merge r3473, r3474, r3385, r3386, r3537:

signal processing stability:

*) use sys_errlist[] in signal handler instead
   of non Async-Signal-Safe strerror_r()
*) do not update time in the timer signal handler,
   since localtime_r() is not Async-Signal-Safe function
*) use previously cached GMT offset value to update time from a signal handler
*) change ngx_time_update() interface since there are no notification methods
   those return time
*) introduce ngx_time_sigsafe_update() to update the error log time only
*) change ngx_time_update() interface

3 files changed, 23 insertions, 10 deletions

diff --git a/src/os/unix/ngx_errno.h b/src/os/unix/ngx_errno.h
index 379f36777..ddc2b2761 100644
--- a/src/os/unix/ngx_errno.h
+++ b/src/os/unix/ngx_errno.h
@@ -64,10 +64,22 @@ u_char *ngx_strerror_r(int err, u_char *errstr, size_t size);
 
 /* Solaris and Tru64 UNIX have thread-safe strerror() */
 
-#define ngx_strerror_r(err, errstr, size)  \
+#define ngx_strerror_r(err, errstr, size)                                    \
     ngx_cpystrn(errstr, (u_char *) strerror(err), size)
 
 #endif
 
 
+#if (NGX_HAVE_SYS_ERRLIST)
+
+#define ngx_sigsafe_strerror(err)                                            \
+    (err > 0 && err < sys_nerr) ? sys_errlist[err] : "Unknown error"
+
+#else
+
+#define ngx_sigsafe_strerror(err)  ""
+
+#endif
+
+
 #endif /* _NGX_ERRNO_H_INCLUDED_ */
diff --git a/src/os/unix/ngx_process.c b/src/os/unix/ngx_process.c
index 21a92f178..5e230f5bb 100644
--- a/src/os/unix/ngx_process.c
+++ b/src/os/unix/ngx_process.c
@@ -315,7 +315,7 @@ ngx_signal_handler(int signo)
         }
     }
 
-    ngx_time_update(0, 0);
+    ngx_time_sigsafe_update();
 
     action = "";
 
@@ -476,16 +476,17 @@ ngx_process_get_status(void)
              */
 
             if (err == NGX_ECHILD) {
-                ngx_log_error(NGX_LOG_INFO, ngx_cycle->log, errno,
-                              "waitpid() failed");
+                ngx_log_error(NGX_LOG_INFO, ngx_cycle->log, 0,
+                              "waitpid() failed (%d: %s)",
+                              err, ngx_sigsafe_strerror(err));
                 return;
             }
 
 #endif
 
-            ngx_log_error(NGX_LOG_ALERT, ngx_cycle->log, errno,
-                          "waitpid() failed");
-
+            ngx_log_error(NGX_LOG_ALERT, ngx_cycle->log, 0,
+                          "waitpid() failed (%d: %s)",
+                          err, ngx_sigsafe_strerror(err));
             return;
         }
 
diff --git a/src/os/unix/ngx_process_cycle.c b/src/os/unix/ngx_process_cycle.c
index e3b054834..812b36fc4 100644
--- a/src/os/unix/ngx_process_cycle.c
+++ b/src/os/unix/ngx_process_cycle.c
@@ -168,7 +168,7 @@ ngx_master_process_cycle(ngx_cycle_t *cycle)
 
         sigsuspend(&set);
 
-        ngx_time_update(0, 0);
+        ngx_time_update();
 
         ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
                        "wake up, sigio %i", sigio);
@@ -1337,7 +1337,7 @@ ngx_cache_manager_process_handler(ngx_event_t *ev)
 
             next = (n <= next) ? n : next;
 
-            ngx_time_update(0, 0);
+            ngx_time_update();
         }
     }
 
@@ -1367,7 +1367,7 @@ ngx_cache_loader_process_handler(ngx_event_t *ev)
 
         if (path[i]->loader) {
             path[i]->loader(path[i]->data);
-            ngx_time_update(0, 0);
+            ngx_time_update();
         }
     }