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| author | Simon Marlow <simonmar@microsoft.com> | 2008-10-08 15:47:02 +0000 |
|---|---|---|
| committer | Simon Marlow <simonmar@microsoft.com> | 2008-10-08 15:47:02 +0000 |
| commit | 6cd3d0dc3021fb705fa7603f24afcb19b49f8b3b (patch) | |
| tree | 86cba45fbcac6228adf1d675d78476ea9de362b8 /rts | |
| parent | 739d8a5b677609d4c4477667b7ced7f352aaac87 (diff) | |
| download | haskell-6cd3d0dc3021fb705fa7603f24afcb19b49f8b3b.tar.gz | |
atomicModifyIORef: use a local cas() instead of the global lock
This should improve scaling when using atomicModifyIORef
Diffstat (limited to 'rts')
| -rw-r--r-- | rts/PrimOps.cmm | 29 |
1 files changed, 16 insertions, 13 deletions
diff --git a/rts/PrimOps.cmm b/rts/PrimOps.cmm index e754eb05bd..c666a4207b 100644 --- a/rts/PrimOps.cmm +++ b/rts/PrimOps.cmm @@ -193,7 +193,7 @@ newMutVarzh_fast atomicModifyMutVarzh_fast { - W_ mv, z, x, y, r; + W_ mv, f, z, x, y, r, h; /* Args: R1 :: MutVar#, R2 :: a -> (a,b) */ /* If x is the current contents of the MutVar#, then @@ -232,19 +232,15 @@ atomicModifyMutVarzh_fast HP_CHK_GEN_TICKY(SIZE, R1_PTR & R2_PTR, atomicModifyMutVarzh_fast); -#if defined(THREADED_RTS) - ACQUIRE_LOCK(atomic_modify_mutvar_mutex "ptr") [R1,R2]; -#endif - - x = StgMutVar_var(R1); + mv = R1; + f = R2; TICK_ALLOC_THUNK_2(); CCCS_ALLOC(THUNK_2_SIZE); z = Hp - THUNK_2_SIZE + WDS(1); SET_HDR(z, stg_ap_2_upd_info, W_[CCCS]); LDV_RECORD_CREATE(z); - StgThunk_payload(z,0) = R2; - StgThunk_payload(z,1) = x; + StgThunk_payload(z,0) = f; TICK_ALLOC_THUNK_1(); CCCS_ALLOC(THUNK_1_SIZE); @@ -253,9 +249,6 @@ atomicModifyMutVarzh_fast LDV_RECORD_CREATE(y); StgThunk_payload(y,0) = z; - StgMutVar_var(R1) = y; - foreign "C" dirty_MUT_VAR(BaseReg "ptr", R1 "ptr") [R1]; - TICK_ALLOC_THUNK_1(); CCCS_ALLOC(THUNK_1_SIZE); r = y - THUNK_1_SIZE; @@ -263,10 +256,20 @@ atomicModifyMutVarzh_fast LDV_RECORD_CREATE(r); StgThunk_payload(r,0) = z; -#if defined(THREADED_RTS) - RELEASE_LOCK(atomic_modify_mutvar_mutex "ptr") []; + retry: + x = StgMutVar_var(mv); + StgThunk_payload(z,1) = x; +#ifdef THREADED_RTS + (h) = foreign "C" cas(mv + SIZEOF_StgHeader + OFFSET_StgMutVar_var, x, y) []; + if (h != x) { goto retry; } +#else + StgMutVar_var(mv) = y; #endif + if (GET_INFO(mv) == stg_MUT_VAR_CLEAN_info) { + foreign "C" dirty_MUT_VAR(BaseReg "ptr", mv "ptr") []; + } + RET_P(r); } |