The seq serialization machinery is a historic artifact from when Go
mobile code had to run in a separate process. Now that Go code is running
in-process, replace the explicit serialization with direct calls and pass
arguments on the stack.
The benefits are a much smaller bind runtime, much less garbage (and, in
Java, fewer objects with finalizers), less argument copying, and faster
cross-language calls.
The cost is a more complex generator, because some of the work from the
bind runtime is moved to generated code. Generated code now handles
conversion between Go and Java/ObjC types, multiple return values and memory
management of byte slice and string arguments.
To overcome the lack of calling C code between Go packages, all bound
packages now end up in the same (fake) package, "gomobile_bind", instead of
separate packages (go_<pkgname>). To avoid name clashes, the package name is
added as a prefix to generated functions and types.
Also, don't copy byte arrays passed to Go, saving call time and
allowing read([]byte)-style interfaces to foreign callers (#12113).
Finally, add support for nil interfaces and struct pointers to objc.
This is a large CL, but most of the changes stem from changing testdata.
The full benchcmp output on the CL/20095 benchmarks on my Nexus 5 is
reproduced below. Note that the savings for the JavaSlice* benchmarks are
skewed because byte slices are no longer copied before passing them to Go.
benchmark old ns/op new ns/op delta
BenchmarkJavaEmpty 26.0 19.0 -26.92%
BenchmarkJavaEmptyDirect 23.0 22.0 -4.35%
BenchmarkJavaNoargs 7685 2339 -69.56%
BenchmarkJavaNoargsDirect 17405 8041 -53.80%
BenchmarkJavaOnearg 26887 2366 -91.20%
BenchmarkJavaOneargDirect 34266 7910 -76.92%
BenchmarkJavaOneret 38325 2245 -94.14%
BenchmarkJavaOneretDirect 46265 7708 -83.34%
BenchmarkJavaManyargs 41720 2535 -93.92%
BenchmarkJavaManyargsDirect 51026 8373 -83.59%
BenchmarkJavaRefjava 38139 21260 -44.26%
BenchmarkJavaRefjavaDirect 42706 28150 -34.08%
BenchmarkJavaRefgo 34403 6843 -80.11%
BenchmarkJavaRefgoDirect 40193 16582 -58.74%
BenchmarkJavaStringShort 32366 9323 -71.20%
BenchmarkJavaStringShortDirect 41973 19118 -54.45%
BenchmarkJavaStringLong 127879 94420 -26.16%
BenchmarkJavaStringLongDirect 133776 114760 -14.21%
BenchmarkJavaStringShortUnicode 32562 9221 -71.68%
BenchmarkJavaStringShortUnicodeDirect 41464 19094 -53.95%
BenchmarkJavaStringLongUnicode 131015 89401 -31.76%
BenchmarkJavaStringLongUnicodeDirect 134130 90786 -32.31%
BenchmarkJavaSliceShort 42462 7538 -82.25%
BenchmarkJavaSliceShortDirect 52940 17017 -67.86%
BenchmarkJavaSliceLong 138391 8466 -93.88%
BenchmarkJavaSliceLongDirect 205804 15666 -92.39%
BenchmarkGoEmpty 3.00 3.00 +0.00%
BenchmarkGoEmptyDirect 3.00 3.00 +0.00%
BenchmarkGoNoarg 40342 13716 -66.00%
BenchmarkGoNoargDirect 46691 13569 -70.94%
BenchmarkGoOnearg 43529 13757 -68.40%
BenchmarkGoOneargDirect 44867 14078 -68.62%
BenchmarkGoOneret 45456 13559 -70.17%
BenchmarkGoOneretDirect 44694 13442 -69.92%
BenchmarkGoRefjava 55111 28071 -49.06%
BenchmarkGoRefjavaDirect 60883 26872 -55.86%
BenchmarkGoRefgo 57038 29223 -48.77%
BenchmarkGoRefgoDirect 56153 27812 -50.47%
BenchmarkGoManyargs 67967 17398 -74.40%
BenchmarkGoManyargsDirect 60617 16998 -71.96%
BenchmarkGoStringShort 57538 22600 -60.72%
BenchmarkGoStringShortDirect 52627 22704 -56.86%
BenchmarkGoStringLong 128485 52530 -59.12%
BenchmarkGoStringLongDirect 138377 52079 -62.36%
BenchmarkGoStringShortUnicode 57062 22994 -59.70%
BenchmarkGoStringShortUnicodeDirect 62563 22938 -63.34%
BenchmarkGoStringLongUnicode 139913 55553 -60.29%
BenchmarkGoStringLongUnicodeDirect 150863 57791 -61.69%
BenchmarkGoSliceShort 59279 20215 -65.90%
BenchmarkGoSliceShortDirect 60160 21136 -64.87%
BenchmarkGoSliceLong 411225 301870 -26.59%
BenchmarkGoSliceLongDirect 399029 298915 -25.09%
Fixesgolang/go#12619Fixesgolang/go#12113Fixesgolang/go#13033
Change-Id: I2b45e9e98a1248e3c23a5137f775f7364908bec7
Reviewed-on: https://go-review.googlesource.com/19821
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
The Seq Java class has a special case for null references. Expand
the special case to Go so that null references from Java are properly
translated to nil.
