remove empty dir

[ghc-hetmet.git] / ghc / includes / Closures.h

diff --git a/ghc/includes/Closures.h b/ghc/includes/Closures.h
index 39af80e..3df208c 100644 (file)
--- a/ghc/includes/Closures.h
+++ b/ghc/includes/Closures.h
@@ -36,9 +36,15 @@ typedef struct {
 
 /* -----------------------------------------------------------------------------
    The SMP header
-
-   In SMP mode, we have an extra word of padding in a thunk's header.
-   (Note: thunks only; other closures do not have this padding word).
+   
+   A thunk has a padding word to take the updated value.  This is so
+   that the update doesn't overwrite the payload, so we can avoid
+   needing to lock the thunk during entry and update.
+   
+   Note: this doesn't apply to THUNK_STATICs, which have no payload.
+
+   Note: we leave this padding word in all ways, rather than just SMP,
+   so that we don't have to recompile all our libraries for SMP.
    -------------------------------------------------------------------------- */
 
 typedef struct {
@@ -62,13 +68,6 @@ typedef struct {
 #endif
 } StgHeader;
 
-/*
- * In SMP mode, a thunk has a padding word to take the updated value.
- * This is so that the update doesn't overwrite the payload, so we can
- * avoid needing to lock the thunk during entry and update.
- *
- * Note: this doesn't apply to THUNK_STATICs, which have no payload.
- */
 typedef struct {
     const struct _StgInfoTable* info;
 #ifdef PROFILING
@@ -77,11 +76,11 @@ typedef struct {
 #ifdef GRAN
     StgGranHeader         gran;
 #endif
-#ifdef SMP
     StgSMPThunkHeader     smp;
-#endif
 } StgThunkHeader;
 
+#define THUNK_EXTRA_HEADER_W (sizeofW(StgThunkHeader)-sizeofW(StgHeader))
+
 /* -----------------------------------------------------------------------------
    Closure Types
 
@@ -189,11 +188,6 @@ typedef struct {
   StgHeader  header;
 } StgRetry;
 
-typedef struct _StgForeignObj {
-  StgHeader      header;
-  StgAddr        data;         /* pointer to data in non-haskell-land */
-} StgForeignObj;
-  
 typedef struct _StgStableName {
   StgHeader      header;
   StgWord        sn;
@@ -327,6 +321,7 @@ typedef struct {
   StgClosure*     value;
 } StgMVar;
 
+
 /* STM data structures
  *
  *  StgTVar defines the only type that can be updated through the STM
@@ -343,6 +338,11 @@ typedef struct {
  *   - In StgTRecHeader, it might be worthwhile having separate chunks
  *     of read-only and read-write locations.  This would save a
  *     new_value field in the read-only locations.
+ *
+ *   - In StgAtomicallyFrame, we could combine the waiting bit into
+ *     the header (maybe a different info tbl for a waiting transaction).
+ *     This means we can specialise the code for the atomically frame
+ *     (it immediately switches on frame->waiting anyway).
  */
 
 typedef struct StgTVarWaitQueue_ {
@@ -354,8 +354,11 @@ typedef struct StgTVarWaitQueue_ {
 
 typedef struct {
   StgHeader                  header;
-  StgClosure                *current_value;
-  StgTVarWaitQueue          *first_wait_queue_entry;
+  StgClosure                *volatile current_value;
+  StgTVarWaitQueue          *volatile first_wait_queue_entry;
+#if defined(THREADED_RTS)
+  StgInt                     volatile num_updates;
+#endif
 } StgTVar;
 
 /* new_value == expected_value for read-only accesses */
@@ -364,9 +367,12 @@ typedef struct {
   StgTVar                   *tvar;
   StgClosure                *expected_value;
   StgClosure                *new_value; 
+#if defined(THREADED_RTS)
+  StgInt                     num_updates;
+#endif
 } TRecEntry;
 
-#define TREC_CHUNK_NUM_ENTRIES 256
+#define TREC_CHUNK_NUM_ENTRIES 16
 
 typedef struct StgTRecChunk_ {
   StgHeader                  header;
@@ -377,8 +383,7 @@ typedef struct StgTRecChunk_ {
 
 typedef enum { 
   TREC_ACTIVE,        /* Transaction in progress, outcome undecided */
-  TREC_CANNOT_COMMIT, /* Transaction in progress, inconsistent writes performed */
-  TREC_MUST_ABORT,    /* Transaction in progress, inconsistent / out of date reads */
+  TREC_CONDEMNED,     /* Transaction in progress, inconsistent / out of date reads */
   TREC_COMMITTED,     /* Transaction has committed, now updating tvars */
   TREC_ABORTED,       /* Transaction has aborted, now reverting tvars */
   TREC_WAITING,       /* Transaction currently waiting */
@@ -393,7 +398,6 @@ typedef struct StgTRecHeader_ {
 
 typedef struct {
     StgHeader   header;
-    StgBool     waiting;
     StgClosure *code;
 } StgAtomicallyFrame;