_write(file, "g", g);
  }
 }
+
+
+
+

pytriqs/wrap_test/my_module_desc.py

@@ -39,6 +39,9 @@ g.add_method(py_name = "sm", c_name = "sm", signature = "int (int u)", is_static
 # older syntax, giving rtype and args (better for automatic scripts).
 g.add_method(py_name = "m1f", c_name = "m1", rtype = "double", doc = "DOC of mm", args = [("int","u"), ("double","y",3)])
 
+g.add_method(py_name = "long_fnt", c_name = "long_fnt", signature = "void()", release_GIL_and_enable_signal = True)
+g.add_member(c_name = "count", c_type = "int",read_only=True)
+
 # add the call operator 
 g.add_call(signature = "int(int u)", doc = "call op")
 

triqs/python_tools/wrapper_tools.hpp

@@ -11,6 +11,9 @@
 
 // I can use the trace in triqs::exception
 #define CATCH_AND_RETURN(MESS,RET)\
+ catch(triqs::keyboard_interrupt const & e) {\
+ PyErr_SetString(PyExc_KeyboardInterrupt, e.what());\
+ return RET; }\
  catch(triqs::exception const & e) {\
  auto err = std::string("Error " MESS "\nC++ error was : \n") + e.what();\
  PyErr_SetString(PyExc_RuntimeError, err.c_str());\

triqs/utility/callbacks.cpp

@@ -18,50 +18,21 @@
  * TRIQS. If not, see <http://www.gnu.org/licenses/>.
  *
  ******************************************************************************/
-
 #include "callbacks.hpp"
 #include "signal_handler.hpp"
-
-// switch to std. Remove old boost code when ok on several compilers
-#ifndef TRIQS_USE_BOOST_CHRONO
 #include <chrono>
 
 namespace triqs {
 namespace utility {
 
  std::function<bool()> clock_callback(int time_in_seconds) {
+  signal_handler::start();
   if (time_in_seconds <= 0)
-   return []() { return (!triqs::signal_handler().empty()); };
-
-  // auto end_time = boost::posix_time::second_clock::local_time() + boost::posix_time::seconds(time_in_seconds);
-  // return [end_time]() { return (!triqs::signal_handler().empty()) || boost::posix_time::second_clock::local_time() > end_time
+   return []() { return (!triqs::signal_handler::received()); };
 
   auto end_time = std::chrono::system_clock::now() + std::chrono::seconds(time_in_seconds);
-  return [end_time]() { return (!triqs::signal_handler().empty()) || (std::chrono::system_clock::now() > end_time); };
+  return [end_time]() { return (!triqs::signal_handler::received()) || (std::chrono::system_clock::now() > end_time); };
  }
 }
 }
 
-#else
-
-#include <boost/date_time/posix_time/posix_time.hpp>
-#include <boost/bind.hpp>
-
-namespace triqs {
-namespace utility {
-
- bool clock_callback_impl(boost::posix_time::ptime const& end_time) {
-  return (!triqs::signal_handler().empty()) || boost::posix_time::second_clock::local_time() > end_time;
- }
-
- bool false_callback_impl() { return (!triqs::signal_handler().empty()); }
-
- std::function<bool()> clock_callback(int time_in_seconds) {
-  return (time_in_seconds > 0 ? boost::bind(&clock_callback_impl, boost::posix_time::second_clock::local_time() +
-                                                                      boost::posix_time::seconds(time_in_seconds))
-                              : std::function<bool()>(&false_callback_impl));
- }
-}
-}
-#endif
-

triqs/utility/exceptions.hpp

@@ -47,10 +47,17 @@ namespace triqs {
   template<typename T> runtime_error & operator  <<( T && x) { exception::operator<<(x); return *this; }
  };
 
+ class keyboard_interrupt : public exception {
+  public:
+  keyboard_interrupt() throw() : exception() {}
+  virtual ~keyboard_interrupt() throw() {}
+  template<typename T> keyboard_interrupt & operator  <<( T && x) { exception::operator<<(x); return *this; }
+ };
 }
 
 #define TRIQS_ERROR(CLASS,NAME) throw CLASS()<<" Triqs "<<NAME<<" at "<<__FILE__<< " : "<<__LINE__<<"\n\n"
 #define TRIQS_RUNTIME_ERROR TRIQS_ERROR(triqs::runtime_error,"runtime error")
+#define TRIQS_KEYBOARD_INTERRUPT TRIQS_ERROR(triqs::keyboard_interrupt,"Ctrl-C")
 
