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| -rw-r--r-- | libps/context.c | 159 |
1 files changed, 159 insertions, 0 deletions
diff --git a/libps/context.c b/libps/context.c new file mode 100644 index 00000000..67b63ced --- /dev/null +++ b/libps/context.c @@ -0,0 +1,159 @@ +/* The type ps_context_t, for per-procserver and somewhat global state. + + Copyright (C) 1995 Free Software Foundation, Inc. + + Written by Miles Bader <miles@gnu.ai.mit.edu> + + This program is free software; you can redistribute it and/or + modify it under the terms of the GNU General Public License as + published by the Free Software Foundation; either version 2, or (at + your option) any later version. + + This program is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ + +#include <hurd.h> +#include <stdio.h> +#include <stdlib.h> +#include <assert.h> + +#include "ps.h" +#include "common.h" + +/* ---------------------------------------------------------------- */ + +/* Returns in PC a new ps_context_t for the proc server SERVER. If a memory + allocation error occurs, ENOMEM is returned, otherwise 0. */ +error_t +ps_context_create(process_t server, ps_context_t *pc) +{ + error_t err_procs, err_ttys, err_ttys_by_cttyid, err_users; + + *pc = NEW(struct ps_context); + if (*pc == NULL) + return ENOMEM; + + (*pc)->server = server; + err_procs = ihash_create(&(*pc)->procs); + err_ttys = ihash_create(&(*pc)->ttys); + err_ttys_by_cttyid = ihash_create(&(*pc)->ttys_by_cttyid); + err_users = ihash_create(&(*pc)->users); + + if (err_procs || err_ttys || err_ttys_by_cttyid) + /* Some allocation error occurred, backout any successful ones and fail. */ + { + if (!err_procs) ihash_free((*pc)->procs); + if (!err_users) ihash_free((*pc)->users); + if (!err_ttys) ihash_free((*pc)->ttys); + if (!err_ttys_by_cttyid) ihash_free((*pc)->ttys_by_cttyid); + free(*pc); + return ENOMEM; + } + + ihash_set_cleanup((*pc)->procs, + (void (*)(void *, void *arg))_proc_stat_free, + NULL); + ihash_set_cleanup((*pc)->ttys, + (void (*)(void *, void *arg))ps_tty_free, + NULL); + ihash_set_cleanup((*pc)->users, + (void (*)(void *, void *arg))ps_user_free, + NULL); + + return 0; +} + +/* Frees PC and any resources it consumes. */ +void +ps_context_free(ps_context_t pc) +{ + ihash_free(pc->procs); + ihash_free(pc->procs); + free(pc); +} + +/* ---------------------------------------------------------------- */ + +/* Return the value in HT indexed by the key ID. If it doesn't exist create + it by calling CREATE with ID and a return location pointer as arguments + (CREATE should return either an error-code or 0 if no error occurs), and + cache it in HT. */ +static error_t +lookup(int id, ihash_t ht, error_t (*create)(int id, void **), void **value) +{ + *value = ihash_find(ht, id); + if (*value == NULL) + { + error_t err = create(id, value); + if (err) + return err; + ihash_add(ht, id, *value, NULL); + } + return 0; +} + +/* Find a proc_stat_t for the process referred to by PID, and return it in + PS. If an error occurs, it is returned, otherwise 0. */ +error_t +ps_context_find_proc_stat(ps_context_t pc, int pid, proc_stat_t *ps) +{ + error_t create(int pid, void **value) + { + return _proc_stat_create(pid, pc, (proc_stat_t *)value); + } + return lookup(pid, pc->procs, create, (void **)ps); +} + +/* Find a ps_tty_t for the terminal referred to by the port TTY_PORT, and + return it in TTY. If an error occurs, it is returned, otherwise 0. */ +error_t +ps_context_find_tty(ps_context_t pc, int tty_port, ps_tty_t *tty) +{ + return lookup(tty_port, + pc->ttys, + (error_t (*)(int id, void **result))ps_tty_create, + (void **)tty); +} + +/* Find a ps_tty_t for the terminal referred to by the ctty id port + CTTYID_PORT, and return it in TTY. If an error occurs, it is returned, + otherwise 0. */ +error_t +ps_context_find_tty_by_cttyid(ps_context_t pc, int cttyid_port, ps_tty_t *tty) +{ + error_t create(int cttyid_port, void **value) + { + if (cttyid_port == MACH_PORT_NULL) + { + *value = 0; + return 0; + } + else + { + int tty_port; + error_t err = termctty_open_terminal(cttyid_port, 0, &tty_port); + if (err) + return err; + else + return ps_context_find_tty(pc, tty_port, (ps_tty_t *)value); + } + } + + return lookup(cttyid_port, pc->ttys, create, (void **)tty); +} + +/* Find a ps_user_t for the user referred to by UID, and return it in U. */ +error_t +ps_context_find_user(ps_context_t pc, int uid, ps_user_t *u) +{ + return lookup(uid, + pc->users, + (error_t (*)(int id, void **result))ps_user_create, + (void **)u); +} |