X-Git-Url: https://git.ozlabs.org/?a=blobdiff_plain;f=ccan%2Faltstack%2Faltstack.h;h=09ffe0b056b504ba99f5e8f176e6ceb9d5f14f52;hb=870b63169c782ef0cc52687397e5b9a7125a61b0;hp=5570e7b53031ad1716729a2596a31b90eb29ae53;hpb=e65a92188aa1ac4c27a86d427acdf09417595ade;p=ccan

diff --git a/ccan/altstack/altstack.h b/ccan/altstack/altstack.h
index 5570e7b5..09ffe0b0 100644
--- a/ccan/altstack/altstack.h
+++ b/ccan/altstack/altstack.h
@@ -52,7 +52,7 @@
  *	static void *wrap(void *i)
  *	{
  *		dn((unsigned long) i);
- *		return 0;
+ *		return NULL;
  *	}
  *
  *	#define MiB (1024UL*1024UL)
@@ -60,9 +60,9 @@
  *	{
  *		unsigned long n;
  *		assert(argc == 2);
- *		n = strtoul(argv[1], 0, 0);
+ *		n = strtoul(argv[1], NULL, 0);
  *
- *		if (altstack(32*MiB, wrap, (void *) n, 0) != 0)
+ *		if (altstack(32*MiB, wrap, (void *) n, NULL) != 0)
  *			altstack_perror();
  *
  *		printf("%d\n", depth);
@@ -103,6 +103,20 @@ char *altstack_geterr(void);
  */
 ptrdiff_t altstack_used(void);
 
+/**
+ * altstack_max - return usable stack size
+ *
+ * Returns: max value from altstack() call
+ */
+rlim_t altstack_max(void);
+
+/**
+ * altstack_remn - return amount of stack remaining
+ *
+ * Returns: altstack_max() minus altstack_used()
+ */
+#define altstack_remn() (altstack_max() - altstack_used())
+
 /**
  * altstack_rsp_save - set initial rsp value
  *