From 49ffe9e1dc9b12fa1c87c103326e0207d0cf45d8 Mon Sep 17 00:00:00 2001 From: Jeremie Koenig Date: Mon, 23 Aug 2010 16:46:04 +0000 Subject: Cleanup pass on process.c * process.c: Reorder some of the code. Improve comments. Jiffies and clock tick are the same thing, right? Replace the stat mode and cleanup hacks by more straightforward solutions. --- process.c | 122 ++++++++++++++++++++++++++++++++++++++++---------------------- 1 file changed, 79 insertions(+), 43 deletions(-) (limited to 'process.c') diff --git a/process.c b/process.c index 61688f7e..1f9d5781 100644 --- a/process.c +++ b/process.c @@ -9,22 +9,20 @@ #include "procfs_dir.h" #include "process.h" #include "main.h" - -/* Implementations for the process_file_desc.get_contents callback. */ -static ssize_t -process_file_gc_cmdline (struct proc_stat *ps, char **contents) -{ - *contents = proc_stat_args(ps); - return proc_stat_args_len(ps); -} +/* This module implements the process directories and the files they + contain. A libps proc_stat structure is created for each process + node, and is used by the individual file content generators as a + source of information. Each possible file (cmdline, environ, ...) is + decribed in a process_file_desc structure, which specifies which bits + of information (ie. libps flags) it needs, and what function should + be used to generate the file's contents. -static ssize_t -process_file_gc_environ (struct proc_stat *ps, char **contents) -{ - *contents = proc_stat_env(ps); - return proc_stat_env_len(ps); -} + The content generators are defined first, followed by glue logic and + entry table. */ + + +/* Helper functions */ static char state_char (struct proc_stat *ps) { @@ -58,17 +56,26 @@ static const char *state_string (struct proc_stat *ps) return "? (unknown)"; } -static long int sc_tv (time_value_t tv) +static long long int timeval_jiffies (time_value_t tv) { - double usecs = ((double) tv.seconds) * 1000000 + tv.microseconds; - return usecs * opt_clk_tck / 1000000; + double secs = tv.seconds + tv.microseconds / 1000000.; + return secs * opt_clk_tck; } -static long long int jiff_tv (time_value_t tv) +/* Actual content generators */ + +static ssize_t +process_file_gc_cmdline (struct proc_stat *ps, char **contents) { - double usecs = ((double) tv.seconds) * 1000000 + tv.microseconds; - /* Let's say a jiffy is 1/100 of a second.. */ - return usecs * 100 / 1000000; + *contents = proc_stat_args(ps); + return proc_stat_args_len(ps); +} + +static ssize_t +process_file_gc_environ (struct proc_stat *ps, char **contents) +{ + *contents = proc_stat_env(ps); + return proc_stat_env_len(ps); } static ssize_t @@ -105,17 +112,18 @@ process_file_gc_stat (struct proc_stat *ps, char **contents) 0, 0, /* no such thing as a major:minor for ctty */ 0, /* no such thing as CLONE_* flags on Hurd */ 0L, 0L, 0L, 0L, /* TASK_EVENTS_INFO is unavailable on GNU Mach */ - sc_tv (thbi->user_time), sc_tv (thbi->system_time), + (long unsigned) timeval_jiffies (thbi->user_time), + (long unsigned) timeval_jiffies (thbi->system_time), 0L, 0L, /* cumulative time for children */ MACH_PRIORITY_TO_NICE(thbi->base_priority) + 20, MACH_PRIORITY_TO_NICE(thbi->base_priority), pi->nthreads, 0L, - jiff_tv (thbi->creation_time), /* FIXME: ... since boot */ - (long unsigned int) tbi->virtual_size, - (long unsigned int) tbi->resident_size / PAGE_SIZE, 0L, + timeval_jiffies (thbi->creation_time), /* FIXME: ... since boot */ + (long unsigned) tbi->virtual_size, + (long unsigned) tbi->resident_size / PAGE_SIZE, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, - (long unsigned int) proc_stat_thread_rpc (ps), /* close enough */ + (long unsigned) proc_stat_thread_rpc (ps), /* close enough */ 0L, 0L, 0, 0, @@ -127,6 +135,7 @@ static ssize_t process_file_gc_statm (struct proc_stat *ps, char **contents) { task_basic_info_t tbi = proc_stat_task_basic_info (ps); + return asprintf (contents, "%lu %lu 0 0 0 0 0\n", tbi->virtual_size / sysconf(_SC_PAGE_SIZE), @@ -137,6 +146,7 @@ static ssize_t process_file_gc_status (struct proc_stat *ps, char **contents) { task_basic_info_t tbi = proc_stat_task_basic_info (ps); + return asprintf (contents, "Name:\t%s\n" "State:\t%s\n" @@ -165,59 +175,70 @@ process_file_gc_status (struct proc_stat *ps, char **contents) proc_stat_num_threads (ps)); } + +/* Implementation of the file nodes. */ -/* Describes a file in a process directory. This is used as an "entry hook" - * for our procfs_dir entry table, passed to process_file_make_node. */ +/* Describes