1 files changed, 29 insertions, 0 deletions
diff --git a/src/libstddjb/sig_stack.c b/src/libstddjb/sig_stack.c
new file mode 100644
index 0000000..c414a88
--- /dev/null
+++ b/src/libstddjb/sig_stack.c
@@ -0,0 +1,29 @@
+/* ISC license. */
+
+/* MT-unsafe */
+
+#include <errno.h>
+#include <signal.h>
+#include <skalibs/sig.h>
+#include <skalibs/nsig.h>
+
+static struct skasigaction skasigstack[NSIG][SIGSTACKSIZE] ;
+static unsigned int sigsp[NSIG] ;
+
+int sig_pusha (int sig, struct skasigaction const *ssa)
+{
+  if ((sig <= 0) || (sig > NSIG)) return (errno = EINVAL, -1) ;
+  if (sigsp[sig-1] >= SIGSTACKSIZE) return (errno = ENOBUFS, -1) ;
+  if (skasigaction(sig, ssa, &skasigstack[sig-1][sigsp[sig-1]]) == -1)
+      return -1 ;
+  return ++sigsp[sig-1] ;
+}
+
+int sig_pop (int sig)
+{
+  if ((sig <= 0) || (sig > NSIG)) return (errno = EINVAL, -1) ;
+  if (!sigsp[sig-1]) return (errno = EFAULT, -1);
+  if (skasigaction(sig, &skasigstack[sig-1][sigsp[sig-1]-1], 0) == -1)
+    return -1 ;
+  return --sigsp[sig-1] ;
+}