Merge pull request #1281 from Araq/new_spawn

New spawn

3 files changed, 66 insertions, 54 deletions

diff --git a/lib/system/assign.nim b/lib/system/assign.nim
index 75c749633..2ae945fb1 100644
--- a/lib/system/assign.nim
+++ b/lib/system/assign.nim
@@ -179,7 +179,8 @@ when not defined(nimmixin):
     # internal proc used for destroying sequences and arrays
     for i in countup(0, r.len - 1): destroy(r[i])
 else:
-  # XXX Why is this exported and no compilerproc?
+  # XXX Why is this exported and no compilerproc? -> compilerprocs cannot be
+  # generic for now
   proc nimDestroyRange*[T](r: T) =
     # internal proc used for destroying sequences and arrays
     mixin destroy
diff --git a/lib/system/atomics.nim b/lib/system/atomics.nim
index b1a96b209..43b3f0438 100644
--- a/lib/system/atomics.nim
+++ b/lib/system/atomics.nim
@@ -1,15 +1,18 @@
 #
 #
 #            Nimrod's Runtime Library
-#        (c) Copyright 2012 Andreas Rumpf
+#        (c) Copyright 2014 Andreas Rumpf
 #
 #    See the file "copying.txt", included in this
 #    distribution, for details about the copyright.
 #
 
 ## Atomic operations for Nimrod.
+{.push stackTrace:off.}
 
-when (defined(gcc) or defined(llvm_gcc)) and hasThreadSupport:
+const someGcc = defined(gcc) or defined(llvm_gcc) or defined(clang)
+
+when someGcc and hasThreadSupport:
   type 
     AtomMemModel* = enum
       ATOMIC_RELAXED,  ## No barriers or synchronization. 
@@ -152,41 +155,16 @@ when (defined(gcc) or defined(llvm_gcc)) and hasThreadSupport:
     ## A value of 0 indicates typical alignment should be used. The compiler may also 
     ## ignore this parameter.
 
+  template fence*() = atomicThreadFence(ATOMIC_SEQ_CST)
 elif defined(vcc) and hasThreadSupport:
   proc addAndFetch*(p: ptr int, val: int): int {.
     importc: "NimXadd", nodecl.}
+
 else:
   proc addAndFetch*(p: ptr int, val: int): int {.inline.} =
     inc(p[], val)
     result = p[]
 
-# atomic compare and swap (CAS) funcitons to implement lock-free algorithms  
-      
-#if defined(windows) and not defined(gcc) and hasThreadSupport:
-#    proc InterlockedCompareExchangePointer(mem: ptr pointer,
-#      newValue: pointer, comparand: pointer) : pointer {.nodecl, 
-#        importc: "InterlockedCompareExchangePointer", header:"windows.h".}
-
-#    proc compareAndSwap*[T](mem: ptr T, 
-#      expected: T, newValue: T): bool {.inline.}=
-#      ## Returns true if successfully set value at mem to newValue when value
-#      ## at mem == expected
-#      return InterlockedCompareExchangePointer(addr(mem), 
-#        addr(newValue), addr(expected))[] == expected
-    
-#elif not hasThreadSupport:
-#  proc compareAndSwap*[T](mem: ptr T, 
-#                          expected: T, newValue: T): bool {.inline.} =
-#      ## Returns true if successfully set value at mem to newValue when value
-#      ## at mem == expected
-#      var oldval = mem[]
-#      if oldval == expected:
-#        mem[] = newValue
-#        return true
-#      return false
-
-
-# Some convenient functions 
 proc atomicInc*(memLoc: var int, x: int = 1): int =
   when defined(gcc) and hasThreadSupport:
     result = atomic_add_fetch(memLoc.addr, x, ATOMIC_RELAXED)
@@ -203,3 +181,37 @@ proc atomicDec*(memLoc: var int, x: int = 1): int =
   else:
     dec(memLoc, x)
     result = memLoc
+
+when defined(windows) and not someGcc:
+  proc interlockedCompareExchange(p: pointer; exchange, comparand: int32): int32
+    {.importc: "InterlockedCompareExchange", header: "<windows.h>", cdecl.}
+
+  proc cas*[T: bool|int|ptr](p: ptr T; oldValue, newValue: T): bool =
+    interlockedCompareExchange(p, newValue.int32, oldValue.int32) != 0
+  # XXX fix for 64 bit build
+else:
+  # this is valid for GCC and Intel C++
+  proc cas*[T: bool|int|ptr](p: ptr T; oldValue, newValue: T): bool
+    {.importc: "__sync_bool_compare_and_swap", nodecl.}
+  # XXX is this valid for 'int'?
+
+
+when (defined(x86) or defined(amd64)) and (defined(gcc) or defined(llvm_gcc)):
+  proc cpuRelax {.inline.} =
+    {.emit: """asm volatile("pause" ::: "memory");""".}
+elif (defined(x86) or defined(amd64)) and defined(vcc):
+  proc cpuRelax {.importc: "YieldProcessor", header: "<windows.h>".}
+elif defined(intelc):
+  proc cpuRelax {.importc: "_mm_pause", header: "xmmintrin.h".}
+elif false:
+  from os import sleep
+
+  proc cpuRelax {.inline.} = os.sleep(1)
+
+when not defined(fence) and hasThreadSupport:
+  # XXX fixme
+  proc fence*() {.inline.} =
+    var dummy: bool
+    discard cas(addr dummy, false, true)
+
+{.pop.}
diff --git a/lib/system/sysspawn.nim b/lib/system/sysspawn.nim
index dabf35a3e..95cdba65d 100644
--- a/lib/system/sysspawn.nim
+++ b/lib/system/sysspawn.nim
@@ -14,30 +14,6 @@ when not defined(NimString):
 
