diff options
Diffstat (limited to 'doc')
39 files changed, 747 insertions, 11 deletions
diff --git a/doc/AddErrInfo.3 b/doc/AddErrInfo.3 index e250127..5462d02 100644 --- a/doc/AddErrInfo.3 +++ b/doc/AddErrInfo.3 @@ -300,6 +300,22 @@ The global variables \fBerrorInfo\fR and \fBerrorCode\fR are not modified by \fBTcl_ResetResult\fR so they continue to hold a record of information about the most recent error seen in an interpreter. +.SH "REFERENCE COUNT MANAGEMENT" +.PP +The result of \fBTcl_GetReturnOptions\fR will have at least one +reference to it from the Tcl interpreter. If not using it immediately, +you should use \fBTcl_IncrRefCount\fR to add your own reference. +.PP +The \fIoptions\fR argument to \fBTcl_SetReturnOptions\fR will have a +reference added by the Tcl interpreter; it may safely be called with a +zero-reference value. +.PP +\fBTcl_AppendObjToErrorInfo\fR only reads its \fIobjPtr\fR argument; +it does not modify its reference count at all. +.PP +The \fIerrorObjPtr\fR argument to \fBTcl_SetObjErrorCode\fR will have a +reference added by the Tcl interpreter; it may safely be called with a +zero-reference value. .SH "SEE ALSO" Tcl_DecrRefCount(3), Tcl_IncrRefCount(3), Tcl_Interp(3), Tcl_ResetResult(3), Tcl_SetErrno(3), errorCode(n), errorInfo(n) diff --git a/doc/BoolObj.3 b/doc/BoolObj.3 index 7268e1f..9bbdc7e 100644 --- a/doc/BoolObj.3 +++ b/doc/BoolObj.3 @@ -88,6 +88,18 @@ will lead to a \fBTCL_OK\fR return (and the boolean value 1), while the same value passed to \fBTcl_GetBoolean\fR will lead to a \fBTCL_ERROR\fR return. +.SH "REFERENCE COUNT MANAGEMENT" +.PP +\fBTcl_NewBooleanObj\fR always returns a zero-reference object, much +like \fBTcl_NewObj\fR. +.PP +\fBTcl_SetBooleanObj\fR does not modify the reference count of its +\fIobjPtr\fR argument, but does require that the object be unshared. +.PP +\fBTcl_GetBooleanFromObj\fR does not modify the reference count of its +\fIobjPtr\fR argument; it only reads. Note however that this function +may set the interpreter result; if that is the only place that +is holding a reference to the object, it will be deleted. .SH "SEE ALSO" Tcl_NewObj, Tcl_IsShared, Tcl_GetBoolean diff --git a/doc/ByteArrObj.3 b/doc/ByteArrObj.3 index 7e75dde..053401a 100644 --- a/doc/ByteArrObj.3 +++ b/doc/ByteArrObj.3 @@ -85,6 +85,18 @@ newly allocated bytes at the end of the array have arbitrary values. If the length of array is reduced to the new length. The return value is a pointer to the value's new array of bytes. +.SH "REFERENCE COUNT MANAGEMENT" +.PP +\fBTcl_NewByteArrayObj\fR always returns a zero-reference object, much +like \fBTcl_NewObj\fR. +.PP +\fBTcl_SetByteArrayObj\fR and \fBTcl_SetByteArrayLength\fR do not modify the +reference count of their \fIobjPtr\fR arguments, but do require that the +object be unshared. +.PP +\fBTcl_GetByteArrayFromObj\fR does not modify the reference count of its +\fIobjPtr\fR argument; it only reads. + .SH "SEE ALSO" Tcl_GetStringFromObj, Tcl_NewObj, Tcl_IncrRefCount, Tcl_DecrRefCount diff --git a/doc/Cancel.3 b/doc/Cancel.3 index def0f2a..4f727b3 100644 --- a/doc/Cancel.3 +++ b/doc/Cancel.3 @@ -67,6 +67,14 @@ other procedures. If an error is returned and this bit is set in result, where it can be retrieved with \fBTcl_GetObjResult\fR or \fBTcl_GetStringResult\fR. If this flag bit is not set then no error message is left and the interpreter's result will not be modified. +.SH "REFERENCE COUNT MANAGEMENT" +.PP +\fBTcl_CancelEval\fR always decrements the reference count of its +\fIresultObjPtr\fR argument (if that is non-NULL). It is expected to +be usually called with an object with zero reference count. If the +object is shared with some other location (including the Tcl +evaluation stack) it should have its reference count incremented +before calling this function. .SH "SEE ALSO" interp(n), Tcl_Eval(3), TIP 285 diff --git a/doc/Class.3 b/doc/Class.3 index 12658ce..8381cf0 100644 --- a/doc/Class.3 +++ b/doc/Class.3 @@ -241,6 +241,29 @@ NULL if the whole chain is to be processed (the argument itself is never NULL); this variable may be updated by the callback. The \fImethodNameObj\fR parameter gives an unshared object containing the name of the method being invoked, as provided by the user; this object may be updated by the callback. +.SH "REFERENCE COUNT MANAGEMENT" +.PP +The \fIobjPtr\fR argument to \fBTcl_GetObjectFromObj\fR will not have its +reference count manipulated, but this function may modify the interpreter +result (to report any error) so interpreter results should not be fed into +this without an additional reference being used. +.PP +The result of \fBTcl_GetObjectName\fR is a value that is owned by the object +that is regenerated when this function is first called after the object is +renamed. If the value is to be retained at all, the caller should increment +the reference count. +.PP +The first \fIobjc\fR values in the \fIobjv\fR argument to +\fBTcl_NewObjectInstance\fR are the arguments to pass to the constructor. They +must have a reference count of at least 1, and may have their reference counts +changed during the running of the constructor. Constructors may modify the +interpreter result, which consequently means that interpreter results should +not be used as arguments without an additional reference being taken. +.PP +The \fImethodNameObj\fR argument to a Tcl_ObjectMapMethodNameProc +implementation will be a value with a reference count of at least 1 where at +least one reference is not held by the interpreter result. It is expected that +method name mappers will only read their \fImethodNameObj\fR arguments. .SH "SEE ALSO" Method(3), oo::class(n), oo::copy(n), oo::define(n), oo::object(n) .SH KEYWORDS diff --git a/doc/CrtAlias.3 b/doc/CrtAlias.3 index 4888b61..3f5ccea 100644 --- a/doc/CrtAlias.3 +++ b/doc/CrtAlias.3 @@ -228,8 +228,16 @@ any script evaluation mechanism will fail. .PP For a description of the Tcl interface to multiple interpreters, see \fIinterp(n)\fR. +.SH "REFERENCE COUNT MANAGEMENT" +.PP +\fBTcl_CreateAliasObj\fR increments the reference counts of the values +in its \fIobjv\fR argument. (That reference lasts the same length of +time as the owning alias.) +.PP +\fBTcl_GetAliasObj\fR returns (via its \fIobjvPtr\fR argument) a +pointer to values that it holds a reference to. .SH "SEE ALSO" -interp +interp(n) .SH KEYWORDS alias, command, exposed commands, hidden commands, interpreter, invoke, diff --git a/doc/CrtObjCmd.3 b/doc/CrtObjCmd.3 index 746faba..d0fa185 100644 --- a/doc/CrtObjCmd.3 +++ b/doc/CrtObjCmd.3 @@ -323,6 +323,21 @@ instead. The result from \fBTcl_GetCommandTypeName\fR will be exactly that string which was registered, and not a copy; use of a compile-time constant string is \fIstrongly recommended\fR. .VE "info cmdtype feature" +.SH "REFERENCE COUNT MANAGEMENT" +.PP +When the \fIproc\fR passed to \fBTcl_CreateObjCommand\fR is called, +the values in its \fIobjv\fR argument will have a reference count of +at least 1, with that guaranteed reference being from the Tcl +evaluation stack. You should not call \fBTcl_DecrRefCount\fR