Add MiniZinc black-box propagator support

CMakeLists.txt

@@ -736,6 +736,38 @@ if(HAVE_FORCE_INLINE)
   set(forceinline "__forceinline")
 endif()
 
+include(CheckCXXSourceCompiles)
+check_cxx_source_compiles("#include <spawn.h>
+#ifndef POSIX_SPAWN_CLOEXEC_DEFAULT
+#error POSIX_SPAWN_CLOEXEC_DEFAULT is unavailable
+#endif
+int main() {
+  posix_spawn_file_actions_t actions;
+  return posix_spawn_file_actions_addinherit_np(&actions, 2);
+}" HAVE_POSIX_SPAWN_CLOEXEC_DEFAULT_AND_ADDINHERIT_NP)
+if(HAVE_POSIX_SPAWN_CLOEXEC_DEFAULT_AND_ADDINHERIT_NP)
+  set(GECODE_HAS_POSIX_SPAWN_CLOEXEC_DEFAULT 1)
+  set(GECODE_HAS_POSIX_SPAWN_ADDINHERIT_NP 1)
+endif()
+
+check_cxx_source_compiles("#ifndef _GNU_SOURCE
+#define _GNU_SOURCE 1
+#endif
+#include <spawn.h>
+int main() {
+  posix_spawn_file_actions_t actions;
+  return posix_spawn_file_actions_addclosefrom_np(&actions, 3);
+}" HAVE_POSIX_SPAWN_ADDCLOSEFROM_NP)
+if(HAVE_POSIX_SPAWN_ADDCLOSEFROM_NP)
+  set(GECODE_HAS_POSIX_SPAWN_ADDCLOSEFROM_NP 1)
+endif()
+
+if((GECODE_HAS_POSIX_SPAWN_CLOEXEC_DEFAULT AND
+    GECODE_HAS_POSIX_SPAWN_ADDINHERIT_NP) OR
+   GECODE_HAS_POSIX_SPAWN_ADDCLOSEFROM_NP)
+  set(GECODE_HAS_POSIX_BLACKBOX_EXEC 1)
+endif()
+
 check_c_source_compiles("int main() { return __builtin_ffsll(0); }" HAVE_BUILTIN_FFSLL)
 if(HAVE_BUILTIN_FFSLL)
   set(GECODE_HAS_BUILTIN_FFSLL "/**/")
@@ -1285,6 +1317,13 @@ if(GECODE_ENABLE_FLATZINC)
       endif()
     endforeach()
   endif()
+  if(CMAKE_DL_LIBS)
+    foreach(kind shared static)
+      if(TARGET gecodeflatzinc_${kind})
+        target_link_libraries(gecodeflatzinc_${kind} PUBLIC ${CMAKE_DL_LIBS})
+      endif()
+    endforeach()
+  endif()
 endif()
 
 # Compatibility aggregate target for downstream projects expecting Gecode::gecode.
@@ -1332,6 +1371,16 @@ if(BUILD_TESTING)
     set(GECODE_CAN_BUILD_TESTS FALSE)
   endif()
 
+  if(GECODE_ENABLE_FLATZINC)
+    add_executable(gecode-test-blackbox-exec
+      ${GECODE_TEST_BLACKBOX_EXEC_SOURCE})
+    target_compile_features(gecode-test-blackbox-exec PRIVATE cxx_std_17)
+
+    add_library(gecode-test-blackbox-dll SHARED
+      ${GECODE_TEST_BLACKBOX_DLL_SOURCE})
+    target_compile_features(gecode-test-blackbox-dll PRIVATE cxx_std_17)
+  endif()
+
   set(GECODE_TEST_SOURCES_SELECTED ${GECODE_TEST_SOURCES})
   if(NOT GECODE_ENABLE_SET_VARS)
     list(FILTER GECODE_TEST_SOURCES_SELECTED EXCLUDE REGEX "^test/set(/|\\.cpp)")
@@ -1355,6 +1404,18 @@ if(BUILD_TESTING)
         ${GECODE_FAULT_TEST_SOURCES})
       target_link_libraries(gecode-fault-test PRIVATE ${GECODE_TEST_LINK_LIBS})
     endif()
+    if(GECODE_ENABLE_FLATZINC)
+      add_dependencies(gecode-test
+        gecode-test-blackbox-exec
+        gecode-test-blackbox-dll)
+      set(GECODE_TEST_BLACKBOX_LOG
+        "${CMAKE_CURRENT_BINARY_DIR}/gecode-test-blackbox")
+      set_property(DIRECTORY APPEND PROPERTY ADDITIONAL_CLEAN_FILES
+        "${GECODE_TEST_BLACKBOX_LOG}.exec_parallel"
+        "${GECODE_TEST_BLACKBOX_LOG}.exec_descendant"
+        "${GECODE_TEST_BLACKBOX_LOG}.dll_model"
+        "${GECODE_TEST_BLACKBOX_LOG}.dll_parallel")
+    endif()
 
