New timing infrastructure. There's a new function schedule_timer()

which pretty much any module can call to request a call-back in the
future. So terminal.c can do its own handling of blinking, visual
bells and deferred screen updates, without having to rely on
term_update() being called 50 times a second (fixes: pterm-timer);
and ssh.c and telnet.c both invoke a new module pinger.c which takes
care of sending keepalives, so they get sent uniformly in all front
ends (fixes: plink-keepalives, unix-keepalives).

[originally from svn r4906]
[this svn revision also touched putty-wishlist]

Recipe

@@ -182,14 +182,15 @@ GUITERM  = TERMINAL window windlg winctrls sizetip winucs winprint
 
 # Same thing on Unix.
 UXTERM   = TERMINAL pterm uxcfg gtkdlg gtkcols gtkpanel uxucs uxprint xkeysym
+         + timing
 
 # Non-SSH back ends (putty, puttytel, plink).
-NONSSH   = telnet raw rlogin ldisc
+NONSSH   = telnet raw rlogin ldisc pinger
 
 # SSH back end (putty, plink, pscp, psftp).
 SSH      = ssh sshcrc sshdes sshmd5 sshrsa sshrand sshsha sshblowf
          + sshdh sshcrcda sshpubk sshzlib sshdss x11fwd portfwd
-         + sshaes sshsh512 sshbn wildcard
+         + sshaes sshsh512 sshbn wildcard pinger
 WINSSH   = SSH winnoise winpgntc
 UXSSH    = SSH uxnoise uxagentc
 MACSSH   = SSH macnoise
@@ -199,12 +200,10 @@ SFTP     = sftp int64 logging
 
 # Miscellaneous objects appearing in all the network utilities (not
 # Pageant or PuTTYgen).
-WINMISC  = misc version winstore settings tree234 winnet proxy cmdline
-         + windefs winmisc pproxy
-UXMISC   = misc version uxstore settings tree234 uxsel uxnet proxy cmdline
-         + uxmisc uxproxy
-MACMISC  = misc version macstore settings tree234 macnet mtcpnet otnet proxy
-         + macmisc macabout pproxy
+MISC     = timing misc version settings tree234 proxy
+WINMISC  = MISC winstore winnet cmdline windefs winmisc pproxy
+UXMISC   = MISC uxstore uxsel uxnet cmdline uxmisc uxproxy
+MACMISC  = MISC macstore macnet mtcpnet otnet macmisc macabout pproxy
 
 # Character set library, for use in pterm.
 CHARSET  = sbcsdat slookup sbcs utf8 toucs fromucs xenc mimeenc macenc localenc

doc/udp.but

@@ -75,21 +75,23 @@ Some ports of PuTTY - notably the in-progress Mac port - are
 constrained by the operating system to run as a single process
 potentially managing multiple sessions.
 
-Therefore, the platform-independent parts of PuTTY use \e{hardly
-any} global variables. The very few that do exist, such as
-\c{flags}, are tolerated because they are not specific to a
-particular login session: instead, they define properties that are
-expected to apply equally to \e{all} the sessions run by a single
-PuTTY process. Any data that is specific to a particular network
-session is stored in dynamically allocated data structures, and
-pointers to these structures are passed around between functions.
+Therefore, the platform-independent parts of PuTTY never use global
+variables to store per-session data. The global variables that do
+exist are tolerated because they are not specific to a particular
+login session: \c{flags} defines properties that are expected to
+apply equally to \e{all} the sessions run by a single PuTTY process,
+the random number state in \cw{sshrand.c} and the timer list in
+\cw{timing.c} serve all sessions equally, and so on. But most data
+is specific to a particular network session, and is therefore stored
+in dynamically allocated data structures, and pointers to these
+structures are passed around between functions.
 
 Platform-specific code can reverse this decision if it likes. The
 Windows code, for historical reasons, stores most of its data as
 global variables. That's OK, because \e{on Windows} we know there is
 only one session per PuTTY process, so it's safe to do that. But
 changes to the platform-independent code should avoid introducing
-any more global variables than already exist.
+global variables, unless they are genuinely cross-session.
 
 \H{udp-pure-c} C, not C++
 

mac/macterm.c

@@ -1,4 +1,4 @@
-/* $Id: macterm.c,v 1.78 2004/10/14 16:42:43 simon Exp $ */
+/* $Id$ */
 /*
  * Copyright (c) 1999 Simon Tatham
  * Copyright (c) 1999, 2002 Ben Harris
@@ -314,7 +314,6 @@ void mac_pollterm(void)
     Session *s;
 
     for (s = sesslist; s != NULL; s = s->next) {
-	term_out(s->term);
 	term_update(s->term);
     }
 }

