Module: SystemTimer

Defined in:
lib/system_timer.rb,
lib/system_timer_stub.rb,
lib/system_timer/thread_timer.rb,
lib/system_timer/concurrent_timer_pool.rb,
ext/system_timer/system_timer_native.c,
ext/system_timer/system_timer_native.c

Overview

Copyright 2008 David Vollbracht & Philippe Hanrigou

Defined Under Namespace

Classes: ConcurrentTimerPool, ThreadTimer

Class Attribute Summary collapse

Class Method Summary collapse

Class Attribute Details

.timer_pool ⇒ Object (readonly)

Returns the value of attribute timer_pool.



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# File 'lib/system_timer.rb', line 43

def timer_pool
  @timer_pool
end

Class Method Details

.debug_enabled? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'ext/system_timer/system_timer_native.c', line 224

static VALUE debug_enabled_p(VALUE self) {
    return debug_enabled ? Qtrue : Qfalse;
}

.disable_debug ⇒ Object 



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# File 'ext/system_timer/system_timer_native.c', line 233

static VALUE disable_debug(VALUE self) {
    debug_enabled = 0;
    return Qnil;	
}

.enable_debug ⇒ Object 



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# File 'ext/system_timer/system_timer_native.c', line 228

static VALUE enable_debug(VALUE self) {
    debug_enabled = 1;
    return Qnil;
}

.install_first_timer_and_save_original_configuration(seconds) ⇒ Object 



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# File 'ext/system_timer/system_timer_native.c', line 42

static VALUE install_first_timer_and_save_original_configuration(VALUE self, VALUE seconds)
{
    struct itimerval timer_interval;

    if (debug_enabled) {
        log_debug("[install_first_timer] %.2lfs\n", NUM2DBL(seconds));
    }

    /*
     * Block SIG_ALRM for safe processing of SIG_ALRM configuration and save mask.
     */
    if (0 != sigprocmask(SIG_BLOCK, &sigalarm_mask, &original_mask)) {
        log_error("[install_first_timer] Could not block SIG_ALRM\n", DISPLAY_ERRNO);
        return Qnil;
    }
    clear_pending_sigalrm_for_ruby_threads();
    log_debug("[install_first_timer] Successfully blocked SIG_ALRM at O.S. level\n");
	
   /*
    * Save previous signal handler.
    */
    log_debug("[install_first_timer] Saving original system handler\n");
    original_signal_handler.sa_handler = NULL;
    if (0 != sigaction(SIGALRM, NULL, &original_signal_handler)) {
        log_error("[install_first_timer] Could not save existing handler for SIG_ALRM\n", DISPLAY_ERRNO);
        restore_original_sigalrm_mask_when_blocked();
        return Qnil;
    }
    log_debug("[install_first_timer] Successfully saved existing SIG_ALRM handler\n");
    
	 /*
	  * Install Ruby Level SIG_ALRM handler
	  */
    install_ruby_sigalrm_handler(self);

    /*
     * Save original real time interval timer and aet new real time interval timer.     
     */	
    set_itimerval(&original_timer_interval, 0.0);
    set_itimerval_with_minimum_1s_interval(&timer_interval, seconds);
    if (0 != setitimer(ITIMER_REAL, &timer_interval, &original_timer_interval)) {
        log_error("[install_first_timer] Could not install our own timer, timeout will not work", DISPLAY_ERRNO);
        restore_original_ruby_sigalrm_handler(self);
        restore_original_sigalrm_mask_when_blocked();
        return Qnil;
    }
    if (debug_enabled) {
      log_debug("[install_first_timer] Successfully installed timer (%ds)\n", 
                timer_interval.it_value.tv_sec);
    }

    /*
     * Unblock SIG_ALRM
     */
    if (0 != sigprocmask(SIG_UNBLOCK, &sigalarm_mask, NULL)) {
        log_error("[install_first_timer] Could not unblock SIG_ALRM, timeout will not work", DISPLAY_ERRNO);
        restore_original_timer_interval();
        restore_original_ruby_sigalrm_handler(self);
        restore_original_sigalrm_mask_when_blocked();		
    }
    log_debug("[install_first_timer] Successfully unblocked SIG_ALRM.\n");

    return Qnil;
}

.install_next_timer(seconds) ⇒ Object 



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# File 'ext/system_timer/system_timer_native.c', line 107

static VALUE install_next_timer(VALUE self, VALUE seconds)
{
    struct itimerval timer_interval;
    sigset_t previous_sigalarm_mask;

    if (debug_enabled) {
        log_debug("[install_next_timer] %.2lfs\n", NUM2DBL(seconds));
    }

