Initial import

third_party/dlmalloc/dlmalloc_stats.c

@@ -0,0 +1,47 @@
+#include "third_party/dlmalloc/dlmalloc.h"
+#include "libc/mem/mem.h"
+#include "libc/str/str.h"
+
+/**
+ * Prints on stderr the amount of space obtained from the system (both
+ * via sbrk and mmap), the maximum amount (which may be more than
+ * current if malloc_trim and/or munmap got called), and the current
+ * number of bytes allocated via malloc (or realloc, etc) but not yet
+ * freed. Note that this is the number of bytes allocated, not the
+ * number requested. It will be larger than the number requested because
+ * of alignment and bookkeeping overhead. Because it includes alignment
+ * wastage as being in use, this figure may be greater than zero even
+ * when no user-level chunks are allocated.
+ *
+ * The reported current and maximum system memory can be inaccurate if a
+ * program makes other calls to system memory allocation functions
+ * (normally sbrk) outside of malloc.
+ *
+ * malloc_stats prints only the most commonly interesting statistics.
+ * More information can be obtained by calling mallinfo.
+ */
+struct MallocStats dlmalloc_stats(mstate m) {
+  struct MallocStats res;
+  memset(&res, 0, sizeof(res));
+  ensure_initialization();
+  if (!PREACTION(m)) {
+    check_malloc_state(m);
+    if (is_initialized(m)) {
+      msegmentptr s = &m->seg;
+      res.maxfp = m->max_footprint;
+      res.fp = m->footprint;
+      res.used = res.fp - (m->topsize + TOP_FOOT_SIZE);
+      while (s != 0) {
+        mchunkptr q = align_as_chunk(s->base);
+        while (segment_holds(s, q) && q != m->top &&
+               q->head != FENCEPOST_HEAD) {
+          if (!is_inuse(q)) res.used -= chunksize(q);
+          q = next_chunk(q);
+        }
+        s = s->next;
+      }
+    }
+    POSTACTION(m); /* drop lock */
+  }
+  return res;
+}