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Diffstat (limited to 'includes/rts/storage/TSO.h')
| -rw-r--r-- | includes/rts/storage/TSO.h | 206 |
1 files changed, 206 insertions, 0 deletions
diff --git a/includes/rts/storage/TSO.h b/includes/rts/storage/TSO.h new file mode 100644 index 0000000000..7cb245909f --- /dev/null +++ b/includes/rts/storage/TSO.h @@ -0,0 +1,206 @@ +/* ----------------------------------------------------------------------------- + * + * (c) The GHC Team, 1998-2009 + * + * The definitions for Thread State Objects. + * + * ---------------------------------------------------------------------------*/ + +#ifndef RTS_STORAGE_TSO_H +#define RTS_STORAGE_TSO_H + +/* + * PROFILING info in a TSO + */ +typedef struct { + CostCentreStack *CCCS; /* thread's current CCS */ +} StgTSOProfInfo; + +/* + * There is no TICKY info in a TSO at this time. + */ + +/* + * Thread IDs are 32 bits. + */ +typedef StgWord32 StgThreadID; + +#define tsoDirty(tso) ((tso)->flags & TSO_DIRTY) +#define tsoLocked(tso) ((tso)->flags & TSO_LOCKED) + +/* + * Type returned after running a thread. Values of this type + * include HeapOverflow, StackOverflow etc. See Constants.h for the + * full list. + */ +typedef unsigned int StgThreadReturnCode; + +#if defined(mingw32_HOST_OS) +/* results from an async I/O request + its request ID. */ +typedef struct { + unsigned int reqID; + int len; + int errCode; +} StgAsyncIOResult; +#endif + +/* Reason for thread being blocked. See comment above struct StgTso_. */ +typedef union { + StgClosure *closure; + struct StgTSO_ *tso; + StgInt fd; /* StgInt instead of int, so that it's the same size as the ptrs */ +#if defined(mingw32_HOST_OS) + StgAsyncIOResult *async_result; +#endif + StgWord target; +} StgTSOBlockInfo; + + +/* + * TSOs live on the heap, and therefore look just like heap objects. + * Large TSOs will live in their own "block group" allocated by the + * storage manager, and won't be copied during garbage collection. + */ + +/* + * Threads may be blocked for several reasons. A blocked thread will + * have the reason in the why_blocked field of the TSO, and some + * further info (such as the closure the thread is blocked on, or the + * file descriptor if the thread is waiting on I/O) in the block_info + * field. + */ + +typedef struct StgTSO_ { + StgHeader header; + + /* The link field, for linking threads together in lists (e.g. the + run queue on a Capability. + */ + struct StgTSO_* _link; + /* + NOTE!!! do not modify _link directly, it is subject to + a write barrier for generational GC. Instead use the + setTSOLink() function. Exceptions to this rule are: + + * setting the link field to END_TSO_QUEUE + * putting a TSO on the blackhole_queue + * setting the link field of the currently running TSO, as it + will already be dirty. + */ + + struct StgTSO_* global_link; /* Links all threads together */ + + StgWord16 what_next; /* Values defined in Constants.h */ + StgWord16 why_blocked; /* Values defined in Constants.h */ + StgWord32 flags; + StgTSOBlockInfo block_info; + StgThreadID id; + int saved_errno; + struct Task_* bound; + struct Capability_* cap; + struct StgTRecHeader_ * trec; /* STM transaction record */ + + /* + A list of threads blocked on this TSO waiting to throw + exceptions. In order to access this field, the TSO must be + locked using lockClosure/unlockClosure (see SMP.h). + */ + struct StgTSO_ * blocked_exceptions; + +#ifdef TICKY_TICKY + /* TICKY-specific stuff would go here. */ +#endif +#ifdef PROFILING + StgTSOProfInfo prof; +#endif +#ifdef mingw32_HOST_OS + StgWord32 saved_winerror; +#endif + + /* The thread stack... */ + StgWord32 stack_size; /* stack size in *words* */ + StgWord32 max_stack_size; /* maximum stack size in *words* */ + StgPtr sp; + + StgWord stack[FLEXIBLE_ARRAY]; +} *StgTSOPtr; + +/* ----------------------------------------------------------------------------- + functions + -------------------------------------------------------------------------- */ + +void dirty_TSO (Capability *cap, StgTSO *tso); +void setTSOLink (Capability *cap, StgTSO *tso, StgTSO *target); + +/* ----------------------------------------------------------------------------- + Invariants: + + An active thread has the following properties: + + tso->stack < tso->sp < tso->stack+tso->stack_size + tso->stack_size <= tso->max_stack_size + + RESERVED_STACK_WORDS is large enough for any heap-check or + stack-check failure. + + The size of the TSO struct plus the stack is either + (a) smaller than a block, or + (b) a multiple of BLOCK_SIZE + + tso->why_blocked tso->block_info location + ---------------------------------------------------------------------- + NotBlocked NULL runnable_queue, or running + + BlockedOnBlackHole the BLACKHOLE blackhole_queue + + BlockedOnMVar the MVAR the MVAR's queue + + BlockedOnSTM END_TSO_QUEUE STM wait queue(s) + + BlockedOnException the TSO TSO->blocked_exception + + BlockedOnRead NULL blocked_queue + BlockedOnWrite NULL blocked_queue + BlockedOnDelay NULL blocked_queue + BlockedOnGA closure TSO blocks on BQ of that closure + BlockedOnGA_NoSend closure TSO blocks on BQ of that closure + + tso->link == END_TSO_QUEUE, if the thread is currently running. + + A zombie thread has the following properties: + + tso->what_next == ThreadComplete or ThreadKilled + tso->link == (could be on some queue somewhere) + tso->su == tso->stack + tso->stack_size + tso->sp == tso->stack + tso->stack_size - 1 (i.e. top stack word) + tso->sp[0] == return value of thread, if what_next == ThreadComplete, + exception , if what_next == ThreadKilled + + (tso->sp is left pointing at the top word on the stack so that + the return value or exception will be retained by a GC). + + The 2 cases BlockedOnGA and BlockedOnGA_NoSend are needed in a GUM + setup only. They mark a TSO that has entered a FETCH_ME or + FETCH_ME_BQ closure, respectively; only the first TSO hitting the + closure will send a Fetch message. + Currently we have no separate code for blocking on an RBH; we use the + BlockedOnBlackHole case for that. -- HWL + + ---------------------------------------------------------------------------- */ + +/* Workaround for a bug/quirk in gcc on certain architectures. + * symptom is that (&tso->stack - &tso->header) /= sizeof(StgTSO) + * in other words, gcc pads the structure at the end. + */ + +extern StgTSO dummy_tso; + +#define TSO_STRUCT_SIZE \ + ((char *)&dummy_tso.stack - (char *)&dummy_tso.header) + +#define TSO_STRUCT_SIZEW (TSO_STRUCT_SIZE / sizeof(W_)) + +/* this is the NIL ptr for a TSO queue (e.g. runnable queue) */ +#define END_TSO_QUEUE ((StgTSO *)(void*)&stg_END_TSO_QUEUE_closure) + +#endif /* RTS_STORAGE_TSO_H */ |