Add support for modifying decay timer.

Add the mallopt function, and only a single option so far.

Bug: 36401135

Test: Built and booted bullhead.
Test: Ran jemalloc unit tests.
Test: Ran bionic unit tests.
Test: Ran a test that allocated and free'd a large piece of memory,
Test: and verified that after changing the parameter, the PSS
Test: sticks around (decay timer set to 1), the PSS is purged (decay
Test: timer set to 0).
Change-Id: I6927929b0c539c1023d34772d9e26bb6a8a45877

1 files changed, 7 insertions, 0 deletions

diff --git a/tests/malloc_test.cpp b/tests/malloc_test.cpp
index 8fba1c449..a7b9d52e5 100644
--- a/tests/malloc_test.cpp
+++ b/tests/malloc_test.cpp
@@ -500,3 +500,10 @@ TEST(malloc, verify_alignment) {
   delete[] values_64;
   delete[] values_ldouble;
 }
+
+TEST(malloc, mallopt_smoke) {
+  errno = 0;
+  ASSERT_EQ(0, mallopt(-1000, 1));
+  // mallopt doesn't set errno.
+  ASSERT_EQ(0, errno);
+}