/* ----------------------------------------------------------------------------
- * $Id: RtsAPI.c,v 1.29 2001/08/29 11:20:40 simonmar Exp $
*
* (c) The GHC Team, 1998-2001
*
#include "PosixSource.h"
#include "Rts.h"
+#include "OSThreads.h"
#include "Storage.h"
#include "RtsAPI.h"
#include "SchedAPI.h"
#include "RtsFlags.h"
#include "RtsUtils.h"
#include "Prelude.h"
+#include "Schedule.h"
+#include "Capability.h"
+
+#include <stdlib.h>
/* ----------------------------------------------------------------------------
Building Haskell objects from C datatypes.
------------------------------------------------------------------------- */
HaskellObj
-rts_mkChar (HsChar c)
+rts_mkChar (Capability *cap, HsChar c)
{
- StgClosure *p = (StgClosure *)allocate(CONSTR_sizeW(0,1));
+ StgClosure *p = (StgClosure *)allocateLocal(cap, CONSTR_sizeW(0,1));
SET_HDR(p, Czh_con_info, CCS_SYSTEM);
- p->payload[0] = (StgClosure *)(StgChar)c;
+ p->payload[0] = (StgClosure *)(StgWord)(StgChar)c;
return p;
}
HaskellObj
-rts_mkInt (HsInt i)
+rts_mkInt (Capability *cap, HsInt i)
{
- StgClosure *p = (StgClosure *)allocate(CONSTR_sizeW(0,1));
+ StgClosure *p = (StgClosure *)allocateLocal(cap,CONSTR_sizeW(0,1));
SET_HDR(p, Izh_con_info, CCS_SYSTEM);
p->payload[0] = (StgClosure *)(StgInt)i;
return p;
}
HaskellObj
-rts_mkInt8 (HsInt8 i)
+rts_mkInt8 (Capability *cap, HsInt8 i)
{
- StgClosure *p = (StgClosure *)allocate(CONSTR_sizeW(0,1));
+ StgClosure *p = (StgClosure *)allocateLocal(cap,CONSTR_sizeW(0,1));
SET_HDR(p, I8zh_con_info, CCS_SYSTEM);
/* Make sure we mask out the bits above the lowest 8 */
p->payload[0] = (StgClosure *)(StgInt)((unsigned)i & 0xff);
}
HaskellObj
-rts_mkInt16 (HsInt16 i)
+rts_mkInt16 (Capability *cap, HsInt16 i)
{
- StgClosure *p = (StgClosure *)allocate(CONSTR_sizeW(0,1));
+ StgClosure *p = (StgClosure *)allocateLocal(cap,CONSTR_sizeW(0,1));
SET_HDR(p, I16zh_con_info, CCS_SYSTEM);
/* Make sure we mask out the relevant bits */
p->payload[0] = (StgClosure *)(StgInt)((unsigned)i & 0xffff);
}
HaskellObj
-rts_mkInt32 (HsInt32 i)
+rts_mkInt32 (Capability *cap, HsInt32 i)
{
- StgClosure *p = (StgClosure *)allocate(CONSTR_sizeW(0,1));
+ StgClosure *p = (StgClosure *)allocateLocal(cap,CONSTR_sizeW(0,1));
SET_HDR(p, I32zh_con_info, CCS_SYSTEM);
p->payload[0] = (StgClosure *)(StgInt)((unsigned)i & 0xffffffff);
return p;
}
HaskellObj
-rts_mkInt64 (HsInt64 i)
+rts_mkInt64 (Capability *cap, HsInt64 i)
{
- long long *tmp;
