ash: code readability enhancements, no real code changes

diff --git a/shell/ash.c b/shell/ash.c
index 2a9e96a3570c69061d717ae8b146f29b86a2a526..ffa4019363b58d70c60b632b1a4f7ffef1ba41f8 100644 (file)
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -229,7 +229,7 @@ static struct globals_misc *const ptr_to_globals_misc __attribute__ ((section ("
 
 /*
  * These macros allow the user to suspend the handling of interrupt signals
- * over a period of time.  This is similar to SIGHOLD to or sigblock, but
+ * over a period of time.  This is similar to SIGHOLD or to sigblock, but
  * much more efficient and portable.  (But hacking the kernel is so much
  * more fun than worrying about efficiency and portability. :-))
  */
@@ -272,10 +272,10 @@ raise_interrupt(void)
        sigset_t mask;
 
        intpending = 0;
-       /* Signal is not automatically re-enabled after it is raised,
-        * do it ourself */
+       /* Signal is not automatically unmasked after it is raised,
+        * do it ourself - unmask all signals */
        sigemptyset(&mask);
-       sigprocmask(SIG_SETMASK, &mask, 0);
+       sigprocmask(SIG_SETMASK, &mask, NULL);
        /* pendingsig = 0; - now done in onsig() */
 
        i = EXSIG;
@@ -3337,8 +3337,8 @@ setsignal(int signo)
 #define CUR_STOPPED 0
 
 /* mode flags for dowait */
-#define DOWAIT_NORMAL 0
-#define DOWAIT_BLOCK 1
+#define DOWAIT_NONBLOCK WNOHANG
+#define DOWAIT_BLOCK    0
 
 #if JOBS
 /* pgrp of shell on invocation */
@@ -3584,7 +3584,7 @@ setjobctl(int on)
                fd = ttyfd;
                pgrp = initialpgrp;
                /* was xtcsetpgrp, but this can make exiting ash
-                * with pty already deleted loop forever */
+                * loop forever if pty is already deleted */
                tcsetpgrp(fd, pgrp);
                setpgid(0, pgrp);
                setsignal(SIGTSTP);
@@ -3757,24 +3757,20 @@ sprint_status(char *s, int status, int sigonly)
  * and the jobs command may give out of date information.
  */
 static int
-waitproc(int block, int *status)
+waitproc(int wait_flags, int *status)
 {
-       int flags = 0;
-
 #if JOBS
        if (jobctl)
-               flags |= WUNTRACED;
+               wait_flags |= WUNTRACED;
 #endif
-       if (block == 0)
-               flags |= WNOHANG;
-       return waitpid(-1, status, flags); // safe_waitpid?
+       return waitpid(-1, status, wait_flags); // safe_waitpid?
 }
 
 /*
  * Wait for a process to terminate.
  */
 static int
-dowait(int block, struct job *job)
+dowait(int wait_flags, struct job *job)
 {
        int pid;
        int status;
@@ -3782,9 +3778,9 @@ dowait(int block, struct job *job)
        struct job *thisjob;
        int state;
 
-       TRACE(("dowait(%d) called\n", block));
-       pid = waitproc(block, &status);
-       TRACE(("wait returns pid %d, status=%d\n", pid, status));
+       TRACE(("dowait(%d) called\n", wait_flags));
+       pid = waitproc(wait_flags, &status);
+       TRACE(("wait returns pid=%d, status=%d\n", pid, status));
        if (pid <= 0)
                return pid;
        INT_OFF;
@@ -3822,7 +3818,6 @@ dowait(int block, struct job *job)
 #if JOBS
        if (!WIFSTOPPED(status))
 #endif
-
                jobless--;
        goto out;
 
@@ -3852,7 +3847,7 @@ dowait(int block, struct job *job)
                len = sprint_status(s, status, 1);
                if (len) {
                        s[len] = '\n';
-                       s[len + 1] = 0;
+                       s[len + 1] = '\0';
                        out2str(s);
                }
        }
@@ -3938,8 +3933,8 @@ showjobs(FILE *out, int mode)
 
        TRACE(("showjobs(%x) called\n", mode));
 
-       /* If not even one one job changed, there is nothing to do */
-       while (dowait(DOWAIT_NORMAL, NULL) > 0)
+       /* If not even one job changed, there is nothing to do */
+       while (dowait(DOWAIT_NONBLOCK, NULL) > 0)
                continue;
 
        for (jp = curjob; jp; jp = jp->prev_job) {
@@ -4029,7 +4024,7 @@ waitcmd(int argc, char **argv)
                                jp->waited = 1;
                                jp = jp->prev_job;
                        }
-                       dowait(DOWAIT_BLOCK, 0);
+                       dowait(DOWAIT_BLOCK, NULL);
                }
        }
 
@@ -4038,20 +4033,18 @@ waitcmd(int argc, char **argv)
                if (**argv != '%') {
                        pid_t pid = number(*argv);
                        job = curjob;
-                       goto start;
-                       do {
+                       while (1) {
+                               if (!job)
+                                       goto repeat;
                                if (job->ps[job->nprocs - 1].pid == pid)
                                        break;
                                job = job->prev_job;
- start:
-                               if (!job)
-                                       goto repeat;
-                       } while (1);
+                       }
                } else
                        job = getjob(*argv, 0);
                /* loop until process terminated or stopped */
                while (job->state == JOBRUNNING)
-                       dowait(DOWAIT_BLOCK, 0);
+                       dowait(DOWAIT_BLOCK, NULL);
                job->waited = 1;
                retval = getstatus(job);
  repeat:
@@ -4526,7 +4519,8 @@ forkparent(struct job *jp, union node *n, int mode, pid_t pid)
 {
        TRACE(("In parent shell: child = %d\n", pid));
        if (!jp) {
-               while (jobless && dowait(DOWAIT_NORMAL, 0) > 0);
+               while (jobless && dowait(DOWAIT_NONBLOCK, NULL) > 0)
+                       continue;
                jobless++;
                return;
        }