top: refactor all the low-level i/o logic for SIGWINCH

This commit primarily involves renaming functions plus
reorganizing logic in preparation for the next changes
which will hopefully yield the 'final solution' to the
excessive SIGWINCH signals under most window managers.

In this specific patch, the most significant change is
the introduction of a new 'ioa' function (io avail) to
focus all logic dealing with unsolicited user keyboard
input and exposed to signals and/or optional timeouts.

That new function is where our signal overload will be
ultimately defeated, if it is at all humanly possible.

(everything is perfectly justified plus right margins)
(are completely filled, but of course it must be luck)

Reference(s):
http://www.freelists.org/post/procps/unwanted-topinspect-window-enclosure-with-the-terminal-size-change

Signed-off-by: Jim Warner <james.warner@comcast.net>

diff --git a/top/top.c b/top/top.c
index 4072333edf0a306a171db91b0ad8efbcc78d82a8..74ac7699565951a2061b0d4c0c12356bc7a242a6 100644 (file)
--- a/top/top.c
+++ b/top/top.c
@@ -869,11 +869,31 @@ static void *alloc_r (void *ptr, size_t num) {
 } // end: alloc_r
 
 
+        /*
+         * This function is used in connection with raw single byte
+         * unsolicited keyboard input that's susceptible to SIGWINCH
+         * interrupts (or any other signal).  He also supports timout
+         * in the absence of user keystrokes or some signal interrupt. */
+static inline int ioa (struct timeval *tv) {
+   fd_set fs;
+   int rc;
+
+   FD_ZERO(&fs);
+   FD_SET(STDIN_FILENO, &fs);
+
+   // hold here until we've got keyboard input, a signal interrupt
+   // or (optionally) we timeout with microsecond granularity
+   rc = select(STDIN_FILENO + 1, &fs, NULL, NULL, tv);
+
+   if (rc < 0) rc = 0;
+   return rc;
+} // end: ioa
+
+
         /*
          * This routine isolates ALL user INPUT and ensures that we
          * wont be mixing I/O from stdio and low-level read() requests */
-static int chin (int ech, char *buf, unsigned cnt) {
-   fd_set fs;
+static int ioch (int ech, char *buf, unsigned cnt) {
    int rc = -1;
 
 #ifndef TERMIO_PROXY
@@ -882,16 +902,12 @@ static int chin (int ech, char *buf, unsigned cnt) {
       rc = read(STDIN_FILENO, buf, cnt);
       tcsetattr(STDIN_FILENO, TCSAFLUSH, &Tty_raw);
    } else {
-      FD_ZERO(&fs);
-      FD_SET(STDIN_FILENO, &fs);
-      if (0 < select(STDIN_FILENO + 1, &fs, NULL, NULL, NULL))
+      if (ioa(NULL))
          rc = read(STDIN_FILENO, buf, cnt);
    }
 #else
    (void)ech;
-   FD_ZERO(&fs);
-   FD_SET(STDIN_FILENO, &fs);
-   if (0 < select(STDIN_FILENO + 1, &fs, NULL, NULL, NULL))
+   if (ioa(NULL))
       rc = read(STDIN_FILENO, buf, cnt);
 #endif
 
@@ -903,14 +919,14 @@ static int chin (int ech, char *buf, unsigned cnt) {
 
    // note: we do NOT produce a vaid 'string'
    return rc;
-} // end: chin
+} // end: ioch
 
 
         /*
          * Support for single keystroke input AND escaped cursor motion keys
          * note: we support more keys than we currently need, in case
          *       we attract new consumers in the future */
-static int keyin (int init) {
+static int iokey (int init) {
    static char buf12[CAPBUFSIZ], buf13[CAPBUFSIZ]
       , buf14[CAPBUFSIZ], buf15[CAPBUFSIZ];
    static struct {
@@ -961,7 +977,7 @@ static int keyin (int init) {
    }
 
    memset(buf, '\0', sizeof(buf));
-   if (1 > chin(0, buf, sizeof(buf)-1)) return 0;
+   if (1 > ioch(0, buf, sizeof(buf)-1)) return 0;
 
