pctx_set_events(3CPC)				    CPU Performance Counters Library Functions				     pctx_set_events(3CPC)

NAME

       pctx_set_events - associate callbacks with process events

SYNOPSIS

       cc [ flag... ] file... -lpctx [ library... ]
       #include <libpctx.h>

       typedef	 enum {
	       PCTX_NULL_EVENT = 0,
	       PCTX_SYSC_EXEC_EVENT,
	       PCTX_SYSC_FORK_EVENT,
	       PCTX_SYSC_EXIT_EVENT,
	       PCTX_SYSC_LWP_CREATE_EVENT,
	       PCTX_INIT_LWP_EVENT,
	       PCTX_FINI_LWP_EVENT,
	       PCTX_SYSC_LWP_EXIT_EVENT
       } pctx_event_t;

       typedef int pctx_sysc_execfn_t(pctx_t *pctx, pid_t pid, id_t lwpid,
	    char *cmd, void *arg);

       typedef void pctx_sysc_forkfn_t(pctx_t *pctx,
	    pid_t pid, id_t lwpid, pid_t child, void *arg);

       typedef void pctx_sysc_exitfn_t(pctx_t *pctx, pid_t pid, id_t lwpid,
	    void *arg);

       typedef int pctx_sysc_lwp_createfn_t(pctx_t *pctx, pid_t pid, id_t lwpid,
	    void *arg);

       typedef int pctx_init_lwpfn_t(pctx_t *pctx, pid_t pid, id_t lwpid,
	    void *arg);

       typedef int pctx_fini_lwpfn_t(pctx_t *pctx, pid_t pid, id_t lwpid,
	    void *arg);

       typedef int pctx_sysc_lwp_exitfn_t(pctx_t *pctx, pid_t pid, id_t lwpid,
	    void *arg);

       int pctx_set_events(pctx_t *pctx...);

DESCRIPTION

       The pctx_set_events() function allows the caller (the controlling process) to express interest in various events in the controlled process.
       See pctx_capture(3CPC) for information about how the controlling process is able to create, capture and manipulate the controlled process.

       The pctx_set_events() function takes a pctx_t handle, followed by a variable length list of pairs of pctx_event_t  tags	and  their  corre-
       sponding handlers, terminated by a PCTX_NULL_EVENT tag.

       Most  of  the events correspond closely to various classes of system calls, though two additional pseudo-events (init_lwp and fini_lwp) are
       provided to allow callers to perform various housekeeping tasks.  The init_lwp handler is called as soon as the library	identifies  a  new
       LWP,  while  fini_lwp  is  called  just	before	the  LWP disappears. Thus the classic "hello world" program would see an init_lwp event, a
       fini_lwp event and (process) exit event, in that order.	 The table below displays the interactions between the states  of  the	controlled
       process and the handlers executed by users of the library.

       +-------------------------------+--------------+------------------------------------+
       |System Calls and pctx Handlers |	      | 				   |
       +-------------------------------+--------------+------------------------------------+
       |	 System call	       |   Handler    | 	    Comments		   |
       +-------------------------------+--------------+------------------------------------+
       |	 exec,execve	       |  fini_lwp    |Invoked serially on all lwps in the |
       |			       |	      |process. 			   |
       |			       |    exec      |Only invoked if the  exec()  system |
       |			       |	      |call succeeded.			   |
       |			       |  init_lwp    |If  the exec succeeds, only invoked |
       |			       |	      |on  lwp	1.  If	the  exec   fails, |
       |			       |	      |invoked serially on all lwps in the |
       |			       |	      |process. 			   |
       +-------------------------------+--------------+------------------------------------+
       |      fork, vfork, fork1       |    fork      |Only invoked if the  fork()  system |
       |			       |	      |call succeeded.			   |
       +-------------------------------+--------------+------------------------------------+
       |	     exit	       |  fini_lwp    |Invoked on all lwps in the process. |
       |			       |    exit      |    Invoked on the exiting lwp.	   |
       +-------------------------------+--------------+------------------------------------+

       Each of the handlers is passed the caller's opaque handle, a pctx_t handle, the pid, and lwpid of the process and lwp generating the event.
       The lwp_exit, and (process) exit events are delivered before the underlying system calls begin, while the exec, fork, and lwp_create events
       are  only  delivered  after the relevant system calls complete successfully. The exec handler is passed a string that describes the command
       being executed. Catching the fork event causes the calling process to fork(2), then capture the	child  of  the	controlled  process  using
       pctx_capture() before handing control to the fork handler.  The process is released on return from the handler.

RETURN VALUES

       Upon successful completion, pctx_set_events() returns 0.  Otherwise, the function returns -1.

EXAMPLES

       Example 1 HandleExec example.

       This  example  captures	an  existing process whose process identifier is pid, and arranges to call the HandleExec routine when the process
       performs an exec(2).

	 static void
	 HandleExec(pctx_t *pctx, pid_t pid, id_t lwpid, char *cmd, void *arg)
	 {
	      (void) printf("pid %d execed '%s'
", (int)pid, cmd);
	 }
	 int
	 main()
	 {
	      ...
	      pctx = pctx_capture(pid, NULL, 1, NULL);
	      (void) pctx_set_events(pctx,
		    PCTX_SYSC_EXEC_EVENT, HandleExec,
		    ...
		    PCTX_NULL_EVENT);
	      (void) pctx_run(pctx, 0, 0, NULL);
	      pctx_release(pctx);
	 }

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Interface Stability	     |Evolving			   |
       +-----------------------------+-----------------------------+
       |MT-Level		     |Unsafe			   |
       +-----------------------------+-----------------------------+

SEE ALSO

       exec(2), exit(2), fork(2), vfork(2), fork1(2), cpc(3CPC), libpctx(3LIB), proc(4), attributes(5)

SunOS 5.11							    13 May 2003 					     pctx_set_events(3CPC)