     set(GECODE_CHECK_TESTS
       Branch::Int::Dense::3
@@ -1370,7 +1431,9 @@ if(BUILD_TESTING)
       NoGoods::Queens
       Search::DFS::Sol::Binary::Nary::Binary::1::1::1)
     if(GECODE_ENABLE_FLATZINC)
-      list(INSERT GECODE_CHECK_TESTS 1 FlatZinc::magic_square)
+      list(INSERT GECODE_CHECK_TESTS 1
+        FlatZinc::magic_square
+        FlatZinc::blackbox)
     endif()
     if(GECODE_ENABLE_SET_VARS)
       list(APPEND GECODE_CHECK_TESTS
@@ -1427,6 +1490,14 @@ if(BUILD_TESTING)
     add_test(NAME test COMMAND gecode-test ${GECODE_CHECK_ARGS})
     set_tests_properties(test PROPERTIES
       FIXTURES_REQUIRED gecode-test-built)
+    if(GECODE_ENABLE_FLATZINC)
+      set(GECODE_TEST_BLACKBOX_ENV
+        "GECODE_TEST_BLACKBOX_EXEC=$<TARGET_FILE:gecode-test-blackbox-exec>"
+        "GECODE_TEST_BLACKBOX_DLL=$<TARGET_FILE:gecode-test-blackbox-dll>"
+        "GECODE_TEST_BLACKBOX_LOG=${GECODE_TEST_BLACKBOX_LOG}")
+      set_tests_properties(test PROPERTIES
+        ENVIRONMENT "${GECODE_TEST_BLACKBOX_ENV}")
+    endif()
     set(GECODE_CHECK_DEPENDS gecode-test)
     if(GECODE_ENABLE_FLOAT_VARS)
       add_custom_target(verify-gecode-check-tests
@@ -1438,10 +1509,24 @@ if(BUILD_TESTING)
         VERBATIM)
       list(APPEND GECODE_CHECK_DEPENDS verify-gecode-check-tests)
     endif()
-    add_custom_target(check
-      COMMAND $<TARGET_FILE:gecode-test> ${GECODE_CHECK_ARGS}
-      DEPENDS ${GECODE_CHECK_DEPENDS}
-      USES_TERMINAL)
+    if(GECODE_ENABLE_FLATZINC)
+      list(APPEND GECODE_CHECK_DEPENDS
+        gecode-test-blackbox-exec
+        gecode-test-blackbox-dll)
+      add_custom_target(check
+        COMMAND ${CMAKE_COMMAND} -E env
+                GECODE_TEST_BLACKBOX_EXEC=$<TARGET_FILE:gecode-test-blackbox-exec>
+                GECODE_TEST_BLACKBOX_DLL=$<TARGET_FILE:gecode-test-blackbox-dll>
+                GECODE_TEST_BLACKBOX_LOG=${GECODE_TEST_BLACKBOX_LOG}
+                $<TARGET_FILE:gecode-test> ${GECODE_CHECK_ARGS}
+        DEPENDS ${GECODE_CHECK_DEPENDS}
+        USES_TERMINAL)
+    else()
+      add_custom_target(check
+        COMMAND $<TARGET_FILE:gecode-test> ${GECODE_CHECK_ARGS}
+        DEPENDS ${GECODE_CHECK_DEPENDS}
+        USES_TERMINAL)
+    endif()
     if(GECODE_ENABLE_FAULT_INJECTION)
       set(GECODE_FAULT_CHECK_ARGS -iter 1 -threads 1 -test "^Fault::")
       add_test(NAME fault COMMAND gecode-fault-test ${GECODE_FAULT_CHECK_ARGS})
@@ -1544,6 +1629,9 @@ if(GECODE_INSTALL)
       PATTERN "**.hpp"
       PATTERN "LICENSE_1_0.txt"
       PATTERN "mznlib" EXCLUDE
+      PATTERN "flatzinc/blackbox.hh" EXCLUDE
+      PATTERN "flatzinc/blackbox-backend.hh" EXCLUDE
+      PATTERN "flatzinc/blackbox-process.hh" EXCLUDE
       PATTERN "exampleplugin" EXCLUDE
       PATTERN "standalone-example" EXCLUDE
       PATTERN "abi*" EXCLUDE)

