1 files changed, 101 insertions, 0 deletions
diff --git a/debian/patches/gpg-agent-idling/agent-Avoid-tight-timer-tick-when-possible.patch b/debian/patches/gpg-agent-idling/agent-Avoid-tight-timer-tick-when-possible.patch
new file mode 100644
index 0000000..3900cf4
--- /dev/null
+++ b/debian/patches/gpg-agent-idling/agent-Avoid-tight-timer-tick-when-possible.patch
@@ -0,0 +1,101 @@
+From: Daniel Kahn Gillmor <dkg@fifthhorseman.net>
+Date: Tue, 1 Nov 2016 00:14:10 -0400
+Subject: agent: Avoid tight timer tick when possible.
+
+* agent/gpg-agent.c (need_tick): Evaluate whether the short-phase
+handle_tick() is needed.
+(handle_connections): On each cycle of the select loop, adjust whether
+we should call handle_tick() or not.
+(start_connection_thread_ssh, do_start_connection_thread): Signal the
+main loop when the child terminates.
+* agent/call-scd.c (start_scd): Call interrupt_main_thread_loop() once
+the scdaemon thread context has started up.
+
+--
+
+With this change, an idle gpg-agent that has no scdaemon running only
+wakes up once a minute (to check_own_socket).
+
+Thanks to Ian Jackson and NIIBE Yutaka who helped me improve some of
+the blocking and corner cases.
+
+Signed-off-by: Daniel Kahn Gillmor <dkg@fifthhorseman.net>
+---
+ agent/call-scd.c  |  2 ++
+ agent/gpg-agent.c | 29 +++++++++++++++++++++++++++--
+ 2 files changed, 29 insertions(+), 2 deletions(-)
+
+diff --git a/agent/call-scd.c b/agent/call-scd.c
+index 6438693..ee69bb4 100644
+--- a/agent/call-scd.c
++++ b/agent/call-scd.c
+@@ -414,6 +414,8 @@ start_scd (ctrl_t ctrl)
+ 
+   primary_scd_ctx = ctx;
+   primary_scd_ctx_reusable = 0;
++  /* notify the main loop that something has changed */
++  interrupt_main_thread_loop ();
+ 
+  leave:
+   xfree (abs_homedir);
+diff --git a/agent/gpg-agent.c b/agent/gpg-agent.c
+index 752552c..eff82ca 100644
+--- a/agent/gpg-agent.c
++++ b/agent/gpg-agent.c
+@@ -2362,6 +2362,26 @@ create_directories (void)
+ }
+ 
+ 
++static int
++need_tick (void)
++{
++#ifdef HAVE_W32_SYSTEM
++  /* We do not know how to interrupt the select loop on Windows, so we
++     always need a short tick there. */
++  return 1;
++#else
++  /* if we were invoked like "gpg-agent cmd arg1 arg2" then we need to
++     watch our parent. */
++  if (parent_pid != (pid_t)(-1))
++    return 1;
++  /* if scdaemon is running, we need to check that it's alive */
++  if (agent_scd_check_running ())
++    return 1;
++  /* otherwise, nothing fine-grained to do. */
++  return 0;
++#endif /*HAVE_W32_SYSTEM*/
++}
++
+ 
+ /* This is the worker for the ticker.  It is called every few seconds
+    and may only do fast operations. */
+@@ -2718,7 +2738,8 @@ do_start_connection_thread (ctrl_t ctrl)
+ 
+   agent_deinit_default_ctrl (ctrl);
+   xfree (ctrl);
+-  active_connections--;
++  if (--active_connections == 0)
++    interrupt_main_thread_loop();
+   return NULL;
+ }
+ 
+@@ -2798,7 +2819,8 @@ start_connection_thread_ssh (void *arg)
+ 
+   agent_deinit_default_ctrl (ctrl);
+   xfree (ctrl);
+-  active_connections--;
++  if (--active_connections == 0)
++    interrupt_main_thread_loop();
+   return NULL;
+ }
+ 
+@@ -3008,6 +3030,9 @@ handle_connections (gnupg_fd_t listen_fd,
+          thus a simple assignment is fine to copy the entire set.  */
+       read_fdset = fdset;
+ 
++      /* avoid a fine-grained timer if we don't need one: */
++      timertbl[0].interval.tv_sec = need_tick () ? TIMERTICK_INTERVAL : 0;
++
+       /* loop through all timers, fire any registered functions, and
+          plan next timer to trigger */
+       npth_clock_gettime (&curtime);