- StgClosure *p = (StgClosure *)allocate(CONSTR_sizeW(0,2));
+ llong *tmp;
+ StgClosure *p = (StgClosure *)allocateLocal(cap,CONSTR_sizeW(0,2));
SET_HDR(p, I64zh_con_info, CCS_SYSTEM);
- tmp = (long long*)&(p->payload[0]);
+ tmp = (llong*)&(p->payload[0]);
*tmp = (StgInt64)i;
return p;
}
HaskellObj
-rts_mkWord (HsWord i)
+rts_mkWord (Capability *cap, HsWord i)
{
- StgClosure *p = (StgClosure *)allocate(CONSTR_sizeW(0,1));
+ StgClosure *p = (StgClosure *)allocateLocal(cap,CONSTR_sizeW(0,1));
SET_HDR(p, Wzh_con_info, CCS_SYSTEM);
p->payload[0] = (StgClosure *)(StgWord)i;
return p;
}
HaskellObj
-rts_mkWord8 (HsWord8 w)
+rts_mkWord8 (Capability *cap, HsWord8 w)
{
/* see rts_mkInt* comments */
- StgClosure *p = (StgClosure *)allocate(CONSTR_sizeW(0,1));
+ StgClosure *p = (StgClosure *)allocateLocal(cap,CONSTR_sizeW(0,1));
SET_HDR(p, W8zh_con_info, CCS_SYSTEM);
p->payload[0] = (StgClosure *)(StgWord)(w & 0xff);
return p;
}
HaskellObj
-rts_mkWord16 (HsWord16 w)
+rts_mkWord16 (Capability *cap, HsWord16 w)
{
/* see rts_mkInt* comments */
- StgClosure *p = (StgClosure *)allocate(CONSTR_sizeW(0,1));
+ StgClosure *p = (StgClosure *)allocateLocal(cap,CONSTR_sizeW(0,1));
SET_HDR(p, W16zh_con_info, CCS_SYSTEM);
p->payload[0] = (StgClosure *)(StgWord)(w & 0xffff);
return p;
}
HaskellObj
-rts_mkWord32 (HsWord32 w)
+rts_mkWord32 (Capability *cap, HsWord32 w)
{
/* see rts_mkInt* comments */
- StgClosure *p = (StgClosure *)allocate(CONSTR_sizeW(0,1));
+ StgClosure *p = (StgClosure *)allocateLocal(cap,CONSTR_sizeW(0,1));
SET_HDR(p, W32zh_con_info, CCS_SYSTEM);
p->payload[0] = (StgClosure *)(StgWord)(w & 0xffffffff);
return p;
}
HaskellObj
-rts_mkWord64 (HsWord64 w)
+rts_mkWord64 (Capability *cap, HsWord64 w)
{
- unsigned long long *tmp;
+ ullong *tmp;
- StgClosure *p = (StgClosure *)allocate(CONSTR_sizeW(0,2));
+ StgClosure *p = (StgClosure *)allocateLocal(cap,CONSTR_sizeW(0,2));
/* see mk_Int8 comment */
SET_HDR(p, W64zh_con_info, CCS_SYSTEM);
- tmp = (unsigned long long*)&(p->payload[0]);
+ tmp = (ullong*)&(p->payload[0]);
*tmp = (StgWord64)w;
return p;
}
HaskellObj
-rts_mkFloat (HsFloat f)
+rts_mkFloat (Capability *cap, HsFloat f)
{
- StgClosure *p = (StgClosure *)allocate(CONSTR_sizeW(0,1));
+ StgClosure *p = (StgClosure *)allocateLocal(cap,CONSTR_sizeW(0,1));
SET_HDR(p, Fzh_con_info, CCS_SYSTEM);
ASSIGN_FLT((P_)p->payload, (StgFloat)f);
return p;
}
HaskellObj
-rts_mkDouble (HsDouble d)
