From 680527cbab9848acb04bfdb47c09ad7e4f3ded75 Mon Sep 17 00:00:00 2001
From: Patrick Mahoney <pat@polycrystal.org>
Date: Wed, 1 Feb 2012 21:34:51 -0600
Subject: [PATCH] Add time and clock Mach functions; implement
 Mach::Semaphore#timedwait.

---
 lib/mach/clock.rb     | 24 ++++++++++++++++++++++++
 lib/mach/functions.rb | 33 +++++++++++++++++++++++++++------
 lib/mach/host.rb      | 28 ++++++++++++++++++++++++++++
 lib/mach/semaphore.rb |  7 ++++++-
 lib/mach/time_spec.rb | 16 ++++++++++++++++
 5 files changed, 101 insertions(+), 7 deletions(-)
 create mode 100644 lib/mach/clock.rb
 create mode 100644 lib/mach/host.rb
 create mode 100644 lib/mach/time_spec.rb

diff --git a/lib/mach/clock.rb b/lib/mach/clock.rb
new file mode 100644
index 0000000..b3d0c34
--- /dev/null
+++ b/lib/mach/clock.rb
@@ -0,0 +1,24 @@
+require 'mach/functions'
+require 'mach/port'
+require 'mach/time_spec'
+
+module Mach
+  class Clock
+    include Functions
+
+    def initialize(clock_id)
+      @clock_id = clock_id
+    end
+
+    def to_s
+      "#<#{self.class} #{@clock_id.to_i}>"
+    end
+
+    def get_time
+      time = TimeSpec.new
+      clock_get_time(@clock_id.to_i, time)
+      time
+    end
+  end
+end
+
diff --git a/lib/mach/functions.rb b/lib/mach/functions.rb
index f4bd59b..e5fd8b8 100644
--- a/lib/mach/functions.rb
+++ b/lib/mach/functions.rb
@@ -1,5 +1,7 @@
 require 'ffi'
 
+require 'mach/time_spec'
+
 module Mach
   # FFI wrapper around a subset of the Mach API (likely Mac OS X
   # specific).
@@ -15,9 +17,12 @@ module Mach
     typedef :int, :kern_return_t # true for 64 bit??
     typedef :int, :mach_error_t
     typedef :int, :sync_policy_t # SyncPolicy
+    typedef :int, :clock_id_t
+    typedef :int, :clock_res_t
 
     typedef :string, :name_t
 
+    typedef :mach_port_t, :host_t
     typedef :mach_port_t, :task_t
     typedef :mach_port_t, :ipc_space_t
     typedef :mach_port_t, :semaphore_t
@@ -128,11 +133,6 @@ module Mach
             :name,
             :bootstrap )
 
-    class Timespec < FFI::ManagedStruct
-      layout(:tv_sec, :uint,
-             :tv_nsec, :int)
-    end
-
     KERN_SUCCESS = 0
 
     # Replace methods in +syms+ with error checking wrappers that
@@ -253,6 +253,18 @@ module Mach
                           MachMsgType],
                          :kern_return_t)
 
+    ##################
+    # Host functions #
+    ##################
+
+    attach_function :mach_host_self, [], :mach_port_t
+
+    attach_mach_function(:host_get_clock_service,
+                         [:host_t,
+                          :clock_id_t,
+                          :pointer],
+                         :kern_return_t)
+
     ##################
     # Task functions #
     ##################
@@ -269,6 +281,15 @@ module Mach
                           :mach_port_t],
                          :kern_return_t)
 
+    ###################
+    # Clock functions #
+    ###################
+
+    attach_mach_function(:clock_get_time,
+                         [:clock_id_t,
+                          TimeSpec],
+                         :kern_return_t)
+
     #####################
     # Message functions #
     #####################
@@ -312,7 +333,7 @@ module Mach
                          [:semaphore_t],
                          :kern_return_t)
     attach_mach_function(:semaphore_timedwait,
-                         [:semaphore_t, Timespec.val],
+                         [:semaphore_t, TimeSpec.val],
                          :kern_return_t)
 
   end
diff --git a/lib/mach/host.rb b/lib/mach/host.rb
new file mode 100644
index 0000000..d310039
--- /dev/null
+++ b/lib/mach/host.rb
@@ -0,0 +1,28 @@
+require 'mach/functions'
+require 'mach/port'
+require 'mach/clock'
+
+module Mach
+  class Host < Port
+    include Functions
+
+    # @return [Task]
+    def self.self
+      new(Functions.mach_host_self)
+    end
+
+    def initialize(host)
+      super(:port => host)
+    end
+
+    alias_method :host, :port
+
+    def get_clock_service
+      mem = new_memory_pointer(:clock_id_t)
+      host_get_clock_service(host, 0, mem)
+      clock_id = Port.new(:port => mem.read_int)
+      Clock.new clock_id
+    end
+  end
+end
+
diff --git a/lib/mach/semaphore.rb b/lib/mach/semaphore.rb
index 007eaaf..3033165 100644
--- a/lib/mach/semaphore.rb
+++ b/lib/mach/semaphore.rb
@@ -1,5 +1,7 @@
 require 'mach/functions'
 require 'mach/port'
+require 'mach/host'
+require 'mach/clock'
 
 module Mach
   class Semaphore < Port
@@ -61,8 +63,11 @@ module Mach
       semaphore_wait(port)
     end
 
-    # TODO: implement
+    # @see http://pkaudio.blogspot.com/2010/05/mac-os-x-no-timed-semaphore-waits.html
     def timedwait(secs)
+      timespec = TimeSpec.new
+      timespec.add_seconds!(secs)
+
       semaphore_timedwait(port, timespec)
     end
   end
diff --git a/lib/mach/time_spec.rb b/lib/mach/time_spec.rb
new file mode 100644
index 0000000..96c9aeb
--- /dev/null
+++ b/lib/mach/time_spec.rb
@@ -0,0 +1,16 @@
+require 'ffi'
+
+module Mach
+  class TimeSpec < FFI::Struct
+    layout(:tv_sec, :uint,
+           :tv_nsec, :int)      # clock_res_t
+
+    def to_s
+      "#<%s tv_sec=%d tv_nsec=%d>" % [self.class,
+                                      self[:tv_sec],
+                                      self[:tv_nsec]]
+      
+    end
+  end
+end
+