fix(transform-metering): only enable meters; the host has to disable

Agoric · Feb 12, 2020 · d1b8e84 · d1b8e84
1 parent 53c4549
commit d1b8e84
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Showing 12 changed files with 46 additions and 30 deletions.
diff --git a/packages/tame-metering/src/tame.js b/packages/tame-metering/src/tame.js
@@ -71,6 +71,14 @@ export function tameMetering() {
       // The wrapper needs construct behaviour.
       isConstructor = true;
       wrapper = function meteredConstructor(...args) {
+        if (!globalMeter) {
+          // Fast path.
+          const newTarget = new.target;
+          if (newTarget) {
+            return construct(target, args, newTarget);
+          }
+          return apply(target, this, args);
+        }
         // We're careful not to use the replaceGlobalMeter function as
         // it may consume some stack.
         // Instead, directly manipulate the globalMeter variable.
@@ -116,6 +124,10 @@ export function tameMetering() {
       const { name = '' } = target;
       ({ [name]: wrapper } = {
         [name](...args) {
+          // Fast path:
+          if (!globalMeter) {
+            return apply(target, this, args);
+          }
           // We're careful not to use the replaceGlobalMeter function as
           // it may consume some stack.
           // Instead, directly manipulate the globalMeter variable.

diff --git a/packages/transform-metering/README.md b/packages/transform-metering/README.md
@@ -19,7 +19,7 @@ import { makeMeteredEvaluator } from '@agoric/transform-metering';
 // Create a new SES instance (root realm).
 const sesRealm = SES1.makeSESRootRealm({
   shims: [SES1TameMeteringShim],
-  deoptimizeStableGlobals: true,
+  configurableGlobals: true,
 });
 
 const replaceGlobalMeter = SES1ReplaceGlobalMeter(sesRealm);
@@ -30,7 +30,15 @@ const meteredEval = makeMeteredEvaluator({
   // Needed for source transforms that prevent runaways.
   babelCore,
   // Create an object with an `evaluate(src, endowments, options)` method
-  makeEvaluator: opts => sesRealm.global.Realm.makeCompartment(opts);
+  makeEvaluator: opts => {
+    const c = sesRealm.global.Realm.makeCompartment(opts);
+    // FIXME: Realms bug doesn't propagate global properties.
+    Object.defineProperties(
+      c.global,
+      Object.getOwnPropertyDescriptors(sesRealm.global),
+    );
+    return c;
+  },
   // Call a callback when the code inside the meteredEval is done evaluating.
   quiesceCallback: cb => setTimeout(cb),
 });

diff --git a/packages/transform-metering/src/evaluator.js b/packages/transform-metering/src/evaluator.js
@@ -38,8 +38,12 @@ export function makeMeteredEvaluator({
 
       if (typeof srcOrThunk === 'string') {
         // Transform the source on our own budget, then evaluate against the meter.
-        endowments.getGlobalMeter = m =>
-          m === true ? meter : replaceGlobalMeter(m);
+        endowments.getGlobalMeter = m => {
+          if (m !== true) {
+            replaceGlobalMeter(meter);
+          }
+          return meter;
+        };
         returned = ev.evaluate(srcOrThunk, endowments);
       } else {
         // Evaluate the thunk with the specified meter.

diff --git a/packages/transform-metering/src/transform.js b/packages/transform-metering/src/transform.js
@@ -192,10 +192,10 @@ const ${reid}=RegExp(${JSON.stringify(pattern)},${JSON.stringify(flags)});`);
 
       // Meter by the regular expressions in use.
       const regexpSource = regexpList.join('');
-      const preSource = `const ${getMeterId}=getGlobalMeter;const ${meterId}=${setMeterId}(true);\
+      const preSource = `const ${getMeterId}=getGlobalMeter;const ${meterId}=${getMeterId}();\
 ${meterId}&&${meterId}.${c.METER_ENTER}();\
 try{${regexpSource}`;
-      const postSource = `\n}finally{${setMeterId}(false);${meterId} && ${meterId}.${c.METER_LEAVE}();}`;
+      const postSource = `\n}finally{${meterId} && ${meterId}.${c.METER_LEAVE}();}`;
 
       // Force into an IIFE, if necessary.
       const maybeSource = output.code;
@@ -212,14 +212,6 @@ try{${regexpSource}`;
 
       // console.log('metered source:', `\n${actualSource}`);
 
-      // Install the specified user meter.
-      const savedMeter = endowments.getGlobalMeter();
-      endowments[setMeterId] = set => {
-        const m = set ? meter : savedMeter;
-        endowments.getGlobalMeter(m);
-        return m;
-      };
-
       return {
         ...ss,
         ast,