+rts_mkDouble (Capability *cap, HsDouble d)
{
- StgClosure *p = (StgClosure *)allocate(CONSTR_sizeW(0,sizeofW(StgDouble)));
+ StgClosure *p = (StgClosure *)allocateLocal(cap,CONSTR_sizeW(0,sizeofW(StgDouble)));
SET_HDR(p, Dzh_con_info, CCS_SYSTEM);
ASSIGN_DBL((P_)p->payload, (StgDouble)d);
return p;
}
HaskellObj
-rts_mkStablePtr (HsStablePtr s)
+rts_mkStablePtr (Capability *cap, HsStablePtr s)
{
- StgClosure *p = (StgClosure *)allocate(sizeofW(StgHeader)+1);
+ StgClosure *p = (StgClosure *)allocateLocal(cap,sizeofW(StgHeader)+1);
SET_HDR(p, StablePtr_con_info, CCS_SYSTEM);
p->payload[0] = (StgClosure *)s;
return p;
}
HaskellObj
-rts_mkPtr (HsPtr a)
+rts_mkPtr (Capability *cap, HsPtr a)
{
- StgClosure *p = (StgClosure *)allocate(sizeofW(StgHeader)+1);
+ StgClosure *p = (StgClosure *)allocateLocal(cap,sizeofW(StgHeader)+1);
SET_HDR(p, Ptr_con_info, CCS_SYSTEM);
p->payload[0] = (StgClosure *)a;
return p;
}
-#ifdef COMPILER /* GHC has em, Hugs doesn't */
HaskellObj
-rts_mkBool (HsBool b)
+rts_mkFunPtr (Capability *cap, HsFunPtr a)
+{
+ StgClosure *p = (StgClosure *)allocateLocal(cap,sizeofW(StgHeader)+1);
+ SET_HDR(p, FunPtr_con_info, CCS_SYSTEM);
+ p->payload[0] = (StgClosure *)a;
+ return p;
+}
+
+HaskellObj
+rts_mkBool (Capability *cap STG_UNUSED, HsBool b)
{
if (b) {
return (StgClosure *)True_closure;
}
HaskellObj
-rts_mkString (char *s)
+rts_mkString (Capability *cap, char *s)
{
- return rts_apply((StgClosure *)unpackCString_closure, rts_mkPtr(s));
+ return rts_apply(cap, (StgClosure *)unpackCString_closure, rts_mkPtr(cap,s));
}
-#endif /* COMPILER */
HaskellObj
-rts_apply (HaskellObj f, HaskellObj arg)
+rts_apply (Capability *cap, HaskellObj f, HaskellObj arg)
{
- StgAP_UPD *ap = (StgAP_UPD *)allocate(AP_sizeW(1));
- SET_HDR(ap, &stg_AP_UPD_info, CCS_SYSTEM);
- ap->n_args = 1;
- ap->fun = f;
- ap->payload[0] = arg;
- return (StgClosure *)ap;
+ StgThunk *ap;
+
+ ap = (StgThunk *)allocateLocal(cap,sizeofW(StgThunk) + 2);
+ SET_HDR(ap, (StgInfoTable *)&stg_ap_2_upd_info, CCS_SYSTEM);
+ ap->payload[0] = f;
+ ap->payload[1] = arg;
+ return (StgClosure *)ap;
}
/* ----------------------------------------------------------------------------
Deconstructing Haskell objects
+
+ We would like to assert that we have the right kind of object in
+ each case, but this is problematic because in GHCi the info table
+ for the D# constructor (say) might be dynamically loaded. Hence we
+ omit these assertions for now.
