Support for jemalloc to replace dlmalloc.

To use jemalloc, add MALLOC_IMPL = jemalloc in a board config file
and you get the new version automatically.

Update the pthread_create_key tests since jemalloc uses a few keys.
Add a new test to verify memalign works as expected.

Bug: 981363

Change-Id: I16eb152b291a95bd2499e90492fc6b4bd7053836
diff --git a/libc/bionic/jemalloc.cpp b/libc/bionic/jemalloc.cpp
new file mode 100644
index 0000000..625d789
--- /dev/null
+++ b/libc/bionic/jemalloc.cpp
@@ -0,0 +1,44 @@
+/*
+ * Copyright (C) 2014 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <unistd.h>
+
+#include "jemalloc.h"
+
+void* je_pvalloc(size_t bytes) {
+  size_t pagesize = sysconf(_SC_PAGESIZE);
+  return je_memalign(pagesize, (bytes + pagesize - 1) & ~(pagesize - 1));
+}
+
+#ifdef je_memalign
+#undef je_memalign
+#endif
+
+// The man page for memalign says it fails if boundary is not a power of 2,
+// but this is not true. Both glibc and dlmalloc round up to the next power
+// of 2, so we'll do the same.
+void* je_memalign_round_up_boundary(size_t boundary, size_t size) {
+  unsigned int power_of_2 = static_cast<unsigned int>(boundary);
+  if (power_of_2 != 0) {
+    power_of_2 = 1UL << (sizeof(unsigned int)*8 - 1 - __builtin_clz(power_of_2));
+    if (power_of_2 != boundary) {
+      boundary = power_of_2 << 1;
+    }
+  } else {
+    boundary = 1;
+  }
+  return je_memalign(boundary, size);
+}