misc.c

@@ -141,6 +141,29 @@ char *dupvprintf(const char *fmt, va_list ap)
     }
 }
 
+/*
+ * Read an entire line of text from a file. Return a buffer
+ * malloced to be as big as necessary (caller must free).
+ */
+char *fgetline(FILE *fp)
+{
+    char *ret = snewn(512, char);
+    int size = 512, len = 0;
+    while (fgets(ret + len, size - len, fp)) {
+	len += strlen(ret + len);
+	if (ret[len-1] == '\n')
+	    break;		       /* got a newline, we're done */
+	size = len + 512;
+	ret = sresize(ret, size, char);
+    }
+    if (len == 0) {		       /* first fgets returned NULL */
+	sfree(ret);
+	return NULL;
+    }
+    ret[len] = '\0';
+    return ret;
+}
+
 /* ----------------------------------------------------------------------
  * Base64 encoding routine. This is required in public-key writing
  * but also in HTTP proxy handling, so it's centralised here.

misc.h

@@ -3,6 +3,7 @@
 
 #include "puttymem.h"
 
+#include <stdio.h>		       /* for FILE * */
 #include <stdarg.h>		       /* for va_list */
 
 #ifndef FALSE
@@ -20,6 +21,8 @@ char *dupcat(const char *s1, ...);
 char *dupprintf(const char *fmt, ...);
 char *dupvprintf(const char *fmt, va_list ap);
 
+char *fgetline(FILE *fp);
+
 void base64_encode_atom(unsigned char *data, int n, char *out);
 
 struct bufchain_granule;

pinger.c

@@ -0,0 +1,71 @@
+/*
+ * pinger.c: centralised module that deals with sending TS_PING
+ * keepalives, to avoid replicating this code in multiple backends.
+ */
+
+#include "putty.h"
+
+struct pinger_tag {
+    int interval;
+    int pending;
+    long next;
+    Backend *back;
+    void *backhandle;
+};
+
+static void pinger_schedule(Pinger pinger);
+
+static void pinger_timer(void *ctx, long now)
+{
+    Pinger pinger = (Pinger)ctx;
+
+    if (pinger->pending && now - pinger->next >= 0) {
+	pinger->back->special(pinger->backhandle, TS_PING);
+	pinger->pending = FALSE;
+	pinger_schedule(pinger);
+    }
+}
+
+static void pinger_schedule(Pinger pinger)
+{
+    int next;
+
+    if (!pinger->interval) {
+	pinger->pending = FALSE;       /* cancel any pending ping */
+	return;
+    }
+
+    next = schedule_timer(pinger->interval * TICKSPERSEC,
+			  pinger_timer, pinger);
+    if (!pinger->pending || next < pinger->next) {
+	pinger->next = next;
+	pinger->pending = TRUE;
+    }
+}
+
+Pinger pinger_new(Config *cfg, Backend *back, void *backhandle)
+{
+    Pinger pinger = snew(struct pinger_tag);
+
+    pinger->interval = cfg->ping_interval;
+    pinger->pending = FALSE;
+    pinger->back = back;
+    pinger->backhandle = backhandle;
+    pinger_schedule(pinger);
+
+    return pinger;
+}
+
+void pinger_reconfig(Pinger pinger, Config *oldcfg, Config *newcfg)
+{
+    if (oldcfg->ping_interval != newcfg->ping_interval) {
+	pinger->interval = newcfg->ping_interval;
+	pinger_schedule(pinger);
+    }
+}
+
+void pinger_free(Pinger pinger)
+{
+    expire_timer_context(pinger);
+    sfree(pinger);
+}

psftp.c

@@ -1361,45 +1361,34 @@ static int sftp_cmd_help(struct sftp_command *cmd)
 struct sftp_command *sftp_getcmd(FILE *fp, int mode, int modeflags)
 {
     char *line;
-    int linelen, linesize;
     struct sftp_command *cmd;
     char *p, *q, *r;
     int quoting;
 
-    if ((mode == 0) || (modeflags & 1)) {
-	printf("psftp> ");
-    }
-    fflush(stdout);
-
     cmd = snew(struct sftp_command);
     cmd->words = NULL;
     cmd->nwords = 0;
     cmd->wordssize = 0;
 
     line = NULL;
-    linesize = linelen = 0;
-    while (1) {
-	int len;
-	char *ret;
-
-	linesize += 512;
-	line = sresize(line, linesize, char);
-	ret = fgets(line + linelen, linesize - linelen, fp);
-
-	if (!ret || (linelen == 0 && line[0] == '\0')) {
-	    cmd->obey = sftp_cmd_quit;
-	    if ((mode == 0) || (modeflags & 1))
-		printf("quit\n");
-	    return cmd;		       /* eof */
-	}
-	len = linelen + strlen(line + linelen);
-	linelen += len;
-	if (line[linelen - 1] == '\n') {
-	    linelen--;
-	    line[linelen] = '\0';
-	    break;
-	}
+
+    if (fp) {
+	if (modeflags & 1)
+	    printf("psftp> ");
+	line = fgetline(fp);
+    } else {
+	line = ssh_sftp_get_cmdline("psftp> ");
+    }
+
+    if (!line || !*line) {
+	cmd->obey = sftp_cmd_quit;
+	if ((mode == 0) || (modeflags & 1))
+	    printf("quit\n");
+	return cmd;		       /* eof */
     }
+
+    line[strcspn(line, "\r\n")] = '\0';
+
     if (modeflags & 1) {
 	printf("%s\n", line);
     }
@@ -1464,7 +1453,8 @@ struct sftp_command *sftp_getcmd(FILE *fp, int mode, int modeflags)
 	}
     }
 
