From 46f314ea3563cbfdf7a41f1f04aad05dfc69c81f Mon Sep 17 00:00:00 2001
From: Danny Yoo <dyoo@cs.wpi.edu>
Date: Sun, 4 Dec 2011 20:04:03 -0500
Subject: [PATCH] chasing a double-release

---
 js-assembler/runtime-src/baselib-functions.js | 39 ++++++++++++-------
 js-assembler/runtime-src/runtime.js           | 21 ++++++----
 version.rkt                                   |  2 +-
 3 files changed, 40 insertions(+), 22 deletions(-)

diff --git a/js-assembler/runtime-src/baselib-functions.js b/js-assembler/runtime-src/baselib-functions.js
index b95e4a5..6576b84 100644
--- a/js-assembler/runtime-src/baselib-functions.js
+++ b/js-assembler/runtime-src/baselib-functions.js
@@ -128,16 +128,24 @@
 
     var coerseClosureToJavaScript = function (v, MACHINE) {
         var f = function (succ, fail) {
+            var args = [];
+            var i;
+            for (i = 0; i < arguments.length; i++) {
+                args.push(arguments[i]);
+            }
+
             MACHINE.exclusiveLock.acquire(
                 "js-as-closure",
                 function(releaseLock) {
                     succ = succ || function () {};
                     fail = fail || function () {};
+
+                    releaseLock();
                     
-                    if (!(baselib.arity.isArityMatching(v.racketArity, arguments.length - 2))) {
+                    if (!(baselib.arity.isArityMatching(v.racketArity, args.length - 2))) {
                         var msg = baselib.format.format(
                             "arity mismatch: ~s expected ~s argument(s) but received ~s",
-                            [v.displayName, v.racketArity, arguments.length - 2]);
+                            [v.displayName, v.racketArity, args.length - 2]);
                         return fail(new baselib.exceptions.RacketError(
                             msg,
                             baselib.exceptions.makeExnFailContractArity(msg,
@@ -177,10 +185,10 @@
 
                     MACHINE.c.push(
                         new baselib.frames.CallFrame(afterGoodInvoke, v));
-                    MACHINE.a = arguments.length - 2;
+                    MACHINE.a = args.length - 2;
                     var i;
-                    for (i = 0; i < arguments.length - 2; i++) {
-                        MACHINE.e.push(arguments[arguments.length - 1 - i]);
+                    for (i = 0; i < args.length - 2; i++) {
+                        MACHINE.e.push(args[args.length - 1 - i]);
                     }
                     MACHINE.p = v;
                     MACHINE.params['currentErrorHandler'] = function (MACHINE, e) {
@@ -191,7 +199,6 @@
                         fail(e);
                         
                     };                    
-                    releaseLock();
                     MACHINE.trampoline(v.label);
                 });
         };
@@ -222,15 +229,20 @@
     // internallCallDuringPause: call a Racket procedure and get its results.
     // The use assumes the machine is in a running-but-paused state.
     var internalCallDuringPause = function (MACHINE, proc, success, fail) {
-        MACHINE.exclusiveLock.acquire(
+        var args = [];
+        var i;
+        for (i = 0; i < arguments.length; i++) {
+            args.push(arguments[i]);
+        }
+       MACHINE.exclusiveLock.acquire(
             "internal call during pause",
             function(releaseLock) {
-
+                releaseLock();
                 var i;
                 var oldArgcount, oldVal, oldProc, oldErrorHandler;
-                if (! baselib.arity.isArityMatching(proc.racketArity, arguments.length - 4)) {
+                if (! baselib.arity.isArityMatching(proc.racketArity, args.length - 4)) {
                     var msg = baselib.format.format("arity mismatch: ~s expected ~s arguments, but received ~s",
-                                                    [proc.displayName, proc.racketArity, arguments.length - 4]);
+                                                    [proc.displayName, proc.racketArity, args.length - 4]);
                     return fail(baselib.exceptions.makeExnFailContractArity(msg,
                                                                             MACHINE.captureContinuationMarks()));
                 }
@@ -268,9 +280,9 @@
 
                     MACHINE.c.push(
                         new baselib.frames.CallFrame(afterGoodInvoke, proc));
-                    MACHINE.a = arguments.length - 4;
-                    for (i = 0; i < arguments.length - 4; i++) {
-                        MACHINE.e.push(arguments[arguments.length - 1 - i]);
+                    MACHINE.a = args.length - 4;
+                    for (i = 0; i < args.length - 4; i++) {
+                        MACHINE.e.push(args[args.length - 1 - i]);
                     }
                     MACHINE.p = proc;
                     MACHINE.params['currentErrorHandler'] = function (MACHINE, e) {
@@ -281,7 +293,6 @@
                         fail(e);
                     };
 
-                    releaseLock();
                     MACHINE.trampoline(proc.label);
                     
                 } else {
diff --git a/js-assembler/runtime-src/runtime.js b/js-assembler/runtime-src/runtime.js
index 398fb9e..9045c05 100644
--- a/js-assembler/runtime-src/runtime.js
+++ b/js-assembler/runtime-src/runtime.js
@@ -191,29 +191,36 @@
         if (id === undefined) {
             id = ExclusiveLock.makeRandomNonce();
         }
+
+        var alreadyReleased = false;
+
         // Allow for re-entrancy if the id is the same as the
         // entity who is locking.
         if (this.locked === false || this.locked === id) {
             this.locked = id;
-            setTimeout(
+            onAcquire.call(
+                that,
+                // releaseLock
                 function() {
-                    onAcquire.call(
-                        that,
-                        // NOTE: the caller must release the lock or else deadlock!
+                    setTimeout(
                         function() {
                             var waiter;
+                            if (alreadyReleased) {
+                                throw new Error(
+                                    "Internal error: trying to release the lock, but already released");
+                            }
                             if (that.locked === false) {
                                 throw new Error(
                                     "Internal error: trying to unlock the lock, but already unlocked");
                             }
                             that.locked = false;
+                            alreadyReleased = true;
                             if (that.waiters.length > 0) {
                                 waiter = that.waiters.shift();
                                 that.acquire(waiter.id, waiter.onAcquire);
                             }
-                        });
-                },
-                0);
+                        }, 0);
+                });
         } else {
             this.waiters.push({ id: id, 
                                 onAcquire: onAcquire } );
diff --git a/version.rkt b/version.rkt
index 750354d..f14d333 100644
--- a/version.rkt
+++ b/version.rkt
@@ -7,4 +7,4 @@
 (provide version)
 (: version String)
 
-(define version "1.100")
+(define version "1.101")