From 2752527e5270b7796ed7f8dded78cf6891d33db1 Mon Sep 17 00:00:00 2001 From: Daniel Kahn Gillmor Date: Tue, 1 Nov 2016 00:14:10 -0400 Subject: [PATCH] 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. * 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). Signed-off-by: Daniel Kahn Gillmor Gbp-Pq: Topic gpg-agent-idling Gbp-Pq: Name 0003-agent-Avoid-tight-timer-tick-when-possible.patch --- agent/call-scd.c | 4 +++- agent/gpg-agent.c | 25 ++++++++++++++++++++++++- 2 files changed, 27 insertions(+), 2 deletions(-) diff --git a/agent/call-scd.c b/agent/call-scd.c index ba59c18..1ac0f6b 100644 --- a/agent/call-scd.c +++ b/agent/call-scd.c @@ -407,7 +407,9 @@ 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); if (err) diff --git a/agent/gpg-agent.c b/agent/gpg-agent.c index 04a775c..1bfe0f3 100644 --- a/agent/gpg-agent.c +++ b/agent/gpg-agent.c @@ -2267,6 +2267,26 @@ 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. */ @@ -2325,7 +2345,7 @@ agent_sigusr2_action (void) #ifndef HAVE_W32_SYSTEM /* The signal handler for this program. It is expected to be run in - its own trhead and not in the context of a signal handler. */ + its own thread and not in the context of a signal handler. */ static void handle_signal (int signo) { @@ -2872,6 +2892,9 @@ 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); -- 2.30.2