Start use DynamicLibrary.invoke() but not only DynamicLibrary.invokeEx()

[mezoni]

You use only invokeEx() and not use invoke().

static dynamic invoke(String name, [List<dynamic> args = const [], List<BinaryType> vartypes]) {
    return libc.invokeEx(name, args, vartypes);
  }

The method invoke() not much slower than invokeEx()
But it are more intellectual way and it will be improved further.

Improved performance of the DynamicLibrary.invoke() with a variable parameters through the precompilation of the commonly used binary types (bool, char, char *,int, double)

This has effect also when you use strings but not only with variadic functions.

Also I plan implement propogating null's (converting) to appropriate pointers.

Code fragment of invoke().

if (argument is String) {
          if (parameter is PointerType) {
            var valueType = parameter.type;
            if (valueType.kind == basicTypes.charType.kind) {
              if (strings == null) {
                strings = <BinaryObject>[];
              }

              var string = valueType.array(argument.length + 1).alloc(argument.codeUnits);
              strings.add(string);
              newArguments[i] = string;
            } else {
              throw new ArgumentError("Unable to allocate string object for parameter $i: $parameter");
            }
          }
        } else if (argument == null) {
          // TODO: "Promoting NULL values not implemented yet"
          throw new UnimplementedError("Promoting NULL values not implemented yet");
        } 

As you can see it automatically perform the following tasks.

• Converts the String (allocates them without invoke the helper.allocString())
• Creates the heap for them
• Promoting NULL values (will be added soon)

P.S.

Also I plan to add segmentation fault handler into unsafe extension for the graceful exits with a Dart stack trace (instead of only exit code 139 "post mortem").

After that I implement "auto NULL pointer promoting" (if SEGFAULT will work with a success in Dart VM).

As for me second looks (and works) better than first.

_checkResult(invoke("sysctlbyname", [n, getType("void*").nullPtr, len, getType("void*").nullPtr, 0]));

_checkResult(invoke__("sysctlbyname", [n, null, len, null, 0]));

Of course, if the idea with a SEGFAULT will be able to display" post mortem "stack trace.

[azenla]

Thanks! @mezoni Let me know when you make the changes to unsafe_extension, I'll recompile for ya :)

[mezoni]

Thanks! @mezoni Let me know when you make the changes to unsafe_extension, I'll recompile for ya :)

It works!

Unhandled exception:
Segmentation fault
#0      Unsafe._readInt32 (package:unsafe_extension/src/unsafe_extension.dart:982:72)
#1      Unsafe.readInt32 (package:unsafe_extension/src/unsafe_extension.dart:450:22)
#2      main (file:///home/andrew/dart/for_web/unsafe_extension/test/test_sigsegv.dart:4:19)
#3      _startIsolate.<anonymous closure> (dart:isolate-patch/isolate_patch.dart:255)
#4      _RawReceivePortImpl._handleMessage (dart:isolate-patch/isolate_patch.dart:142)

Update instruction.

1. Clone from GitHub latest version of unsafe_extension
2. Delete files that you want recompile (eg. compiled/X86/macos/libunsafe_extension.dylib)
3. Delete any binaries in lib/src
4. Open and run tool/setup.dart

If you want repeat a recompilation then you should repeat steps everything from step 2

Last step:
5. Delete any binaries in lib/src

P.S.

This binary already compiled X86/linux/libunsafe_extension.so
I will recompile other later today (Windows 32/64, Linux 64)

Temporary test file can be found here test/test_sigsegv.dart