 {.push stackTrace:off.}
 
-when (defined(x86) or defined(amd64)) and defined(gcc):
-  proc cpuRelax {.inline.} =
-    {.emit: """asm volatile("pause" ::: "memory");""".}
-elif (defined(x86) or defined(amd64)) and defined(vcc):
-  proc cpuRelax {.importc: "YieldProcessor", header: "<windows.h>".}
-elif defined(intelc):
-  proc cpuRelax {.importc: "_mm_pause", header: "xmmintrin.h".}
-elif false:
-  from os import sleep
-
-  proc cpuRelax {.inline.} = os.sleep(1)
-
-when defined(windows) and not defined(gcc):
-  proc interlockedCompareExchange(p: pointer; exchange, comparand: int32): int32
-    {.importc: "InterlockedCompareExchange", header: "<windows.h>", cdecl.}
-
-  proc cas(p: ptr bool; oldValue, newValue: bool): bool =
-    interlockedCompareExchange(p, newValue.int32, oldValue.int32) != 0
-
-else:
-  # this is valid for GCC and Intel C++
-  proc cas(p: ptr bool; oldValue, newValue: bool): bool
-    {.importc: "__sync_bool_compare_and_swap", nodecl.}
-
 # We declare our own condition variables here to get rid of the dummy lock
 # on Windows:
 
@@ -54,6 +30,9 @@ proc createCondVar(): CondVar =
     initSysLock(result.stupidLock)
     #acquireSys(result.stupidLock)
 
+proc destroyCondVar(c: var CondVar) {.inline.} =
+  deinitSysCond(c.c)
+
 proc await(cv: var CondVar) =
   when defined(posix):
     acquireSys(cv.stupidLock)
@@ -100,6 +79,26 @@ proc signal(cv: var FastCondVar) =
   #if cas(addr cv.slowPath, true, false):
   signal(cv.slow)
 
+type
+  Barrier* {.compilerProc.} = object
+    counter: int
+    cv: CondVar
+
+proc barrierEnter*(b: ptr Barrier) {.compilerProc.} =
+  atomicInc b.counter
+
+proc barrierLeave*(b: ptr Barrier) {.compilerProc.} =
+  atomicDec b.counter
+  if b.counter <= 0: signal(b.cv)
+
+proc openBarrier*(b: ptr Barrier) {.compilerProc.} =
+  b.counter = 0
+  b.cv = createCondVar()
+
+proc closeBarrier*(b: ptr Barrier) {.compilerProc.} =
+  await(b.cv)
+  destroyCondVar(b.cv)
+
 {.pop.}
 
 # ----------------------------------------------------------------------------