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attempt to fix a critical memory leak in Nim's collections

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This commit is contained in:
Andreas Rumpf 2016-06-15 17:15:20 +02:00
commit 5f83e869fa
2 changed files with 12 additions and 0 deletions
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4
lib/pure/collections/sets.nim
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@ -261,6 +261,8 @@ template doWhile(a: expr, b: stmt): stmt =
b b
if not a: break if not a: break
proc default[T](t: typedesc[T]): T {.inline.} = discard
proc excl*[A](s: var HashSet[A], key: A) = proc excl*[A](s: var HashSet[A], key: A) =
## Excludes `key` from the set `s`. ## Excludes `key` from the set `s`.
## ##
@ -277,11 +279,13 @@ proc excl*[A](s: var HashSet[A], key: A) =
var msk = high(s.data) var msk = high(s.data)
if i >= 0: if i >= 0:
s.data[i].hcode = 0 s.data[i].hcode = 0
s.data[i].key = default(type(s.data[i].key))
dec(s.counter) dec(s.counter)
while true: # KnuthV3 Algo6.4R adapted for i=i+1 instead of i=i-1 while true: # KnuthV3 Algo6.4R adapted for i=i+1 instead of i=i-1
var j = i # The correctness of this depends on (h+1) in nextTry, var j = i # The correctness of this depends on (h+1) in nextTry,
var r = j # though may be adaptable to other simple sequences. var r = j # though may be adaptable to other simple sequences.
s.data[i].hcode = 0 # mark current EMPTY s.data[i].hcode = 0 # mark current EMPTY
s.data[i].key = default(type(s.data[i].key))
doWhile ((i >= r and r > j) or (r > j and j > i) or (j > i and i >= r)): doWhile ((i >= r and r > j) or (r > j and j > i) or (j > i and i >= r)):
i = (i + 1) and msk # increment mod table size i = (i + 1) and msk # increment mod table size
if isEmpty(s.data[i].hcode): # end of collision cluster; So all done if isEmpty(s.data[i].hcode): # end of collision cluster; So all done

8
lib/pure/collections/tableimpl.nim
View file

@ -110,18 +110,24 @@ template hasKeyOrPutImpl(enlarge) {.dirty, immediate.} =
maybeRehashPutImpl(enlarge) maybeRehashPutImpl(enlarge)
else: result = true else: result = true
proc default[T](t: typedesc[T]): T {.inline.} = discard
template delImpl() {.dirty, immediate.} = template delImpl() {.dirty, immediate.} =
var hc: Hash var hc: Hash
var i = rawGet(t, key, hc) var i = rawGet(t, key, hc)
let msk = maxHash(t) let msk = maxHash(t)
if i >= 0: if i >= 0:
t.data[i].hcode = 0 t.data[i].hcode = 0
t.data[i].key = default(type(t.data[i].key))
t.data[i].val = default(type(t.data[i].val))
dec(t.counter) dec(t.counter)
block outer: block outer:
while true: # KnuthV3 Algo6.4R adapted for i=i+1 instead of i=i-1 while true: # KnuthV3 Algo6.4R adapted for i=i+1 instead of i=i-1
var j = i # The correctness of this depends on (h+1) in nextTry, var j = i # The correctness of this depends on (h+1) in nextTry,
var r = j # though may be adaptable to other simple sequences. var r = j # though may be adaptable to other simple sequences.
t.data[i].hcode = 0 # mark current EMPTY t.data[i].hcode = 0 # mark current EMPTY
t.data[i].key = default(type(t.data[i].key))
t.data[i].val = default(type(t.data[i].val))
while true: while true:
i = (i + 1) and msk # increment mod table size i = (i + 1) and msk # increment mod table size
if isEmpty(t.data[i].hcode): # end of collision cluster; So all done if isEmpty(t.data[i].hcode): # end of collision cluster; So all done
@ -137,4 +143,6 @@ template delImpl() {.dirty, immediate.} =
template clearImpl() {.dirty, immediate.} = template clearImpl() {.dirty, immediate.} =
for i in 0 .. <t.data.len: for i in 0 .. <t.data.len:
t.data[i].hcode = 0 t.data[i].hcode = 0
t.data[i].key = default(type(t.data[i].key))
t.data[i].val = default(type(t.data[i].val))
t.counter = 0 t.counter = 0