116 lines
4.5 KiB
Plaintext
116 lines
4.5 KiB
Plaintext
'\"
|
|
'\" Copyright (c) 1992-1999 Karl Lehenbauer & Mark Diekhans
|
|
'\" Copyright (c) 2000 Scriptics Corporation.
|
|
'\" All rights reserved.
|
|
'\"
|
|
.TH memory n 8.1 Tcl "Tcl Built-In Commands"
|
|
.so man.macros
|
|
.BS
|
|
.SH NAME
|
|
memory \- Control Tcl memory debugging capabilities
|
|
.SH SYNOPSIS
|
|
\fBmemory \fIoption \fR?\fIarg arg ...\fR?
|
|
.BE
|
|
.SH DESCRIPTION
|
|
.PP
|
|
The \fBmemory\fR command gives the Tcl developer control of Tcl's memory
|
|
debugging capabilities. The memory command has several suboptions, which are
|
|
described below. It is only available when Tcl has been compiled with
|
|
memory debugging enabled (when \fBTCL_MEM_DEBUG\fR is defined at
|
|
compile time), and after \fBTcl_InitMemory\fR has been called.
|
|
.TP
|
|
\fBmemory active\fR \fIfile\fR
|
|
.
|
|
Write a list of all currently allocated memory to the specified \fIfile\fR.
|
|
.TP
|
|
\fBmemory break_on_malloc\fR \fIcount\fR
|
|
.
|
|
After the \fIcount\fR allocations have been performed, \fBckalloc\fR
|
|
outputs a message to this effect and that it is now attempting to enter
|
|
the C debugger. Tcl will then issue a \fISIGINT\fR signal against itself.
|
|
If you are running Tcl under a C debugger, it should then enter the debugger
|
|
command mode.
|
|
.TP
|
|
\fBmemory info\fR
|
|
.
|
|
Returns a report containing the total allocations and frees since
|
|
Tcl began, the current packets allocated (the current
|
|
number of calls to \fBckalloc\fR not met by a corresponding call
|
|
to \fBckfree\fR), the current bytes allocated, and the maximum number
|
|
of packets and bytes allocated.
|
|
.TP
|
|
\fBmemory init \fR[\fBon\fR|\fBoff\fR]
|
|
.
|
|
Turn on or off the pre-initialization of all allocated memory
|
|
with bogus bytes. Useful for detecting the use of uninitialized
|
|
values.
|
|
.TP
|
|
\fBmemory objs \fIfile\fR
|
|
.
|
|
Causes a list of all allocated Tcl_Obj values to be written to the specified
|
|
\fIfile\fR immediately, together with where they were allocated. Useful for
|
|
checking for leaks of values.
|
|
.TP
|
|
\fBmemory onexit\fR \fIfile\fR
|
|
.
|
|
Causes a list of all allocated memory to be written to the specified \fIfile\fR
|
|
during the finalization of Tcl's memory subsystem. Useful for checking
|
|
that memory is properly cleaned up during process exit.
|
|
.TP
|
|
\fBmemory tag\fR \fIstring\fR
|
|
.
|
|
Each packet of memory allocated by \fBckalloc\fR can have associated
|
|
with it a string-valued tag. In the lists of allocated memory generated
|
|
by \fBmemory active\fR and \fBmemory onexit\fR, the tag for each packet
|
|
is printed along with other information about the packet. The
|
|
\fBmemory tag\fR command sets the tag value for subsequent calls
|
|
to \fBckalloc\fR to be \fIstring\fR.
|
|
.TP
|
|
\fBmemory trace \fR[\fBon\fR|\fBoff\fR]
|
|
.
|
|
Turns memory tracing on or off. When memory tracing is on, every call
|
|
to \fBckalloc\fR causes a line of trace information to be written to
|
|
\fIstderr\fR, consisting of the word \fIckalloc\fR, followed by the
|
|
address returned, the amount of memory allocated, and the C filename
|
|
and line number of the code performing the allocation. For example:
|
|
.RS
|
|
.PP
|
|
.CS
|
|
ckalloc 40e478 98 tclProc.c 1406
|
|
.CE
|
|
.PP
|
|
Calls to \fBckfree\fR are traced in the same manner.
|
|
.RE
|
|
.TP
|
|
\fBmemory trace_on_at_malloc\fR \fIcount\fR
|
|
.
|
|
Enable memory tracing after \fIcount\fR \fBckalloc\fRs have been performed.
|
|
For example, if you enter \fBmemory trace_on_at_malloc 100\fR,
|
|
after the 100th call to \fBckalloc\fR, memory trace information will begin
|
|
being displayed for all allocations and frees. Since there can be a lot
|
|
of memory activity before a problem occurs, judicious use of this option
|
|
can reduce the slowdown caused by tracing (and the amount of trace information
|
|
produced), if you can identify a number of allocations that occur before
|
|
the problem sets in. The current number of memory allocations that have
|
|
occurred since Tcl started is printed on a guard zone failure.
|
|
.TP
|
|
\fBmemory validate \fR[\fBon\fR|\fBoff\fR]
|
|
.
|
|
Turns memory validation on or off. When memory validation is enabled,
|
|
on every call to \fBckalloc\fR or \fBckfree\fR, the guard zones are
|
|
checked for every piece of memory currently in existence that was
|
|
allocated by \fBckalloc\fR. This has a large performance impact and
|
|
should only be used when overwrite problems are strongly suspected.
|
|
The advantage of enabling memory validation is that a guard zone
|
|
overwrite can be detected on the first call to \fBckalloc\fR or
|
|
\fBckfree\fR after the overwrite occurred, rather than when the
|
|
specific memory with the overwritten guard zone(s) is freed, which may
|
|
occur long after the overwrite occurred.
|
|
.SH "SEE ALSO"
|
|
ckalloc, ckfree, Tcl_ValidateAllMemory, Tcl_DumpActiveMemory, TCL_MEM_DEBUG
|
|
.SH KEYWORDS
|
|
memory, debug
|
|
'\"Local Variables:
|
|
'\"mode: nroff
|
|
'\"End:
|