fix(orchestration): fix race in getChain

Agoric · Oct 4, 2024 · 609867c · 609867c
1 parent 2ab7df9
commit 609867c
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Showing 2 changed files with 41 additions and 21 deletions.
diff --git a/packages/orchestration/src/exos/orchestrator.js b/packages/orchestration/src/exos/orchestrator.js
@@ -67,7 +67,12 @@ const prepareOrchestratorKit = (
     vowTools: { watch, asVow },
   },
 ) => {
-  /** @type {MapStore<string, HostInterface<Chain>>} */
+  /**
+   * @template T
+   * @typedef {{ vow: Vow<T>; pending: true } | { value: T; pending: false }} MaybePendingValue
+   */
+
+  /** @type {MapStore<string, MaybePendingValue<HostInterface<Chain>>>} */
   const chainByName = zone.mapStore('chainName');
 
   return zone.exoClassKit(
@@ -98,7 +103,7 @@ const prepareOrchestratorKit = (
          */
         onFulfilled(agoricChainInfo) {
           const it = makeLocalChainFacade(agoricChainInfo);
-          chainByName.init('agoric', it);
+          chainByName.set('agoric', harden({ value: it, pending: false }));
           return it;
         },
       },
@@ -116,27 +121,32 @@ const prepareOrchestratorKit = (
          */
         onFulfilled([_agoricChainInfo, remoteChainInfo, connectionInfo], name) {
           const it = makeRemoteChainFacade(remoteChainInfo, connectionInfo);
-          chainByName.init(name, it);
+          chainByName.set(name, harden({ value: it, pending: false }));
           return it;
         },
       },
       orchestrator: {
         /** @type {HostOf<Orchestrator['getChain']>} */
         getChain(name) {
-          if (chainByName.has(name)) {
-            return asVow(() => chainByName.get(name));
-          }
-          if (name === 'agoric') {
-            return watch(
-              chainHub.getChainInfo('agoric'),
-              this.facets.makeLocalChainFacadeWatcher,
-            );
-          }
-          return watch(
-            chainHub.getChainsAndConnection('agoric', name),
-            this.facets.makeRemoteChainFacadeWatcher,
-            name,
-          );
+          return asVow(() => {
+            if (chainByName.has(name)) {
+              const maybeChain = chainByName.get(name);
+              return maybeChain.pending ? maybeChain.vow : maybeChain.value;
+            }
+            const vow =
+              name === 'agoric'
+                ? watch(
+                    chainHub.getChainInfo('agoric'),
+                    this.facets.makeLocalChainFacadeWatcher,
+                  )
+                : watch(
+                    chainHub.getChainsAndConnection('agoric', name),
+                    this.facets.makeRemoteChainFacadeWatcher,
+                    name,
+                  );
+            chainByName.init(name, harden({ vow, pending: true }));
+            return vow;
+          });
         },
         makeLocalAccount() {
           return watch(E(localchain).makeAccount());
@@ -148,10 +158,18 @@ const prepareOrchestratorKit = (
           const { chainName, baseName, baseDenom, brand } = denomDetail;
           chainByName.has(chainName) ||
             Fail`use getChain(${q(chainName)}) before getDenomInfo(${q(denom)})`;
-          const chain = chainByName.get(chainName);
+          const maybeChain = chainByName.get(chainName);
+          if (maybeChain.pending) {
+            throw Fail`wait until getChain(${q(chainName)}) completes before getDenomInfo(${q(denom)})`;
+          }
+          const chain = maybeChain.value;
           chainByName.has(baseName) ||
             Fail`use getChain(${q(baseName)}) before getDenomInfo(${q(denom)})`;
-          const base = chainByName.get(baseName);
+          const maybeBase = chainByName.get(baseName);
+          if (maybeBase.pending) {
+            throw Fail`wait until getChain(${q(baseName)}) completes before getDenomInfo(${q(denom)})`;
+          }
+          const base = maybeBase.value;
           return harden({ chain, base, brand, baseDenom });
         },
         /** @type {HostOf<Orchestrator['asAmount']>} */

diff --git a/packages/orchestration/test/facade-durability.test.ts b/packages/orchestration/test/facade-durability.test.ts
@@ -127,7 +127,7 @@ test.serial('faulty chain info', async t => {
   });
 });
 
-test.serial.failing('racy chain info', async t => {
+test.serial('racy chain info', async t => {
   const { facadeServices, commonPrivateArgs } = await commonSetup(t);
 
   // XXX relax again
@@ -244,7 +244,9 @@ test.serial('asset / denom info', async t => {
         });
       }
 
-      const ag = await orc.getChain('agoric');
+      const agP = orc.getChain('agoric');
+      t.throws(() => orc.getDenomInfo(agDenom));
+      const ag = await agP;
       {
         const actual = orc.getDenomInfo(agDenom);