Provided by: systemtap_0.0.20071201-1_i386 bug

NAME

       stapfuncs - systemtap functions

DESCRIPTION

       The  following  sections  enumerate  the  public  functions provided by
       standard tapsets  installed  under  /usr/share/systemtap/tapset.   Each
       function  is described with a signature, and its behavior/restrictions.
       The signature line includes the name of the function, the type  of  its
       return  value (if any), and the names and types of all parameters.  The
       syntax is the same as printed with the stap option -p2.  Examples:

       example1:long (v:string, k:long)
              In function "example1", do something with the given  string  and
              integer.  Return some integer.

       example2:unknown ()
              In  function  "example2",  do  something.   There is no explicit
              return value and take no parameters.

   PRINTING
       log:unknown (msg:string)
              Writes the given string to the common trace buffer.   Append  an
              implicit  end-of-line.  Deprecated.  Please use the faster print
              functions.

       warn:unknown (msg:string)
              Write the  given  string  to  the  warning  stream.   Append  an
              implicit end-of-line.  staprun prepends the string "WARNING:".

       error:unknown (msg:string)
              An  error  has  occurred.   Write  the given string to the error
              stream.  Append an implicit end-of-line.  staprun  prepends  the
              string  "ERROR:".   Block any further execution of statements in
              this probe.   If  the  number  of  errors  so  far  exceeds  the
              MAXERRORS parameter, also trigger an exit().

       exit:unknown ()
              Enqueue a request to shut down the systemtap session.  This does
              not unwind the  current  probe  handler,  nor  block  new  probe
              handlers.   staprun  will  shortly  respond  to  the request and
              initiate an orderly shutdown.

   CONVERSIONS
       These functions access kernel or user-space data.  They try to validate
       the  supplied  addresses, and can thus result in errors if the pointers
       are invalid, or if a user-space access would cause a fault.

       kernel_string:string (addr:long)
              Copy a 0-terminated string from kernel space at given address.

       kernel_string_n:string (addr:long, n:long)
              Similar with kernel_string, except that not more  than  n  bytes
              are  copied.   Thus,  if  there are null bytes among the first n
              bytes, it is same as kernel_string(addr). If not, n  bytes  will
              be copied and a null byte will be padded to the end.

       kernel_long:long (addr:long)
              Copy a long from kernel space at given address.

       kernel_int:long (addr:long)
              Copy an int from kernel space at given address.

       kernel_short:long (addr:long)
              Copy a short from kernel space at given address.

       kernel_char:long (addr:long)
              Copy a char from kernel space at given address.

       user_string:string (addr:long)
              Copy  a  string from user space at given address.  If the access
              would fault, return "<unknown>" and signal no errors.

       user_string2:string (addr:long, err_msg:string)
              Copy a string from user space at given address.  If  the  access
              would fault, return instead the err_msg value.

       user_string_warn:string (addr:long)
              Copy  a  string from user space at given address.  If the access
              would fault, signal a warning and return "<unknown>".

   STRING
       strlen:long (str:string)
              Return the number of characters in str.

       substr:string (str:string,start:long, stop:long)
              Return the substring of str starting from  character  start  and
              ending at character stop.

       isinstr:long (s1:string, s2:string)
              Return 1 if string s1 contains string s2, returns 0 otherwise.

       strtol:long (str:string, base:long)
              Convert  the  string  representation of a number to a long using
              the  numbering  system  specified   by   base.    For   example,
              strtol("1000", 16) returns 4096.  Returns 0 if the string cannot
              be converted.

       tokenize:string (str:string, delim:string)
              Return the next token in the given str string, where the  tokens
              are  delimited by one of the characters in the delim string.  If
              the str string is not blank, it returns the first token.  If the
              str  string  is  blank,  it returns the next token in the string
              passed in the previous call to  tokenize.  If  no  delimiter  is
              found,  the  entire  remaining  str string is returned.  Returns
              blank when no more tokens are left.

   TIMESTAMP
       get_cycles:long ()
              Return the processor cycle counter value, or 0 if unavailable.

       gettimeofday_ns:long ()
              Return the number of nanoseconds since the UNIX epoch.

       gettimeofday_us:long ()
              Return the number of microseconds since the UNIX epoch.

       gettimeofday_ms:long ()
              Return the number of milliseconds since the UNIX epoch.

       gettimeofday_s:long ()
              Return the number of seconds since the UNIX epoch.