Makefile.in

@@ -77,6 +77,7 @@ export QT_CPPFLAGS = @QTDEFINES@ @QTINCLUDES@
 export LINKQT = @QTLIBS@
 export LINKCPPROFILER = @LINKCPPROFILER@
 export LINKATOMIC = @LINKATOMIC@
+export LINKDL = @GECODE_DL_LIBS@
 export MPFR_CPPFLAGS = @GMP_CPPFLAGS@ @MPFR_CPPFLAGS@
 ifeq "@enable_mpfr@" "yes"
 export LINKMPFR = @MPFR_LIB_PATH@ @GMP_LIB_PATH@ @MPFR_LINK@ @GMP_LINK@
@@ -820,15 +821,20 @@ endif
 # FLATZINC
 #
 
-FLATZINCSRC0 = flatzinc.cpp registry.cpp branch.cpp
+FLATZINCSRC0 = flatzinc.cpp registry.cpp branch.cpp blackbox-backend.cpp \
+  blackbox-process-none.cpp blackbox-process-posix.cpp \
+  blackbox-process-windows.cpp blackbox-propagator.cpp
 FLATZINC_GENSRC0 = parser.tab.cpp lexer.yy.cpp
 FLATZINCHDR0 = ast.hh conexpr.hh option.hh parser.hh \
 	plugin.hh registry.hh symboltable.hh varspec.hh \
 	branch.hh branch.hpp lastval.hh complete.hh
+FLATZINCPRIVATEHDR0 = blackbox.hh blackbox-backend.hh blackbox-process.hh
 
 FLATZINCSRC = $(FLATZINCSRC0:%=gecode/flatzinc/%)
 FLATZINC_GENSRC = $(FLATZINC_GENSRC0:%=gecode/flatzinc/%)
 FLATZINCHDR = $(FLATZINCHDR0:%=gecode/flatzinc/%) gecode/flatzinc.hh
+FLATZINCPRIVATEHDR = $(FLATZINCPRIVATEHDR0:%=gecode/flatzinc/%)
+FLATZINCALLHDR = $(FLATZINCHDR) $(FLATZINCPRIVATEHDR)
 
 FLATZINCOBJ = \
 	$(FLATZINCSRC:%.cpp=%$(OBJSUFFIX)) \
@@ -1168,6 +1174,7 @@ FLATZINCTESTSRC0 = \
   test/flatzinc/battleships5.cpp \
   test/flatzinc/battleships7.cpp \
   test/flatzinc/battleships9.cpp \
+  test/flatzinc/blackbox.cpp \
   test/flatzinc/blocksworld_instance_1.cpp \
   test/flatzinc/blocksworld_instance_2.cpp \
   test/flatzinc/cumulatives.cpp \
@@ -1249,14 +1256,18 @@ SEARCHTESTSRC0 = \
 ARRAYTESTSRC0 = \
 	test/array.cpp
 
+BLACKBOXEXECSRC = test/flatzinc/blackbox-exec.cpp
+BLACKBOXDLLSRC = test/flatzinc/blackbox-dll.cpp
+BLACKBOXSRC = $(BLACKBOXEXECSRC) $(BLACKBOXDLLSRC)
+
 TESTSRC0 = test/test.cpp test/afc.cpp test/ldsb.cpp test/region.cpp \
 	test/groups.cpp
 # FailPoint is CMake-only; keep the Autoconf test executable fault-free.
 