 #endif
 

triqs/utility/signal_handler.cpp

@@ -1,9 +1,8 @@
-
 /*******************************************************************************
  *
  * TRIQS: a Toolbox for Research in Interacting Quantum Systems
  *
- * Copyright (C) 2011 by M. Ferrero, O. Parcollet
+ * Copyright (C) 2014 by O. Parcollet
  *
  * TRIQS is free software: you can redistribute it and/or modify it under the
  * terms of the GNU General Public License as published by the Free Software
@@ -19,38 +18,30 @@
  * TRIQS. If not, see <http://www.gnu.org/licenses/>.
  *
  ******************************************************************************/
-
 #include "signal_handler.hpp"
-//#include <time.h>
 #include <signal.h>
 #include <string.h>
-//#include <stdlib.h>
-//#include <unistd.h>
-// volatile sig_atomic_t signal_handler::keep_going;
-
-
+#include <vector>
+#include <iostream>
 namespace triqs {
+namespace signal_handler {
 
- /*
-    namespace signal_details { 
- // The signal handler just clears the flag and re-enables itself. 
- // to replace with settimer if needed 
- void catch_alarm (int sig)
- {
- MySignalHandler::keep_going = 0;
- signal (sig, Catch_alarm);
+ namespace {
+
+  std::vector<int> signals_list;
+  bool initialized = false;
+
+  void slot(int signal) {
+   std::cerr << "TRIQS : Received signal " << signal << std::endl;
+   signals_list.push_back(signal);
   }
  }
- */
- std::vector<int> signal_handler::signals_list;
 
- signal_handler::signal_handler() {
-  static bool initialized;
+ void start() {
   if (initialized) return;
-  //keep_going = 1; /* Establish a handler for SIGALRM signals. */  
   static struct sigaction action;
   memset(&action, 0, sizeof(action));
-  action.sa_handler = &signal_handler::slot;
+  action.sa_handler = slot;
   sigaction(SIGINT, &action, NULL);
   sigaction(SIGTERM, &action, NULL);
   sigaction(SIGXCPU, &action, NULL);
@@ -58,15 +49,23 @@ namespace triqs {
   sigaction(SIGUSR1, &action, NULL);
   sigaction(SIGUSR2, &action, NULL);
   sigaction(SIGSTOP, &action, NULL);
-  //signal (SIGALRM, _MYSIGNAL::Catch_alarm);
-  //alarm (0);  
   initialized = true;
  }
 
- void signal_handler::slot(int signal) {
-  std::cerr << "Received signal " << signal << std::endl;
-  signals_list.push_back(signal);
+ void stop() {
+  signals_list.clear();
+  initialized = false;
  }
 
+ bool received(bool pop_) {
+  if (!initialized) start();
+  bool r = signals_list.size() != 0;
+  if (r && pop_) pop();
+  return r;
+ }
+
+ int last() { return signals_list.back(); }
+ void pop() { return signals_list.pop_back(); }
+}
 }
 

triqs/utility/signal_handler.hpp

@@ -3,7 +3,7 @@
  *
  * TRIQS: a Toolbox for Research in Interacting Quantum Systems
  *
- * Copyright (C) 2011 by M. Ferrero, O. Parcollet
+ * Copyright (C) 2014 by O. Parcollet
  *
  * TRIQS is free software: you can redistribute it and/or modify it under the
  * terms of the GNU General Public License as published by the Free Software
@@ -19,25 +19,23 @@
  * TRIQS. If not, see <http://www.gnu.org/licenses/>.
  *
  ******************************************************************************/
-
-#ifndef TRIQS_SIGNAL_HANDLER_H
-#define TRIQS_SIGNAL_HANDLER_H
-#include <iostream>
-#include <assert.h>
-#include <vector>
-
+#pragma once
 namespace triqs {
+namespace signal_handler {
 
- class signal_handler {
-  static std::vector<int> signals_list;
-  //static volatile sig_atomic_t keep_going;
-  public:
-  signal_handler();
-  bool empty(){ return (signals_list.size() ==0); }
-  int top(){ return signals_list.back(); }
-  void pop(){ return signals_list.pop_back(); }
-  static void slot(int signal);
- };
+ /// Start the signal handler
+ void start();
+
+ /// Stop it. ?
+ void stop();
+ 
+ /// A signal has been received. If pop, and there is a signal, pop it.
+ bool received(bool pop = false);
+
+ /// Last received.
+ int last();
+
+ /// pop the last signal
+ void pop();
+}
 }
-
-#endif