   CONTEXT INFO
       cpu:long ()
              Return the current cpu number.

       execname:string ()
              Return the name of the current process.

       pexecname:string()
              Return the name of the parent process.

       tid:long ()
              Return the id of the current thread.

       pid:long ()
              Return the id of the current process.

       ppid:long ()
              Return the id of the parent process.

       uid:long ()
              Return the uid of the current process.

       euid:long ()
              Return the effective uid of the current process.

       gid:long ()
              Return the gid of the current process.

       egid:long ()
              Return the effective gid of the current process.

       print_regs:unknown ()
              Print a register dump.

       backtrace:string ()
              Return a string of hex addresses that are  a  backtrace  of  the
              stack.  It may be truncated due to maximum string length.

       print_stack:unknown (bt:string)
              Perform  a symbolic lookup of the addresses in the given string,
              which  is  assumed  to  be  the  result  of  a  prior  call   to
              backtrace().  Print one line per address, including the address,
              the name of the function containing the address, and an estimate
              of its position within that function.  Return nothing.

       print_backtrace:unknown ()
              Equivalent to print_stack(backtrace()), except that deeper stack
              nesting may be supported.  Return nothing.

       pp:string ()
              Return the probe point associated  with  the  currently  running
              probe handler, including alias and wildcard expansion effects.

       probefunc:string ()
              Return the probe point’s function name, if known.

       probemod:string ()
              Return the probe point’s module name, if known.

       target:long ()
              Return the pid of the target process.

       is_return:long ()
              Return 1 if the probe point is a return probe.  Deprecated.

   TARGET_SET
       target_set_pid:long (tid:long)
              Return  whether the given process-id is within the "target set",
              that is whether it is a descendent  of  the  top-level  target()
              process.

       target_set_report:unknown ()
              Print a report about the target set, and their ancestry.

   ERRNO
       errno_str:string (e:long)
              Return the symbolic string associated with the given error code,
              like "ENOENT" for the number 2, or "E#3333" for an  out-of-range
              value like 3333.

   TASK
       These  functions  return  data  about  a task.  They all require a task
       handle as input, such as the value  return  by  task_current()  or  the
       variables  prev_task  and  next_task  in  the scheduler.ctxswitch probe
       alias.

       task_current:long()
              Return the task_struct of the current process.

       task_parent:long(task:long)
              Return the parent task_struct of the given task.

       task_state:long(task:long)
              Return the state of the given task, which  can  be  one  of  the
              following:

                 TASK_RUNNING           0
                 TASK_INTERRUPTIBLE     1
                 TASK_UNINTERRUPTIBLE   2
                 TASK_STOPPED           4
                 TASK_TRACED            8
                 EXIT_ZOMBIE           16
                 EXIT_DEAD             32

       task_execname:string(task:long)
              Return the name of the given task.

       task_pid:long(task:long)
              Return the process id of the given task.

       task_tid:long(task:long)
              Return the thread id of the given task.

       task_gid:long(task:long)
              Return the group id of the given task.

       task_egid:long(task:long)
              Return the effective group id of the given task.

       task_uid:long(task:long)
              Return the user id of the given task.

       task_euid:long(task:long)
              Return the effective user id of the given task.

       task_prio:long(task:long)
              Return the priority of the given task.

       task_nice:long(task:long)
              Return the nice value of the given task.

       task_cpu:long(task:long)
              Return the scheduled cpu for the given task.

       task_open_file_handles:long(task:long)
              Return the number of open file handles for the given task.

       task_max_file_handles:long(task:long)
              Return the maximum number of file handles for the given task.

   QUEUE_STATS
       The  queue_stats tapset provides functions that, given notifications of
       elementary queuing events (wait, run, done), tracks  averages  such  as
       queue length, service and wait times, utilization.  The following three
       functions should be called from appropriate probes, in sequence.

       qs_wait:unknown (qname:string)
              Record that a new request was enqueued for the given queue name.

       qs_run:unknown (qname:string)
              Record  that  a previously enqueued request was removed from the
              given wait queue and is now being serviced.

       qs_done:unknown (qname:string)
              Record that a  request  originally  from  the  given  queue  has
              completed being serviced.