 TESTSRC = \
 	$(TESTSRC0) $(INTTESTSRC0) $(SETTESTSRC0) $(FLOATTESTSRC0) \
 	$(BRANCHTESTSRC0) $(SEARCHTESTSRC0) \
-	$(ARRAYTESTSRC0) $(FLATZINCTESTSRC0)
+	$(ARRAYTESTSRC0) $(FLATZINCTESTSRC0) $(BLACKBOXSRC)
 
 TESTHDR0 = \
 	test.hh test.hpp int.hh int.hpp set.hh set.hpp float.hh float.hpp \
@@ -1270,6 +1281,18 @@ TESTOBJ	= $(INTTESTOBJ) $(SETTESTOBJ) $(FLOATTESTOBJ) \
 	$(TESTSRC0:%.cpp=%$(OBJSUFFIX))
 TESTSBJ	= $(TESTOBJ:%$(OBJSUFFIX)=%$(SBJSUFFIX))
 TESTEXE	= test/test$(EXESUFFIX)
+BLACKBOXEXECOBJ = $(BLACKBOXEXECSRC:%.cpp=%$(OBJSUFFIX))
+BLACKBOXDLLOBJ = $(BLACKBOXDLLSRC:%.cpp=%$(OBJSUFFIX))
+BLACKBOXEXEC = test/flatzinc/blackbox-exec$(EXESUFFIX)
+BLACKBOXDLL = test/flatzinc/blackbox-dll$(DLLSUFFIX)
+BLACKBOXDLLLIB = $(BLACKBOXDLL:%$(DLLSUFFIX)=%$(LIBSUFFIX))
+BLACKBOXLOG = $(abspath test/flatzinc/blackbox)
+ifeq "@enable_flatzinc@" "yes"
+BLACKBOXFIXTURES = $(BLACKBOXEXEC) $(BLACKBOXDLL)
+else
+BLACKBOXFIXTURES =
+endif
+
 TESTBUILDDIRS = \
 	test test/int test/set test/float \
 	test/branch test/assign \
@@ -1302,7 +1325,7 @@ compilelib: mkcompiledirs
 
 compileexamples: $(EXAMPLEEXE)
 
-test: mkcompiledirs
+test: mkcompiledirs $(BLACKBOXFIXTURES)
 	@$(MAKE) $(VARIMP) $(TESTEXE)
 
 CHECKTESTS = Branch::Int::Dense::3 \
@@ -1323,6 +1346,14 @@ CHECKTESTS = Branch::Int::Dense::3 \
 	Set::Sequence::SeqU1 \
 	Set::Wait
 
+ifeq "@enable_flatzinc@" "yes"
+CHECKTESTS += FlatZinc::blackbox
+BLACKBOXCHECKENV = \
+	GECODE_TEST_BLACKBOX_EXEC=$(abspath $(BLACKBOXEXEC)) \
+	GECODE_TEST_BLACKBOX_DLL=$(abspath $(BLACKBOXDLL)) \
+	GECODE_TEST_BLACKBOX_LOG=$(BLACKBOXLOG)
+endif
+
 ifeq "@enable_float_vars@" "yes"
 FLOATCHECKTESTS = Float::Arithmetic::PositiveNRootBounds \
 	Float::Arithmetic::PowConsistency \
@@ -1350,7 +1381,8 @@ check: test
 			exit 1; \
 		fi; \
 	done
-	$(RUNENVIRONMENT) $(TESTEXE) -iter 2 -threads 0 -fixprob 1 \
+	$(BLACKBOXCHECKENV) $(RUNENVIRONMENT) \
+		$(TESTEXE) -iter 2 -threads 0 -fixprob 1 \
 		$(CHECKTESTS:%=-test %)
 
 .PHONY: regenerate
@@ -1395,6 +1427,8 @@ gecode/kernel/var-type.hpp: $(VISDEP)
 gecode/kernel/var-imp.hpp: $(VISDEP)
 	$(UVRUN) $(top_srcdir)/misc/genvarimp.py -header $(VIS) > $@
 
+$(ALLOBJ) $(ALLSBJ) $(TESTOBJ) $(TESTSBJ): $(VARIMP)
+
 #
 # Object targets
 #
@@ -1566,7 +1600,7 @@ else
 export LINKALL = \
 	$(LINKFLATZINC) $(LINKDRIVER) $(LINKGIST) \
 	$(LINKSEARCH) $(LINKMM) $(LINKSET) $(LINKFLOAT) $(LINKMPFR) $(LINKINT) \
-	$(LINKKERNEL) $(LINKSUPPORT) $(LINKATOMIC)
+	$(LINKKERNEL) $(LINKSUPPORT) $(LINKATOMIC) $(LINKDL)
 endif
 