------------------------------------------------------------------------- */
HsChar
rts_getChar (HaskellObj p)
{
- if ( p->header.info == Czh_con_info ||
- p->header.info == Czh_static_info) {
+ // See comment above:
+ // ASSERT(p->header.info == Czh_con_info ||
+ // p->header.info == Czh_static_info);
return (StgChar)(StgWord)(p->payload[0]);
- } else {
- barf("rts_getChar: not a Char");
- }
}
HsInt
rts_getInt (HaskellObj p)
{
- if ( 1 ||
- p->header.info == Izh_con_info ||
- p->header.info == Izh_static_info ) {
+ // See comment above:
+ // ASSERT(p->header.info == Izh_con_info ||
+ // p->header.info == Izh_static_info);
return (HsInt)(p->payload[0]);
- } else {
- barf("rts_getInt: not an Int");
- }
}
HsInt8
rts_getInt8 (HaskellObj p)
{
- if ( 1 ||
- p->header.info == I8zh_con_info ||
- p->header.info == I8zh_static_info ) {
+ // See comment above:
+ // ASSERT(p->header.info == I8zh_con_info ||
+ // p->header.info == I8zh_static_info);
return (HsInt8)(HsInt)(p->payload[0]);
- } else {
- barf("rts_getInt8: not an Int8");
- }
}
HsInt16
rts_getInt16 (HaskellObj p)
{
- if ( 1 ||
- p->header.info == I16zh_con_info ||
- p->header.info == I16zh_static_info ) {
+ // See comment above:
+ // ASSERT(p->header.info == I16zh_con_info ||
+ // p->header.info == I16zh_static_info);
return (HsInt16)(HsInt)(p->payload[0]);
- } else {
- barf("rts_getInt16: not an Int16");
- }
}
HsInt32
rts_getInt32 (HaskellObj p)
{
- if ( 1 ||
- p->header.info == I32zh_con_info ||
- p->header.info == I32zh_static_info ) {
- return (HsInt32)(p->payload[0]);
- } else {
- barf("rts_getInt32: not an Int32");
- }
+ // See comment above:
+ // ASSERT(p->header.info == I32zh_con_info ||
+ // p->header.info == I32zh_static_info);
+ return (HsInt32)(HsInt)(p->payload[0]);
}
HsInt64
rts_getInt64 (HaskellObj p)
{
- HsInt64* tmp;
- if ( 1 ||
- p->header.info == I64zh_con_info ||
- p->header.info == I64zh_static_info ) {
+ HsInt64* tmp;
+ // See comment above:
+ // ASSERT(p->header.info == I64zh_con_info ||
+ // p->header.info == I64zh_static_info);
tmp = (HsInt64*)&(p->payload[0]);
return *tmp;
- } else {
- barf("rts_getInt64: not an Int64");
- }
}
HsWord
rts_getWord (HaskellObj p)
{
- if ( 1 || /* see above comment */
- p->header.info == Wzh_con_info ||
- p->header.info == Wzh_static_info ) {
+ // See comment above:
+ // ASSERT(p->header.info == Wzh_con_info ||
+ // p->header.info == Wzh_static_info);
return (HsWord)(p->payload[0]);
- } else {
- barf("rts_getWord: not a Word");
- }
}
HsWord8
rts_getWord8 (HaskellObj p)
{
- if ( 1 || /* see above comment */
- p->header.info == W8zh_con_info ||
- p->header.info == W8zh_static_info ) {
+ // See comment above:
+ // ASSERT(p->header.info == W8zh_con_info ||
+ // p->header.info == W8zh_static_info);
return (HsWord8)(HsWord)(p->payload[0]);
- } else {
- barf("rts_getWord8: not a Word8");
- }
}
HsWord16
rts_getWord16 (HaskellObj p)
{
- if ( 1 || /* see above comment */
- p->header.info == W16zh_con_info ||
- p->header.info == W16zh_static_info ) {
+ // See comment above:
+ // ASSERT(p->header.info == W16zh_con_info ||
+ // p->header.info == W16zh_static_info);
return (HsWord16)(HsWord)(p->payload[0]);
- } else {
- barf("rts_getWord16: not a Word16");
- }
}
HsWord32
rts_getWord32 (HaskellObj p)
{
- if ( 1 || /* see above comment */
- p->header.info == W32zh_con_info ||
- p->header.info == W32zh_static_info ) {
- return (unsigned int)(p->payload[0]);
- } else {
- barf("rts_getWord: not a Word");
- }
+ // See comment above:
+ // ASSERT(p->header.info == W32zh_con_info ||
