crond: code shrink

function                                             old     new   delta
ForkJob                                              513     457     -56

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 65 insertions, 62 deletions

diff --git a/miscutils/crond.c b/miscutils/crond.c
index 4a3103cb9..49ecf745e 100644
--- a/miscutils/crond.c
+++ b/miscutils/crond.c
@@ -54,8 +54,8 @@ typedef struct CronLine {
         pid_t cl_Pid;           /* running pid, 0, or armed (-1)        */
 #if ENABLE_FEATURE_CROND_CALL_SENDMAIL
         int cl_MailPos;         /* 'empty file' size                    */
-        smallint cl_MailFlag;   /* running pid is for mail              */
         char *cl_MailTo;        /* whom to mail results                 */
+        smallint cl_MailFlag;   /* running pid is for mail              */
 #endif
         /* ordered by size, not in natural order. makes code smaller: */
         char cl_Dow[7];         /* 0-6, beginning sunday                */
@@ -166,6 +166,9 @@ static void crondlog(const char *ctl, ...)
 int crond_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int crond_main(int argc UNUSED_PARAM, char **argv)
 {
+        time_t t2;
+        int rescan;
+        int sleep_time;
         unsigned opts;
 
         INIT_G();
@@ -195,62 +198,62 @@ int crond_main(int argc UNUSED_PARAM, char **argv)
         xsetenv("SHELL", DEFAULT_SHELL); /* once, for all future children */
         crondlog(LVL8 "crond (busybox "BB_VER") started, log level %d", LogLevel);
         SynchronizeDir();
+        write_pidfile("/var/run/crond.pid");
 
         /* main loop - synchronize to 1 second after the minute, minimum sleep
          * of 1 second. */
-        {
-                time_t t1 = time(NULL);
-                int rescan = 60;
-                int sleep_time = 60;
+        t2 = time(NULL);
+        rescan = 60;
+        sleep_time = 60;
+        for (;;) {
+                time_t t1;
+                long dt;
 
-                write_pidfile("/var/run/crond.pid");
-                for (;;) {
-                        time_t t2;
-                        long dt;
+                t1 = t2;
+                sleep((sleep_time + 1) - (time(NULL) % sleep_time));
 
-                        sleep((sleep_time + 1) - (time(NULL) % sleep_time));
+                t2 = time(NULL);
+                dt = (long)t2 - (long)t1;
 
-                        t2 = time(NULL);
-                        dt = (long)t2 - (long)t1;
-
-                        /*
-                         * The file 'cron.update' is checked to determine new cron
-                         * jobs.  The directory is rescanned once an hour to deal
-                         * with any screwups.
-                         *
-                         * check for disparity.  Disparities over an hour either way
-                         * result in resynchronization.  A reverse-indexed disparity
-                         * less then an hour causes us to effectively sleep until we
-                         * match the original time (i.e. no re-execution of jobs that
-                         * have just been run).  A forward-indexed disparity less then
-                         * an hour causes intermediate jobs to be run, but only once
-                         * in the worst case.
-                         *
-                         * when running jobs, the inequality used is greater but not
-                         * equal to t1, and less then or equal to t2.
-                         */
-                        if (--rescan == 0) {
-                                rescan = 60;
-                                SynchronizeDir();
-                        }
-                        CheckUpdates();
-                        if (DebugOpt)
-                                crondlog(LVL5 "wakeup dt=%ld", dt);
-                        if (dt < -60 * 60 || dt > 60 * 60) {
-                                crondlog(WARN9 "time disparity of %ld minutes detected", dt / 60);
-                        } else if (dt > 0) {
-                                TestJobs(t1, t2);
-                                RunJobs();
-                                sleep(5);
-                                if (CheckJobs() > 0) {
-                                        sleep_time = 10;
-                                } else {
-                                        sleep_time = 60;
-                                }
+                /*
+                 * The file 'cron.update' is checked to determine new cron
+                 * jobs.  The directory is rescanned once an hour to deal
+                 * with any screwups.
+                 *
+                 * Check for time jump.  Disparities over an hour either way
+                 * result in resynchronization.  A negative disparity
+                 * less than an hour causes us to effectively sleep until we
+                 * match the original time (i.e. no re-execution of jobs that
+                 * have just been run).  A positive disparity less than
+                 * an hour causes intermediate jobs to be run, but only once
+                 * in the worst case.
+                 *
+                 * When running jobs, the inequality used is greater but not
+                 * equal to t1, and less then or equal to t2.
+                 */
+                if (--rescan == 0) {
+                        rescan = 60;
+                        SynchronizeDir();
+                }
+                CheckUpdates();
+                if (DebugOpt)
+                        crondlog(LVL5 "wakeup dt=%ld", dt);
+                if (dt < -60 * 60 || dt > 60 * 60) {
+                        crondlog(WARN9 "time disparity of %ld minutes detected", dt / 60);
+                        /* and we do not run any jobs in this case */
+                } else if (dt > 0) {
+                        /* Usual case: time advances forwad, as expected */
+                        TestJobs(t1, t2);
+                        RunJobs();
+                        sleep(5);
+                        if (CheckJobs() > 0) {
+                                sleep_time = 10;
+                        } else {
+                                sleep_time = 60;
                         }
-                        t1 = t2;
-                } /* for (;;) */
-        }
+                }
+                /* else: time jumped back, do not run any jobs */
+        } /* for (;;) */
 
         return 0; /* not reached */
 }
@@ -277,7 +280,7 @@ static void SetEnv(struct passwd *pas)
         safe_setenv(&env_var_user, "USER", pas->pw_name);
         safe_setenv(&env_var_home, "HOME", pas->pw_dir);
         /* if we want to set user's shell instead: */
-        /*safe_setenv(env_var_user, "SHELL", pas->pw_shell);*/
+        /*safe_setenv(env_var_shell, "SHELL", pas->pw_shell);*/
 #else
         xsetenv("USER", pas->pw_name);
         xsetenv("HOME", pas->pw_dir);
@@ -597,10 +600,10 @@ static void SynchronizeDir(void)
 }
 
 /*
- *  DeleteFile() - delete user database
+ * DeleteFile() - delete user database
  *
- *  Note: multiple entries for same user may exist if we were unable to
- *  completely delete a database due to running processes.
+ * Note: multiple entries for same user may exist if we were unable to
+ * completely delete a database due to running processes.
  */
 static void DeleteFile(const char *userName)
 {
@@ -806,14 +809,14 @@ ForkJob(const char *user, CronLine *line, int mailFd,
                 if (mail_filename) {
                         unlink(mail_filename);
                 }
-        } else if (mail_filename) {
-                /* PARENT, FORK SUCCESS
-                 * rename mail-file based on pid of process
-                 */
-                char mailFile2[128];
-
-                snprintf(mailFile2, sizeof(mailFile2), "%s/cron.%s.%d", TMPDIR, user, pid);
-                rename(mail_filename, mailFile2); // TODO: xrename?
+        } else {
+                /* PARENT, FORK SUCCESS */
+                if (mail_filename) {
+                        /* rename mail-file based on pid of process */
+                        char *mailFile2 = xasprintf("%s/cron.%s.%d", TMPDIR, user, (int)pid);
+                        rename(mail_filename, mailFile2); // TODO: xrename?
+                        free(mailFile2);
+                }
         }
 
         /*