    /* some emulators implement 'key repeat' too well and we get duplicate
       key sequences -- so we'll focus on the last escaped sequence, while
@@ -976,27 +992,27 @@ static int keyin (int init) {
    // no match, so we'll return single non-escaped keystrokes only
    if (buf[0] == '\033' && buf[1]) return 0;
    return buf[0];
-} // end: keyin
+} // end: iokey
 
 
 #ifndef TERMIO_PROXY
         /*
          * Get line oriented interactive input from the user,
          * using native tty support */
-static char *linein (const char *prompt) {
+static char *ioline (const char *prompt) {
    static const char ws[] = "\b\f\n\r\t\v\x1b\x9b";  // 0x1b + 0x9b are escape
    static char buf[MEDBUFSIZ];
    char *p;
 
    show_pmt(prompt);
    memset(buf, '\0', sizeof(buf));
-   chin(1, buf, sizeof(buf)-1);
+   ioch(1, buf, sizeof(buf)-1);
    putp(Cap_curs_norm);
 
    if ((p = strpbrk(buf, ws))) *p = '\0';
    // note: we DO produce a vaid 'string'
    return buf;
-} // end: linein
+} // end: ioline
 
 #else
         /*
@@ -1008,7 +1024,7 @@ static char *linein (const char *prompt) {
          * . immediate signal response without the need to wait for '\n'
          * However, the user will lose the ability to paste keystrokes
          * when this function is chosen over the smaller alternative above! */
-static char *linein (const char *prompt) {
+static char *ioline (const char *prompt) {
     // thank goodness memmove allows the two strings to overlap
  #define sqzSTR  { memmove(&buf[pos], &buf[pos+1], bufMAX-pos); \
        buf[sizeof(buf)-1] = '\0'; }
@@ -1026,7 +1042,7 @@ static char *linein (const char *prompt) {
    memset(buf, '\0', sizeof(buf));
    do {
       len = strlen(buf);
-      key = keyin(0);
+      key = iokey(0);
       switch (key) {
          case kbd_ESC:
             buf[0] = '\0';             // fall through !
@@ -1071,7 +1087,7 @@ static char *linein (const char *prompt) {
  #undef logCOL
  #undef phyCOL
  #undef bufMAX
-} // end: linein
+} // end: ioline
 #endif
 
 
@@ -1113,7 +1129,7 @@ static float get_float (const char *prompt) {
    char *line;
    float f;
 
-   if (!(*(line = linein(prompt)))) return -1.0;
+   if (!(*(line = ioline(prompt)))) return -1.0;
    // note: we're not allowing negative floats
    if (strcspn(line, "+,.0123456789")) {
       show_msg(N_txt(BAD_numfloat_txt));
@@ -1133,7 +1149,7 @@ static int get_int (const char *prompt) {
    char *line;
    int n;
 
-   if (!(*(line = linein(prompt)))) return GET_INTNONE;
+   if (!(*(line = ioline(prompt)))) return GET_INTNONE;
    // note: we've got to allow negative ints (renice)
    if (strcspn(line, "-+0123456789")) {
       show_msg(N_txt(BAD_integers_txt));
@@ -1897,7 +1913,7 @@ signify_that:
       display_fields(i, (p != NULL));
       fflush(stdout);
 
-      key = keyin(0);
+      key = iokey(0);
       if (key < 1) goto signify_that;
 
       switch (key) {
@@ -2590,7 +2606,7 @@ static void insp_find_str (int ch, int *col, int *row) {
       return;
    }
    if (ch == 'L' || ch == '/') {
-      snprintf(Insp_sel->fstr, FNDBUFSIZ, "%s", linein(N_txt(GET_find_str_txt)));
+      snprintf(Insp_sel->fstr, FNDBUFSIZ, "%s", ioline(N_txt(GET_find_str_txt)));
       Insp_sel->flen = strlen(Insp_sel->fstr);
       found = 0;
    }
@@ -2756,11 +2772,11 @@ signify_that:
          lest repeated <Enter> keys produce immediate re-selection in caller */
       tcflush(STDIN_FILENO, TCIFLUSH);
 