Fixesgolang/go#14228
Change-Id: I915d1f843c9db299d6910480f6d10dae0121a3b4
Reviewed-on: https://go-review.googlesource.com/19460
Reviewed-by: David Crawshaw <crawshaw@golang.org>
seq.Transact is called when Go calls a method of a foreign object
that implements a Go interface. Currently, we assume that the foreign
object has an instance method that can conduct the message routing,
so the object id and the method code is sufficient for transact.
Passing the interface descriptor (e.g. go.testpkg.I) however allows
the bind internal to use non-instance methods to implement the routing.
Change-Id: I1f61a04f919fbd09117ea332d678cd50e4861e46
Reviewed-on: https://go-review.googlesource.com/12685
Reviewed-by: David Crawshaw <crawshaw@golang.org>
Package app contains some logic that we want to share with
gobind-based libraries. So move it to a new internal package
that both can import.
Long term the log changes should be in the standard library,
but the Go tree is currently frozen.
Fixesgolang/go#11630.
Change-Id: I9ff622fc499bf255bce18df23cb68b03f667947f
Reviewed-on: https://go-review.googlesource.com/11981
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
The gobind framework is supposed to use reference counting to
keep track of objects (e.g. pointer to a Go struct, interface
values) crossing the language boundary. This change fixes two bugs:
1) no reference counting on Java object: Previously, the lifetime
of a Java object was manages in the following way.
a. The Java object is pinned in an internal map (javaObjs) when it's
constructed.
b. When Go receives the reference to the Java object, it creates a
proxy object and sets a finalizer on it. The finalizer signals Java
to unpin the Java object (remove from the javaObjs map).
c. The javaObjs map is also used to identify the Java object when
Go asks to invoke a method on it later.
When the same Java object is sent to Java more than once, and the
finalizer (b) runs after the first use, the second use of the Java
object can cause the crash described in golang/go#10933.
This change fixes the bug by reference counting the Java object.
Java side pins the Java object and increments the refcount whenever it
sees the object sent to Go (in Seq.writeRef). When the Go proxy
object's finalizer runs, the refcount is decremented. When the refcount
becomes 0, the object gets unpined.
2) race in Go object lifetime management: Pinning on a Go object
has been done when the Go object is sent to Java but the Go object
is not in the pinned object map yet. (bind/seq.WriteGoRef).
Unpinning the object occurs when Java finds there are no proxy objects
on its side. For this, Java maintains a reference count map (goObjs).
When the refcount becomes zero, Java notifies Go so the object is
unpinned. Here is a race case:
a. Java has a proxy object for a Go object.
b. Go is preparing for sending the same Go object. seq.WriteGoRef
notices the corresponding entry in the pinned object map already,
and returns. The remaining work for sending the object continues.
c. The proxy object in Java finalizes and triggers deletion of the
object from the pinned object map.
d. The remaining work for (b) completes and Java creates a new proxy
object. When a method is called for the Go object, the Go object is
already removed from the object map on Go side and maybe already GC'd.
This change fixes it by converting the pinned object map to reference
counter map maintained in Go. The counter increments for each
seq.WriteGoRef call. The finalizer of the proxy object in Java causes
a decrement of the counter.
Fixesgolang/go#10933.
Renables the skipped testJavaRefGC.
Change-Id: I0992e002b1050b6183689e5ab821e058adbb420f
Reviewed-on: https://go-review.googlesource.com/10638
Reviewed-by: David Crawshaw <crawshaw@golang.org>
This is to enable more flexible encoding/decoding of Go string.
For Java, we use UTF16 to be compatible with java string.
For other languages, we will want other way to represent a string.
Change-Id: Iccd53e2eea18d37636c3c619d06cb473facef0cd
Reviewed-on: https://go-review.googlesource.com/8628
Reviewed-by: David Crawshaw <crawshaw@golang.org>
This change makes gobind to generate proper Go-side proxy code to
handle interface methods that have parameters and return values.
It allows gobind to accept struct pointer types as parameters
or a return value of a method.
Fixesgolang/go#9487, golang/go#9488.
Change-Id: Id243c42ee0701d40e3871e392140368c2f8f9bc6
Reviewed-on: https://go-review.googlesource.com/2348
Reviewed-by: David Crawshaw <crawshaw@golang.org>
