Implement malloc_info(3).
Expose jemalloc stats through the malloc_info(3) interface.
Bug: 16874689
Change-Id: I4358ac283002e60ff161107028d1a3fb1e9afb0a
diff --git a/libc/bionic/malloc_info.cpp b/libc/bionic/malloc_info.cpp
new file mode 100644
index 0000000..99caedb
--- /dev/null
+++ b/libc/bionic/malloc_info.cpp
@@ -0,0 +1,94 @@
+/*
+ * 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 "malloc_info.h"
+
+#include <errno.h>
+#include "private/bionic_macros.h"
+
+class __LIBC_HIDDEN__ Elem {
+public:
+ // name must be valid throughout lifetime of the object.
+ explicit Elem(FILE* fp, const char* name,
+ const char* attr_fmt = nullptr, ...) {
+ this->fp = fp;
+ this->name = name;
+
+ fprintf(fp, "<%s", name);
+ if (attr_fmt != nullptr) {
+ va_list args;
+ va_start(args, attr_fmt);
+ fputc(' ', fp);
+ vfprintf(fp, attr_fmt, args);
+ va_end(args);
+ }
+ fputc('>', fp);
+ }
+
+ ~Elem() noexcept {
+ fprintf(fp, "</%s>", name);
+ }
+
+ void contents(const char* fmt, ...) {
+ va_list args;
+ va_start(args, fmt);
+ vfprintf(fp, fmt, args);
+ va_end(args);
+ }
+
+private:
+ FILE* fp;
+ const char* name;
+
+ DISALLOW_COPY_AND_ASSIGN(Elem);
+};
+
+int malloc_info(int options, FILE* fp) {
+ if (options != 0) {
+ errno = EINVAL;
+ return -1;
+ }
+
+ Elem root(fp, "malloc", "version=\"jemalloc-1\"");
+
+ // Dump all of the large allocations in the arenas.
+ for (size_t i = 0; i < __mallinfo_narenas(); i++) {
+ struct mallinfo mi = __mallinfo_arena_info(i);
+ if (mi.hblkhd != 0) {
+ Elem arena_elem(fp, "heap", "nr=\"%d\"", i);
+ {
+ Elem(fp, "allocated-large").contents("%zu", mi.ordblks);
+ Elem(fp, "allocated-huge").contents("%zu", mi.uordblks);
+ Elem(fp, "allocated-bins").contents("%zu", mi.fsmblks);
+
+ size_t total = 0;
+ for (size_t j = 0; j < __mallinfo_nbins(); j++) {
+ struct mallinfo mi = __mallinfo_bin_info(i, j);
+ if (mi.ordblks != 0) {
+ Elem bin_elem(fp, "bin", "nr=\"%d\"", j);
+ Elem(fp, "allocated").contents("%zu", mi.ordblks);
+ Elem(fp, "nmalloc").contents("%zu", mi.uordblks);
+ Elem(fp, "ndalloc").contents("%zu", mi.fordblks);
+ total += mi.ordblks;
+ }
+ }
+ Elem(fp, "bins-total").contents("%zu", total);
+ }
+ }
+ }
+
+ return 0;
+}