crond: code shrink

function                                             old     new   delta
ForkJob                                              513     457     -56

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

diff --git a/miscutils/crond.c b/miscutils/crond.c
index 4a3103cb9762c393ace16bdf12cbb20d20a479a4..49ecf745e2b8e6cf870fa7d0ec098b0ed4125a3c 100644 (file)
--- 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);
+               }
        }
 
        /*