The gobind and gomobile bind tools have historically overlapped:
gobind outputs generated bindings, and gomobile bind will generate
bindings before building them. However, the gobind bindings were
never used for building and thus allowed to not be complete.
To simplify version control, debugging, instrumentation and build
system flexibility, this CL upgrades the gobind tool to be the
canonical binding generator and change gomobile bind to use gobind
instead of its own generator code.
This greatly simplifies gomobile bind, but also paves the way to skip
gomobile bind entirely. For example:
$ gobind -outdir=$GOPATH golang.org/x/mobile/example/bind/hello
$ GOOS=android GOARCH=arm64 CC=<ndk-toolchain>/bin/clang go build -buildmode=c-shared -o libgobind.so gobind
$ ls libgobind.*
libgobind.h libgobind.so
The same applies to iOS, although the go build command line is more
involved.
By skipping gomobile it is possible to freely customize the Android
or iOS SDK level or any other flags not supported by gomobile bind.
By checking in the generated source code, the cost of supporting
gomobile in a custom build system is also decreased.
Change-Id: I59c14a77d625ac1377c23b3213672e0d83a48c85
Reviewed-on: https://go-review.googlesource.com/99316
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
The Go runtime doesn't handle SIGIPE signals from writing to closed
sockets or pipes in c-archive and c-shared mode (issue 17393).
Work around it in gomobile by simply ignoring all SIGPIPE signals;
they're not useful in mobile apps anyway.
Change-Id: Ibd7ee41058856c5eddb4a519345a3851a29e9b44
Reviewed-on: https://go-review.googlesource.com/33771
Reviewed-by: David Crawshaw <crawshaw@golang.org>
Gobind uses strings for passing errors across the language barrier.
However, since Gobind doesn't have a concept of a nil string, it
can't separate an empty native string from a nil string.
In turn, that means that empty errors, exceptions or NSError * with
an empty description are treated as no error. With ObjC, empty errors
are replaced with a default string to workaround the issue, while
with Java empty errors are silently ignored.
Fix this by replacing strings with actual error objects, wrapping
the Go error, Java Throwable or ObjC NSError *, and letting the
existing bind machinery take care of passing the references across.
It's a large change for a small corner case, but I believe objects
are a better fit for exception that strings. Error objects also
naturally leads to future additions, for example accessing the
exception class name or chained exception.
Change-Id: Ie03b47cafcb231ad1e12a80195693fa7459c6265
Reviewed-on: https://go-review.googlesource.com/24100
Reviewed-by: David Crawshaw <crawshaw@golang.org>
Each side of the language barrier maintains a map of reference numbers
to objects. Each entry has a reference count that exactly matches
the number of active proxy objects on the other side. When a reference
crosses the barrier, the count is incremented and when a proxy finalizer
is run, the count is decremented. If the count reaches 0, the reference
number and its object are removed from the map.
There is a possibility that a reference number is passed to the other
side, and the last proxy is then immediately garbage collected and
finalized. The reference counter then reaches 0 before the other side has
converted the reference number to its object, crashing the program.
This is possible in both Go/Java/ObjC but is most likely to happen in
ObjC because its own automatic reference count runtime frees objects
as soon as they are statically never referenced again.
Fix the race by always incrementing the reference count before sending
a reference across the barrier. When converting the reference back into
an object on the other side, decrement the counter again.
Only the new ObjC test fails without this fix, but I left the Java
counterpart in for good measure.
Change-Id: I92743aabec275b4a5b82b952052e7e284872ce02
Reviewed-on: https://go-review.googlesource.com/21311
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
Rename the refnum field, Num, to something much less likely to clash
with an interface method set.
Change-Id: If334966b2430f38118baded44461bd39298bafb0
Reviewed-on: https://go-review.googlesource.com/20983
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
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>