on any of +those values unless you call \fBTcl_IncrRefCount\fR on them first. +Also, when the \fIproc\fR is called, the interpreter result is +guaranteed to be an empty string value with a reference count of 1. +.PP +\fBTcl_GetCommandFullName\fR does not modify the reference count of its +\fIobjPtr\fR argument, but does require that the object be unshared. +.PP +\fBTcl_GetCommandFromObj\fR does not modify the reference count of its +\fIobjPtr\fR argument; it only reads. .SH "SEE ALSO" Tcl_CreateCommand(3), Tcl_ResetResult(3), Tcl_SetObjResult(3) .SH KEYWORDS diff --git a/doc/CrtTrace.3 b/doc/CrtTrace.3 index 888c462..3c30869 100644 --- a/doc/CrtTrace.3 +++ b/doc/CrtTrace.3 @@ -187,5 +187,14 @@ There is no way to be notified when the trace created by \fBTcl_CreateTrace\fR is deleted. There is no way for the \fIproc\fR associated with a call to \fBTcl_CreateTrace\fR to abort execution of \fIcommand\fR. +.SH "REFERENCE COUNT MANAGEMENT" +.PP +When the \fIproc\fR passed to \fBTcl_CreateObjTrace\fR is called, +the values in its \fIobjv\fR argument will have a reference count of +at least 1, with that guaranteed reference being from the Tcl +evaluation stack. You should not call \fBTcl_DecrRefCount\fR on any of +those values unless you call \fBTcl_IncrRefCount\fR on them first. +.SH "SEE ALSO" +trace(n) .SH KEYWORDS command, create, delete, interpreter, trace diff --git a/doc/DictObj.3 b/doc/DictObj.3 index 2c111c4..0b4c1ca 100644 --- a/doc/DictObj.3 +++ b/doc/DictObj.3 @@ -190,6 +190,73 @@ path as this is easy to construct from repeated use of dictionaries are created for non-terminal keys where they do not already exist. With \fBTcl_DictObjRemoveKeyList\fR, all non-terminal keys must exist and have dictionaries as their values. +.SH "REFERENCE COUNT MANAGEMENT" +.PP +\fBTcl_NewDictObj\fR always returns a zero-reference object, much like +\fBTcl_NewObj\fR. +.PP +\fBTcl_DictObjPut\fR does not modify the reference count of its \fIdictPtr\fR +argument, but does require that the object be unshared. If +\fBTcl_DictObjPut\fR returns \fBTCL_ERROR\fR it does not manipulate any +reference counts; but if it returns \fBTCL_OK\fR then it definitely increments +the reference count of \fIvaluePtr\fR and may increment the reference count of +\fIkeyPtr\fR; the latter case happens exactly when the key did not previously +exist in the dictionary. Note however that this function may set the +interpreter result; if that is the only place that is holding a reference to +an object, it will be deleted. +.PP +\fBTcl_DictObjGet\fR only reads from its \fIdictPtr\fR and \fIkeyPtr\fR +arguments, and does not manipulate their reference counts at all. If the +\fIvaluePtrPtr\fR argument is not set to NULL (and the function doesn't return +\fBTCL_ERROR\fR), it will be set to a value with a reference count of at least +1, with a reference owned by the dictionary. Note however that this function +may set the interpreter result; if that is the only place that is holding a +reference to an object, it will be deleted. +.PP +\fBTcl_DictObjRemove\fR does not modify the reference count of its +\fIdictPtr\fR argument, but does require that the object be unshared. It does +not manipulate the reference count of its \fIkeyPtr\fR argument at all. Note +however that this function may set the interpreter result; if that is the only +place that is holding a reference to an object, it will be deleted. +.PP +\fBTcl_DictObjSize\fR does not modify the reference count of its \fIdictPtr\fR +argument; it only reads. Note however that this function may set the +interpreter result; if that is the only place that is holding a reference to +the dictionary object, it will be deleted. +.PP +\fBTcl_DictObjFirst\fR does not modify the reference count of its +\fIdictPtr\fR argument; it only reads. The variables given by the +\fIkeyPtrPtr\fR and \fIvaluePtrPtr\fR arguments (if not NULL) will be updated +to contain references to the relevant values in the dictionary; their +reference counts will be at least 1 (due to the dictionary holding a reference +to them). It may also manipulate internal references; these are not exposed to +user code, but require a matching \fBTcl_DictObjDone\fR call. Note however +that this function may set the interpreter result; if that is the only place +that is holding a reference to the dictionary object, it will be deleted. +.PP +Similarly for \fBTcl_DictObjNext\fR; the variables given by the +\fIkeyPtrPtr\fR and \fIvaluePtrPtr\fR arguments (if not NULL) will be updated +to contain references to the relevant values in the dictionary; their +reference counts will be at least 1 (due to the dictionary holding a reference +to them). +.PP +\fBTcl_DictObjDone\fR does not manipulate (user-visible) reference counts. +.PP +\fBTcl_DictObjPutKeyList\fR is similar to \fBTcl_DictObjPut\fR; it does not +modify the reference count of its \fIdictPtr\fR argument, but does require +that the object be unshared. It may increment the reference count of any value +passed in the \fIkeyv\fR argument, and will increment the reference count of +the \fIvaluePtr\fR argument on success. It is recommended that values passed +via \fIkeyv\fR and \fIvaluePtr\fR do not have zero reference counts. Note +however that this function may set the interpreter result; if that is the only +place that is holding a reference to an object, it will be deleted. +.PP +\fBTcl_DictObjRemoveKeyList\fR is similar to \fBTcl_DictObjRemove\fR; it does +not modify the reference count of its \fIdictPtr\fR argument, but does require +that the object be unshared, and does not modify the reference counts of any +of the values passed in the \fIkeyv\fR argument. Note however that this +function may set the interpreter result; if that is the only place that is +holding a reference to an object, it will be deleted. .SH EXAMPLE Using the dictionary iteration interface to search determine if there is a key that maps to itself: diff --git a/doc/DoubleObj.3 b/doc/DoubleObj.3 index 85e4de5..c70f5d1 100644 --- a/doc/DoubleObj.3 +++ b/doc/DoubleObj.3 @@ -58,6 +58,18 @@ and if \fIinterp\fR is non-NULL, an error message is left in \fIinterp\fR. The \fBTcl_ObjType\fR of \fIobjPtr\fR may be changed to make subsequent calls to \fBTcl_GetDoubleFromObj\fR more efficient. '\" TODO: add discussion of treatment of NaN value +.SH "REFERENCE COUNT MANAGEMENT" +.PP +\fBTcl_NewDoubleObj\fR always returns a zero-reference object, much +like \fBTcl_NewObj\fR. +.PP +\fBTcl_SetDoubleObj\fR does not modify the reference count of its +\fIobjPtr\fR argument, but does require that the object be unshared. +.PP +\fBTcl_GetDoubleFromObj\fR does not modify the reference count of its +\fIobjPtr\fR argument; it only reads. Note however that this function +may set the interpreter result; if that is the only place that +is holding a reference to the object, it will be deleted. .SH "SEE ALSO" Tcl_NewObj, Tcl_DecrRefCount, Tcl_IncrRefCount, Tcl_GetObjResult .SH KEYWORDS diff --git a/doc/Encoding.3 b/doc/Encoding.3 index 497683d..c36744b 100644 --- a/doc/Encoding.3 +++ b/doc/Encoding.3 @@ -523,5 +523,16 @@ been loaded, it attempts to load an encoding file called \fIname\fB.enc\fR from the \fBencoding\fR subdirectory of each directory that Tcl searches for its script library. If the encoding file exists, but is malformed, an error message will be left in \fIinterp\fR. +.SH "REFERENCE COUNT MANAGEMENT" +.PP +\fBTcl_GetEncodingFromObj\fR does not modify the reference count of its +\fIobjPtr\fR argument; it only reads. Note however that this function may set +the interpreter result; if that is the only place that is holding a reference +to the object, it will be deleted. +.PP +\fBTcl_GetEncodingSearchPath\fR returns an object with a reference count of at +least 1. +.SH "SEE ALSO" +encoding(n) .SH KEYWORDS utf, encoding, convert diff --git a/doc/Ensemble.3 b/doc/Ensemble.3 index febc48f..b768fd6 100644 --- a/doc/Ensemble.3 +++ b/doc/Ensemble.3 @@ -209,6 +209,27 @@ namespace whose list of exported commands is used if both the mapping dictionary and the subcommand list properties are NULL. May be read using \fBTcl_GetEnsembleNamespace\fR which returns a Tcl result code (\fBTCL_OK\fR, or \fBTCL_ERROR\fR if the token does not refer to an ensemble). +.SH "REFERENCE COUNT MANAGEMENT" +.PP +\fBTcl_FindEnsemble\fR does not modify the reference count of its +\fIcmdNameObj\fR argument; it only reads. Note however that this function may +set the interpreter result; if that is the only place that is holding a +reference to the object, it will be deleted. +.PP +The ensemble property getters (\fBTcl_GetEnsembleMappingDict\fR, +\fBTcl_GetEnsembleParameterList\fR, \fBTcl_GetEnsembleSubcommandList\fR, and +\fBTcl_GetEnsembleUnknownHandler\fR) do not manipulate the reference count of +the values they provide out; if those are non-NULL, they will have a reference +count of at least 1. Note that these functions may set the interpreter +result. +.PP +The ensemble property setters (\fBTcl_SetEnsembleMappingDict\fR, +\fBTcl_SetEnsembleParameterList\fR, \fBTcl_SetEnsembleSubcommandList\fR, and +\fBTcl_SetEnsembleUnknownHandler\fR) will increment the reference count of the +new value of the property they are given if they succeed (and decrement the +reference count of the old value of the property, if relevant). If the +property setters return \fBTCL_ERROR\fR, the reference count of the Tcl_Obj +argument is left unchanged. .SH "SEE ALSO" namespace(n), Tcl_DeleteCommandFromToken(3) .SH KEYWORDS @@ -190,6 +190,20 @@ the \fBreturn\fR, \fBbreak\fR, or \fBcontinue\fR command was invoked in an inappropriate place. This means that top-level applications should never see a return code from \fBTcl_EvalObjEx\fR other than \fBTCL_OK\fR or \fBTCL_ERROR\fR. +.SH "REFERENCE COUNT MANAGEMENT" +.PP +\fBTcl_EvalObjEx\fR and \fBTcl_GlobalEvalObj\fR both increment and +decrement the reference count of their \fIobjPtr\fR argument; you must +not pass them any value with a reference count of zero. They also +manipulate the interpreter result; you must not count on the +interpreter result to hold the reference count of any value over +these calls. +.PP +\fBTcl_EvalObjv\fR may increment and decrement the reference count of +any value passed via its \fIobjv\fR argument; you must not pass any +value with a reference count of zero. This function also manipulates +the interpreter result; you must not count on the interpreter result +to hold the reference count of any value over this call. .SH KEYWORDS execute, file, global, result, script, value diff --git a/doc/ExprLongObj.3 b/doc/ExprLongObj.3 index 837e0a8..59413e1 100644 --- a/doc/ExprLongObj.3 +++ b/doc/ExprLongObj.3 @@ -98,6 +98,15 @@ containing the expression's value at \fI*resultPtrPtr\fR. In this case, the caller is responsible for calling \fBTcl_DecrRefCount\fR to decrement the value's reference count when it is finished with the value. +.SH "REFERENCE COUNT MANAGEMENT" +.PP +\fBTcl_ExprLongObj\fR, \fBTcl_ExprDoubleObj\fR, +\fBTcl_ExprBooleanObj\fR, and \fBTcl_ExprObj\fR all increment and +decrement the reference count of their \fIobjPtr\fR arguments; you +must not pass them any value with a reference count of zero. They also +manipulate the interpreter result; you must not count on the +interpreter result to hold the reference count of any value over these +calls. .SH "SEE ALSO" Tcl_ExprLong, Tcl_ExprDouble, Tcl_ExprBoolean, Tcl_ExprString, Tcl_GetObjResult diff --git a/doc/FileSystem.3 b/doc/FileSystem.3 index 9b291fb..fc78cff 100644 --- a/doc/FileSystem.3 +++ b/doc/FileSystem.3 @@ -45,7 +45,7 @@ int \fBTcl_FSDeleteFile\fR(\fIpathPtr\fR) .sp int -\fBTcl_FSRemoveDirectory\fR(\fIpathPtr, int recursive, errorPtr\fR) +\fBTcl_FSRemoveDirectory\fR(\fIpathPtr, recursive, errorPtr\fR) .sp int \fBTcl_FSRenameFile\fR(\fIsrcPathPtr, destPathPtr\fR) @@ -79,10 +79,10 @@ int \fBTcl_FSUtime\fR(\fIpathPtr, tval\fR) .sp int -\fBTcl_FSFileAttrsGet\fR(\fIinterp, int index, pathPtr, objPtrRef\fR) +\fBTcl_FSFileAttrsGet\fR(\fIinterp, index, pathPtr, objPtrRef\fR) .sp int -\fBTcl_FSFileAttrsSet\fR(\fIinterp, int index, pathPtr, Tcl_Obj *objPtr\fR) +\fBTcl_FSFileAttrsSet\fR(\fIinterp, index, pathPtr, objPtr\fR) .sp const char *const * \fBTcl_FSFileAttrStrings\fR(\fIpathPtr, objPtrRef\fR) @@ -197,6 +197,8 @@ rename operation. .AP Tcl_Obj *destPathPtr in As for \fIpathPtr\fR, but used for the destination filename for a copy or rename operation. +.AP int recursive in +Whether to remove subdirectories and their contents as well. .AP "const char" *encodingName in The encoding of the data stored in the file identified by \fIpathPtr\fR and to be evaluated. @@ -224,6 +226,10 @@ be joined together. If negative, then all elements are joined. .AP Tcl_Obj **errorPtr out In the case of an error, filled with a value containing the name of the file which caused an error in the various copy/rename operations. +.AP int index in +The index of the attribute in question. +.AP Tcl_Obj *objPtr in +The value to set in the operation. .AP Tcl_Obj **objPtrRef out Filled with a value containing the result of the operation. .AP Tcl_Obj *resultPtr out @@ -1628,6 +1634,158 @@ typedef int \fBTcl_FSChdirProc\fR( The \fBTcl_FSChdirProc\fR changes the applications current working directory to the value specified in \fIpathPtr\fR. The function returns -1 on error or 0 on success. +.SH "REFERENCE COUNT MANAGEMENT" +.SS "PUBLIC API CALLS" +.PP +For all of these functions, \fIpathPtr\fR (including the \fIsrcPathPtr\fR and +\fIdestPathPtr\fR arguments to \fBTcl_FSCopyFile\fR, +\fBTcl_FSCopyDirectory\fR, and \fBTcl_FSRenameFile\fR, the \fIfirstPtr\fR and +\fIsecondPtr\fR arguments to \fBTcl_FSEqualPaths\fR, and the \fIlinkNamePtr\fR +and \fItoPtr\fR arguments to \fBTcl_FSLink\fR) must not be a zero reference +count value; references may be retained in internal caches even for +theoretically read-only operations. These functions may also manipulate the +interpreter result (if they take and are given a non-NULL \fIinterp\fR +argument); you must not count on the interpreter result to hold the reference +count of any argument value over these calls and should manage your own +references