This commit adds support for JavaScript callbacks back into
WebAssembly. This is experimental API, just like the rest of the
syscall/js package. The time package now also uses this mechanism
to properly support timers without resorting to a busy loop.
JavaScript code can call into the same entry point multiple times.
The new RUN register is used to keep track of the program's
run state. Possible values are: starting, running, paused and exited.
If no goroutine is ready any more, the scheduler can put the
program into the "paused" state and the WebAssembly code will
stop running. When a callback occurs, the JavaScript code puts
the callback data into a queue and then calls into WebAssembly
to allow the Go code to continue running.
Updates #18892
Updates #25506
Change-Id: Ib8701cfa0536d10d69bd541c85b0e2a754eb54fb
Reviewed-on: https://go-review.googlesource.com/114197
Reviewed-by: Austin Clements <austin@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
This commit addresses a FIXME left in the code of wasm_exec.js to
properly get the upper 32 bit of a JS number to be stored as an
64-bit integer. A bitshift operation is not possible, because in
JavaScript bitshift operations only operate on the lower 32 bits.
Change-Id: I8f627fd604e592682d9d322942a4852db64a7f66
Reviewed-on: https://go-review.googlesource.com/113076
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
This commit adds the syscall/js package, which is used by the wasm
architecture to access the WebAssembly host environment (and the
operating system through it). Currently, web browsers and Node.js
are supported hosts, which is why the API is based on JavaScript APIs.
There is no common API standardized in the WebAssembly ecosystem yet.
This package is experimental. Its current scope is only to allow
tests to run, but not yet to provide a comprehensive API for users.
Updates #18892
Change-Id: I236ea10a70d95cdd50562212f2c18c3db5009230
Reviewed-on: https://go-review.googlesource.com/109195
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