+ // p->header.info == W32zh_static_info);
+ return (HsWord32)(HsWord)(p->payload[0]);
}
HsWord64
rts_getWord64 (HaskellObj p)
{
- HsWord64* tmp;
- if ( 1 || /* see above comment */
- p->header.info == W64zh_con_info ||
- p->header.info == W64zh_static_info ) {
+ HsWord64* tmp;
+ // See comment above:
+ // ASSERT(p->header.info == W64zh_con_info ||
+ // p->header.info == W64zh_static_info);
tmp = (HsWord64*)&(p->payload[0]);
return *tmp;
- } else {
- barf("rts_getWord64: not a Word64");
- }
}
HsFloat
rts_getFloat (HaskellObj p)
{
- if ( p->header.info == Fzh_con_info ||
- p->header.info == Fzh_static_info ) {
+ // See comment above:
+ // ASSERT(p->header.info == Fzh_con_info ||
+ // p->header.info == Fzh_static_info);
return (float)(PK_FLT((P_)p->payload));
- } else {
- barf("rts_getFloat: not a Float");
- }
}
HsDouble
rts_getDouble (HaskellObj p)
{
- if ( p->header.info == Dzh_con_info ||
- p->header.info == Dzh_static_info ) {
+ // See comment above:
+ // ASSERT(p->header.info == Dzh_con_info ||
+ // p->header.info == Dzh_static_info);
return (double)(PK_DBL((P_)p->payload));
- } else {
- barf("rts_getDouble: not a Double");
- }
}
HsStablePtr
rts_getStablePtr (HaskellObj p)
{
- if ( p->header.info == StablePtr_con_info ||
- p->header.info == StablePtr_static_info ) {
+ // See comment above:
+ // ASSERT(p->header.info == StablePtr_con_info ||
+ // p->header.info == StablePtr_static_info);
return (StgStablePtr)(p->payload[0]);
- } else {
- barf("rts_getStablePtr: not a StablePtr");
- }
}
HsPtr
rts_getPtr (HaskellObj p)
{
- if ( p->header.info == Ptr_con_info ||
- p->header.info == Ptr_static_info ) {
+ // See comment above:
+ // ASSERT(p->header.info == Ptr_con_info ||
+ // p->header.info == Ptr_static_info);
+ return (Capability *)(p->payload[0]);
+}
+
+HsFunPtr
+rts_getFunPtr (HaskellObj p)
+{
+ // See comment above:
+ // ASSERT(p->header.info == FunPtr_con_info ||
+ // p->header.info == FunPtr_static_info);
return (void *)(p->payload[0]);
- } else {
- barf("rts_getPtr: not an Ptr");
- }
}
-#ifdef COMPILER /* GHC has em, Hugs doesn't */
HsBool
rts_getBool (HaskellObj p)
{
- if (p == True_closure) {
- return 1;
- } else if (p == False_closure) {
- return 0;
- } else {
- barf("rts_getBool: not a Bool");
- }
+ StgInfoTable *info;
+
+ info = get_itbl((StgClosure *)p);
+ if (info->srt_bitmap == 0) { // srt_bitmap is the constructor tag
+ return 0;
+ } else {
+ return 1;
+ }
+}
+
+/* -----------------------------------------------------------------------------
+ Creating threads
+ -------------------------------------------------------------------------- */
+
+INLINE_HEADER void pushClosure (StgTSO *tso, StgWord c) {
+ tso->sp--;
+ tso->sp[0] = (W_) c;
+}
+
+StgTSO *
+createGenThread (Capability *cap, nat stack_size, StgClosure *closure)
+{
+ StgTSO *t;
+#if defined(GRAN)
+ t = createThread (cap, stack_size, NO_PRI);
+#else
+ t = createThread (cap, stack_size);
+#endif
+ pushClosure(t, (W_)closure);
+ pushClosure(t, (W_)&stg_enter_info);
+ return t;
+}
+
+StgTSO *
+createIOThread (Capability *cap, nat stack_size, StgClosure *closure)
+{
+ StgTSO *t;
+#if defined(GRAN)
+ t = createThread (cap, stack_size, NO_PRI);
+#else
+ t = createThread (cap, stack_size);
+#endif
+ pushClosure(t, (W_)&stg_noforceIO_info);
+ pushClosure(t, (W_)&stg_ap_v_info);
+ pushClosure(t, (W_)closure);
+ pushClosure(t, (W_)&stg_enter_info);
+ return t;
+}
+
+/*
+ * Same as above, but also evaluate the result of the IO action
+ * to whnf while we're at it.
