jyapayne/swig
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Fix crashes in swig_connect_director during director class construction.

Browse source 
Occurs when using the director class from multiple threads - a race condition
initialising block scope static variables.

Block scope static variables are guaranteed to be thread safe in C++11,
so the fix is guaranteed when using C++11. However, most modern compilers
also fix it when using C++03/C++98.

Closes #1862
This commit is contained in:
William S Fulton 2020-08-28 18:23:47 +01:00
commit b018c32f9d
3 changed files with 30 additions and 21 deletions
Download patch file Download diff file Expand all files Collapse all files

31
Source/Modules/java.cxx
View file

@ -4835,34 +4835,27 @@ public:
// .'s to delimit namespaces, so we need to replace those with /'s
Replace(internal_classname, NSPACE_SEPARATOR, "/", DOH_REPLACE_ANY);
Wrapper_add_localv(w, "baseclass", "static jclass baseclass", "= 0", NIL);
Printf(w->def, "void %s::swig_connect_director(JNIEnv *jenv, jobject jself, jclass jcls, bool swig_mem_own, bool weak_global) {", director_classname);
Printf(w->def, "static jclass baseclass = swig_new_global_ref(jenv, \"%s\");\n", internal_classname);
Printf(w->def, "if (!baseclass) return;\n");
if (first_class_dmethod != curr_class_dmethod) {
Printf(w->def, "static struct {\n");
Printf(w->def, "const char *mname;\n");
Printf(w->def, "const char *mdesc;\n");
Printf(w->def, "jmethodID base_methid;\n");
Printf(w->def, "} methods[] = {\n");
Printf(w->def, "static SwigDirectorMethod methods[] = {\n");
for (int i = first_class_dmethod; i < curr_class_dmethod; ++i) {
UpcallData *udata = Getitem(dmethods_seq, i);
Printf(w->def, "{ \"%s\", \"%s\", NULL }", Getattr(udata, "method"), Getattr(udata, "fdesc"));
Printf(w->def, "SwigDirectorMethod(jenv, baseclass, \"%s\", \"%s\")", Getattr(udata, "method"), Getattr(udata, "fdesc"));
if (i != curr_class_dmethod - 1)
Putc(',', w->def);
Putc('\n', w->def);
}
Printf(w->def, "};\n");
Printf(w->def, "};");
}
Printf(w->code, "if (swig_set_self(jenv, jself, swig_mem_own, weak_global)) {\n");
Printf(w->code, "if (!baseclass) {\n");
Printf(w->code, "baseclass = jenv->FindClass(\"%s\");\n", internal_classname);
Printf(w->code, "if (!baseclass) return;\n");
Printf(w->code, "baseclass = (jclass) jenv->NewGlobalRef(baseclass);\n");
Printf(w->code, "}\n");
int n_methods = curr_class_dmethod - first_class_dmethod;
@ -4877,12 +4870,8 @@ public:
/* Emit the code to look up the class's methods, initialize the override array */
Printf(w->code, "bool derived = (jenv->IsSameObject(baseclass, jcls) ? false : true);\n");
Printf(w->code, "for (int i = 0; i < %d; ++i) {\n", n_methods);
Printf(w->code, " if (!methods[i].base_methid) {\n");
Printf(w->code, " methods[i].base_methid = jenv->GetMethodID(baseclass, methods[i].mname, methods[i].mdesc);\n");
Printf(w->code, " if (!methods[i].base_methid) return;\n");
Printf(w->code, " }\n");
Printf(w->code, " bool derived = (jenv->IsSameObject(baseclass, jcls) ? false : true);\n");
Printf(w->code, " for (int i = 0; i < %d; ++i) {\n", n_methods);
// Generally, derived classes have a mix of overridden and
// non-overridden methods and it is worth making a GetMethodID
// check during initialization to determine if each method is
@ -4902,8 +4891,8 @@ public:
} else {
Printf(w->code, " swig_override[i] = false;\n");
Printf(w->code, " if (derived) {\n");
Printf(w->code, " jmethodID methid = jenv->GetMethodID(jcls, methods[i].mname, methods[i].mdesc);\n");
Printf(w->code, " swig_override[i] = (methid != methods[i].base_methid);\n");
Printf(w->code, " jmethodID methid = jenv->GetMethodID(jcls, methods[i].name, methods[i].desc);\n");
Printf(w->code, " swig_override[i] = methods[i].methid && (methid != methods[i].methid);\n");
Printf(w->code, " jenv->ExceptionClear();\n");
Printf(w->code, " }\n");
}