Coroutine support for i386/amd64 platforms unix/windows OSes markAndSweep/refCounting GCs.

This commit is contained in:
rku 2015-07-31 17:18:16 +03:00
commit 43bfda057b
13 changed files with 843 additions and 320 deletions

View file

@ -9,6 +9,9 @@
# A simple mark&sweep garbage collector for Nim. Define the
# symbol ``gcUseBitvectors`` to generate a variant of this GC.
import arch
{.push profiler:off.}
const
@ -44,8 +47,16 @@ type
maxStackSize: int # max stack size
freedObjects: int # max entries in cycle table
GcStack {.final.} = object
prev: ptr GcStack
next: ptr GcStack
starts: pointer
pos: pointer
maxStackSize: int
GcHeap = object # this contains the zero count and
# non-zero count table
stack: ptr GcStack
stackBottom: pointer
cycleThreshold: int
when useCellIds:
@ -118,7 +129,6 @@ when BitsPerPage mod (sizeof(int)*8) != 0:
# forward declarations:
proc collectCT(gch: var GcHeap) {.benign.}
proc isOnStack*(p: pointer): bool {.noinline, benign.}
proc forAllChildren(cell: PCell, op: WalkOp) {.benign.}
proc doOperation(p: pointer, op: WalkOp) {.benign.}
proc forAllChildrenAux(dest: pointer, mt: PNimType, op: WalkOp) {.benign.}
@ -169,20 +179,6 @@ proc initGC() =
init(gch.allocated)
init(gch.marked)
var
localGcInitialized {.rtlThreadVar.}: bool
proc setupForeignThreadGc*() =
## call this if you registered a callback that will be run from a thread not
## under your control. This has a cheap thread-local guard, so the GC for
## this thread will only be initialized once per thread, no matter how often
## it is called.
if not localGcInitialized:
localGcInitialized = true
var stackTop {.volatile.}: pointer
setStackBottom(addr(stackTop))
initGC()
proc forAllSlotsAux(dest: pointer, n: ptr TNimNode, op: WalkOp) {.benign.} =
var d = cast[ByteAddress](dest)
case n.kind
@ -407,145 +403,14 @@ proc gcMark(gch: var GcHeap, p: pointer) {.inline.} =
if objStart != nil:
mark(gch, objStart)
# ----------------- stack management --------------------------------------
# inspired from Smart Eiffel
include gc_common
when defined(sparc):
const stackIncreases = false
elif defined(hppa) or defined(hp9000) or defined(hp9000s300) or
defined(hp9000s700) or defined(hp9000s800) or defined(hp9000s820):
const stackIncreases = true
else:
const stackIncreases = false
when not defined(useNimRtl):
{.push stack_trace: off.}
proc setStackBottom(theStackBottom: pointer) =
#c_fprintf(c_stdout, "stack bottom: %p;\n", theStackBottom)
# the first init must be the one that defines the stack bottom:
if gch.stackBottom == nil: gch.stackBottom = theStackBottom
else:
var a = cast[ByteAddress](theStackBottom) # and not PageMask - PageSize*2
var b = cast[ByteAddress](gch.stackBottom)
#c_fprintf(c_stdout, "old: %p new: %p;\n",gch.stackBottom,theStackBottom)
when stackIncreases:
gch.stackBottom = cast[pointer](min(a, b))
else:
gch.stackBottom = cast[pointer](max(a, b))
{.pop.}
proc stackSize(): int {.noinline.} =
var stackTop {.volatile.}: pointer
result = abs(cast[int](addr(stackTop)) - cast[int](gch.stackBottom))
when defined(sparc): # For SPARC architecture.
proc isOnStack(p: pointer): bool =
var stackTop {.volatile.}: pointer
stackTop = addr(stackTop)
var b = cast[ByteAddress](gch.stackBottom)
var a = cast[ByteAddress](stackTop)
var x = cast[ByteAddress](p)
result = a <=% x and x <=% b
proc markStackAndRegisters(gch: var GcHeap) {.noinline, cdecl.} =
when defined(sparcv9):
asm """"flushw \n" """
else:
asm """"ta 0x3 ! ST_FLUSH_WINDOWS\n" """
var
max = gch.stackBottom
sp: PPointer
stackTop: array[0..1, pointer]
sp = addr(stackTop[0])
# Addresses decrease as the stack grows.
while sp <= max:
gcMark(gch, sp[])
sp = cast[ppointer](cast[ByteAddress](sp) +% sizeof(pointer))
elif defined(ELATE):
{.error: "stack marking code is to be written for this architecture".}
elif stackIncreases:
# ---------------------------------------------------------------------------
# Generic code for architectures where addresses increase as the stack grows.
# ---------------------------------------------------------------------------
proc isOnStack(p: pointer): bool =
