1 files changed, 131 insertions, 0 deletions
diff --git a/vere/pkg/noun/events.h b/vere/pkg/noun/events.h
new file mode 100644
index 0000000..d9cdb50
--- /dev/null
+++ b/vere/pkg/noun/events.h
@@ -0,0 +1,131 @@
+/// @file
+
+#ifndef U3_EVENTS_H
+#define U3_EVENTS_H
+
+#include "c3/c3.h"
+#include "allocate.h"
+#include "version.h"
+
+  /** Data structures.
+  **/
+    /* u3e_line: control line.
+    */
+      typedef struct _u3e_line {
+        c3_w pag_w;
+        c3_w has_w;
+      } u3e_line;
+
+    /* u3e_control: memory change, control file.
+    */
+      typedef struct _u3e_control {
+        u3e_version ver_w;                  //  version number
+        c3_w        has_w;                  //  control checksum
+        c3_w        tot_w;                  //  new page count
+        c3_w        pgs_w;                  //  number of changed pages
+        u3e_line    mem_u[];                //  per page
+      } u3e_control;
+
+    /* u3_cs_patch: memory change, top level.
+    */
+      typedef struct _u3_cs_patch {
+        c3_i         ctl_i;
+        c3_i         mem_i;
+        c3_w         sip_w;
+        u3e_control* con_u;
+      } u3_ce_patch;
+
+    /* u3e_image: memory segment, open file.
+    */
+      typedef struct _u3e_image {
+        c3_c* nam_c;                        //  segment name
+        c3_i  fid_i;                        //  open file, or 0
+        c3_w  pgs_w;                        //  length in pages
+      } u3e_image;
+
+    /* u3e_pool: entire memory system.
+    */
+      typedef struct _u3e_pool {
+        c3_c*     dir_c;                     //  path to
+        c3_i      eph_i;                     //  ephemeral file descriptor
+        c3_w      dit_w[u3a_pages >> 5];     //  touched since last save
+        c3_w      pag_w;                     //  number of pages (<= u3a_pages)
+        c3_w      gar_w;                     //  guard page
+        u3e_image img_u;                     //  image
+      } u3e_pool;
+
+    /* u3e_flaw: loom fault result.
+    */
+      typedef enum {
+        u3e_flaw_sham = 0,                  //  bogus state
+        u3e_flaw_base = 1,                  //  vm fail (mprotect)
+        u3e_flaw_meme = 2,                  //  bail:meme
+        u3e_flaw_good = 3                   //  handled
+      } u3e_flaw;
+
+  /** Globals.
+  **/
+      /// Snapshotting system.
+      extern u3e_pool u3e_Pool;
+#     define u3P u3e_Pool
+
+  /** Constants.
+  **/
+
+  /** Functions.
+  **/
+    /* u3e_backup(): copy the snapshot from [pux_c] to [pax_c],
+     * overwriting optional.
+    */
+      c3_o
+      u3e_backup(c3_c* pux_c, c3_c* pax_c, c3_o ovw_o);
+
+    /* u3e_fault(): handle a memory fault.
+    */
+      u3e_flaw
+      u3e_fault(u3_post low_p, u3_post hig_p, u3_post off_p);
+
+    /* u3e_save(): update the checkpoint.
+    */
+      void
+      u3e_save(u3_post low_p, u3_post hig_p);
+
+    /* u3e_toss(): discard ephemeral pages.
+    */
+      void
+      u3e_toss(u3_post low_p, u3_post hig_p);
+
+    /* u3e_live(): start the persistence system.  Return c3y if no image.
+    */
+      c3_o
+      u3e_live(c3_o nuu_o, c3_c* dir_c);
+
+    /* u3e_stop(): gracefully stop the persistence system.
+    */
+      void
+      u3e_stop(void);
+
+    /* u3e_yolo(): disable dirty page tracking, read/write whole loom.
+    */
+      c3_o
+      u3e_yolo(void);
+
+    /* u3e_foul(): dirty all the pages of the loom.
+    */
+      void
+      u3e_foul(void);
+
+    /* u3e_init(): initialize guard page tracking.
+    */
+      void
+      u3e_init(void);
+
+    /* u3e_ward(): reposition guard page if needed.
+    */
+      void
+      u3e_ward(u3_post low_p, u3_post hig_p);
+
+      c3_i
+      u3e_image_open_any(c3_c* nam_c, c3_c* dir_c, c3_z* len_z);
+
+#endif /* ifndef U3_EVENTS_H */