PS_PSTOP(3PROC)PS_PSTOP(3PROC)NAME
ps_pstop, ps_pcontinue, ps_lstop, ps_lcontinue, ps_lrolltoaddr, ps_kill
- process and LWP control in libthread_db
SYNOPSIS
#include <proc_service.h>
ps_err_e ps_pstop(struct ps_prochandle *ph);
ps_err_e ps_pcontinue(struct ps_prochandle *ph);
ps_err_e ps_lstop(struct ps_prochandle *ph, lwpid_t lwpid);
ps_err_e ps_lcontinue(struct ps_prochandle *ph,
lwpid_t lwpid);
ps_err_e ps_lrolltoaddr(struct ps_prochandle *ph,
lwpid_t lwpid, psaddr_t go_addr, psaddr_t stop_addr);
ps_err_e ps_kill(struct ps_prochandle *ph, int signum);
DESCRIPTION
The ps_pstop() function stops the target process identified by ph,
while the ps_pcontinue() function allows it to resume.
The libthread_db() function uses ps_pstop() to freeze the target
process while it is under inspection. Within the scope of any single
call from outside libthread_db to a libthread_db routine, libthread_db
will call ps_pstop(), at most once. If it does, it will call ps_pcon‐
tinue() within the scope of the same routine.
The controlling process may already have stopped the target process
when it calls libthread_db. In that case, it is not obligated to resume
the target process when libthread_db calls ps_pcontinue(). In other
words, ps_pstop() is mandatory, while ps_pcontinue() is advisory.
After ps_pstop(), the target process must be stopped; after ps_pcon‐
tinue(), the target process may be running.
The ps_lstop() and ps_lcontinue() functions stop and resume a single
lightweight process (LWP) within the target process ph.
The ps_lrolltoaddr() function is used to roll an LWP forward out of a
critical section when the process is stopped. It is also used to run
the libthread_db agent thread on behalf of libthread. The ps_lroll‐
toaddr() function is always called with the target process stopped,
that is, there has been a preceding call to ps_pstop(). The specified
LWP must be continued at the address go_addr, or at its current address
if go_addr is NULL. It should then be stopped when its execution
reaches stop_addr. This routine does not return until the LWP has
stopped at stop_addr.
The ps_kill() function directs the signal signum to the target process
for which the handle is ph. It has the same semantics as kill(2).
RETURN VALUES
PS_OK
The call completed successfully. In the case of
ps_pstop(), the target process is stopped.
PS_BADLID
For ps_lstop(), ps_lcontinue() and ps_lrolltoaddr();
there is no LWP with id lwipd in the target process.
PS_ERR
The function did not return successfully.
ATTRIBUTES
See attributes(5) for description of the following attributes:
┌───────────────┬─────────────────┐
│ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
├───────────────┼─────────────────┤
│MT Level │ Safe │
└───────────────┴─────────────────┘
SEE ALSOkill(2), libc_db(3LIB), proc_service(3PROC), attributes(5), threads(5)
Mar 22, 2001 PS_PSTOP(3PROC)