Subprocess support

TODO.md

@@ -32,3 +32,6 @@
    some formulations of the game-restart logic in the flappy bird
    demo.
 
+ - driver-streams-node/src/subprocess.js: perhaps figure out some way
+   of blocking SIGQUIT, which I'm currently using to get debug output,
+   in children, so they don't terminate too?

packages/driver-streams-node/src/index.js

@@ -19,3 +19,4 @@
 
 Object.assign(module.exports, activate require('./streams.js'));
 Object.assign(module.exports, activate require('./net.js'));
+Object.assign(module.exports, activate require('./subprocess.js'));

packages/driver-streams-node/src/subprocess.js

@@ -0,0 +1,87 @@
+//---------------------------------------------------------------------------
+// @syndicate-lang/driver-streams-node, Stream support for Syndicate/js
+// Copyright (C) 2016-2018 Tony Garnock-Jones <tonyg@leastfixedpoint.com>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+//---------------------------------------------------------------------------
+
+import { currentFacet, Observe, Dataspace, genUuid, Bytes } from "@syndicate-lang/core";
+const S = activate require("./streams");
+const child_process = require('child_process');
+
+assertion type Subprocess(id, command, args, options);
+message type SubprocessError(id, err);
+
+assertion type SubprocessRunning(id, pid, stdio);
+assertion type SubprocessExit(id, code, signal);
+
+message type SubprocessKill(id, signal); // also on frame teardown
+
+export {
+  Subprocess, SubprocessError,
+  SubprocessRunning, SubprocessExit,
+  SubprocessKill,
+};
+
+spawn named 'driver/Subprocess' {
+  during Subprocess($id, $command, $args, $options) spawn named ['Subprocess', id] {
+    const sp = child_process.spawn(command, args.toJS(), options ? options.toJS() : void 0);
+
+    const stdio = sp.stdio.map((s, i) => {
+      if (s !== null) {
+        const fd = genUuid('fd');
+        if (s.readable && s.writable) {
+          on start react S.duplexStreamBehaviour(fd, s);
+        } else if (s.readable) {
+          on start react S.readableStreamBehaviour(fd, s);
+        } else if (s.writable) {
+          on start react S.writableStreamBehaviour(fd, s);
+        }
+        return fd;
+      } else {
+        return null;
+      }
+    });
+
+    field this.isRunning = null;
+
+    on stop if (this.isRunning !== false) sp.kill('SIGKILL');
+
+    assert SubprocessRunning(id, sp.pid, stdio) when (this.isRunning === true);
+
+    sp.on('exit', Dataspace.wrapExternal((code, signal) => {
+      this.isRunning = false;
+      react assert SubprocessExit(id, code, signal);
+    }));
+
+    sp.on('error', Dataspace.wrapExternal((err) => {
+      this.isRunning = false;
+      send SubprocessError(id, err);
+      currentFacet().stop();
+    }));
+
+    process.nextTick(Dataspace.wrapExternal(() => {
+      if (this.isRunning === null) {
+        this.isRunning = true;
+      }
+    }));
+
+    on message SubprocessKill(id, $signal) {
+      if (this.isRunning !== false) {
+        this.isRunning = false;
+        sp.kill(signal);
+      }
+    }
+  }
+}

packages/syntax-playground/src/ncchatclient.js

@@ -0,0 +1,57 @@
+//---------------------------------------------------------------------------
+// @syndicate-lang/syntax-test, a demo of Syndicate extensions to JS.
+// Copyright (C) 2016-2018 Tony Garnock-Jones <tonyg@leastfixedpoint.com>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+//---------------------------------------------------------------------------
+
+const { Observe, currentFacet, genUuid } = require("@syndicate-lang/core");
+const { sleep } = activate require("@syndicate-lang/driver-timer");
+const S = activate require("@syndicate-lang/driver-streams-node");
+
+const stdin = genUuid('stdin');
+const stdout = genUuid('stdout');
+spawn named 'stdioServer' {
+  during Observe(S.Readable(stdin)) spawn S.readableStreamBehaviour(stdin, process.stdin);
+  during Observe(S.Writable(stdout)) spawn S.writableStreamBehaviour(stdout, process.stdout);
+}
+
+spawn named 'chatclient-via-nc' {
+  const id = genUuid('p');
+  assert S.Subprocess(id, 'nc', ['localhost', '5999'], {stdio: ['pipe', 'pipe', 'ignore']});
+  stop on message S.SubprocessError(id, $err) {
+    console.error("Couldn't start subprocess", err);
+  }
+  stop on retracted S.Readable(stdin);
+  stop on retracted S.Writable(stdout);
+  on asserted S.SubprocessRunning(id, _, [$i, $o, _]) {
+    react {
+      on message S.Line(stdin, $line) {
+        console.log('INPUT:', line);
+        send S.Push(i, line.toString('utf-8') + '\n', null);
+      }
+      on message S.End(stdin) {
+        console.log('INPUT EOF');
+        send S.Close(i, null);
+      }
+
+      on message S.Line(o, $line) send S.Push(stdout, line.toString('utf-8') + '\n', null);
+    }
+  }
+  stop on asserted S.SubprocessExit(id, $code, $signal) {
+    if (code !== 0) {
+      console.error('Subprocess exited with code', code, 'signal', signal);
+    }
+  }
+}

packages/syntax-playground/src/subprocess.js

@@ -0,0 +1,46 @@
+//---------------------------------------------------------------------------
+// @syndicate-lang/syntax-test, a demo of Syndicate extensions to JS.
+// Copyright (C) 2016-2018 Tony Garnock-Jones <tonyg@leastfixedpoint.com>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+//---------------------------------------------------------------------------
+
+const { currentFacet, genUuid } = require("@syndicate-lang/core");
+const { sleep } = activate require("@syndicate-lang/driver-timer");
+const S = activate require("@syndicate-lang/driver-streams-node");
+
+spawn named 'lister' {
+  const go = () => {
+    react {
+      const id = genUuid('p');
+      assert S.Subprocess(id, 'nc', ['localhost', '80'], {stdio: ['pipe', 'pipe', 'ignore']});
+      stop on message S.SubprocessError(id, $err) {
+        console.error("Couldn't start subprocess", err);
+      }
+      on asserted S.SubprocessRunning(id, _, [$i, $o, _]) {
+        send S.Push(i, "GET / HTTP/1.0\r\n\r\n", null);
+        send S.Close(i, null);
+        react {
+          on message S.Data(o, $chunk) console.log(chunk);
+          on asserted S.End(o) console.log('DONE!');
+        }
+      }
+      stop on asserted S.SubprocessExit(id, $code, $signal) {
+        console.log('No longer running', new Date(), code, signal);
+        sleep(1000, go);
+      }
+    }
+  };
+  on start go();
+}