ps_pstop(3T)

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(const struct ps_prochandle ∗ph)

ps_err_e ps_pcontinue(const struct ps_prochandle ∗ph)

ps_err_e ps_lstop(const struct ps_prochandle ∗ph, lwpid_t lwpid)

ps_err_e ps_lcontinue(const struct ps_prochandle ∗ph, lwpid_t lwpid)

ps_err_e ps_lrolltoaddr(const struct ps_prochandle ∗ph,

lwpid_t lwpid, psaddr_t go_addr, psaddr_t stop_addr)

ps_err_e ps_kill(const struct ps_prochandle ∗ph, int signum)

DESCRIPTION

ps_pstop() stops the target process identified by ph, while ps_pcontinue() allows it to resume.

libthread_db 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_pcontinue() 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_pcontinue(), the target process may be running.

ps_lstop() and ps_lcontinue() stop and resume a single lightweight process ( LWP ) within the target process ph. They are not currently used by libthread_db.

ps_lrolltoaddr() 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. ps_lrolltoaddr() 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.

ps_kill() directs the signal signum to the target process for which the handle is ph. ps_kill() 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 and ps_lcontinue only: 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

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