Awake Mac host display when remote session starts.

remoting/host/capturer_mac.cc

Index: remoting/host/capturer_mac.cc
diff --git a/remoting/host/capturer_mac.cc b/remoting/host/capturer_mac.cc
index 42b362afe3629843b6030a0a956235d9a9931d74..aae79923220001f8ec339fded8e1461714d636c2 100644
--- a/remoting/host/capturer_mac.cc
+++ b/remoting/host/capturer_mac.cc
@@ -6,6 +6,7 @@
 
 #include <ApplicationServices/ApplicationServices.h>
 #include <dlfcn.h>
+#include <IOKit/pwr_mgt/IOPMLib.h>
 #include <OpenGL/CGLMacro.h>
 #include <OpenGL/OpenGL.h>
 #include <stddef.h>
@@ -15,6 +16,8 @@
 #include "base/mac/scoped_cftyperef.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/synchronization/waitable_event.h"
+#include "base/time.h"
+#include "base/timer.h"
 #include "remoting/base/util.h"
 #include "remoting/host/capturer_helper.h"
 
@@ -23,6 +26,8 @@ namespace remoting {
 
 namespace {
 
+const int64 kPMAssertionTimeoutMs = 5 * 1000; // 30 seconds

[Wez, 2012/04/14 00:08:22]

This looks like five seconds, not thirty?

[Wez, 2012/04/14 00:08:22]

See note below re naming.

[dcaiafa, 2012/04/14 00:21:41]

Done.

[dcaiafa, 2012/04/14 00:21:41]

Done.

+
 SkIRect CGRectToSkIRect(const CGRect& rect) {
   SkIRect sk_rect = {
     SkScalarRound(rect.origin.x),
@@ -192,6 +197,9 @@ class CapturerMac : public Capturer {
                                            void *user_parameter);
 
   void ReleaseBuffers();
+  void RefreshPowerManagementAssertion();
+  void ReleasePowerManagementAssertion();
+
   CGLContextObj cgl_context_;
   static const int kNumBuffers = 2;
   scoped_pixel_buffer_object pixel_buffer_object_;
@@ -221,6 +229,16 @@ class CapturerMac : public Capturer {
   // Will be non-null on lion.
   CGDisplayCreateImageFunc display_create_image_func_;
 
+  // Power management assertion to prevent the screen from sleeping.
+  IOPMAssertionID pm_assertion_id_;

[Wez, 2012/04/14 00:08:22]

Style guide requires that names not be abbreviated unless the abbreviation is
well established - consider changing this to power_assertion_id, and renaming
the methods to Refresh/ReleasePowerAssertion.

[dcaiafa, 2012/04/14 00:21:41]

Done.

+
+  // Indicates that a power management assertion was created and that
+  // pm_assertion_id_ is valid.
+  bool pm_assertion_created_;

[Wez, 2012/04/14 00:08:22]

Why not just check whether the timer is started, rather than keeping a separate
flag?

[dcaiafa, 2012/04/14 00:21:41]

Because when ReleasePowerAssertion is called by the timer, the timer will have
been stopped.

On 2012/04/14 00:08:22, Wez wrote:

[Wez, 2012/04/14 00:24:39]

OK.  Is zero a valid power management assertion Id?  If not then testing the Id
for being zero would avoid the need for the separate flag.

On 2012/04/14 00:21:41, dcaiafa wrote:

[dcaiafa, 2012/04/14 00:37:43]

Turns out that there is a constant called kIOPMNullAssertionID. I failed to find
it in my first look at the headers.

On 2012/04/14 00:24:39, Wez wrote:

+
+  // Timer to remove the power management assertion on inactivity
+  base::OneShotTimer<CapturerMac> pm_assertion_timer_;
+
   DISALLOW_COPY_AND_ASSIGN(CapturerMac);
 };
 
@@ -230,7 +248,9 @@ CapturerMac::CapturerMac()
       last_buffer_(NULL),
       pixel_format_(media::VideoFrame::RGB32),
       display_configuration_capture_event_(false, true),
-      display_create_image_func_(NULL) {
+      display_create_image_func_(NULL),
+      pm_assertion_id_(0),
+      pm_assertion_created_(false) {
 }
 
 CapturerMac::~CapturerMac() {
@@ -242,6 +262,7 @@ CapturerMac::~CapturerMac() {
   if (err != kCGErrorSuccess) {
     LOG(ERROR) << "CGDisplayRemoveReconfigurationCallback " << err;
   }
+  ReleasePowerManagementAssertion();
 }
 
 bool CapturerMac::Init() {
@@ -360,6 +381,8 @@ void CapturerMac::CaptureInvalidRegion(
   // Only allow captures when the display configuration is not occurring.
   scoped_refptr<CaptureData> data;
 
+  RefreshPowerManagementAssertion();
+
   // Critical section shared with DisplaysReconfigured(...).
   CHECK(display_configuration_capture_event_.TimedWait(
       base::TimeDelta::FromSeconds(kDisplayReconfigurationTimeoutInSeconds)));
@@ -626,6 +649,38 @@ void CapturerMac::DisplaysReconfiguredCallback(
   capturer->DisplaysReconfigured(display, flags);
 }
 
+// Creates or refreshes a power management assertion to prevent the display from
+// going to sleep.
+void CapturerMac::RefreshPowerManagementAssertion() {
+  if (pm_assertion_timer_.IsRunning()) {
+    DCHECK(pm_assertion_created_);
+    pm_assertion_timer_.Reset();
+    return;
+  }
+
+  IOReturn result = IOPMAssertionCreateWithName(
+      kIOPMAssertionTypeNoDisplaySleep, kIOPMAssertionLevelOn,
+      CFSTR("Chromoting"), &pm_assertion_id_);
+
+  if (result == kIOReturnSuccess) {
+    pm_assertion_created_ = true;
+    pm_assertion_timer_.Start(FROM_HERE,
+                              base::TimeDelta::FromMilliseconds(
+                                  kPMAssertionTimeoutMs),
+                              this,
+                              &CapturerMac::ReleasePowerManagementAssertion);
+  }
+}
+
+void CapturerMac::ReleasePowerManagementAssertion() {
+  if (pm_assertion_created_) {
+    IOPMAssertionRelease(pm_assertion_id_);
+    pm_assertion_id_ = 0;

[Wez, 2012/04/14 00:08:22]

nit: Zeroing this when it's not started effectively duplicates the
pm_assertion_created_ flag's function, and since you never DCHECK()
pm_assertion_id_ there's no real need to zero it here.

[dcaiafa, 2012/04/14 00:21:41]

Done.

+    pm_assertion_created_ = false;
+    pm_assertion_timer_.Stop();
+  }
+}
+
 }  // namespace
 
 // static