there. However, references held by the arguments to a Tcl command +\fIare\fR suitable for reference count management purposes for the duration of +the implementation of that command. +.PP +The \fIerrorPtr\fR argument to \fBTcl_FSCopyDirectory\fR and +\fBTcl_FSRemoveDirectory\fR is, when an object is set into it at all, set to +an object with a non-zero reference count that should be passed to +\fBTcl_DecrRefCount\fR when no longer needed. +.PP +\fBTcl_FSListVolumes\fR always returns a zero-reference object, much +like \fBTcl_NewObj\fR. +.PP +\fBTcl_FSLink\fR always returns a non-zero-reference object when it is +asked to read; you must call \fBTcl_DecrRefCount\fR on the object +once you no longer need it. +.PP +\fBTcl_FSGetCwd\fR always returns a non-zero-reference object; you +must call \fBTcl_DecrRefCount\fR on the object once you no longer need +it. +.PP +\fBTcl_FSPathSeparator\fR always returns a zero-reference object, much +like \fBTcl_NewObj\fR. +.PP +\fBTcl_FSJoinPath\fR always returns a zero-reference object, much +like \fBTcl_NewObj\fR. Its \fIlistObj\fR argument can have any reference +count; it is only read by this function. +.PP +\fBTcl_FSSplitPath\fR always returns a zero-reference object, much +like \fBTcl_NewObj\fR. +.PP +\fBTcl_FSGetNormalizedPath\fR returns an object with a non-zero +reference count where Tcl is the owner. You should increment its +reference count if you want to retain it, but do not need to if you +are just using the value immediately. +.PP +\fBTcl_FSJoinToPath\fR always returns a zero-reference object, much like +\fBTcl_NewObj\fR. Its \fIbasePtr\fR argument follows the rules above for +\fIpathPtr\fR, as do the values in the \fIobjv\fR argument. +.PP +\fBTcl_FSGetTranslatedPath\fR returns a non-zero-reference object (or +NULL in the error case); you must call \fBTcl_DecrRefCount\fR on the +object once you no longer need it. +.PP +\fBTcl_FSNewNativePath\fR always returns a zero-reference object (or +NULL), much like \fBTcl_NewObj\fR. +.PP +\fBTcl_FSFileSystemInfo\fR always returns a zero-reference object (or +NULL), much like \fBTcl_NewObj\fR. +.PP +The \fIobjPtr\fR and \fIobjPtrRef\fR arguments to \fBTcl_FSFileAttrsGet\fR, +\fBTcl_FSFileAttrsSet\fR and \fBTcl_FSFileAttrStrings\fR are conventional Tcl +values; the \fIobjPtr\fR argument will be read but not retained, and the +\fIobjPtrRef\fR argument will have (on success) a zero-reference value written +into it (as with \fBTcl_NewObj\fR). \fBTcl_FSFileAttrsGet\fR and +\fBTcl_FSFileAttrsSet\fR may also manipulate the interpreter result. +.PP +The \fIresultPtr\fR argument to \fBTcl_FSMatchInDirectory\fR will not have its +reference count manipulated, but it should have a reference count of no more +than 1, and should not be the current interpreter result (as the function may +overwrite that on error). +.SS "VIRTUAL FILESYSTEM INTERFACE" +.PP +For all virtual filesystem implementation functions, any \fIpathPtr\fR +arguments should not have their reference counts manipulated. If they take an +\fIinterp\fR argument, they may set an error message in that, but must not +manipulate the \fIpathPtr\fR afterwards. Aside from that: +.TP +\fIinternalToNormalizedProc\fR +. +This should return a zero-reference count value, as if allocated with +\fBTcl_NewObj\fR. +.TP +\fInormalizePathProc\fR +. +Unlike with other API implementation functions, the \fIpathPtr\fR argument +here is guaranteed to be an unshared object that should be updated. Its +reference count should not be modified. +.TP +\fIfilesystemPathTypeProc\fR +. +The return value (if non-NULL) either has a reference count of zero or needs +to be maintained (on a per-thread basis) by the filesystem. Tcl will increment +the reference count of the value if it wishes to retain it. +.TP +\fIfilesystemSeparatorProc\fR +. +The return value should be a value with reference count of zero. +.TP +\fImatchInDirectoryProc\fR +. +The \fIresultPtr\fR argument should be assumed to hold a list that can be +appended to (i.e., that has a reference count no greater than 1). No reference +to it should be retained. +.TP +\fIlinkProc\fR +. +If \fItoPtr\fR is NULL, this should return a value with reference count 1 that +has just been allocated and passed to \fBTcl_IncrRefCount\fR. If \fItoPtr\fR +is not NULL, it should be returned on success. +.TP +\fIlistVolumesProc\fR +. +The result value should be a list (if non-NULL); it will have its reference +count decremented once (with \fBTcl_DecrRefCount\fR) by Tcl once done. +.TP +\fIfileAttrStringsProc\fR +. +If the result is NULL, the \fIobjPtrRef\fR should have a list value written to +it; that list will have its reference count both incremented (with +\fBTcl_IncrRefCount\fR) and decremented (with \fBTcl_DecrRefCount\fR). +.TP +\fIfileAttrsGetProc\fR +. +The \fIobjPtrRef\fR argument should have (on non-error return) a zero +reference count value written to it (allocated as if with \fBTcl_NewObj\fR). +.TP +\fIfileAttrsSetProc\fR +. +The \fIobjPtr\fR argument should either just be read or its reference count +incremented to retain it. +.TP +\fIremoveDirectoryProc\fR +. +If an error is being reported, the problem filename reported via +\fIerrorPtr\fR should be newly allocated (as if with \fBTcl_NewObj\fR) and +have a reference count of 1 (i.e., have been passed to +\fBTcl_IncrRefCount\fR). +.TP +\fIcopyDirectoryProc\fR +. +If an error is being reported, the problem filename reported via +\fIerrorPtr\fR should be newly allocated (as if with \fBTcl_NewObj\fR) and +have a reference count of 1 (i.e., have been passed to +\fBTcl_IncrRefCount\fR). +.TP +\fIgetCwdProc\fR +. +The result will be passed to \fBTcl_DecrRefCount\fR by the implementation of +\fBTcl_FSGetCwd\fR after it has been normalized. .SH "SEE ALSO" cd(n), file(n), filename(n), load(n), open(n), pwd(n), source(n), unload(n) .SH KEYWORDS diff --git a/doc/GetIndex.3 b/doc/GetIndex.3 index 8591c56..a788848 100644 --- a/doc/GetIndex.3 +++ b/doc/GetIndex.3 @@ -105,6 +105,12 @@ array of characters at \fItablePtr\fR+\fIoffset\fR bytes, etc.) This is particularly useful when processing things like \fBTk_ConfigurationSpec\fR, whose string keys are in the same place in each of several array elements. +.SH "REFERENCE COUNT MANAGEMENT" +.PP +\fBTcl_GetIndexFromObj\fR and \fBTcl_GetIndexFromObjStruct\fR do not modify +the reference count of their \fIobjPtr\fR arguments; they only read. Note +however that these functions may set the interpreter result; if that is the +only place that is holding a reference to the object, it will be deleted. .SH "SEE ALSO" prefix(n), Tcl_WrongNumArgs(3) .SH KEYWORDS @@ -324,5 +324,19 @@ typedef void \fBTcl_FreeHashEntryProc\fR( If this is NULL then \fBTcl_Free\fR is used to free the space for the entry. Tcl_Obj* keys use this function to decrement the reference count on the value. +.SH "REFERENCE COUNT MANAGEMENT" +.PP +When a hash table is created with \fBTcl_InitCustomHashTable\fR, the +\fBTcl_CreateHashEntry\fR function will increment the reference count of its +\fIkey\fR argument when it creates a key (but not if