Fix memfs init racing with FS.staticInit. NFC (#24527)

sbc100 · web-flow · commit 48258d467002 · 2025-06-09T19:13:14.000Z
Fixes: #24523
diff --git a/src/lib/libmemfs.js b/src/lib/libmemfs.js
@@ -6,15 +6,6 @@
 
 addToLibrary({
   $MEMFS__deps: ['$FS', '$mmapAlloc'],
-#if !ASSERTIONS
-  $MEMFS__postset: `
-    // This error may happen quite a bit. To avoid overhead we reuse it (and
-    // suffer a lack of stack info).
-    MEMFS.doesNotExistError = new FS.ErrnoError({{{ cDefs.ENOENT }}});
-    /** @suppress {checkTypes} */
-    MEMFS.doesNotExistError.stack = '<generic error, no stack>';
-    `,
-#endif
   $MEMFS: {
     ops_table: null,
     mount(mount) {
@@ -183,6 +174,13 @@ addToLibrary({
 #if ASSERTIONS
         throw new FS.ErrnoError({{{ cDefs.ENOENT }}});
 #else
+        // This error may happen quite a bit. To avoid overhead we reuse it (and
+        // suffer a lack of stack info).
+        if (!MEMFS.doesNotExistError) {
+          MEMFS.doesNotExistError = new FS.ErrnoError({{{ cDefs.ENOENT }}});
+          /** @suppress {checkTypes} */
+          MEMFS.doesNotExistError.stack = '<generic error, no stack>';
+        }
         throw MEMFS.doesNotExistError;
 #endif
       },
diff --git a/test/other/codesize/test_codesize_cxx_ctors1.gzsize b/test/other/codesize/test_codesize_cxx_ctors1.gzsize
@@ -1 +1 @@
-8168
+8167
diff --git a/test/other/codesize/test_codesize_cxx_ctors1.jssize b/test/other/codesize/test_codesize_cxx_ctors1.jssize
@@ -1 +1 @@
-19792
+19798
diff --git a/test/other/codesize/test_codesize_cxx_ctors2.gzsize b/test/other/codesize/test_codesize_cxx_ctors2.gzsize
@@ -1 +1 @@
-8158
+8155
diff --git a/test/other/codesize/test_codesize_cxx_ctors2.jssize b/test/other/codesize/test_codesize_cxx_ctors2.jssize
@@ -1 +1 @@
-19770
+19776
diff --git a/test/other/codesize/test_codesize_cxx_except.gzsize b/test/other/codesize/test_codesize_cxx_except.gzsize
@@ -1 +1 @@
-9148
+9154
diff --git a/test/other/codesize/test_codesize_cxx_except.jssize b/test/other/codesize/test_codesize_cxx_except.jssize
@@ -1 +1 @@
-23452
+23459
diff --git a/test/other/codesize/test_codesize_cxx_except_wasm.gzsize b/test/other/codesize/test_codesize_cxx_except_wasm.gzsize
@@ -1 +1 @@
-8113
+8115
diff --git a/test/other/codesize/test_codesize_cxx_except_wasm.jssize b/test/other/codesize/test_codesize_cxx_except_wasm.jssize
@@ -1 +1 @@
-19681
+19687
diff --git a/test/other/codesize/test_codesize_cxx_except_wasm_legacy.gzsize b/test/other/codesize/test_codesize_cxx_except_wasm_legacy.gzsize
@@ -1 +1 @@
-8113
+8115
diff --git a/test/other/codesize/test_codesize_cxx_except_wasm_legacy.jssize b/test/other/codesize/test_codesize_cxx_except_wasm_legacy.jssize
@@ -1 +1 @@
-19681
+19687
diff --git a/test/other/codesize/test_codesize_cxx_lto.jssize b/test/other/codesize/test_codesize_cxx_lto.jssize
@@ -1 +1 @@
-19496
+19502
diff --git a/test/other/codesize/test_codesize_cxx_mangle.gzsize b/test/other/codesize/test_codesize_cxx_mangle.gzsize
@@ -1 +1 @@
-9167
+9171
diff --git a/test/other/codesize/test_codesize_cxx_mangle.jssize b/test/other/codesize/test_codesize_cxx_mangle.jssize
@@ -1 +1 @@
-23502
+23509
diff --git a/test/other/codesize/test_codesize_cxx_noexcept.gzsize b/test/other/codesize/test_codesize_cxx_noexcept.gzsize
@@ -1 +1 @@
-8168
+8167
diff --git a/test/other/codesize/test_codesize_cxx_noexcept.jssize b/test/other/codesize/test_codesize_cxx_noexcept.jssize
@@ -1 +1 @@
-19792
+19798
diff --git a/test/other/codesize/test_codesize_files_js_fs.gzsize b/test/other/codesize/test_codesize_files_js_fs.gzsize
@@ -1 +1 @@
-7473
+7480
diff --git a/test/other/codesize/test_codesize_files_js_fs.jssize b/test/other/codesize/test_codesize_files_js_fs.jssize
@@ -1 +1 @@
-18394
+18401
diff --git a/test/other/codesize/test_codesize_hello_dylink.gzsize b/test/other/codesize/test_codesize_hello_dylink.gzsize
@@ -1 +1 @@
-11653
+11659
diff --git a/test/other/codesize/test_codesize_hello_dylink.jssize b/test/other/codesize/test_codesize_hello_dylink.jssize
@@ -1 +1 @@
-27537
+27545
