1 files changed, 22 insertions, 0 deletions
diff --git a/src/w32-thread.c b/src/w32-thread.c
index 6860075..aef421f 100644
--- a/src/w32-thread.c
+++ b/src/w32-thread.c
@@ -35,10 +35,32 @@
 
 #include "thread.h"
 
+/*
+ * Functions called before and after blocking syscalls.
+ * gpgrt_set_syscall_clamp is used to set them.
+ */
+static void (*pre_syscall_func)(void);
+static void (*post_syscall_func)(void);
+
+
+/* Helper to set the clamp functions.  This is called as a helper from
+ * _gpgrt_set_syscall_clamp to keep the function pointers local. */
+void
+_gpgrt_thread_set_syscall_clamp (void (*pre)(void), void (*post)(void))
+{
+  pre_syscall_func = pre;
+  post_syscall_func = post;
+}
+
+
 
 gpg_err_code_t
 _gpgrt_yield (void)
 {
+  if (pre_syscall_func)
+    pre_syscall_func ();
   Sleep (0);
+  if (post_syscall_func)
+    post_syscall_func ();
   return 0;
 }