 $(SUPPORTDLL): $(SUPPORTOBJ)
@@ -1627,7 +1661,7 @@ $(FLATZINCDLL): $(FLATZINCOBJ) $(SUPPORTDLL) $(KERNELDLL) $(SEARCHDLL) \
 	$(CXX) $(DLLFLAGS) $(FLATZINCOBJ) $(FLATZINCSONAME) \
 		@DLLPATH@ $(LINKSUPPORT) $(LINKKERNEL) $(LINKSEARCH) $(LINKINT) \
 		$(LINKSET) $(LINKFLOAT) $(LINKMM) $(LINKGIST) $(LINKDRIVER) $(LINKQT) \
-		@LINKOUTPUT@$(FLATZINCDLL)
+		$(LINKDL) @LINKOUTPUT@$(FLATZINCDLL)
 	$(CREATELINK) $@ $(@:%$(DLLSUFFIX)=%$(SOLINKSUFFIX))
 	$(CREATELINK) $@ $(@:%$(DLLSUFFIX)=%$(SOSUFFIX))
 else
@@ -1729,13 +1763,13 @@ $(GISTDLL) $(GISTLIB): $(GISTOBJ) $(GISTRES) \
 		    -outputresource:$(GISTDLL)\;2
 ifeq "@enable_resource@" "yes"
 $(FLATZINCRC):
-	$(RCGEN) $(FLATZINCDLL) $(FLATZINCHDR) $(FLATZINCSRC) > $@
+	$(RCGEN) $(FLATZINCDLL) $(FLATZINCALLHDR) $(FLATZINCSRC) > $@
 endif
 $(FLATZINCDLL) $(FLATZINCLIB): $(FLATZINCOBJ) $(FLATZINCRES) \
 	$(SUPPORTDLL) $(KERNELDLL) $(SEARCHDLL) $(INTDLL) \
 	$(SETDLL) $(FLOATDLL) $(GISTDLL) $(MMDLL) $(DRIVERDLL)
 	$(CXX) $(DLLFLAGS) $(FLATZINCOBJ) $(FLATZINCRES) \
-		@DLLPATH@ @LINKOUTPUT@$(FLATZINCDLL) $(GLDFLAGS) $(LINKQT)
+		@DLLPATH@ @LINKOUTPUT@$(FLATZINCDLL) $(GLDFLAGS) $(LINKQT) $(LINKDL)
 	$(FIXMANIFEST) $(FLATZINCDLL).manifest
 	$(MANIFEST) -manifest $(FLATZINCDLL).manifest \
 		    -outputresource:$(FLATZINCDLL)\;2
@@ -1842,6 +1876,22 @@ $(TESTEXE): $(TESTOBJ) $(TESTRES) $(ALLLIB)
 	$(FIXMANIFEST) $@.manifest $(DLLSUFFIX)
 	$(MANIFEST) -manifest $@.manifest -outputresource:$@\;1
 
