Manual Pages for UNIX Operating System command usage for man memory

Tcl Built-In Commands                                  memory(1T)



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NAME
     memory - Control Tcl memory debugging capabilities.

SYNOPSIS
     memory option ?arg arg ...?
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DESCRIPTION
     The memory 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 TCL_MEM_DEBUG is defined at compile time), and
     after Tcl_InitMemory has been called.

     memory active file
          Write a list of all currently allocated memory  to  the
          specified file.

     memory break_on_malloc count
          After the count allocations have been performed,  ckal-
          loc outputs a message to this effect and that it is now
          attempting to enter the  C  debugger.   Tcl  will  then
          issue  a SIGINT signal against itself.  If you are run-
          ning Tcl under a C debugger, it should then  enter  the
          debugger command mode.

     memory info
          Returns a report containing the total  allocations  and
          frees  since  Tcl  began, the current packets allocated
          (the current number of calls to ckalloc not  met  by  a
          corresponding  call to ckfree), the current bytes allo-
          cated, and the maximum  number  of  packets  and  bytes
          allocated.

      memory init [on|off]
          Turn on or off the pre-initialization of all  allocated
          memory  with bogus bytes.  Useful for detecting the use
          of uninitialized values.

     memory onexit file
          Causes a list of all allocated memory to be written  to
          the  specified  file  during  the finalization of Tcl's
          memory subsystem.  Useful for checking that  memory  is
          properly cleaned up during process exit.

     memory tag string
          Each packet of memory allocated  by  ckalloc  can  have
          associated  with  it a string-valued tag.  In the lists



Tcl                     Last change: 8.1                        1






Tcl Built-In Commands                                  memory(1T)



          of allocated memory  generated  by  memory  active  and
          memory onexit, the tag for each packet is printed along
          with other information about the  packet.   The  memory
          tag  command sets the tag value for subsequent calls to
          ckalloc to be string.

     memory trace [on|off]
          Turns memory tracing on or off.  When memory tracing is
          on, every call to ckalloc causes a line of trace infor-
          mation to be written to stderr, consisting of the  word
          ckalloc,  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:
               ckalloc 40e478 98 tclProc.c 1406
          Calls to ckfree are traced in the same manner.

     memory trace_on_at_malloc count
          Enable memory tracing after count ckalloc's  have  been
          performed.    For   example,   if   you   enter  memory
          trace_on_at_malloc 100, after the 100th call  to  ckal-
          loc,   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.

     memory validate [on|off]
          Turns memory validation on or off. When memory  valida-
          tion  is  enabled,  on every call to ckalloc or ckfree,
          the guard zones are checked for every piece  of  memory
          currently  in  existence that was allocated by ckalloc.
          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 ckalloc or  ckfree  after  the  overwrite  occurred,
          rather than when the specific memory with the overwrit-
          ten guard zone(s) is freed, which may occur long  after
          the overwrite occurred.


SEE ALSO
     ckalloc,           ckfree,            Tcl_ValidateAllMemory,
     Tcl_DumpActiveMemory, TCL_MEM_DEBUG


KEYWORDS
     memory, debug



Tcl                     Last change: 8.1                        2






Tcl Built-In Commands                                  memory(1T)



ATTRIBUTES
     See attributes(5) for descriptions of the  following  attri-
     butes:

     _______________________________________
    |   ATTRIBUTE TYPE   |  ATTRIBUTE VALUE|
    |____________________|__________________|_
    | Availability       |  runtime/tcl-8  |
    |____________________|__________________|_
    | Interface Stability|  Uncommitted    |
    |____________________|_________________|

NOTES
     Source for Tcl is available on http://opensolaris.org.









































Tcl                     Last change: 8.1                        3