/* ---------------------------------------------------------------------------
*
- * (c) The GHC Team, 2001-2003
+ * (c) The GHC Team, 2001-2006
*
* Capabilities
*
* The notion of a capability is used when operating in multi-threaded
- * environments (which the SMP and Threads builds of the RTS do), to
+ * environments (which the THREADED_RTS build of the RTS does), to
* hold all the state an OS thread/task needs to run Haskell code:
* its STG registers, a pointer to its TSO, a nursery etc. During
* STG execution, a pointer to the capabilitity is kept in a
* register (BaseReg).
*
- * Only in an SMP build will there be multiple capabilities, the threaded
- * RTS and other non-threaded builds, there is one global capability,
- * namely MainRegTable.
+ * Only in an THREADED_RTS build will there be multiple capabilities,
+ * in the non-threaded builds there is one global capability, namely
+ * MainCapability.
*
* This header file contains the functions for working with capabilities.
* (the main, and only, consumer of this interface is the scheduler).
// this list.
Task *suspended_ccalling_tasks;
+ // One mutable list per generation, so we don't need to take any
+ // locks when updating an old-generation thunk. These
+ // mini-mut-lists are moved onto the respective gen->mut_list at
+ // each GC.
+ bdescr **mut_lists;
+
#if defined(THREADED_RTS)
// Worker Tasks waiting in the wings. Singly-linked.
Task *spare_workers;
Task *returning_tasks_hd; // Singly-linked, with head/tail
Task *returning_tasks_tl;
#endif
+
+ // Per-capability STM-related data
+ StgTVarWaitQueue *free_tvar_wait_queues;
+ StgTRecChunk *free_trec_chunks;
+ StgTRecHeader *free_trec_headers;
+ nat transaction_tokens;
}; // typedef Capability, defined in RtsAPI.h
+
+#if defined(THREADED_RTS)
+#define ASSERT_TASK_ID(task) ASSERT(task->id == osThreadId())
+#else
+#define ASSERT_TASK_ID(task) /*empty*/
+#endif
+
+// These properties should be true when a Task is holding a Capability
+#define ASSERT_FULL_CAPABILITY_INVARIANTS(cap,task) \
+ ASSERT(cap->running_task != NULL && cap->running_task == task); \
+ ASSERT(task->cap == cap); \
+ ASSERT_PARTIAL_CAPABILITY_INVARIANTS(cap,task)
+
+// Sometimes a Task holds a Capability, but the Task is not associated
+// with that Capability (ie. task->cap != cap). This happens when
+// (a) a Task holds multiple Capabilities, and (b) when the current
+// Task is bound, its thread has just blocked, and it may have been
+// moved to another Capability.
+#define ASSERT_PARTIAL_CAPABILITY_INVARIANTS(cap,task) \
+ ASSERT(cap->run_queue_hd == END_TSO_QUEUE ? \
+ cap->run_queue_tl == END_TSO_QUEUE : 1); \
+ ASSERT(myTask() == task); \
+ ASSERT_TASK_ID(task);
+
// Converts a *StgRegTable into a *Capability.
//
INLINE_HEADER Capability *
INLINE_HEADER void releaseCapability_ (Capability* cap STG_UNUSED) {};
#endif
-#if !IN_STG_CODE && !defined(SMP)
-// for non-SMP, we have one global capability
+#if !IN_STG_CODE
+// one global capability
extern Capability MainCapability;
#endif
//
void waitForReturnCapability (Capability **cap/*in/out*/, Task *task);
+INLINE_HEADER void recordMutableCap (StgClosure *p, Capability *cap, nat gen);
+
#if defined(THREADED_RTS)
// Gives up the current capability IFF there is a higher-priority
//
void shutdownCapability (Capability *cap, Task *task);
+// Attempt to gain control of a Capability if it is free.
+//
+rtsBool tryGrabCapability (Capability *cap, Task *task);
+
#else // !THREADED_RTS
// Grab a capability. (Only in the non-threaded RTS; in the threaded
#endif /* !THREADED_RTS */
+/* -----------------------------------------------------------------------------
+ * INLINE functions... private below here
+ * -------------------------------------------------------------------------- */
+
+INLINE_HEADER void
+recordMutableCap (StgClosure *p, Capability *cap, nat gen)
+{
+ bdescr *bd;
+
+ bd = cap->mut_lists[gen];
+ if (bd->free >= bd->start + BLOCK_SIZE_W) {
+ bdescr *new_bd;
+ new_bd = allocBlock_lock();
+ new_bd->link = bd;
+ bd = new_bd;
+ cap->mut_lists[gen] = bd;
+ }
+ *bd->free++ = (StgWord)p;
+}
+
#endif /* CAPABILITY_H */