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make memory regions robust; disable free lists for now

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This commit is contained in:
Andreas Rumpf 2018-05-27 11:15:45 +02:00
commit 88bc2d8df4
1 changed files with 32 additions and 28 deletions
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60
lib/system/gc_regions.nim
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@ -70,8 +70,9 @@ type
bump: pointer bump: pointer
head, tail: Chunk head, tail: Chunk
nextChunkSize, totalSize: int nextChunkSize, totalSize: int
freeLists: array[MaxSmallObject div MemAlign, FreeEntry] when false:
holes: SizedFreeEntry freeLists: array[MaxSmallObject div MemAlign, FreeEntry]
holes: SizedFreeEntry
when hasThreadSupport: when hasThreadSupport:
lock: SysLock lock: SysLock
@ -145,21 +146,22 @@ proc allocSlowPath(r: var MemRegion; size: int) =
r.remaining = s - sizeof(BaseChunk) r.remaining = s - sizeof(BaseChunk)
proc allocFast(r: var MemRegion; size: int): pointer = proc allocFast(r: var MemRegion; size: int): pointer =
if size <= MaxSmallObject: when false:
var it = r.freeLists[size div MemAlign] if size <= MaxSmallObject:
if it != nil: var it = r.freeLists[size div MemAlign]
r.freeLists[size div MemAlign] = it.next if it != nil:
return pointer(it) r.freeLists[size div MemAlign] = it.next
else:
var it = r.holes
var prev: SizedFreeEntry = nil
while it != nil:
if it.size >= size:
if prev != nil: prev.next = it.next
else: r.holes = it.next
return pointer(it) return pointer(it)
prev = it else:
it = it.next var it = r.holes
var prev: SizedFreeEntry = nil
while it != nil:
if it.size >= size:
if prev != nil: prev.next = it.next
else: r.holes = it.next
return pointer(it)
prev = it
it = it.next
if size > r.remaining: if size > r.remaining:
allocSlowPath(r, size) allocSlowPath(r, size)
sysAssert(size <= r.remaining, "size <= r.remaining") sysAssert(size <= r.remaining, "size <= r.remaining")
@ -184,15 +186,16 @@ proc dealloc(r: var MemRegion; p: pointer; size: int) =
# it is benefitial to not use the free lists here: # it is benefitial to not use the free lists here:
if r.bump -! size == p: if r.bump -! size == p:
dec r.bump, size dec r.bump, size
elif size <= MaxSmallObject: when false:
let it = cast[FreeEntry](p) if size <= MaxSmallObject:
it.next = r.freeLists[size div MemAlign] let it = cast[FreeEntry](p)
r.freeLists[size div MemAlign] = it it.next = r.freeLists[size div MemAlign]
else: r.freeLists[size div MemAlign] = it
let it = cast[SizedFreeEntry](p) else:
it.size = size let it = cast[SizedFreeEntry](p)
it.next = r.holes it.size = size
r.holes = it it.next = r.holes
r.holes = it
proc deallocAll(r: var MemRegion; head: Chunk) = proc deallocAll(r: var MemRegion; head: Chunk) =
var it = head var it = head
@ -220,9 +223,10 @@ proc setObstackPtr*(r: var MemRegion; sp: StackPtr) =
if sp.current.next != nil: if sp.current.next != nil:
deallocAll(r, sp.current.next) deallocAll(r, sp.current.next)
sp.current.next = nil sp.current.next = nil
# better leak this memory than be sorry: when false:
for i in 0..high(r.freeLists): r.freeLists[i] = nil # better leak this memory than be sorry:
r.holes = nil for i in 0..high(r.freeLists): r.freeLists[i] = nil
r.holes = nil
#else: #else:
# deallocAll(r, r.head) # deallocAll(r, r.head)
# r.head = nil # r.head = nil