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author | dkf <donal.k.fellows@manchester.ac.uk> | 2016-05-21 09:30:02 (GMT) |
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committer | dkf <donal.k.fellows@manchester.ac.uk> | 2016-05-21 09:30:02 (GMT) |
commit | c559956bdbeb3be7c36bff03736f2f58b326085b (patch) | |
tree | d4e67308decc65c55eb0f926021d438365dcc6ef /generic | |
parent | 4fad9227456604fb7bf7903a8a9245a55d421838 (diff) | |
parent | ca66ff4b66c7c2c37cf104ead999ae2fc8c85747 (diff) | |
download | tcl-c559956bdbeb3be7c36bff03736f2f58b326085b.zip tcl-c559956bdbeb3be7c36bff03736f2f58b326085b.tar.gz tcl-c559956bdbeb3be7c36bff03736f2f58b326085b.tar.bz2 |
Fix for [f97d4ee020]; use a two-stage approach to avoid quadratic behavior.
Diffstat (limited to 'generic')
-rw-r--r-- | generic/tclNamesp.c | 86 |
1 files changed, 64 insertions, 22 deletions
diff --git a/generic/tclNamesp.c b/generic/tclNamesp.c index dfab185..58a86d9 100644 --- a/generic/tclNamesp.c +++ b/generic/tclNamesp.c @@ -1105,8 +1105,6 @@ TclTeardownNamespace( Interp *iPtr = (Interp *) nsPtr->interp; register Tcl_HashEntry *entryPtr; Tcl_HashSearch search; - Tcl_Namespace *childNsPtr; - Tcl_Command cmd; int i; /* @@ -1121,16 +1119,31 @@ TclTeardownNamespace( /* * Delete all commands in this namespace. Be careful when traversing the * hash table: when each command is deleted, it removes itself from the - * command table. - * - * Don't optimize to Tcl_NextHashEntry() because of traces. + * command table. Because of traces (and the desire to avoid the quadratic + * problems of just using Tcl_FirstHashEntry over and over, [Bug + * f97d4ee020]) we copy to a temporary array and then delete all those + * commands. */ - for (entryPtr = Tcl_FirstHashEntry(&nsPtr->cmdTable, &search); - entryPtr != NULL; - entryPtr = Tcl_FirstHashEntry(&nsPtr->cmdTable, &search)) { - cmd = Tcl_GetHashValue(entryPtr); - Tcl_DeleteCommandFromToken((Tcl_Interp *) iPtr, cmd); + while (nsPtr->cmdTable.numEntries > 0) { + int length = nsPtr->cmdTable.numEntries; + Command **cmds = TclStackAlloc((Tcl_Interp *) iPtr, + sizeof(Command *) * length); + + i = 0; + for (entryPtr = Tcl_FirstHashEntry(&nsPtr->cmdTable, &search); + entryPtr != NULL; + entryPtr = Tcl_NextHashEntry(&search)) { + cmds[i] = Tcl_GetHashValue(entryPtr); + cmds[i]->refCount++; + i++; + } + for (i = 0 ; i < length ; i++) { + Tcl_DeleteCommandFromToken((Tcl_Interp *) iPtr, + (Tcl_Command) cmds[i]); + TclCleanupCommandMacro(cmds[i]); + } + TclStackFree((Tcl_Interp *) iPtr, cmds); } Tcl_DeleteHashTable(&nsPtr->cmdTable); Tcl_InitHashTable(&nsPtr->cmdTable, TCL_STRING_KEYS); @@ -1175,25 +1188,54 @@ TclTeardownNamespace( * * BE CAREFUL: When each child is deleted, it will divorce itself from its * parent. You can't traverse a hash table properly if its elements are - * being deleted. We use only the Tcl_FirstHashEntry function to be safe. + * being deleted. Because of traces (and the desire to avoid the + * quadratic problems of just using Tcl_FirstHashEntry over and over, [Bug + * f97d4ee020]) we copy to a temporary array and then delete all those + * namespaces. * - * Don't optimize to Tcl_NextHashEntry() because of traces. + * Important: leave the hash table itself still live. */ #ifndef BREAK_NAMESPACE_COMPAT - for (entryPtr = Tcl_FirstHashEntry(&nsPtr->childTable, &search); - entryPtr != NULL; - entryPtr = Tcl_FirstHashEntry(&nsPtr->childTable, &search)) { - childNsPtr = Tcl_GetHashValue(entryPtr); - Tcl_DeleteNamespace(childNsPtr); + while (nsPtr->childTable.numEntries > 0) { + int length = nsPtr->childTable.numEntries; + Namespace **children = TclStackAlloc((Tcl_Interp *) iPtr, + sizeof(Namespace *) * length); + + i = 0; + for (entryPtr = Tcl_FirstHashEntry(&nsPtr->childTable, &search); + entryPtr != NULL; + entryPtr = Tcl_NextHashEntry(&search)) { + children[i] = Tcl_GetHashValue(entryPtr); + children[i]->refCount++; + i++; + } + for (i = 0 ; i < length ; i++) { + Tcl_DeleteNamespace((Tcl_Namespace *) children[i]); + TclNsDecrRefCount(children[i]); + } + TclStackFree((Tcl_Interp *) iPtr, children); } #else if (nsPtr->childTablePtr != NULL) { - for (entryPtr = Tcl_FirstHashEntry(nsPtr->childTablePtr, &search); - entryPtr != NULL; - entryPtr = Tcl_FirstHashEntry(nsPtr->childTablePtr,&search)) { - childNsPtr = Tcl_GetHashValue(entryPtr); - Tcl_DeleteNamespace(childNsPtr); + while (nsPtr->childTablePtr->numEntries > 0) { + int length = nsPtr->childTablePtr->numEntries; + Namespace **children = TclStackAlloc((Tcl_Interp *) iPtr, + sizeof(Namespace *) * length); + + i = 0; + for (entryPtr = Tcl_FirstHashEntry(nsPtr->childTablePtr, &search); + entryPtr != NULL; + entryPtr = Tcl_NextHashEntry(&search)) { + children[i] = Tcl_GetHashValue(entryPtr); + children[i]->refCount++; + i++; + } + for (i = 0 ; i < length ; i++) { + Tcl_DeleteNamespace((Tcl_Namespace *) children[i]); + TclNsDecrRefCount(children[i]); + } + TclStackFree((Tcl_Interp *) iPtr, children); } } #endif |