+ */
+
+StgTSO *
+createStrictIOThread(Capability *cap, nat stack_size, StgClosure *closure)
+{
+ StgTSO *t;
+#if defined(GRAN)
+ t = createThread(cap, stack_size, NO_PRI);
+#else
+ t = createThread(cap, stack_size);
+#endif
+ pushClosure(t, (W_)&stg_forceIO_info);
+ pushClosure(t, (W_)&stg_ap_v_info);
+ pushClosure(t, (W_)closure);
+ pushClosure(t, (W_)&stg_enter_info);
+ return t;
}
-#endif /* COMPILER */
/* ----------------------------------------------------------------------------
Evaluating Haskell expressions
------------------------------------------------------------------------- */
-SchedulerStatus
-rts_eval (HaskellObj p, /*out*/HaskellObj *ret)
+
+Capability *
+rts_eval (Capability *cap, HaskellObj p, /*out*/HaskellObj *ret)
{
- StgTSO *tso = createGenThread(RtsFlags.GcFlags.initialStkSize, p);
- scheduleThread(tso);
- return waitThread(tso, ret);
+ StgTSO *tso;
+
+ tso = createGenThread(cap, RtsFlags.GcFlags.initialStkSize, p);
+ return scheduleWaitThread(tso,ret,cap);
}
-SchedulerStatus
-rts_eval_ (HaskellObj p, unsigned int stack_size, /*out*/HaskellObj *ret)
+Capability *
+rts_eval_ (Capability *cap, HaskellObj p, unsigned int stack_size,
+ /*out*/HaskellObj *ret)
{
- StgTSO *tso = createGenThread(stack_size, p);
- scheduleThread(tso);
- return waitThread(tso, ret);
+ StgTSO *tso;
+
+ tso = createGenThread(cap, stack_size, p);
+ return scheduleWaitThread(tso,ret,cap);
}
/*
* rts_evalIO() evaluates a value of the form (IO a), forcing the action's
* result to WHNF before returning.
*/
-SchedulerStatus
-rts_evalIO (HaskellObj p, /*out*/HaskellObj *ret)
+Capability *
+rts_evalIO (Capability *cap, HaskellObj p, /*out*/HaskellObj *ret)
{
- StgTSO* tso = createStrictIOThread(RtsFlags.GcFlags.initialStkSize, p);
- scheduleThread(tso);
- return waitThread(tso, ret);
+ StgTSO* tso;
+
+ tso = createStrictIOThread(cap, RtsFlags.GcFlags.initialStkSize, p);
+ return scheduleWaitThread(tso,ret,cap);
+}
+
+/*
+ * rts_evalStableIO() is suitable for calling from Haskell. It
+ * evaluates a value of the form (StablePtr (IO a)), forcing the
+ * action's result to WHNF before returning. The result is returned
+ * in a StablePtr.
+ */
+Capability *
+rts_evalStableIO (Capability *cap, HsStablePtr s, /*out*/HsStablePtr *ret)
+{
+ StgTSO* tso;
+ StgClosure *p, *r;
+ SchedulerStatus stat;
+
+ p = (StgClosure *)deRefStablePtr(s);
+ tso = createStrictIOThread(cap, RtsFlags.GcFlags.initialStkSize, p);
+ cap = scheduleWaitThread(tso,&r,cap);
+ stat = rts_getSchedStatus(cap);
+
+ if (stat == Success && ret != NULL) {
+ ASSERT(r != NULL);
+ *ret = getStablePtr((StgPtr)r);
+ }
+
+ return cap;
}
/*
* Like rts_evalIO(), but doesn't force the action's result.
