RTS tidyup sweep, first phase

[ghc-hetmet.git] / rts / parallel / WSDeque.h

diff --git a/rts/parallel/WSDeque.h b/rts/parallel/WSDeque.h
deleted file mode 100644 (file)
index d85567c..0000000
--- a/rts/parallel/WSDeque.h
+++ /dev/null
@@ -1,126 +0,0 @@
-/* -----------------------------------------------------------------------------
- *
- * (c) The GHC Team, 2009
- *
- * Work-stealing Deque data structure
- * 
- * ---------------------------------------------------------------------------*/
-
-#ifndef WSDEQUE_H
-#define WSDEQUE_H
-
-typedef struct WSDeque_ {
-    // Size of elements array. Used for modulo calculation: we round up
-    // to powers of 2 and use the dyadic log (modulo == bitwise &) 
-    StgWord size; 
-    StgWord moduloSize; /* bitmask for modulo */
-
-    // top, index where multiple readers steal() (protected by a cas)
-    volatile StgWord top;
-
-    // bottom, index of next free place where one writer can push
-    // elements. This happens unsynchronised.
-    volatile StgWord bottom;
-
-    // both top and bottom are continuously incremented, and used as
-    // an index modulo the current array size.
-  
-    // lower bound on the current top value. This is an internal
-    // optimisation to avoid unnecessarily accessing the top field
-    // inside pushBottom
-    volatile StgWord topBound;
-
-    // The elements array
-    void ** elements;
-
-    //  Please note: the dataspace cannot follow the admin fields
-    //  immediately, as it should be possible to enlarge it without
-    //  disposing the old one automatically (as realloc would)!
-
-} WSDeque;
-
-/* INVARIANTS, in this order: reasonable size,
-   topBound consistent, space pointer, space accessible to us.
-   
-   NB. This is safe to use only (a) on a spark pool owned by the
-   current thread, or (b) when there's only one thread running, or no
-   stealing going on (e.g. during GC).
-*/
-#define ASSERT_WSDEQUE_INVARIANTS(p)         \
-  ASSERT((p)->size > 0);                        \
-  ASSERT((p)->topBound <= (p)->top);            \
-  ASSERT((p)->elements != NULL);                \
-  ASSERT(*((p)->elements) || 1);                \
-  ASSERT(*((p)->elements - 1  + ((p)->size)) || 1);
-
-// No: it is possible that top > bottom when using pop()
-//  ASSERT((p)->bottom >= (p)->top);           
-//  ASSERT((p)->size > (p)->bottom - (p)->top);
-
-/* -----------------------------------------------------------------------------
- * Operations
- *
- * A WSDeque has an *owner* thread.  The owner can perform any operation;
- * other threads are only allowed to call stealWSDeque_(),
- * stealWSDeque(), looksEmptyWSDeque(), and dequeElements().
- *
- * -------------------------------------------------------------------------- */
-
-// Allocation, deallocation
-WSDeque * newWSDeque  (nat size);
-void      freeWSDeque (WSDeque *q);
-
-// Take an element from the "write" end of the pool.  Can be called
-// by the pool owner only.
-void* popWSDeque (WSDeque *q);
-
-// Push onto the "write" end of the pool.  Return true if the push
-// succeeded, or false if the deque is full.
-rtsBool pushWSDeque (WSDeque *q, void *elem);
-
-// Removes all elements from the deque
-INLINE_HEADER void discardElements (WSDeque *q);
-
-// Removes an element of the deque from the "read" end, or returns
-// NULL if the pool is empty, or if there was a collision with another
-// thief.
-void * stealWSDeque_ (WSDeque *q);
-
-// Removes an element of the deque from the "read" end, or returns
-// NULL if the pool is empty.
-void * stealWSDeque (WSDeque *q);
-
-// "guesses" whether a deque is empty. Can return false negatives in
-//  presence of concurrent steal() calls, and false positives in
-//  presence of a concurrent pushBottom().
-INLINE_HEADER rtsBool looksEmptyWSDeque (WSDeque* q);
-
-INLINE_HEADER long dequeElements   (WSDeque *q);
-
-/* -----------------------------------------------------------------------------
- * PRIVATE below here
- * -------------------------------------------------------------------------- */
-
-INLINE_HEADER long
-dequeElements (WSDeque *q)
-{
-    StgWord t = q->top;
-    StgWord b = q->bottom;
-    // try to prefer false negatives by reading top first
-    return ((long)b - (long)t);
-}
-
-INLINE_HEADER rtsBool
-looksEmptyWSDeque (WSDeque *q)
-{
-    return (dequeElements(q) <= 0);
-}
-
-INLINE_HEADER void
-discardElements (WSDeque *q)
-{
-    q->top = q->bottom;
-//    pool->topBound = pool->top;
-}
-
-#endif // WSDEQUE_H