       Functions with the prefix qsq_ are for querying the statistics averaged
       since the first queue operation (or when qsq_start was  called).  Since
       statistics  are  often  fractional, a scale parameter is multiplies the
       result to a more useful scale.  For some fractions, a scale of 100 will
       usefully return percentage numbers.

       qsq_start:unknown (qname:string)
              Reset  the  statistics  counters  for the given queue, and start
              tracking anew from this moment.

       qsq_print:unknown (qname:string)
              Print a  line  containing  a  selection  of  the  given  queue’s
              statistics.

       qsq_utilization:long (qname:string, scale:long)
              Return  the  fraction  of  elapsed  time  when  the resource was
              utilized.

       qsq_blocked:long (qname:string, scale:long)
              Return the fraction of elapsed time  when  the  wait  queue  was
              used.

       qsq_wait_queue_length:long (qname:string, scale:long)
              Return the average length of the wait queue.

       qsq_service_time:long (qname:string, scale:long)
              Return the average time required to service a request.

       qsq_wait_time:long (qname:string, scale:long)
              Return  the  average  time a request took from being enqueued to
              completed.

       qsq_throughput:long (qname:string, scale:long)
              Return the average rate of requests per scale units of time.

   INDENT
       The indent tapset provides functions to  generate  indented  lines  for
       nested  kinds  of  trace  messages.   Each  line  contains  a  relative
       timestamp, and the process name / pid.

       thread_indent:string (delta:long)
              Return a string with an appropriate indentation for this thread.
              Call  it  with  a small positive or matching negative delta.  If
              this is the outermost, initial level of indentation,  reset  the
              relative timestamp base to zero.

       thread_timestamp:long ()
              Return  an  absolute  timestamp value for use by the indentation
              function.  The default function uses gettimeofday_us

   SYSTEM
       system (cmd:string)
              Runs a command on the  system.  The  command  will  run  in  the
              background when the current probe completes.

   NUMA
       addr_to_node:long (addr:long)
              Return which node the given address belongs to in a NUMA system.

   CTIME
       ctime:string (seconds:long)
              Return     a      simple      textual      rendering      (e.g.,
              "Wed Jun 30 21:49:008 1993")  of  the  given  number  of seconds
              since the epoch, as perhaps returned by gettimeofday_s().

   PERFMON
       read_counter:long (handle:long)
              Returns the value for the processor’s  performance  counter  for
              the  associated  handle.  The body of the a perfmon probe should
              set record the handle being used for that event.

   SOCKETS
       These functions convert arguments in the socket tapset back  and  forth
       between    their    numeric    and    string    representations.    See
       stapprobes.socket(5) for details.

       sock_prot_num2str:string (proto:long)
              Returns the string representation of the given protocol value.

       sock_prot_str2num:long (proto:string)
              Returns the numeric value associated  with  the  given  protocol
              string.

       sock_fam_num2str:string (family:long)
              Returns  the  string representation of the given protocol family
              value.

       sock_fam_str2num:long (family:string)
              Returns the numeric value associated  with  the  given  protocol
              family string.

       sock_state_num2str:string (state:long)
              Returns  the  string  representation  of  the given socket state
              value.

       sock_state_str2num:long (state:string)
              Returns the numeric value associated with the given socket state
              string.

       sock_type_num2str:string (type:long)
              Returns  the  string  representation  of  the  given socket type
              value.

       sock_type_str2num:long (type:string)
              Returns the numeric value associated with the given socket  type
              string.

       sock_flags_num2str:string (flags:long)
              Returns  the  string  representation  of  the given socket flags
              value.

       msg_flags_num2str:string (flags:long)
              Returns the string representation of the given message flags bit
              map.

   INET
       These  functions  convert  between  network  (big-endian) and host byte
       order, like their namesake C functions.

       ntohll:long (x:long)
              Convert from network to host byte order, 64-bit.

       ntohl:long (x:long)
              Convert from network to host byte order, 32-bit.

       ntohs:long (x:long)
              Convert from network to host byte order, 16-bit.

       htonll:long (x:long)
              Convert from host to network byte order, 64-bit.

       htonl:long (x:long)
              Convert from host to network byte order, 32-bit.

       htons:long (x:long)
              Convert from host to network byte order, 16-bit.

FILES

       /usr/share/systemtap/tapset

SEE ALSO

       stap(1)