diff --git a/packages/transform-metering/testdata/arrow-function-block/rewrite.js b/packages/transform-metering/testdata/arrow-function-block/rewrite.js
@@ -1,3 +1,3 @@
-const $h‍_meter_get=getGlobalMeter;const $m=$h‍_meter_set(true);$m&&$m.e();try{() => {const $m = $h‍_meter_get();$m && $m.e();try {
+const $h‍_meter_get=getGlobalMeter;const $m=$h‍_meter_get();$m&&$m.e();try{() => {const $m = $h‍_meter_get();$m && $m.e();try {
     f();} finally {$m && $m.l();}};
-}finally{$h‍_meter_set(false);$m && $m.l();}
+}finally{$m && $m.l();}
diff --git a/packages/transform-metering/testdata/arrow-function-expression/rewrite.js b/packages/transform-metering/testdata/arrow-function-expression/rewrite.js
@@ -1,3 +1,3 @@
-const $h‍_meter_get=getGlobalMeter;const $m=$h‍_meter_set(true);$m&&$m.e();try{() => {const $m = $h‍_meter_get();$m && $m.e();try {return (
+const $h‍_meter_get=getGlobalMeter;const $m=$h‍_meter_get();$m&&$m.e();try{() => {const $m = $h‍_meter_get();$m && $m.e();try {return (
       f());} finally {$m && $m.l();}};
-}finally{$h‍_meter_set(false);$m && $m.l();}
+}finally{$m && $m.l();}
diff --git a/packages/transform-metering/testdata/classes/rewrite.js b/packages/transform-metering/testdata/classes/rewrite.js
@@ -1,5 +1,5 @@
-const $h‍_meter_get=getGlobalMeter;const $m=$h‍_meter_set(true);$m&&$m.e();try{class Abc {
+const $h‍_meter_get=getGlobalMeter;const $m=$h‍_meter_get();$m&&$m.e();try{class Abc {
   f() {const $m = $h‍_meter_get();$m && $m.e();try {
       return doit();
     } finally {$m && $m.l();}}}
-}finally{$h‍_meter_set(false);$m && $m.l();}
+}finally{$m && $m.l();}
diff --git a/packages/transform-metering/testdata/concise-method/rewrite.js b/packages/transform-metering/testdata/concise-method/rewrite.js
@@ -1,5 +1,5 @@
-const $h‍_meter_get=getGlobalMeter;const $m=$h‍_meter_set(true);$m&&$m.e();try{a = {
+const $h‍_meter_get=getGlobalMeter;const $m=$h‍_meter_get();$m&&$m.e();try{a = {
   f() {const $m = $h‍_meter_get();$m && $m.e();try {
       doit();
     } finally {$m && $m.l();}} };
-}finally{$h‍_meter_set(false);$m && $m.l();}
+}finally{$m && $m.l();}
diff --git a/packages/transform-metering/testdata/for-loops/rewrite.js b/packages/transform-metering/testdata/for-loops/rewrite.js
@@ -1,9 +1,9 @@
-const $h‍_meter_get=getGlobalMeter;const $m=$h‍_meter_set(true);$m&&$m.e();try{for (const f of b) {$m && $m.c();
+const $h‍_meter_get=getGlobalMeter;const $m=$h‍_meter_get();$m&&$m.e();try{for (const f of b) {$m && $m.c();
   doit(f);}
 
 for (const p in bar) {$m && $m.c();
   doit(p);}
 
 for (let i = 0; i < 3; i++) {$m && $m.c();
   doit(i);}
-}finally{$h‍_meter_set(false);$m && $m.l();}
+}finally{$m && $m.l();}
diff --git a/packages/transform-metering/testdata/function-expression/rewrite.js b/packages/transform-metering/testdata/function-expression/rewrite.js
@@ -1,4 +1,4 @@
-const $h‍_meter_get=getGlobalMeter;const $m=$h‍_meter_set(true);$m&&$m.e();try{(function () {const $m = $h‍_meter_get();$m && $m.e();try {
+const $h‍_meter_get=getGlobalMeter;const $m=$h‍_meter_get();$m&&$m.e();try{(function () {const $m = $h‍_meter_get();$m && $m.e();try {
     f();
   } finally {$m && $m.l();}});
-}finally{$h‍_meter_set(false);$m && $m.l();}
+}finally{$m && $m.l();}
diff --git a/packages/transform-metering/testdata/regexp-literal/rewrite.js b/packages/transform-metering/testdata/regexp-literal/rewrite.js
@@ -1,4 +1,4 @@
-const $h‍_meter_get=getGlobalMeter;const $m=$h‍_meter_set(true);$m&&$m.e();try{const $re_0=RegExp("^my-favourite-regexp","");if ($re_0.test('myf')) {
+const $h‍_meter_get=getGlobalMeter;const $m=$h‍_meter_get();$m&&$m.e();try{const $re_0=RegExp("^my-favourite-regexp","");if ($re_0.test('myf')) {
   doit();
 }
-}finally{$h‍_meter_set(false);$m && $m.l();}
+}finally{$m && $m.l();}
diff --git a/packages/transform-metering/testdata/while-loops/rewrite.js b/packages/transform-metering/testdata/while-loops/rewrite.js
@@ -1,4 +1,4 @@
-const $h‍_meter_get=getGlobalMeter;const $m=$h‍_meter_set(true);$m&&$m.e();try{while (a) {$m && $m.c();}
+const $h‍_meter_get=getGlobalMeter;const $m=$h‍_meter_get();$m&&$m.e();try{while (a) {$m && $m.c();}
 
 while (a) {$m && $m.c();doit();}
 
@@ -9,4 +9,4 @@ while (a) {$m && $m.c();
 do {$m && $m.c();
   doit();} while (
 a);
-}finally{$h‍_meter_set(false);$m && $m.l();}
+}finally{$m && $m.l();}