basic message passing working

1 files changed, 21 insertions, 6 deletions

diff --git a/lib/system/inboxes.nim b/lib/system/inboxes.nim
index 8f683f612..1f5d56c16 100644
--- a/lib/system/inboxes.nim
+++ b/lib/system/inboxes.nim
@@ -22,6 +22,8 @@ type
   PInbox = ptr TInbox

   TLoadStoreMode = enum mStore, mLoad

 

+const ThreadDeadMask = -2

+

 proc initInbox(p: pointer) =

   var inbox = cast[PInbox](p)

   initSysLock(inbox.lock)

@@ -30,6 +32,9 @@ proc initInbox(p: pointer) =
 

 proc freeInbox(p: pointer) =

   var inbox = cast[PInbox](p)

+  # we need to grab the lock to be save against sending threads!

+  acquireSys(inbox.lock)

+  inbox.mask = ThreadDeadMask

   deallocOsPages(inbox.region)

   deinitSys(inbox.lock)

   deinitSysCond(inbox.cond)

@@ -158,7 +163,6 @@ proc rawSend(q: PInbox, data: pointer, typ: PNimType) =
     q.mask = cap*2 - 1

     q.wr = q.count

     q.rd = 0

-    #echo "came here"

   storeAux(addr(q.data[q.wr * typ.size]), data, typ, q, mStore)

   inc q.count

   q.wr = (q.wr + 1) and q.mask

@@ -177,23 +181,34 @@ template lockInbox(q: expr, action: stmt) =
 proc send*[TMsg](receiver: var TThread[TMsg], msg: TMsg) =

   ## sends a message to a thread. `msg` is deeply copied.

   var q = cast[PInbox](getInBoxMem(receiver))

+  if q.mask == ThreadDeadMask:

+    raise newException(EDeadThread, "cannot send message; thread died")

   acquireSys(q.lock)

   var m: TMsg

   shallowCopy(m, msg)

-  rawSend(q, addr(m), cast[PNimType](getTypeInfo(msg)))

+  var typ = cast[PNimType](getTypeInfo(msg))

+  rawSend(q, addr(m), typ)

+  q.elemType = typ

   releaseSys(q.lock)

   SignalSysCond(q.cond)

 

-proc recv*[TMsg](): TMsg =

-  ## receives a message from its internal message queue. This blocks until

-  ## a message has arrived! You may use ``peek`` to avoid the blocking.

+proc llRecv(res: pointer, typ: PNimType) =

+  # to save space, the generic is as small as possible

   var q = cast[PInbox](getInBoxMem())

   acquireSys(q.lock)

   while q.count <= 0:

     WaitSysCond(q.cond, q.lock)

-  rawRecv(q, addr(result), cast[PNimType](getTypeInfo(result)))

+  if typ != q.elemType:

+    releaseSys(q.lock)

+    raise newException(EInvalidValue, "cannot receive message of wrong type")

+  rawRecv(q, res, typ)

   releaseSys(q.lock)

 

+proc recv*[TMsg](): TMsg =

+  ## receives a message from its internal message queue. This blocks until

+  ## a message has arrived! You may use ``peek`` to avoid the blocking.

+  llRecv(addr(result), cast[PNimType](getTypeInfo(result)))

+

 proc peek*(): int =

   ## returns the current number of messages in the inbox.

   var q = cast[PInbox](getInBoxMem())