there is an existing +matching key). The reference count of the key will be decremented when the +corresponding hash entry is deleted, whether with \fBTcl_DeleteHashEntry\fR or +with \fBTcl_DeleteHashTable\fR. The \fBTcl_GetHashKey\fR function will return +the key without further modifying its reference count. +.PP +Custom hash tables that use a Tcl_Obj* as key will generally need to do +something similar in their \fIallocEntryProc\fR. +.SH "SEE ALSO" +Dict(3) .SH KEYWORDS hash table, key, lookup, search, value diff --git a/doc/IntObj.3 b/doc/IntObj.3 index 36bfa7d..d640dbb 100644 --- a/doc/IntObj.3 +++ b/doc/IntObj.3 @@ -160,6 +160,27 @@ If anything later in the caller requires The \fBTcl_InitBignumFromDouble\fR routine is a utility procedure that extracts the integer part of \fIdoubleValue\fR and stores that integer value in the \fBmp_int\fR value \fIbigValue\fR. +.SH "REFERENCE COUNT MANAGEMENT" +.PP +\fBTcl_NewIntObj\fR, \fBTcl_NewLongObj\fR, \fBTcl_NewWideIntObj\fR, and +\fBTcl_NewBignumObj\fR always return a zero-reference object, much like +\fBTcl_NewObj\fR. +.PP +\fBTcl_SetIntObj\fR, \fBTcl_SetLongObj\fR, \fBTcl_SetWideIntObj\fR, and +\fBTcl_SetBignumObj\fR do not modify the reference count of their \fIobjPtr\fR +arguments, but do require that the object be unshared. +.PP +\fBTcl_GetIntFromObj\fR, \fBTcl_GetIntForIndex\fR, \fBTcl_GetLongFromObj\fR, +\fBTcl_GetWideIntFromObj\fR, \fBTcl_GetBignumFromObj\fR, and +\fBTcl_TakeBignumFromObj\fR do not modify the reference count of their +\fIobjPtr\fR arguments; they only read. Note however that this function may +set the interpreter result; if that is the only place that is holding a +reference to the object, it will be deleted. Also note that if +\fBTcl_TakeBignumFromObj\fR is given an unshared value, the value of that +object may be modified; it is intended to be used when the value is +.QW consumed +by the operation at this point. + .SH "SEE ALSO" Tcl_NewObj, Tcl_DecrRefCount, Tcl_IncrRefCount, Tcl_GetObjResult .SH KEYWORDS diff --git a/doc/ListObj.3 b/doc/ListObj.3 index ab836d8..67721c9 100644 --- a/doc/ListObj.3 +++ b/doc/ListObj.3 @@ -246,6 +246,31 @@ with a NULL \fIobjvPtr\fR: result = \fBTcl_ListObjReplace\fR(interp, listPtr, first, count, 0, NULL); .CE +.SH "REFERENCE COUNT MANAGEMENT" +.PP +\fBTcl_NewListObj\fR always returns a zero-reference object, much like +\fBTcl_NewObj\fR. If a non-NULL \fIobjv\fR argument is given, the reference +counts of the first \fIobjc\fR values in that array are incremented. +.PP +\fBTcl_SetListObj\fR does not modify the reference count of its \fIobjPtr\fR +argument, but does require that the object be unshared. The reference counts +of the first \fIobjc\fR values in the \fIobjv\fR array are incremented. +.PP +\fBTcl_ListObjGetElements\fR, \fBTcl_ListObjIndex\fR, and +\fBTcl_ListObjLength\fR do not modify the reference count of their +\fIlistPtr\fR arguments; they only read. Note however that these three +functions may set the interpreter result; if that is the only place that is +holding a reference to the object, it will be deleted. +.PP +\fBTcl_ListObjAppendList\fR, \fBTcl_ListObjAppendElement\fR, and +\fBTcl_ListObjReplace\fR require an unshared \fIlistPtr\fR argument. +\fBTcl_ListObjAppendList\fR only reads its \fIelemListPtr\fR argument. +\fBTcl_ListObjAppendElement\fR increments the reference count of its +\fIobjPtr\fR on success. \fBTcl_ListObjReplace\fR increments the reference +count of the first \fIobjc\fR values in the \fIobjv\fR array on success. Note +however that all these three functions may set the interpreter result on +failure; if that is the only place that is holding a reference to the object, +it will be deleted. .SH "SEE ALSO" Tcl_NewObj(3), Tcl_DecrRefCount(3), Tcl_IncrRefCount(3), Tcl_GetObjResult(3) .SH KEYWORDS @@ -60,6 +60,10 @@ be unloaded with \fBTcl_FSUnloadFile\fR. the symbol cannot be found, it returns NULL and sets an error message in the given \fIinterp\fR (if that is non-NULL). Note that it is unsafe to use this operation on a handle that has been passed to \fBTcl_FSUnloadFile\fR. +.SH "REFERENCE COUNT MANAGEMENT" +.PP +The reference count of the \fIpathPtr\fR argument to \fBTcl_LoadFile\fR may be +incremented. As such, it should not be given a zero reference count value. .SH "SEE ALSO" Tcl_FSLoadFile(3), Tcl_FSUnloadFile(3), load(n), unload(n) .SH KEYWORDS diff --git a/doc/Method.3 b/doc/Method.3 index 41e190d..ac71890 100644 --- a/doc/Method.3 +++ b/doc/Method.3 @@ -258,8 +258,32 @@ also return TCL_ERROR; it should return TCL_OK otherwise. The \fIoldClientData\fR field to a Tcl_CloneProc gives the value from the method being copied from, and the \fInewClientDataPtr\fR field will point to a variable in which to write the value for the method being copied to. +.SH "REFERENCE COUNT MANAGEMENT" +.PP +The \fInameObj\fR argument to \fBTcl_NewMethod\fR and +\fBTcl_NewInstanceMethod\fR (when non-NULL) will have its reference count +incremented if there is no existing method with that name in that +class/object. +.PP +The result of \fBTcl_MethodName\fR is a value with a reference count of at +least one. It should not be modified without first duplicating it (with +\fBTcl_DuplicateObj\fR). +.PP +The values in the first \fIobjc\fR values of the \fIobjv\fR argument to +\fBTcl_ObjectContextInvokeNext\fR are assumed to have a reference count of at +least 1; the containing array is assumed to endure until the next method +implementation (see \fBnext\fR) returns. Be aware that methods may +\fByield\fR; if any post-call actions are desired (e.g., decrementing the +reference count of values passed in here), they must be scheduled with +\fBTcl_NRAddCallback\fR. +.PP +The \fIcallProc\fR of the \fBTcl_MethodType\fR structure takes values of at +least reference count 1 in its \fIobjv\fR argument. It may add its own +references, but must not decrement the reference count below that level; the +caller of the method will decrement the reference count once the method +returns properly (and the reference will be held if the method \fByield\fRs). .SH "SEE ALSO" -Class(3), oo::class(n), oo::define(n), oo::object(n) +Class(3), NRE(3), oo::class(n), oo::define(n), oo::object(n) .SH KEYWORDS constructor, method, object @@ -227,6 +227,25 @@ int Any function comprising a routine can push other functions, making it possible implement looping and sequencing constructs using the function stack. .PP +.SH "REFERENCE COUNT MANAGEMENT" +.PP +The first \fIobjc\fR values in the \fIobjv\fR array passed to the functions +\fBTcl_NRCallObjProc\fR, \fBTcl_NREvalObjv\fR, and \fBTcl_NRCmdSwap\fR should +have a reference count of at least 1; they may have additional references +taken during the execution. +.PP +The \fIobjPtr\fR argument to \fBTcl_NREvalObj\fR and \fBTcl_NRExprObj\fR +should have a reference count of at least 1, and may have additional +references taken to it during execution. +.PP +The \fIresultObj\fR argument to \fBTcl_NRExprObj\fR should be an unshared +object. +.PP +Use \fBTcl_NRAddCallback\fR to schedule any required final decrementing of the +reference