add threaded example

Signed-off-by: Mattias Andrée <maandree@operamail.com>

1 files changed, 200 insertions, 0 deletions

diff --git a/examples/threaded b/examples/threaded
new file mode 100644
index 0000000..962563a
--- /dev/null
+++ b/examples/threaded
@@ -0,0 +1,200 @@
+# -*- python -*-
+
+# This example demonstrates how you can make a
+# multithreaded configurations script
+
+import threading
+
+
+# Geographical coodinates.
+# (KTH building D computer laboratories in this example.)
+latitude, longitude = 59.3472, 18.0728
+
+# Adjust settings by solar elevation.
+get_dayness = lambda : sun(latitude, longitude)
+
+# Colour temperature at high day and high night, respectively.
+temperature_day, temperature_night = [6500], [3700]
+
+# Gamma of the monitors.
+gamma_red   = [1.16, 1.10]
+gamma_green = [1.15, 1.16]
+gamma_blue  = [1.11, 1.10]
+
+
+# Make colour curves thread local
+class threadlocal:
+    def __init__(self, obj):
+        self.default = obj
+        self.tmap = {}
+    
+    def __getitem__(self, i):
+        t = threading.current_thread()
+        if t not in self.tmap:
+            self.tmap[t] = self.default[:]
+        return self.tmap[t][i]
+    
+    def __len__(self):
+        t = threading.current_thread()
+        if t not in self.tmap:
+            self.tmap[t] = self.default[:]
+        return len(self.tmap[t])
+    
+    def __setitem__(self, i, x):
+        t = threading.current_thread()
+        if t not in self.tmap:
+            self.tmap[t] = self.default[:]
+        self.tmap[t][i] = x
+    
+    def __delitem__(self, i):
+        t = threading.current_thread()
+        if t not in self.tmap:
+            self.tmap[t] = self.default[:]
+        del self.tmap[t][x]
+
+r_curve = threadlocal([i / (i_size - 1) for i in range(i_size)])
+g_curve = threadlocal([i / (i_size - 1) for i in range(i_size)])
+b_curve = threadlocal([i / (i_size - 1) for i in range(i_size)])
+
+## cmf_10deg uses non-thread safe cache, run once in advance so it is not done by the threads
+cmf_10deg(0)
+
+
+# Thread synchronisation barrier
+barrier = threading.Barrier(len(gamma_red) + 1)
+
+# Help functions for colour interpolation.
+interpol, purify = None, None
+
+# Parameters in `periodically`
+fade_ = None
+
+def adjust(m):
+    '''
+    Adjust monitor colours
+    
+    @param  m:int  The CRTC index
+    '''
+    while True:
+        # Wait for start cue.
+        barrier.wait()
+        
+        # Calculate temperature.
+        temperature_ = interpol(temperature_day, temperature_night)
+        if fade_ is not None:
+            temperature_ = purify(temperature_, 6500)
+        
+        # Remove settings from last run.
+        start_over()
+        
+        # Apply colour temperature using raw CIE 1964 10 degree CMF data with interpolation.
+        temperature(temperature_, lambda t : divide_by_maximum(cmf_10deg(t)))
+        
+        # Clip colour curves to fit [0, 1] to avoid errors by complex numbers.
+        clip()
+        
+        # Apply gamma correction to monitor.
+        gamma(gamma_red[m], gamma_green[m], gamma_blue[m])
+        
+        # Flush settings to monitor.
+        randr(m)
+        
+        # Signal thread completion.
+        barrier.wait()
+
+# Create threads.
+for m in range(len(gamma_red)):
+    thread = threading.Thread(target = adjust, args = (m,))
+    thread.setDaemon(True)
+    thread.start()
+
+last_dayness = None
+def periodically(year, month, day, hour, minute, second, weekday, fade):
+    '''
+    :(int, int, int, int, int, int, int, float?)?→void  Place holder for periodically invoked function
+    
+    Invoked periodically
+    
+    If you want to control at what to invoke this function next time
+    you can set the value of the global variable `wait_period` to the
+    number of seconds to wait before invoking this function again.
+    The value does not need to be an integer.
+    
+    @param   year:int     The year
+    @param   month:int    The month, 1 = January, 12 = December
+    @param   day:int      The day, minimum value is 1, probable maximum value is 31 (*)
+    @param   hour:int     The hour, minimum value is 0, maximum value is 23
+    @param   minute:int   The minute, minimum value is 0, maximum value is 59
+    @param   second:int   The second, minimum value is 0, probable maximum value is 60 (**)
+    @param   weekday:int  The weekday, 1 = Monday, 7 = Sunday
+    @param   fade:float?  Blueshift can use this function to fade into a state when it start
+                          or exits. `fade` can either be negative, zero or positive or `None`,
+                          but the magnitude of value cannot exceed 1. When Blueshift starts,
+                          this function will be invoked multiple with the time parameters
+                          of the time it is invoked and each time `fade` will increase towards
+                          1, starting at 0, when the value is 1, the settings should be applied
+                          to 100 %. After this this function will be invoked once again with
+                          `fade` being `None`. When Blueshift exits the same behaviour is used
+                          except, `fade` decrease towards -1 but start slightly below 0, when
+                          -1 is reached all settings should be normal. Then Blueshift will NOT
+                          invoke this function with `fade` being `None`, instead it will by
+                          itself revert all settings and quit.
+    
+    (*)  Can be exceeded if the calendar system is changed, like in 1712-(02)Feb-30
+    (**) See https://en.wikipedia.org/wiki/Leap_second
+    '''
+    global last_dayness, wait_period, interpol, purify, fade_
+    
+    dayness = get_dayness()
+    # Do not do unnecessary work.
+    if fade is None:
+        if dayness == last_dayness:
+            return
+        last_dayness = dayness
+    
+    # Pass parameters to threads.
+    fade_ = fade
+    
+    # Help functions for colour interpolation.
+    interpol = lambda _day, _night : _day[m % len(_day)] * dayness + _night[m % len(_night)] * (1 - dayness)
+    purify = lambda current, pure : current * abs(fade) + pure * (1 - abs(fade))
+    
+    # Signal all threads to start.
+    barrier.wait()
+    
+    # Wait for all threads.
+    barrier.wait()
+
+
+def reset():
+    '''
+    Invoked to reset the displays
+    '''
+    for m in range(len(gamma_red)):
+        # Remove settings from last run.
+        start_over()
+        
+        # Apply gamma correction to monitor.
+        gamma(gamma_red[m], gamma_green[m], gamma_blue[m])
+        
+        # Flush settings to monitor.
+        randr(m)
+
+
+# Set transition time, 0 on high day and 5 seconds on high night.
+fadein_time = 5 * (1 - get_dayness())
+# Do 10 changes per second.
+fadein_steps = fadein_time * 10
+
+# Transition on exit in the same way, calculated on exit.
+old_signal_SIGTERM = signal_SIGTERM
+if 'SIGTERM' not in conf_storage:
+    conf_storage['SIGTERM'] = old_signal_SIGTERM
+else:
+    old_signal_SIGTERM = conf_storage['SIGTERM']
+def signal_SIGTERM(signum, frame):
+    global fadeout_time, fadeout_steps
+    fadeout_time = 5 * (1 - get_dayness())
+    fadeout_steps = fadeout_time * 10
+    old_signal_SIGTERM(signum, frame)
+