*/
-SchedulerStatus
-rts_evalLazyIO (HaskellObj p, unsigned int stack_size, /*out*/HaskellObj *ret)
+Capability *
+rts_evalLazyIO (Capability *cap, HaskellObj p, /*out*/HaskellObj *ret)
{
- StgTSO *tso = createIOThread(stack_size, p);
- scheduleThread(tso);
- return waitThread(tso, ret);
+ StgTSO *tso;
+
+ tso = createIOThread(cap, RtsFlags.GcFlags.initialStkSize, p);
+ return scheduleWaitThread(tso,ret,cap);
+}
+
+Capability *
+rts_evalLazyIO_ (Capability *cap, HaskellObj p, unsigned int stack_size,
+ /*out*/HaskellObj *ret)
+{
+ StgTSO *tso;
+
+ tso = createIOThread(cap, stack_size, p);
+ return scheduleWaitThread(tso,ret,cap);
}
/* Convenience function for decoding the returned status. */
void
-rts_checkSchedStatus ( char* site, SchedulerStatus rc )
+rts_checkSchedStatus (char* site, Capability *cap)
{
+ SchedulerStatus rc = cap->running_task->stat;
switch (rc) {
case Success:
return;
case Killed:
- barf("%s: uncaught exception",site);
+ errorBelch("%s: uncaught exception",site);
+ stg_exit(EXIT_FAILURE);
case Interrupted:
- barf("%s: interrupted", site);
- case Deadlock:
- barf("%s: no threads to run: infinite loop or deadlock?", site);
+ errorBelch("%s: interrupted", site);
+ stg_exit(EXIT_FAILURE);
default:
- barf("%s: Return code (%d) not ok",(site),(rc));
+ errorBelch("%s: Return code (%d) not ok",(site),(rc));
+ stg_exit(EXIT_FAILURE);
}
}
+
+SchedulerStatus
+rts_getSchedStatus (Capability *cap)
+{
+ return cap->running_task->stat;
+}
+
+Capability *
+rts_lock (void)
+{
+ Capability *cap;
+ Task *task;
+
+ // ToDo: get rid of this lock in the common case. We could store
+ // a free Task in thread-local storage, for example. That would
+ // leave just one lock on the path into the RTS: cap->lock when
+ // acquiring the Capability.
+ ACQUIRE_LOCK(&sched_mutex);
+ task = newBoundTask();
+ RELEASE_LOCK(&sched_mutex);
+
+ cap = NULL;
+ waitForReturnCapability(&cap, task);
+ return (Capability *)cap;
+}
+
+// Exiting the RTS: we hold a Capability that is not necessarily the
+// same one that was originally returned by rts_lock(), because
+// rts_evalIO() etc. may return a new one. Now that we have
+// investigated the return value, we can release the Capability,
+// and free the Task (in that order).
+
+void
+rts_unlock (Capability *cap)
+{
+ Task *task;
+
+ task = cap->running_task;
+ ASSERT_FULL_CAPABILITY_INVARIANTS(cap,task);
+
+ // slightly delicate ordering of operations below, pay attention!
+
+ // We are no longer a bound task/thread. This is important,
+ // because the GC can run when we release the Capability below,
+ // and we don't want it to treat this as a live TSO pointer.
+ task->tso = NULL;
+
+ // Now release the Capability. With the capability released, GC
+ // may happen. NB. does not try to put the current Task on the
+ // worker queue.
+ releaseCapability(cap);
+
+ // Finally, we can release the Task to the free list.
+ boundTaskExiting(task);
+}
projects / ghc-hetmet.git / blobdiff