counts of arguments to any of the other functions on this page, as +with any other post-processing step in the non-recursive execution engine. +.PP +The .SH "SEE ALSO" Tcl_CreateCommand(3), Tcl_CreateObjCommand(3), Tcl_EvalObjEx(3), Tcl_GetCommandFromObj(3), Tcl_ExprObj(3) .SH KEYWORDS diff --git a/doc/Namespace.3 b/doc/Namespace.3 index c69d547..c4c893a 100644 --- a/doc/Namespace.3 +++ b/doc/Namespace.3 @@ -46,10 +46,10 @@ Tcl_Command \fBTcl_FindCommand\fR(\fIinterp, name, contextNsPtr, flags\fR) .sp Tcl_Obj * -\fBTcl_GetNamespaceUnknownHandler(\fIinterp, nsPtr\fR) +\fBTcl_GetNamespaceUnknownHandler\fR(\fIinterp, nsPtr\fR) .sp int -\fBTcl_SetNamespaceUnknownHandler(\fIinterp, nsPtr, handlerPtr\fR) +\fBTcl_SetNamespaceUnknownHandler\fR(\fIinterp, nsPtr, handlerPtr\fR) .SH ARGUMENTS .AS Tcl_NamespaceDeleteProc allowOverwrite in/out .AP Tcl_Interp *interp in/out @@ -159,6 +159,18 @@ for the namespace, or NULL if none is set. \fBTcl_SetNamespaceUnknownHandler\fR sets the unknown command handler for the namespace. If \fIhandlerPtr\fR is NULL, then the handler is reset to its default. +.SH "REFERENCE COUNT MANAGEMENT" +.PP +The \fIobjPtr\fR argument to \fBTcl_AppendExportList\fR should be an +unshared object, as it will be modified by this function. The +reference count of \fIobjPtr\fR will not be altered. +.PP +\fBTcl_GetNamespaceUnknownHandler\fR returns a possibly shared value. +Its reference count should be incremented if the value is to be +retained. +.PP +The \fIhandlerPtr\fR argument to \fBTcl_SetNamespaceUnknownHandler\fR +will have its reference count incremented if it is a non-empty list. .SH "SEE ALSO" Tcl_CreateCommand(3), Tcl_ListObjAppendList(3), Tcl_SetVar(3) .SH KEYWORDS diff --git a/doc/Object.3 b/doc/Object.3 index 117e631..91ee397 100644 --- a/doc/Object.3 +++ b/doc/Object.3 @@ -283,7 +283,12 @@ to reduce storage requirements. Reference counting is used to determine when a value is no longer needed and can safely be freed. A value just created by \fBTcl_NewObj\fR or \fBTcl_NewStringObj\fR -has \fIrefCount\fR 0. +has \fIrefCount\fR 0, meaning that the object can often be given to a function +like \fBTcl_SetObjResult\fR, \fBTcl_ListObjAppendElement\fR, or +\fBTcl_DictObjPut\fR (as a value) without explicit reference management, all +of which are common use cases. (The latter two require that the the target +list or dictionary be well-formed, but that is often easy to arrange when the +value is being initially constructed.) The macro \fBTcl_IncrRefCount\fR increments the reference count when a new reference to the value is created. The macro \fBTcl_DecrRefCount\fR decrements the count diff --git a/doc/ObjectType.3 b/doc/ObjectType.3 index fb76ef7..9f8d04f 100644 --- a/doc/ObjectType.3 +++ b/doc/ObjectType.3 @@ -248,6 +248,28 @@ The \fIfreeIntRepProc\fR implementation must not access the uses of that field during value deletion. The defined tasks for the \fIfreeIntRepProc\fR have no need to consult the \fIbytes\fR member. +.PP +Note that if a subsidiary value has its reference count reduced to zero +during the running of a \fIfreeIntRepProc\fR, that value may be not freed +immediately, in order to limit stack usage. However, the value will be freed +before the outermost current \fBTcl_DecrRefCount\fR returns. +.SH "REFERENCE COUNT MANAGEMENT" +.PP +The \fIobjPtr\fR argument to \fBTcl_AppendAllObjTypes\fR should be an unshared +value; this function will not modify the reference count of that value, but +will modify its contents. If \fIobjPtr\fR is not (interpretable as) a list, +this function will set the interpreter result and produce an error; using an +unshared empty value is strongly recommended. +.PP +The \fIobjPtr\fR argument to \fBTcl_ConvertToType\fR can have any non-zero +reference count; this function will not modify the reference count, but may +write to the interpreter result on error so values that originate from there +should have an additional reference made before calling this. +.PP +None of the callback functions in the \fBTcl_ObjType\fR structure should +modify the reference count of their arguments, but if the values contain +subsidiary values (e.g., the elements of a list or the keys of a dictionary) +then those subsidiary values may have their reference counts modified. .SH "SEE ALSO" Tcl_NewObj(3), Tcl_DecrRefCount(3), Tcl_IncrRefCount(3) .SH KEYWORDS diff --git a/doc/OpenFileChnl.3 b/doc/OpenFileChnl.3 index 23b0863..0555520 100644 --- a/doc/OpenFileChnl.3 +++ b/doc/OpenFileChnl.3 @@ -641,6 +641,24 @@ the channel was created with \fBTcl_OpenFileChannel\fR, \fBTcl_OpenCommandChannel\fR, or \fBTcl_MakeFileChannel\fR. Other channel types may return a different type of handle on Windows platforms. +.SH "REFERENCE COUNT MANAGEMENT" +.PP +The \fIreadObjPtr\fR argument to \fBTcl_ReadChars\fR must be an unshared +value; it will be modified by this function. Using the interpreter result for +this purpose is \fIstrongly\fR not recommended; the preferred pattern is to +use a new value from \fBTcl_NewObj\fR to receive the data and only to pass it +to \fBTcl_SetObjResult\fR if this function succeeds. +.PP +The \fIlineObjPtr\fR argument to \fBTcl_GetsObj\fR must be an unshared value; +it will be modified by this function. Using the interpreter result for this +purpose is \fIstrongly\fR not recommended; the preferred pattern is to use a +new value from \fBTcl_NewObj\fR to receive the data and only to pass it to +\fBTcl_SetObjResult\fR if this function succeeds. +.PP +The \fIwriteObjPtr\fR argument to \fBTcl_WriteObj\fR should be a value with +any reference count. This function will not modify the reference count. Using +the interpreter result without adding an additional reference to it is not +recommended. .SH "SEE ALSO" DString(3), fconfigure(n), filename(n), fopen(3), Tcl_CreateChannel(3) .SH KEYWORDS diff --git a/doc/ParseArgs.3 b/doc/ParseArgs.3 index 30a1dd2..2189551 100644 --- a/doc/ParseArgs.3 +++ b/doc/ParseArgs.3 @@ -189,6 +189,12 @@ will be stored at \fIdstPtr\fR; the string inside will have a lifetime linked to the lifetime of the string representation of the argument value that it came from, and so should be copied if it needs to be retained. The \fIsrcPtr\fR and \fIclientData\fR fields are ignored. +.SH "REFERENCE COUNT MANAGEMENT" +.PP +The values in the \fiobjv\fR argument to \fBTcl_ParseArgsObjv\fR will not have +their reference counts modified by this function. The interpreter result may +be modified on error; the values passed should not be the interpreter result +with no further reference added. .SH "SEE ALSO" Tcl_GetIndexFromObj(3), Tcl_Main(3), Tcl_CreateObjCommand(3) .SH KEYWORDS diff --git a/doc/PkgRequire.3 b/doc/PkgRequire.3 index f32c936..77e73f1 100644 --- a/doc/PkgRequire.3 +++ b/doc/PkgRequire.3 @@ -91,6 +91,10 @@ functions. \fBTcl_PkgRequireProc\fR is the form of \fBpackage require\fR handling multiple requirements. The other forms are present for backward compatibility and translate their invocations to this form. +.SH "REFERENCE COUNT MANAGEMENT" +.PP +The requirements values given (in the \fIobjv\fR argument) to +\fBTcl_PkgRequireProc\fR must have non-zero reference counts. .SH KEYWORDS package, present, provide, require, version .SH "SEE ALSO" diff --git a/doc/RecEvalObj.3 b/doc/RecEvalObj.3 index 1d77c12..0835904 100644 --- a/doc/RecEvalObj.3 +++ b/doc/RecEvalObj.3 @@ -44,6 +44,12 @@ allow the user to re-issue recently invoked commands. If the \fIflags\fR argument contains the \fBTCL_NO_EVAL\fR bit then the command is recorded without being evaluated. +.SH "REFERENCE COUNT MANAGEMENT" +.PP +The reference count of the \fIcmdPtr\fR argument to \fBTcl_RecordAndEvalObj\fR +must be at least 1. This function will modify the interpreter result; do not +use an existing result as \fIcmdPtr\fR directly without incrementing its +reference count. .SH "SEE ALSO" Tcl_EvalObjEx, Tcl_GetObjResult diff --git a/doc/RegExp.3 b/doc/RegExp.3 index 95716e9..9016ee3 100644 --- a/doc/RegExp.3 +++ b/doc/RegExp.3 @@ -377,6 +377,22 @@ If no match was found, then it indicates the earliest point at which a match might occur if additional text is appended to the string. If it is no match is possible even with further text, this field will be set to \-1. +.SH "REFERENCE COUNT MANAGEMENT" +.PP +The \fItextObj\fR and \fIpatObj\fR arguments to \fBTcl_RegExpMatchObj\fR must +have reference counts of at least 1. Note however that this function may set +the interpreter result; neither argument should be the direct interpreter +result without an additional reference being taken. +.PP +The \fIpatObj\fR argument to \fBTcl_GetRegExpFromObj\fR must have a reference +count of at least 1. Note however that this function may set the interpreter +result; the argument should not be the direct interpreter result without an +additional reference being taken. +.PP +The \fItextObj\fR argument to \fBTcl_RegExpExecObj\fR must have a reference +count of at least 1. Note however that this function may set the interpreter +result; the argument should not be the direct interpreter result without an +additional reference being taken. .SH "SEE ALSO" re_syntax(n) .SH KEYWORDS diff --git a/doc/SetChanErr.3 b/doc/SetChanErr.3 index e73c38f..72157c6 100644 --- a/doc/SetChanErr.3 +++ b/doc/SetChanErr.3 @@ -35,20 +35,20 @@ Refers to the Tcl interpreter whose bypass area is accessed. .AP Tcl_Obj* msg in Error message put into a bypass area. A list of return options and values, followed by a string message. Both message and the option/value information -are optional. +are optional. This \fImust\fR be a well-formed list. .AP Tcl_Obj** msgPtr out Reference to a place where the message stored in the accessed bypass area can be stored in. .BE .SH DESCRIPTION .PP -The current definition of a Tcl channel driver does not permit the direct +The standard definition of a Tcl channel driver does not permit the direct return of arbitrary error messages, except for the setting and retrieval of channel options. All other functions are restricted to POSIX error codes. .PP The functions described here overcome this limitation. Channel drivers are allowed to use \fBTcl_SetChannelError\fR and \fBTcl_SetChannelErrorInterp\fR -to place arbitrary error messages in \fBbypass areas\fR defined for channels +to place arbitrary error messages in \fIbypass areas\fR defined for channels and interpreters. And the generic I/O layer uses \fBTcl_GetChannelError\fR and \fBTcl_GetChannelErrorInterp\fR to look for messages in the bypass areas and arrange for their return as errors. The POSIX error codes set by a driver are @@ -130,6 +130,15 @@ leave all their error information in the interpreter result. .ta 1.9i 4i \fBTcl_Close\fR \fBTcl_UnstackChannel\fR \fBTcl_UnregisterChannel\fR .DE +.SH "REFERENCE COUNT MANAGEMENT" +.PP +The \fImsg\fR argument to \fBTcl_SetChannelError\fR and +\fBTcl_SetChannelErrorInterp\fR, if not NULL, may have any reference count; +these functions will copy. +.PP +\fBTcl_GetChannelError\fR and \fBTcl_GetChannelErrorInterp\fR write a value +reference into their \fImsgPtr\fR, but do not manipulate its reference count. +The reference count will be at least 1 (unless the reference is NULL). .SH "SEE ALSO" Tcl_Close(3), Tcl_OpenFileChannel(3), Tcl_SetErrno(3) .SH KEYWORDS diff --git a/doc/SetResult.3 b/doc/SetResult.3 index 1355d6b..42e3ce0 100644 --- a/doc/SetResult.3 +++ b/doc/SetResult.3 @@ -214,6 +214,33 @@ typedef void \fBTcl_FreeProc\fR( .PP When \fIfreeProc\fR is called, its \fIblockPtr\fR will be set to the value of \fIresult\fR passed to \fBTcl_SetResult\fR. + +.SH "REFERENCE COUNT MANAGEMENT" +.PP +The interpreter result is one of the main places that owns references to +values, along with the bytecode execution stack, argument lists, variables, +and the list and dictionary collection values. +.PP +\fBTcl_SetObjResult\fR takes a value with an arbitrary reference count +\fI(specifically including zero)\fR and guarantees to increment the reference +count. If code wishes to continue using the value after setting it as the +result, it should add its own reference to it with \fBTcl_IncrRefCount\fR. +.PP +\fBTcl_GetObjResult\fR returns the current interpreter result value. This will +have a reference count of at least 1. If the caller wishes to keep the +interpreter result value, it should increment its reference count. +.PP +\fBTcl_GetStringResult\fR does not manipulate reference counts, but the string +it returns is owned by (and has a lifetime controlled by) the current +interpreter result value; it should be copied instead of being relied upon to +persist after the next Tcl API call, as most Tcl operations can modify the +interpreter result. +.PP +\fBTcl_SetResult\fR, \fBTcl_AppendResult\fR, \fBTcl_AppendResultVA\fR, +\fBTcl_AppendElement\fR, and \fBTcl_ResetResult\fR all modify the interpreter +result. They may cause the old interpreter result to have its reference count +decremented and a new interpreter result to be allocated. After they have been +called, the reference count of the interpreter result is guaranteed to be 1. .SH "SEE ALSO" Tcl_AddErrorInfo, Tcl_CreateObjCommand, Tcl_SetErrorCode, Tcl_Interp, Tcl_GetReturnOptions diff --git a/doc/SetVar.3 b/doc/SetVar.3 index 4aa671a..eb8333b 100644 --- a/doc/SetVar.3 +++ b/doc/SetVar.3 @@ -242,6 +242,27 @@ but the array remains. If an array name is specified without an index, then the entire array is removed. +.SH "REFERENCE COUNT MANAGEMENT" +.PP +The result of \fBTcl_SetVar2Ex\fR, \fBTcl_ObjSetVar2\fR, \fBTcl_GetVar2Ex\fR, +and \fBTcl_ObjGetVar2\fR is (if non-NULL) a value with a reference of at least +1, where that reference is held by the variable that the function has just +operated upon. +.PP +The \fInewValuePtr\fR argument to \fBTcl_SetVar2Ex\fR and \fBTcl_ObjSetVar2\fR +may be an arbitrary reference count value; its reference count will be +incremented on success. However, it is recommended to not use a zero reference +count value, as that makes correct handling of the error case tricky. +.PP +The \fIpart1\fR argument to \fBTcl_ObjSetVar2\fR and \fBTcl_ObjGetVar2\fR can +have any reference count; these functions never modify it. It is recommended +to not use a zero reference count for this argument. +.PP +The \fIpart2\fR argument to \fBTcl_ObjSetVar2\fR and \fBTcl_ObjGetVar2\fR, if +non-NULL, should not have a zero reference count as these functions may +retain a reference to it (particularly when it is used to create an array +element that did not previously exist). + .SH "SEE ALSO" Tcl_GetObjResult, Tcl_GetStringResult, Tcl_TraceVar diff --git a/doc/StringObj.3 b/doc/StringObj.3 index 10e747f..7db739d 100644 --- a/doc/StringObj.3 +++ b/doc/StringObj.3 @@ -374,6 +374,33 @@ white space, then that value is ignored entirely. This white-space removal was added to make the output of the \fBconcat\fR command cleaner-looking. \fBTcl_ConcatObj\fR returns a pointer to a newly-created value whose ref count is zero. +.SH "REFERENCE COUNT MANAGEMENT" +.PP +\fBTcl_NewStringObj\fR, \fBTcl_NewUnicodeObj\fB, \fBTcl_Format\fR, +\fBTcl_ObjPrintf\fR, and \fBTcl_ConcatObj\fR always return a zero-reference +object, much like \fBTcl_NewObj\fR. +.PP +\fBTcl_GetStringFromObj\fR, \fBTcl_GetString\fR, \fBTcl_GetUnicodeFromObj\fR, +\fBTcl_GetUnicode\fR, \fBTcl_GetUniChar\fR, \fBTcl_GetCharLength\fR, and +\fBTcl_GetRange\fR all only work with an existing value; they do not +manipulate its reference count in any way. +.PP +\fBTcl_SetStringObj\fR, \fBTcl_SetUnicodeObj\fR, \fBTcl_AppendToObj\fR, +\fBTcl_AppendUnicodeToObj\fR, \fBTcl_AppendObjToObj\fR, +\fBTcl_AppendStringsToObj\fR, \fBTcl_AppendStringsToObjVA\fR, +\fBTcl_AppendLimitedToObj\fR, \fBTcl_AppendFormatToObj\fR, +\fBTcl_AppendPrintfToObj\fR, \fBTcl_SetObjLength\fR, and +\fBTcl_AttemptSetObjLength\fR and require their \fIobjPtr\fR to be an unshared +value (i.e, a reference count no more than 1) as they will modify it. +.PP +Additional arguments to the above functions (the \fIappendObjPtr\fR argument +to \fBTcl_AppendObjToObj\fR, values in the \fIobjv\fR argument to +\fBTcl_Format\fR, \fBTcl_AppendFormatToObj\fR, and \fBTcl_ConcatObj\fR) can +have any reference count, but reference counts of zero are not recommended. +.PP +\fBTcl_Format\fR and \fBTcl_AppendFormatToObj\fR may modify the interpreter +result, which involves changing the reference count of a value. + .SH "SEE ALSO" Tcl_NewObj(3), Tcl_IncrRefCount(3), Tcl_DecrRefCount(3), format(n), sprintf(3) .SH KEYWORDS diff --git a/doc/SubstObj.3 b/doc/SubstObj.3 index a2b6214..fa30fb1 100644 --- a/doc/SubstObj.3 +++ b/doc/SubstObj.3 @@ -62,6 +62,13 @@ result of the whole substitution on \fIobjPtr\fR will be truncated at the point immediately before the start of the command substitution, and no characters will be added to the result or substitutions performed after that point. +.SH "REFERENCE COUNT MANAGEMENT" +.PP +The \fIobjPtr\fR argument to \fBTcl_SubstObj\fR must not have a reference +count of zero. This function modifies the interpreter result, both on success +and on failure; the result of this function on success is exactly the current +interpreter result. Successful results should have their reference count +incremented if they are to be retained. .SH "SEE ALSO" subst(n) .SH KEYWORDS diff --git a/doc/TclZlib.3 b/doc/TclZlib.3 index 6d9179d..bd37f9c 100644 --- a/doc/TclZlib.3 +++ b/doc/TclZlib.3 @@ -262,6 +262,31 @@ file named by the \fBfilename\fR field was modified. Suitable for use with . The type of the uncompressed data (either \fBbinary\fR or \fBtext\fR) if known. +.SH "REFERENCE COUNT MANAGEMENT" +.PP +\fBTcl_ZlibDeflate\fR and \fBTcl_ZlibInflate\fR take a value with arbitrary +reference count for their \fIdataObj\fR and \fIdictObj\fR arguments (the +latter often being NULL instead), and set the interpreter result with their +output value (or an error). The existing interpreter result should not be +passed as any argument value unless an additional reference is held. +.PP +\fBTcl_ZlibStreamInit\fR takes a value with arbitrary reference count for its +\fIdictObj\fR argument; it only reads from it. The existing interpreter result +should not be passed unless an additional reference is held. +.PP +\fBTcl_ZlibStreamGetCommandName\fR returns a zero reference count value, much +like \fBTcl_NewObj\fR. +.PP +The \fIdataObj\fR argument to \fBTcl_ZlibStreamPut\fR is a value with +arbitrary reference count; it is only ever read from. +.PP +The \fIdataObj\fR argument to \fBTcl_ZlibStreamGet\fR is an unshared value +(see \fBTcl_IsShared\fR) that will be updated by the function. +.PP +The \fIcompDict\fR argument to \fBTcl_ZlibStreamSetCompressionDictionary\fR, +if non-NULL, may be duplicated or may have its reference count incremented. +Using a zero reference count value is not recommended. + .SH "PORTABILITY NOTES" These functions will fail gracefully if Tcl is not linked with the zlib library. diff --git a/doc/Tcl_Main.3 b/doc/Tcl_Main.3 index 5817c10..904ecbe 100644 --- a/doc/Tcl_Main.3 +++ b/doc/Tcl_Main.3 @@ -201,6 +201,15 @@ procedure (if any) returns, \fBTcl_Main\fR will also evaluate the \fBexit\fR command. .PP \fBTcl_Main\fR can not be used in stub-enabled extensions. +.SH "REFERENCE COUNT MANAGEMENT" +.PP +\fBTcl_SetStartupScript\fR takes a value (or NULL) for its \fIpath\fR +argument, and will increment the reference count of it. +.PP +\fBTcl_GetStartupScript\fR returns a value with reference count at least 1, or +NULL. It's \fIencodingPtr\fR is also used (if non-NULL) to return a value with +a reference count at least 1, or NULL. In both cases, the owner of the values +is the current thread. .SH "SEE ALSO" tclsh(1), Tcl_GetStdChannel(3), Tcl_StandardChannels(3), Tcl_AppInit(3), exit(n), encoding(n) diff --git a/doc/TraceVar.3 b/doc/TraceVar.3 index dd72563..649565a 100644 --- a/doc/TraceVar.3 +++ b/doc/TraceVar.3 @@ -360,6 +360,14 @@ Traces on a variable are always removed whenever the variable is deleted; the only time \fBTCL_TRACE_DESTROYED\fR is not set is for a whole-array trace invoked when only a single element of an array is unset. +.SH "REFERENCE COUNT MANAGEMENT" +.PP +When a \fIproc\fR callback is invoked, and that callback was installed with +the \fBTCL_TRACE_RESULT_OBJECT\fR flag, the result of the callback is a +Tcl_Obj reference when there is an error. The result will have its reference +count decremented once when no longer needed, or may have additional +references made to it (e.g., by setting it as the interpreter result with +\fBTcl_SetObjResult\fR). .SH BUGS .PP Array traces are not yet integrated with the Tcl \fBinfo exists\fR command, diff --git a/doc/WrongNumArgs.3 b/doc/WrongNumArgs.3 index 93e2ebb..533cb4f 100644 --- a/doc/WrongNumArgs.3 +++ b/doc/WrongNumArgs.3 @@ -73,6 +73,12 @@ is now an \fIindexObject\fR because it was passed to .CS wrong # args: should be "foo barfly fileName count" .CE +.SH "REFERENCE COUNT MANAGEMENT" +.PP +The \fIobjv\fR argument to \fBTcl_WrongNumArgs\fR should be the exact +arguments passed to the command or method implementation function that is +calling \fBTcl_WrongNumArgs\fR. As such, all values referenced in it should +have reference counts greater than zero; this is usually a non-issue. .SH "SEE ALSO" Tcl_GetIndexFromObj(3) .SH KEYWORDS |