a file in the process directories. This structure is + filled in as an "entry hook" in our procfs_dir entry table and is + passed to the process_file_make_node function defined below. */ struct process_file_desc { /* The proc_stat information required to get the contents of this file. */ ps_flags_t needs; - /* Once we have acquired the necessary information, there can be only - memory allocation errors, hence this simplified signature. */ + /* Content generator to use for this file. Once we have acquired the + necessary information, there can be only memory allocation errors, + hence this simplified signature. */ ssize_t (*get_contents) (struct proc_stat *ps, char **contents); - /* The cmdline and environ contents don't need any cleaning since they are - part of a proc_stat structure. */ + /* The cmdline and environ contents don't need any cleaning since they + point directly into the proc_stat structure. */ int no_cleanup; /* If specified, the file mode to be set with procfs_node_chmod(). */ mode_t mode; }; -/* Information associated to an actual file node. */ struct process_file_node { const struct process_file_desc *desc; struct proc_stat *ps; }; +/* FIXME: lock the parent! */ static error_t process_file_get_contents (void *hook, char **contents, ssize_t *contents_len) { struct process_file_node *file = hook; error_t err; + /* Fetch the required information. */ err = proc_stat_set_flags (file->ps, file->desc->needs); if (err) return EIO; if ((proc_stat_flags (file->ps) & file->desc->needs) != file->desc->needs) return EIO; + /* Call the actual content generator (see the definitions below). */ *contents_len = file->desc->get_contents (file->ps, contents); return 0; } +static void +process_file_cleanup_contents (void *hook, char *contents, ssize_t len) +{ + struct process_file_node *file = hook; + + if (! file->desc->no_cleanup) + free (contents); +} + static struct node * process_file_make_node (void *dir_hook, const void *entry_hook) { static const struct procfs_node_ops ops = { .get_contents = process_file_get_contents, - .cleanup_contents = procfs_cleanup_contents_with_free, - .cleanup = free, - }; - static const struct procfs_node_ops ops_no_cleanup = { - .get_contents = process_file_get_contents, + .cleanup_contents = process_file_cleanup_contents, .cleanup = free, }; struct process_file_node *f; @@ -230,7 +251,7 @@ process_file_make_node (void *dir_hook, const void *entry_hook) f->desc = entry_hook; f->ps = dir_hook; - np = procfs_make_node (f->desc->no_cleanup ? &ops_no_cleanup : &ops, f); + np = procfs_make_node (&ops, f); if (! np) return NULL; @@ -241,6 +262,18 @@ process_file_make_node (void *dir_hook, const void *entry_hook) return np; } +/* Stat needs its own constructor in oreder to set its mode according to + the --stat-mode command-line option. */ +static struct node * +process_stat_make_node (void *dir_hook, const void *entry_hook) +{ + struct node *np = process_file_make_node (dir_hook, entry_hook); + if (np) procfs_node_chmod (np, opt_stat_mode); + return np; +} + + +/* Implementation of the process directory per se. */ static struct procfs_dir_entry entries[] = { { @@ -261,22 +294,22 @@ static struct procfs_dir_entry entries[] = { }, }, { - /* Beware of the hack below, which requires this to be entries[2]. */ .name = "stat", .hook = & (struct process_file_desc) { .get_contents = process_file_gc_stat, .needs = PSTAT_PID | PSTAT_ARGS | PSTAT_STATE | PSTAT_PROC_INFO | PSTAT_TASK | PSTAT_TASK_BASIC | PSTAT_THREAD_BASIC | PSTAT_THREAD_WAIT, - .mode = 0400, }, + .ops = { + .make_node = process_stat_make_node, + } }, { .name = "statm", .hook = & (struct process_file_desc) { .get_contents = process_file_gc_statm, .needs = PSTAT_TASK_BASIC, - .mode = 0444, }, }, { @@ -285,7 +318,6 @@ static struct procfs_dir_entry entries[] = { .get_contents = process_file_gc_status, .needs = PSTAT_PID | PSTAT_ARGS | PSTAT_STATE | PSTAT_PROC_INFO | PSTAT_TASK_BASIC | PSTAT_OWNER_UID | PSTAT_NUM_THREADS, - .mode = 0444, }, }, {} @@ -319,6 +351,10 @@ process_lookup_pid (struct ps_context *pc, pid_t pid, struct node **np) accessed in a more robust and straightforward way. */ ((struct process_file_desc *) entries[2].hook)->mode = opt_stat_mode; + /* FIXME: have a separate proc_desc structure for each file, so this can be + accessed in a more robust and straightforward way. */ + ((struct process_file_desc *) entries[2].hook)->mode = opt_stat_mode; + *np = procfs_dir_make_node (&dir_ops, ps); if (! *np) return ENOMEM; -- cgit v1.2.3