-      key = keyin(0);
+      key = iokey(0);
       if (key < 1) goto signify_that;
 
       switch (key) {
-         case kbd_ENTER:          // must force new keyin()
+         case kbd_ENTER:          // must force new iokey()
             key = INT_MAX;        // fall through !
          case kbd_ESC:
          case 'q':
@@ -2805,7 +2821,7 @@ signify_that:
          case '=':
             snprintf(buf, sizeof(buf), "%s: %s", Insp_sel->type, Insp_sel->fmts);
             INSP_MKSL(1, buf);    // show an extended SL
-            if (keyin(0) < 1)
+            if (iokey(0) < 1)
                goto signify_that;
             break;
          default:                 // keep gcc happy
@@ -2860,7 +2876,7 @@ signify_that:
          , pid, p->cmd, p->euser, sels));
       INSP_MKSL(0, " ");
 
-      if (key == INT_MAX) key = keyin(0);
+      if (key == INT_MAX) key = iokey(0);
       if (key < 1) goto signify_that;
 
       switch (key) {
@@ -3453,8 +3469,8 @@ static void whack_terminal (void) {
    // thanks anyway stdio, but we'll manage buffering at the frame level...
    setbuffer(stdout, Stdout_buf, sizeof(Stdout_buf));
 #endif
-   // and don't forget to ask keyin to initialize his tinfo_tab
-   keyin(1);
+   // and don't forget to ask iokey to initialize his tinfo_tab
+   iokey(1);
 } // end: whack_terminal
 \f
 /*######  Windows/Field Groups support  #################################*/
@@ -3479,7 +3495,7 @@ static WIN_t *win_select (int ch) {
       so we must try to get our own darn ch by begging the user... */
    if (!ch) {
       show_pmt(N_txt(CHOOSE_group_txt));
-      if (1 > (ch = keyin(0))) return w;
+      if (1 > (ch = iokey(0))) return w;
    }
    switch (ch) {
       case 'a':                         // we don't carry 'a' / 'w' in our
@@ -3568,7 +3584,7 @@ signify_that:
       putp(Cap_clr_eos);
       fflush(stdout);
 
-      key = keyin(0);
+      key = iokey(0);
       if (key < 1) goto signify_that;
 
       switch (key) {
@@ -3727,7 +3743,7 @@ static void file_writerc (void) {
 
    if (Rc_questions) {
       show_pmt(N_txt(XTRA_warncfg_txt));
-      if ('y' != tolower(keyin(0)))
+      if ('y' != tolower(iokey(0)))
          return;
       Rc_questions = 0;
    }
@@ -3797,7 +3813,7 @@ static void find_string (int ch) {
       return;
    }
    if ('L' == ch) {
-      snprintf(Curwin->findstr, FNDBUFSIZ, "%s", linein(N_txt(GET_find_str_txt)));
+      snprintf(Curwin->findstr, FNDBUFSIZ, "%s", ioline(N_txt(GET_find_str_txt)));
       Curwin->findlen = strlen(Curwin->findstr);
       found = 0;
 #ifndef USE_X_COLHDR
@@ -3840,7 +3856,7 @@ signify_that:
    putp(Cap_clr_eos);
    fflush(stdout);
 
-   key = keyin(0);
+   key = iokey(0);
    if (key < 1) goto signify_that;
 
