time handling: Support use of CLOCK_MONOTONIC

[adns.git] / src / event.c

diff --git a/src/event.c b/src/event.c
index 95386f42c4fed8351a939290cd85dcfdf5bed53b..c326c2809714d5313ef6844912cf11ed2e9b6f1e 100644 (file)
--- a/src/event.c
+++ b/src/event.c
@@ -6,7 +6,7 @@
  */
 /*
  *  This file is part of adns, which is
- *    Copyright (C) 1997-2000,2003,2006,2014-2016  Ian Jackson
+ *    Copyright (C) 1997-2000,2003,2006,2014-2016,2020  Ian Jackson
  *    Copyright (C) 2014  Mark Wooding
  *    Copyright (C) 1999-2000,2003,2006  Tony Finch
  *    Copyright (C) 1991 Massachusetts Institute of Technology
@@ -36,6 +36,7 @@
 #include <sys/socket.h>
 #include <netinet/in.h>
 #include <arpa/inet.h>
+#include <time.h>
 
 #include "internal.h"
 #include "tvarith.h"
@@ -149,6 +150,19 @@ void adns__tcp_tryconnect(adns_state ads, struct timeval now) {
 
 /* Timeout handling functions. */
 
+int adns__gettimeofday(adns_state ads, struct timeval *tv) {
+  if (!(ads->iflags & adns_if_monotonic))
+    return gettimeofday(tv,0);
+
+  struct timespec ts;
+  int r = clock_gettime(CLOCK_MONOTONIC,&ts);
+  if (r) return r;
+
+  tv->tv_sec =  ts.tv_sec;
+  tv->tv_usec = ts.tv_nsec / 1000;
+  return 0;
+}
+
 void adns__must_gettimeofday(adns_state ads, const struct timeval **now_io,
                             struct timeval *tv_buf) {
   const struct timeval *now;
@@ -156,8 +170,9 @@ void adns__must_gettimeofday(adns_state ads, const struct timeval **now_io,
 
   now= *now_io;
   if (now) return;
-  r= gettimeofday(tv_buf,0); if (!r) { *now_io= tv_buf; return; }
-  adns__diag(ads,-1,0,"gettimeofday failed: %s",strerror(errno));
+  r= adns__gettimeofday(ads,tv_buf); if (!r) { *now_io= tv_buf; return; }
+  adns__diag(ads,-1,0,"gettimeofday/clock_gettime failed: %s",
+            strerror(errno));
   adns_globalsystemfailure(ads);
   return;
 }
@@ -209,11 +224,16 @@ static void timeouts_queue(adns_state ads, int act,
                           struct timeval **tv_io, struct timeval *tvbuf,
                           struct timeval now, struct query_queue *queue) {
   adns_query qu, nqu;
+  struct timeval expires;
   
   for (qu= queue->head; qu; qu= nqu) {
     nqu= qu->next;
-    if (!timercmp(&now,&qu->timeout,>)) {
-      inter_maxtoabs(tv_io,tvbuf,now,qu->timeout);
+    if (timercmp(&now,&qu->timeout_started,<)) /* clock rewound */
+      qu->timeout_started= now;
+    expires= qu->timeout_started;
+    timevaladd(&expires, qu->timeout_ms);
+    if (!timercmp(&now,&expires,>)) {
+      inter_maxtoabs(tv_io,tvbuf,now,expires);
     } else {
       if (!act) { inter_immed(tv_io,tvbuf); return; }
       LIST_UNLINK(*queue,qu);
@@ -284,7 +304,7 @@ void adns__timeouts(adns_state ads, int act,
 void adns_firsttimeout(adns_state ads,
                       struct timeval **tv_io, struct timeval *tvbuf,
                       struct timeval now) {
-  adns__consistency(ads,0,cc_entex);
+  adns__consistency(ads,0,cc_enter);
   adns__timeouts(ads, 0, tv_io,tvbuf, now);
   adns__returning(ads,0);
 }
@@ -292,7 +312,7 @@ void adns_firsttimeout(adns_state ads,
 void adns_processtimeouts(adns_state ads, const struct timeval *now) {
   struct timeval tv_buf;
 
