From 66a0e6e0caccf66afc0667567aa6f6ab0ecf6375 Mon Sep 17 00:00:00 2001
From: Christian Thaeter <ct@pipapo.org>
Date: Mon, 18 Jan 2010 19:58:31 +0100
Subject: [PATCH] Experiment: remove custom states, syncs are 2-thread barriers

---
 src/backend/threads.c | 12 ++++++------
 src/backend/threads.h | 25 +++++++++++++------------
 2 files changed, 19 insertions(+), 18 deletions(-)

diff --git a/src/backend/threads.c b/src/backend/threads.c
index dfbcdadfe..4aeebbf23 100644
--- a/src/backend/threads.c
+++ b/src/backend/threads.c
@@ -288,14 +288,14 @@ lumiera_thread_deadline_clear (void)
 
 
 LumieraThread
-lumiera_thread_sync_other (LumieraThread other, int state)
+lumiera_thread_sync_other (LumieraThread other)
 {
   TRACE(threads);
 
   LUMIERA_CONDITION_SECTION (threads, &other->signal)
     {
-      REQUIRE (other->state == ~state);        TODO("Runtime error when state expectation isnt met");
-      other->state = state;
+      REQUIRE (other->state == LUMIERA_THREADSTATE_SYNCING);        TODO("Runtime error when state expectation isnt met");
+      other->state = LUMIERA_THREADSTATE_RUNNING;
       LUMIERA_CONDITION_SIGNAL;
     }
   return other;
@@ -303,18 +303,18 @@ lumiera_thread_sync_other (LumieraThread other, int state)
 
 
 LumieraThread
-lumiera_thread_sync (int state)
+lumiera_thread_sync (void)
 {
   TRACE(threads);
 
   LumieraThread self = lumiera_thread_self ();
   REQUIRE(self, "not a lumiera thread");
 
-  self->state = ~state;
+  self->state = LUMIERA_THREADSTATE_SYNCING;
 
   TODO("error handing, maybe timed mutex (using the threads heartbeat timeout, shortly before timeout)");
 
-  while (self->state != state) {
+  while (self->state == LUMIERA_THREADSTATE_SYNCING) {
     lumiera_condition_wait (&self->signal, &NOBUG_FLAG(threads), self->rh);
   }
 
diff --git a/src/backend/threads.h b/src/backend/threads.h
index 131d25911..980a168e3 100644
--- a/src/backend/threads.h
+++ b/src/backend/threads.h
@@ -103,6 +103,7 @@ extern const char* lumiera_threadclass_names[];
   LUMIERA_THREAD_STATE(ERROR)                        \
   LUMIERA_THREAD_STATE(IDLE)                         \
   LUMIERA_THREAD_STATE(RUNNING)                      \
+  LUMIERA_THREAD_STATE(SYNCING)                      \
   LUMIERA_THREAD_STATE(WAKEUP)                       \
   LUMIERA_THREAD_STATE(SHUTDOWN)                     \
   LUMIERA_THREAD_STATE(ZOMBIE)                       \
@@ -118,9 +119,6 @@ extern const char* lumiera_threadclass_names[];
 typedef enum
   {
     LUMIERA_THREAD_STATES
-
-    LUMIERA_THREADSTATE_CUSTOM_START = 1024,
-    LUMIERA_THREADSTATE_CUSTOM_END = 32768,
   }
   lumiera_thread_state;
 
@@ -152,7 +150,7 @@ struct lumiera_thread_struct
   int kind;
 
   // this is used both as a command and as a state tracker
-  int state;
+  lumiera_thread_state state;
   void (*function)(void *);
   void * arguments;
 };
@@ -249,30 +247,33 @@ lumiera_thread_deadline_clear (void);
 
 /**
  * Thread syncronization
- * Lumiera threads can be syncronized with custom states.
  * The syncronization primitives act as barrier over 2 threads, any thread reaching a syncronization
- * point first is blocked until the other one reaches it with the same state.
- * Providing different states is errorneous!
+ * point first is blocked until the other one reaches it too.
  */
 
 
 /**
  * Syncronize with another threads state
  *
- * this blocks until/unless the other thread reaches 'state'
+ * this blocks until/unless the other thread reaches a syncronization point
  */
 LumieraThread
-lumiera_thread_sync_other (LumieraThread other, int state);
+lumiera_thread_sync_other (LumieraThread other);
 
 /**
  * Syncronize current thread
  *
- * signifies that this thread reached 'state' and blocks until/unless
- * some other thread synced with this state
+ * this blocks until/unless the other thread reaches a syncronization point
  * @return on success pointer to self (opaque), or NULL on error
  */
 LumieraThread
-lumiera_thread_sync (int state);
+lumiera_thread_sync (void);
+
+// TODO implement timedsync, this is bit tricky because after a timeout, syncronization points are desynced
+// we possibly need some way to reset/resync this
+//LumieraThread
+//lumiera_thread_timedsync (struct timespec timeout);
+
 
 /**
  * Joining threads