// Check all the formats of native implementation name to see if there is one // for the specified method. address NativeLookup::lookup_entry(methodHandle method, bool& in_base_library, TRAPS) { address entry = NULL; in_base_library = false; // Compute pure name char* pure_name = pure_jni_name(method); //计算指定本地方法的参数数量 int args_size = 1 // JNIEnv + (method->is_static() ? 1 : 0) // class for static methods + method->size_of_parameters(); // actual parameters // 1) Try JNI short style entry = lookup_style(method, pure_name, "", args_size, true, in_base_library, CHECK_NULL); if (entry != NULL) return entry; // Compute long name char* long_name = long_jni_name(method); // 2) Try JNI long style entry = lookup_style(method, pure_name, long_name, args_size, true, in_base_library, CHECK_NULL); if (entry != NULL) return entry; // 3) Try JNI short style without os prefix/suffix entry = lookup_style(method, pure_name, "", args_size, false, in_base_library, CHECK_NULL); if (entry != NULL) return entry; // 4) Try JNI long style without os prefix/suffix entry = lookup_style(method, pure_name, long_name, args_size, false, in_base_library, CHECK_NULL); return entry; // NULL indicates not found }
// Check all the formats of native implementation name to see if there is one // for the specified method. address NativeLookup::lookup_critical_entry(methodHandle method) { if (!CriticalJNINatives) return NULL; if (method->is_synchronized() || !method->is_static()) { // Only static non-synchronized methods are allowed return NULL; } ResourceMark rm; address entry = NULL; Symbol* signature = method->signature(); for (int end = 0; end < signature->utf8_length(); end++) { if (signature->byte_at(end) == 'L') { // Don't allow object types return NULL; } } // Compute critical name char* critical_name = critical_jni_name(method); // Compute argument size int args_size = 1 // JNIEnv + (method->is_static() ? 1 : 0) // class for static methods + method->size_of_parameters(); // actual parameters // 1) Try JNI short style entry = lookup_critical_style(method, critical_name, "", args_size, true); if (entry != NULL) return entry; // Compute long name char* long_name = long_jni_name(method); // 2) Try JNI long style entry = lookup_critical_style(method, critical_name, long_name, args_size, true); if (entry != NULL) return entry; // 3) Try JNI short style without os prefix/suffix entry = lookup_critical_style(method, critical_name, "", args_size, false); if (entry != NULL) return entry; // 4) Try JNI long style without os prefix/suffix entry = lookup_critical_style(method, critical_name, long_name, args_size, false); return entry; // NULL indicates not found }