    switch (key) {
@@ -3855,7 +3871,7 @@ signify_that:
                , Winstk[2].rc.winname, Winstk[3].rc.winname));
             putp(Cap_clr_eos);
             fflush(stdout);
-            key = keyin(0);
+            key = iokey(0);
             if (key < 1) adj_geometry();
             else w = win_select(key);
          } while (key != kbd_ENTER && key != kbd_ESC);
@@ -3928,7 +3944,7 @@ static void keys_global (int ch) {
             if (GET_INT_BAD < (pid = get_int(fmtmk(N_txt(GET_pid2kill_fmt), def)))) {
                char *str;
                if (0 > pid) pid = def;
-               str = linein(fmtmk(N_fmt(GET_sigs_num_fmt), pid, SIGTERM));
+               str = ioline(fmtmk(N_fmt(GET_sigs_num_fmt), pid, SIGTERM));
                if (*str) sig = signal_name_to_number(str);
                if (0 < sig && kill(pid, sig))
                   show_msg(fmtmk(N_fmt(FAIL_signals_fmt)
@@ -3961,7 +3977,7 @@ static void keys_global (int ch) {
          break;
       case 'Y':
          if (!Inspect.total)
-            linein(N_txt(YINSP_noents_txt));
+            ioline(N_txt(YINSP_noents_txt));
          else {
             int pid, def = w->ppt[w->begtask]->tid;
             if (GET_INT_BAD < (pid = get_int(fmtmk(N_fmt(YINSP_pidsee_fmt), def)))) {
@@ -4114,7 +4130,7 @@ static void keys_task (int ch) {
       case 'u':
          if (VIZCHKw(w)) {
             const char *errmsg;
-            if ((errmsg = user_certify(w, linein(N_txt(GET_user_ids_txt)), ch)))
+            if ((errmsg = user_certify(w, ioline(N_txt(GET_user_ids_txt)), ch)))
                show_msg(errmsg);
          }
          break;
@@ -4202,7 +4218,7 @@ static void keys_window (int ch) {
       case 'G':
          if (ALTCHKw) {
             char tmp[SMLBUFSIZ];
-            STRLCPY(tmp, linein(fmtmk(N_fmt(NAME_windows_fmt), w->rc.winname)));
+            STRLCPY(tmp, ioline(fmtmk(N_fmt(NAME_windows_fmt), w->rc.winname)));
             if (tmp[0]) win_names(w, tmp);
          }
          break;
@@ -5064,18 +5080,15 @@ int main (int dont_care_argc, char **argv) {
       if (Batch)
          select(0, NULL, NULL, NULL, &tv);
       else {
-         fd_set fs;
-
-         FD_ZERO(&fs);
-         FD_SET(STDIN_FILENO, &fs);
-         if (0 < select(STDIN_FILENO + 1, &fs, NULL, NULL, &tv))
-            do_key(keyin(0));
-         /* note:  above select might have been interrupted by some signal
-                   in which case the return code would have been -1 and an
-                   integer (volatile) switch set.  that in turn will cause
-                   frame_make() to deal with it if we survived the handler
-         */
+         if (ioa(&tv))
+            do_key(iokey(0));
       }
+         /* note:  the above ioa() routine exists to consolidate all logic
+                   which is susceptible to signal interrupts and must then
+                   produce a screen refresh.  in this main loop frame_make
+                   assumes responsibility for such refreshes.  other logic
+                   interacting with users must deal more directly with it.
+          */
    }
    return 0;
 } // end: main

diff --git a/top/top.h b/top/top.h
index 6837f6859f8c516fa42015d984516fcf633196cb..7151594aae946fbaf92ce3605feaf0b58b7e2d6c 100644 (file)
--- a/top/top.h
+++ b/top/top.h
@@ -126,7 +126,7 @@ char *strcasestr(const char *haystack, const char *needle);
 #define ROWMAXSIZ  ( SCREENMAX + 16 * (CAPBUFSIZ + CLRBUFSIZ) )
    // minimum size guarantee for dynamically acquired 'readfile' buffer
 #define READMINSZ  2048
-   // size of preallocated search string buffers, same as linein()
+   // size of preallocated search string buffers, same as ioline()
 #define FNDBUFSIZ  MEDBUFSIZ
 
 
@@ -630,9 +630,10 @@ typedef struct WIN_t {
 /*------  Low Level Memory/Keyboard/File I/O support  --------------------*/
 //atic void         *alloc_c (size_t num);
 //atic void         *alloc_r (void *ptr, size_t num);
-//atic int           chin (int ech, char *buf, unsigned cnt);
-//atic int           keyin (int init);
-//atic char         *linein (const char *prompt);
+//atic inline int    ioa (struct timeval *tv);
+//atic int           ioch (int ech, char *buf, unsigned cnt);
+//atic int           iokey (int init);
+//atic char         *ioline (const char *prompt);
 //atic int           readfile (FILE *fp, char **baddr, size_t *bsize, size_t *bread);
 /*------  Small Utility routines  ----------------------------------------*/
 //atic float         get_float (const char *prompt);