js/src/jsapi-tests/testExternalStrings.cpp

   1 /* This Source Code Form is subject to the terms of the Mozilla Public
   2  * License, v. 2.0. If a copy of the MPL was not distributed with this
   3  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   4
   5 #include "jsapi-tests/tests.h"
   6 #include "util/Text.h"
   7
   8 static const char16_t arr[] = u"hi, don't delete me";
   9 static const size_t arrlen = js_strlen(arr);
  10
  11 static int finalized1 = 0;
  12 static int finalized2 = 0;
  13
  14 struct ExternalStringCallbacks : public JSExternalStringCallbacks {
  15   int* finalizedCount = nullptr;
  16
  17   explicit ExternalStringCallbacks(int* finalizedCount)
  18       : finalizedCount(finalizedCount) {}
  19
  20   void finalize(char16_t* chars) const override {
  21     MOZ_ASSERT(chars == arr);
  22     (*finalizedCount)++;
  23   }
  24
  25   size_t sizeOfBuffer(const char16_t* chars,
  26                       mozilla::MallocSizeOf mallocSizeOf) const override {
  27     MOZ_CRASH("Unexpected call");
  28   }
  29 };
  30
  31 static const ExternalStringCallbacks callbacks1(&finalized1);
  32 static const ExternalStringCallbacks callbacks2(&finalized2);
  33
  34 BEGIN_TEST(testExternalStrings) {
  35   const unsigned N = 1000;
  36
  37   for (unsigned i = 0; i < N; ++i) {
  38     CHECK(JS_NewExternalString(cx, arr, arrlen, &callbacks1));
  39     CHECK(JS_NewExternalString(cx, arr, arrlen, &callbacks2));
  40   }
  41
  42   JS_GC(cx);
  43
  44   // a generous fudge factor to account for strings rooted by conservative gc
  45   const unsigned epsilon = 10;
  46
  47   CHECK((N - finalized1) < epsilon);
  48   CHECK((N - finalized2) < epsilon);
  49
  50   return true;
  51 }
  52 END_TEST(testExternalStrings)