adding limit-memory flag to the sandboxed server, preliminary README.

whalesong/repl-prototype/README

@@ -0,0 +1,30 @@
+This is an experiment in the dynamic evaluation of whalesong-generated
+code.
+
+----------------------------------------------------------------------
+
+1.  Run 'write-runtime.rkt'.  This generates the runtime.js and
+library.js files in htdocs/collects.  At the moment, the only files
+written out are those that support whalesong/wescheme, though to make
+this work, we'll want to parameterize write-runtime.rkt so it can take
+in the name of the languages that the REPL should know about.
+
+2.  Start the sandboxed server.  Run sandboxed-server.rkt.
+
+Warning: you may need to first "raco make" both "sandboxed-server.rkt"
+and "server.rkt", because the Racket compilation may otherwise hit the
+memory ceiling imposed by the sandbox itself!
+
+----------------------------------------------------------------------
+
+TODO:
+
+1.  Parameterize write-runtime so it can take in a list of the
+language modules we need to compile.  Similarly, parameterize
+sandbox-server.rkt so it knows which languages to allow.
+
+2.  Allow non-sexp-based language support.  Currently, there's a nasty
+location bug in Racket 5.3.3's module-reader that makes us lose
+location information.  I'm considering just forking a copy of the
+module reader just so we're not blocked on waiting for Racket 5.3.4,
+either that or losing location information altogether.

whalesong/repl-prototype/htdocs/repl.js

@@ -133,7 +133,20 @@
 
     Repl.prototype.compileProgram = function(programName, code,
                                              onDone, onDoneError) {
-        getXhr(this).replCompile(programName, code, onDone, onDoneError);
+        var that = this;
+        getXhr(this).replCompile(
+            programName, 
+            code,
+            onDone, 
+            function(err) {
+                // If we get a 503, try again.
+                if (err.status == 503) {
+                    that.compileProgram(programName, code,
+                                        onDone, onDoneError);
+                } else {
+                    onDoneError(err);
+                }
+            });
     };
 
 

whalesong/repl-prototype/htdocs/rpc.js

@@ -13,7 +13,13 @@
                       'data': {'name' : name,
                                'src' : code },
                       'dataType': 'json',
-                      'type' : 'post'
+                      'type' : 'post',
+                      'statusCode': {
+                          // On a 503, try again.
+                          503: function() {
+                              replCompile(name, code, onDone, onDoneError);
+                          }
+                      }
                     });
     };
     
@@ -34,7 +40,13 @@
                                'src' : options.code,
                                'm' : 't'},
                       'dataType': 'json',
-                      'type' : 'post'
+                      'type' : 'post',
+                      'statusCode': {
+                          // On 503, try again.
+                          503: function() {
+                              moduleCompile(options, onDone, onDoneError);
+                          }
+                      }
                     });
     };
 

whalesong/repl-prototype/sandboxed-server.rkt

@@ -8,10 +8,13 @@
 
 
 (define current-port (make-parameter 8080))
+(define current-memory-limit (make-parameter 256))
 (void (command-line
        #:once-each 
        [("-p" "--port") p "Port (default 8080)" 
-                        (current-port (string->number p))]))
+                        (current-port (string->number p))]
+       [("--memory-limit") memlimit "Memory limit in MB (default 256)"
+                           (current-memory-limit (string->number memlimit))]))
 
 
 
@@ -24,7 +27,7 @@
 
 (let loop ()
   (define eval
-    (parameterize ([sandbox-memory-limit 256]
+    (parameterize ([sandbox-memory-limit (current-memory-limit)]
                    [sandbox-eval-limits '(+inf.0 256)]
                    [sandbox-output (current-output-port)]
                    [sandbox-network-guard my-network-guard])

whalesong/whalesong-helpers.rkt

@@ -88,6 +88,9 @@
                         (match msg
                           [(vector level msg data)
                            (fprintf (current-report-port)"~a: ~a\n" level msg)
+                           (flush-output (current-report-port))]
+                          [else
+                           (fprintf (current-report-port)"~a\n" msg)
                            (flush-output (current-report-port))]))
                       (loop)))))))