+$(BLACKBOXEXECOBJ) $(BLACKBOXDLLOBJ): | mkcompiledirs
+
+$(BLACKBOXEXEC): $(BLACKBOXEXECOBJ)
+	$(CXX) @EXEOUTPUT@$@ $(BLACKBOXEXECOBJ) $(CXXFLAGS)
+
+ifeq "$(DLLSUFFIX)" "$(LIBSUFFIX)"
+$(BLACKBOXDLL): $(BLACKBOXDLLOBJ)
+	$(CXX) $(DLLFLAGS) $(BLACKBOXDLLOBJ) @LINKOUTPUT@$@
+else
+$(BLACKBOXDLL) $(BLACKBOXDLLLIB): $(BLACKBOXDLLOBJ)
+	$(CXX) $(DLLFLAGS) $(BLACKBOXDLLOBJ) @LINKOUTPUT@$(BLACKBOXDLL) $(GLDFLAGS)
+	$(FIXMANIFEST) $(BLACKBOXDLL).manifest
+	$(MANIFEST) -manifest $(BLACKBOXDLL).manifest \
+		    -outputresource:$(BLACKBOXDLL)\;2
+endif
+
 .PHONY: flatzinc
 ifeq "@enable_flatzinc@" "yes"
 flatzinc: $(FLATZINCEXE)
@@ -2091,6 +2141,13 @@ clean:
 		 changelog.hh doxygen.hh license.hh header.html
 	$(RMF) $(ALLOBJ) $(ALLSBJ) $(ALLOBJ:%$(OBJSUFFIX)=%.pdb)
 	$(RMF) $(TESTOBJ) $(TESTSBJ) $(TESTOBJ:%$(OBJSUFFIX)=%.pdb)
+	$(RMF) $(BLACKBOXEXECOBJ) $(BLACKBOXDLLOBJ) \
+		$(BLACKBOXEXECOBJ:%$(OBJSUFFIX)=%.pdb) \
+		$(BLACKBOXDLLOBJ:%$(OBJSUFFIX)=%.pdb)
+	$(RMF) $(BLACKBOXEXECOBJ:%$(OBJSUFFIX)=%.gcno) \
+		$(BLACKBOXDLLOBJ:%$(OBJSUFFIX)=%.gcno)
+	$(RMF) $(BLACKBOXEXECOBJ:%$(OBJSUFFIX)=%.gcda) \
+		$(BLACKBOXDLLOBJ:%$(OBJSUFFIX)=%.gcda)
 	$(RMF) $(GISTMOCSRC)
 	$(RMF) $(LIBTARGETS:%$(DLLSUFFIX)=%$(MANIFESTSUFFIX)) \
 		$(LIBTARGETS:%$(DLLSUFFIX)=%$(RCSUFFIX)) \
@@ -2100,6 +2157,13 @@ clean:
 		$(EXAMPLEEXE:%=%.rc) $(EXAMPLEEXE:%=%.res)
 	$(RMF) $(TESTEXE:%.exe=%.pdb) $(TESTEXE:%=%.manifest) \
 		$(TESTEXE:%=%.rc) $(TESTEXE:%=%.res)
+	$(RMF) $(BLACKBOXEXEC:%.exe=%.pdb) $(BLACKBOXEXEC:%=%.manifest) \
+		$(BLACKBOXDLL:%$(DLLSUFFIX)=%$(LIBSUFFIX)) \
+		$(BLACKBOXDLL:%$(DLLSUFFIX)=%$(PDBSUFFIX)) \
+		$(BLACKBOXDLL:%$(DLLSUFFIX)=%$(EXPSUFFIX)) \
+		$(BLACKBOXDLL:%$(DLLSUFFIX)=%$(MANIFESTSUFFIX))
+	$(RMF) $(BLACKBOXLOG).exec_parallel $(BLACKBOXLOG).exec_descendant \
+		$(BLACKBOXLOG).dll_model $(BLACKBOXLOG).dll_parallel
 	$(RMF) $(FLATZINCEXE:%.exe=%.pdb) $(FLATZINCEXE:%=%.manifest) \
 		$(FLATZINCEXE:%=%.rc) $(FLATZINCEXE:%=%.res)
 
@@ -2111,6 +2175,7 @@ veryclean: clean
 		$(LIBTARGETS:%$(DLLSUFFIX)=%$(SOSUFFIX))
 	$(RMF) $(EXAMPLEEXE)
 	$(RMF) $(TESTEXE)
+	$(RMF) $(BLACKBOXFIXTURES)
 	$(RMF) $(FLATZINCEXE)
 	$(RMF) doc ChangeLog
 	$(RMF) $(ALLOBJ:%$(OBJSUFFIX)=%.gcno) $(TESTOBJ:%$(OBJSUFFIX)=%.gcno)

changelog.in

@@ -75,6 +75,21 @@ This release modernizes the Gecode build infrastructure, adds a
 first-class CMake package for downstream consumers, refreshes the
 autoconf build path, and updates CI coverage for current platforms.
 
+[ENTRY]
+Module: flatzinc
+What:   new
+Rank:   minor
+Thanks: Jip J. Dekker
+[DESCRIPTION]
+Add support for the experimental MiniZinc black-box propagator interface,
+contributed by Jip J. Dekker.
+[MORE]
+FlatZinc models can implement custom value and bounds propagation in a shared
+library or persistent subprocess. The blackbox_dll and blackbox_exec annotations
+select the backend and pass its arguments. Bounds callbacks return enclosing
+intervals together with the dependencies that determine when the callback must
+run again.
+
 [ENTRY]
 Module: minimodel
 What:   bug