    /*
     * Block SIG_ALRM for safe processing of SIG_ALRM configuration and save mask.
     */
    if (0 != sigprocmask(SIG_BLOCK, &sigalarm_mask, &previous_sigalarm_mask)) {
        log_error("[install_next_timer] Could not block SIG_ALRM\n", DISPLAY_ERRNO);
        return Qnil;
    }
    clear_pending_sigalrm_for_ruby_threads();
    log_debug("[install_next_timer] Successfully blocked SIG_ALRM at O.S. level\n");
	
    /*
     * Set new real time interval timer.
     */	
    set_itimerval_with_minimum_1s_interval(&timer_interval, seconds);
    if (0 != setitimer(ITIMER_REAL, &timer_interval, NULL)) {
        log_error("[install_next_timer] Could not install our own timer, timeout will not work", DISPLAY_ERRNO);
        restore_sigalrm_mask(&previous_sigalarm_mask);
        return Qnil;
    }
    if (debug_enabled) {
      log_debug("[install_next_timer] Successfully installed timer (%ds + %dus)\n", 
                timer_interval.it_value.tv_sec, timer_interval.it_value.tv_usec);
    }

    /*
     * Unblock SIG_ALRM
     */
    if (0 != sigprocmask(SIG_UNBLOCK, &sigalarm_mask, NULL)) {
        log_error("[install_next_timer] Could not unblock SIG_ALRM, timeout will not work", DISPLAY_ERRNO);
        restore_sigalrm_mask(&previous_sigalarm_mask);
    }
    log_debug("[install_next_timer] Successfully unblocked SIG_ALRM.\n");

    return Qnil;
}

.restore_original_configuration ⇒ Object 



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# File 'ext/system_timer/system_timer_native.c', line 152

static VALUE restore_original_configuration(VALUE self)
{
   /*
    * Block SIG_ALRM for safe processing of SIG_ALRM configuration.
    */
    if (0 != sigprocmask(SIG_BLOCK, &sigalarm_mask, NULL)) {
        log_error("restore_original_configuration: Could not block SIG_ALRM", errno);
    }
    clear_pending_sigalrm_for_ruby_threads();
    log_debug("[restore_original_configuration] Blocked SIG_ALRM\n");

   /*
    * Install Ruby Level SIG_ALRM handler
    */
    restore_original_ruby_sigalrm_handler(self);
	
    if (original_signal_handler.sa_handler == NULL) {
        log_error("[restore_original_configuration] Previous SIG_ALRM handler not initialized!", DO_NOT_DISPLAY_ERRNO);
    } else if (0 == sigaction(SIGALRM, &original_signal_handler, NULL)) {
        log_debug("[restore_original_configuration] Successfully restored previous handler for SIG_ALRM\n");
    } else {
        log_error("[restore_original_configuration] Could not restore previous handler for SIG_ALRM", DISPLAY_ERRNO);
    }
    original_signal_handler.sa_handler = NULL;
	
    restore_original_timer_interval();
    restore_original_sigalrm_mask_when_blocked();	
}

.timeout_after(seconds) ⇒ Object Also known as: timeout

Executes the method’s block. If the block execution terminates before seconds seconds has passed, it returns true. If not, it terminates the execution and raises a Timeout::Error.



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# File 'lib/system_timer.rb', line 48

def timeout_after(seconds, exception_class = nil)
  new_timer = nil                                      # just for scope
  @monitor.synchronize do
    new_timer = timer_pool.add_timer seconds, exception_class
    timer_interval = timer_pool.next_trigger_interval_in_seconds
    debug "==== Install Timer ==== at #{Time.now.to_f}, next interval: #{timer_interval}"
    if timer_pool.first_timer?
      install_first_timer_and_save_original_configuration timer_interval
    else
      install_next_timer timer_interval
    end
  end
  return yield
ensure
  @monitor.synchronize do
    debug "==== Cleanup Timer ==== at #{Time.now.to_f}, #{new_timer} "
    timer_pool.cancel new_timer
    timer_pool.log_registered_timers if debug_enabled?
    next_interval = timer_pool.next_trigger_interval_in_seconds
    debug "Cleanup Timer : next interval #{next_interval.inspect} "
    if next_interval
      install_next_timer next_interval
    else
      restore_original_configuration
    end
  end
end