-  adns__consistency(ads,0,cc_entex);
+  adns__consistency(ads,0,cc_enter);
   adns__must_gettimeofday(ads,&now,&tv_buf);
   if (now) adns__timeouts(ads, 1, 0,0, *now);
   adns__returning(ads,0);
@@ -346,7 +366,7 @@ int adns_processreadable(adns_state ads, int fd, const struct timeval *now) {
   struct udpsocket *udp;
   adns_sockaddr udpaddr;
   
-  adns__consistency(ads,0,cc_entex);
+  adns__consistency(ads,0,cc_enter);
 
   switch (ads->tcpstate) {
   case server_disconnected:
@@ -433,7 +453,7 @@ xit:
 int adns_processwriteable(adns_state ads, int fd, const struct timeval *now) {
   int r;
   
-  adns__consistency(ads,0,cc_entex);
+  adns__consistency(ads,0,cc_enter);
 
   switch (ads->tcpstate) {
   case server_disconnected:
@@ -506,7 +526,7 @@ xit:
   
 int adns_processexceptional(adns_state ads, int fd,
                            const struct timeval *now) {
-  adns__consistency(ads,0,cc_entex);
+  adns__consistency(ads,0,cc_enter);
   switch (ads->tcpstate) {
   case server_disconnected:
   case server_broken:
@@ -575,7 +595,7 @@ void adns_beforeselect(adns_state ads, int *maxfd_io, fd_set *readfds_io,
   struct pollfd pollfds[MAX_POLLFDS];
   int i, fd, maxfd, npollfds;
   
-  adns__consistency(ads,0,cc_entex);
+  adns__consistency(ads,0,cc_enter);
 
   if (tv_mod && (!*tv_mod || (*tv_mod)->tv_sec || (*tv_mod)->tv_usec)) {
     /* The caller is planning to sleep. */
@@ -606,7 +626,7 @@ void adns_afterselect(adns_state ads, int maxfd, const fd_set *readfds,
   struct pollfd pollfds[MAX_POLLFDS];
   int npollfds, i;
 
-  adns__consistency(ads,0,cc_entex);
+  adns__consistency(ads,0,cc_enter);
   adns__must_gettimeofday(ads,&now,&tv_buf);
   if (!now) goto xit;
   adns_processtimeouts(ads,now);
@@ -624,7 +644,10 @@ xit:
 /* General helpful functions. */
 
 void adns_globalsystemfailure(adns_state ads) {
-  adns__consistency(ads,0,cc_entex);
+  /* Must not be called by adns during actual processing of a
+   * particular query, since it reenters adns.  Only safe to call in
+   * situations where it would be safe to call adns_returning. */
+  adns__consistency(ads,0,cc_enter);
 
   for (;;) {
     adns_query qu;
@@ -660,9 +683,9 @@ int adns_processany(adns_state ads) {
   struct pollfd pollfds[MAX_POLLFDS];
   int npollfds;
 
-  adns__consistency(ads,0,cc_entex);
+  adns__consistency(ads,0,cc_enter);
 
-  r= gettimeofday(&now,0);
+  r= adns__gettimeofday(ads,&now);
   if (!r) adns_processtimeouts(ads,&now);
 
   /* We just use adns__fdevents to loop over the fd's trying them.
@@ -719,7 +742,7 @@ int adns_wait(adns_state ads,
   fd_set readfds, writefds, exceptfds;
   struct timeval tvbuf, *tvp;
   
-  adns__consistency(ads,*query_io,cc_entex);
+  adns__consistency(ads,*query_io,cc_enter);
   for (;;) {
     r= adns__internal_check(ads,query_io,answer_r,context_r);
     if (r != EAGAIN) break;
@@ -751,8 +774,8 @@ int adns_check(adns_state ads,
   struct timeval now;
   int r;
   
-  adns__consistency(ads,*query_io,cc_entex);
-  r= gettimeofday(&now,0);
+  adns__consistency(ads,*query_io,cc_enter);
+  r= adns__gettimeofday(ads,&now);
   if (!r) adns__autosys(ads,now);
 
   r= adns__internal_check(ads,query_io,answer_r,context_r);