var stackTop {.volatile.}: pointer
stackTop = addr(stackTop)
var a = cast[ByteAddress](gch.stackBottom)
var b = cast[ByteAddress](stackTop)
var x = cast[ByteAddress](p)
result = a <=% x and x <=% b
var
jmpbufSize {.importc: "sizeof(jmp_buf)", nodecl.}: int
# a little hack to get the size of a JmpBuf in the generated C code
# in a platform independent way
proc markStackAndRegisters(gch: var GcHeap) {.noinline, cdecl.} =
var registers: C_JmpBuf
if c_setjmp(registers) == 0'i32: # To fill the C stack with registers.
var max = cast[ByteAddress](gch.stackBottom)
var sp = cast[ByteAddress](addr(registers)) +% jmpbufSize -% sizeof(pointer)
# sp will traverse the JMP_BUF as well (jmp_buf size is added,
# otherwise sp would be below the registers structure).
while sp >=% max:
gcMark(gch, cast[ppointer](sp)[])
sp = sp -% sizeof(pointer)
else:
# ---------------------------------------------------------------------------
# Generic code for architectures where addresses decrease as the stack grows.
# ---------------------------------------------------------------------------
proc isOnStack(p: pointer): bool =
var stackTop {.volatile.}: pointer
stackTop = addr(stackTop)
var b = cast[ByteAddress](gch.stackBottom)
var a = cast[ByteAddress](stackTop)
var x = cast[ByteAddress](p)
result = a <=% x and x <=% b
proc markStackAndRegisters(gch: var GcHeap) {.noinline, cdecl.} =
# We use a jmp_buf buffer that is in the C stack.
# Used to traverse the stack and registers assuming
# that 'setjmp' will save registers in the C stack.
type PStackSlice = ptr array [0..7, pointer]
var registers {.noinit.}: C_JmpBuf
if c_setjmp(registers) == 0'i32: # To fill the C stack with registers.
var max = cast[ByteAddress](gch.stackBottom)
var sp = cast[ByteAddress](addr(registers))
when defined(amd64):
# words within the jmp_buf structure may not be properly aligned.
let regEnd = sp +% sizeof(registers)
while sp <% regEnd:
gcMark(gch, cast[PPointer](sp)[])
gcMark(gch, cast[PPointer](sp +% sizeof(pointer) div 2)[])
sp = sp +% sizeof(pointer)
# Make sure sp is word-aligned
sp = sp and not (sizeof(pointer) - 1)
# loop unrolled:
while sp <% max - 8*sizeof(pointer):
gcMark(gch, cast[PStackSlice](sp)[0])
gcMark(gch, cast[PStackSlice](sp)[1])
gcMark(gch, cast[PStackSlice](sp)[2])
gcMark(gch, cast[PStackSlice](sp)[3])
gcMark(gch, cast[PStackSlice](sp)[4])
gcMark(gch, cast[PStackSlice](sp)[5])
gcMark(gch, cast[PStackSlice](sp)[6])
gcMark(gch, cast[PStackSlice](sp)[7])
sp = sp +% sizeof(pointer)*8
# last few entries:
while sp <=% max:
gcMark(gch, cast[PPointer](sp)[])
sp = sp +% sizeof(pointer)
# ----------------------------------------------------------------------------
# end of non-portable code
# ----------------------------------------------------------------------------
proc markStackAndRegisters(gch: var GcHeap) {.noinline, cdecl.} =
forEachStackSlot(gch, gcMark)
proc collectCTBody(gch: var GcHeap) =
gch.stat.maxStackSize = max(gch.stat.maxStackSize, stackSize())
when not defined(nimCoroutines):
gch.stat.maxStackSize = max(gch.stat.maxStackSize, stackSize())
prepareForInteriorPointerChecking(gch.region)
markStackAndRegisters(gch)
markGlobals(gch)
@ -599,8 +464,13 @@ when not defined(useNimRtl):
"[GC] occupied memory: " & $getOccupiedMem() & "\n" &
"[GC] collections: " & $gch.stat.collections & "\n" &
"[GC] max threshold: " & $gch.stat.maxThreshold & "\n" &
"[GC] freed objects: " & $gch.stat.freedObjects & "\n" &
"[GC] max stack size: " & $gch.stat.maxStackSize & "\n"
"[GC] freed objects: " & $gch.stat.freedObjects & "\n"
when defined(nimCoroutines):
result = result & "[GC] number of stacks: " & $gch.stack.len & "\n"
for stack in items(gch.stack):
result = result & "[GC] stack " & stack.starts.repr & "[GC] max stack size " & $stack.maxStackSize & "\n"
else:
result = result & "[GC] max stack size: " & $gch.stat.maxStackSize & "\n"
GC_enable()
{.pop.}