Initial import

third_party/dlmalloc/malloc_set_footprint_limit.c

@@ -0,0 +1,25 @@
+#include "libc/limits.h"
+#include "libc/mem/mem.h"
+#include "third_party/dlmalloc/dlmalloc.h"
+
+/**
+ * Sets the maximum number of bytes to obtain from the system, causing
+ * failure returns from malloc and related functions upon attempts to
+ * exceed this value. The argument value may be subject to page rounding
+ * to an enforceable limit; this actual value is returned. Using an
+ * argument of the maximum possible size_t effectively disables checks.
+ * If the argument is less than or equal to the current
+ * malloc_footprint, then all future allocations that require additional
+ * system memory will fail. However, invocation cannot retroactively
+ * deallocate existing used memory.
+ */
+size_t malloc_set_footprint_limit(size_t bytes) {
+  size_t result;                                 /* invert sense of 0 */
+  if (bytes == 0) result = granularity_align(1); /* Use minimal size */
+  if (bytes == SIZE_MAX) {
+    result = 0; /* disable */
+  } else {
+    result = granularity_align(bytes);
+  }
+  return gm->footprint_limit = result;
+}