-	sfree(line);
+    sfree(line);
+
     /*
      * Now parse the first word and assign a function.
      */
@@ -1551,7 +1541,7 @@ void do_sftp(int mode, int modeflags, char *batchfile)
          */
         while (1) {
 	    struct sftp_command *cmd;
-	    cmd = sftp_getcmd(stdin, 0, 0);
+	    cmd = sftp_getcmd(NULL, 0, 0);
 	    if (!cmd)
 		break;
 	    ret = cmd->obey(cmd);

psftp.h

@@ -32,6 +32,12 @@ void get_file_times(char *filename, unsigned long *mtime,
  */
 int ssh_sftp_loop_iteration(void);
 
+/*
+ * Read a command line for PSFTP from standard input. Caller must
+ * free.
+ */
+char *ssh_sftp_get_cmdline(char *prompt);
+
 /*
  * The main program in psftp.c. Called from main() in the platform-
  * specific code, after doing any platform-specific initialisation.

putty.h

@@ -578,6 +578,7 @@ void ldisc_update(void *frontend, int echo, int edit);
  * shutdown. */
 void update_specials_menu(void *frontend);
 int from_backend(void *frontend, int is_stderr, const char *data, int len);
+void notify_remote_exit(void *frontend);
 #define OPTIMISE_IS_SCROLL 1
 
 void set_iconic(void *frontend, int iconic);
@@ -744,6 +745,14 @@ int random_byte(void);
 void random_get_savedata(void **data, int *len);
 extern int random_active;
 
+/*
+ * Exports from pinger.c.
+ */
+typedef struct pinger_tag *Pinger;
+Pinger pinger_new(Config *cfg, Backend *back, void *backhandle);
+void pinger_reconfig(Pinger, Config *oldcfg, Config *newcfg);
+void pinger_free(Pinger);
+
 /*
  * Exports from misc.c.
  */
@@ -895,4 +904,39 @@ int filename_is_null(Filename fn);
 char *get_username(void);	       /* return value needs freeing */
 char *get_random_data(int bytes);      /* used in cmdgen.c */
 
+/*
+ * Exports and imports from timing.c.
+ *
+ * schedule_timer() asks the front end to schedule a callback to a
+ * timer function in a given number of ticks. The returned value is
+ * the time (in ticks since an arbitrary offset) at which the
+ * callback can be expected. This value will also be passed as the
+ * `now' parameter to the callback function. Hence, you can (for
+ * example) schedule an event at a particular time by calling
+ * schedule_timer() and storing the return value in your context
+ * structure as the time when that event is due. The first time a
+ * callback function gives you that value or more as `now', you do
+ * the thing.
+ * 
+ * expire_timer_context() drops all current timers associated with
+ * a given value of ctx (for when you're about to free ctx).
+ * 
+ * run_timers() is called from the front end when it has reason to
+ * think some timers have reached their moment, or when it simply
+ * needs to know how long to wait next. We pass it the time we
+ * think it is. It returns TRUE and places the time when the next
+ * timer needs to go off in `next', or alternatively it returns
+ * FALSE if there are no timers at all pending.
+ * 
+ * timer_change_notify() must be supplied by the front end; it
+ * notifies the front end that a new timer has been added to the
+ * list which is sooner than any existing ones. It provides the
+ * time when that timer needs to go off.
+ */
+typedef void (*timer_fn_t)(void *ctx, long now);
+long schedule_timer(int ticks, timer_fn_t fn, void *ctx);
+void expire_timer_context(void *ctx);
+int run_timers(long now, long *next);
+void timer_change_notify(long next);
+
 #endif

raw.c

@@ -37,6 +37,7 @@ static int raw_closing(Plug plug, const char *error_msg, int error_code,
     if (raw->s) {
         sk_close(raw->s);
         raw->s = NULL;
+	notify_remote_exit(raw->frontend);
     }
     if (error_msg) {
 	/* A socket error has occurred. */

rlogin.c

@@ -39,6 +39,7 @@ static int rlogin_closing(Plug plug, const char *error_msg, int error_code,
     if (rlogin->s) {
         sk_close(rlogin->s);
         rlogin->s = NULL;
+	notify_remote_exit(rlogin->frontend);
     }
     if (error_msg) {
 	/* A socket error has occurred. */