Fix for 158927 on the 1.0 branch. r=wtc, sdagley. a=adt.

2 files changed, 43 insertions, 16 deletions

diff --git a/pr/include/md/_macos.h b/pr/include/md/_macos.h
index d2c25d1d..4b301377 100644
--- a/pr/include/md/_macos.h
+++ b/pr/include/md/_macos.h
@@ -65,6 +65,7 @@
 
 #include <Errors.h>
 #include <OpenTransport.h>
+#include <DriverServices.h>
 
 #define _PR_HAVE_PEEK_BUFFER
 #define _PR_PEEK_BUFFER_MAX (16 * 1024)
@@ -105,7 +106,9 @@ struct _MDSegment {
 };
 
 struct _MDCPU {
-    PRInt8 notused;
+    AbsoluteTime    lastThreadSwitch;
+    AbsoluteTime    lastWakeUpProcess;
+    PRBool          trackScheduling;
 };
 
 typedef struct _MDSocketCallerInfo {
@@ -175,7 +178,7 @@ extern void _MD_SetIntsOff(PRInt32 ints);
 #define _MD_CLEANUP_BEFORE_EXIT()
 #define _MD_EXIT(status)	exit(status)
 #define _MD_INIT_CPUS()
-#define _MD_INIT_RUNNING_CPU(cpu)
+#define _MD_INIT_RUNNING_CPU(cpu) _MD_InitRunningCPU(cpu)
 
 /*
 ** Process Related definitions
@@ -299,16 +302,20 @@ extern PRStatus _MD_InitThread(PRThread *thread);
 ** context switch because it might have changed.
 */
 /*    	ResetTimer();	before _PR_Schedule()		   		*/
-#define _MD_SWITCH_CONTEXT(_thread)    	\
-    PR_BEGIN_MACRO                     	\
-    PR_ASSERT(_thread->no_sched);       \
-	if (!setjmp(_thread->md.jb)) { 		\
-        _MD_SET_LAST_THREAD(_thread);   \
-	    _PR_Schedule();            		\
-    } else {                            \
-        PR_ASSERT(_MD_LAST_THREAD() !=_MD_CURRENT_THREAD()); \
-        _MD_LAST_THREAD()->no_sched = 0; \
-	}                              		\
+
+
+#define _MD_SWITCH_CONTEXT(_thread)                                 \
+    PR_BEGIN_MACRO                                                  \
+    PR_ASSERT(_thread->no_sched);                                   \
+    if (!setjmp(_thread->md.jb)) {                                  \
+        _MD_SET_LAST_THREAD(_thread);                               \
+        if (_PR_MD_CURRENT_CPU()->md.trackScheduling)               \
+            _PR_MD_CURRENT_CPU()->md.lastThreadSwitch = UpTime();   \
+        _PR_Schedule();                                             \
+    } else {                                                        \
+        PR_ASSERT(_MD_LAST_THREAD() !=_MD_CURRENT_THREAD());        \
+        _MD_LAST_THREAD()->no_sched = 0;                            \
+    }                                                               \
     PR_END_MACRO
 
 /*
@@ -517,7 +524,6 @@ extern PRStatus _MD_gethostname(char *name, int namelen);
 ** Time Related definitions
 */
 
-#define kMacTimerInMiliSecs				8L
 #define _MD_GET_INTERVAL 				_MD_GetInterval
 #define _MD_INTERVAL_PER_SEC() 			PR_MSEC_PER_SEC
 #define _MD_INTERVAL_INIT()
diff --git a/pr/src/md/mac/macthr.c b/pr/src/md/mac/macthr.c
index 6a1f18d4..fd3b489d 100644
--- a/pr/src/md/mac/macthr.c
+++ b/pr/src/md/mac/macthr.c
@@ -39,7 +39,7 @@
 #include <MacTypes.h>
 #include <Timer.h>
 #include <OSUtils.h>
-
+#include <Math64.h>
 #include <LowMem.h>
 #include <Multiprocessing.h>
 #include <Gestalt.h>
@@ -184,6 +184,8 @@ _PRInterruptTable _pr_interruptTable[] = {
     { 0 }
 };
 
+#define kMacTimerInMiliSecs 8L
+
 pascal void TimerCallback(TMTaskPtr tmTaskPtr)
 {
     _PRCPU *cpu = _PR_MD_CURRENT_CPU();
@@ -201,8 +203,17 @@ pascal void TimerCallback(TMTaskPtr tmTaskPtr)
     _PR_ClockInterrupt();
 	
     if ((_PR_RUNQREADYMASK(cpu)) >> ((_PR_MD_CURRENT_THREAD()->priority))) {
-        if (gTimeManagerTaskDoesWUP)
-            WakeUpProcess(&gApplicationProcess);
+        if (gTimeManagerTaskDoesWUP) {
+            // We only want to call WakeUpProcess if we know that NSPR has managed to switch threads
+            // since the last call, otherwise we end up spewing out WakeUpProcess() calls while the
+            // application is blocking somewhere. This can interfere with events loops other than
+            // our own (see bug 158927).
+            if (UnsignedWideToUInt64(cpu->md.lastThreadSwitch) > UnsignedWideToUInt64(cpu->md.lastWakeUpProcess))
+            {
+                WakeUpProcess(&gApplicationProcess);
+                cpu->md.lastWakeUpProcess = UpTime();
+            }
+        }
         _PR_SET_RESCHED_FLAG();
 	}
 	
@@ -263,6 +274,16 @@ void _MD_PauseCPU(PRIntervalTime timeout)
     }
 }
 
+void _MD_InitRunningCPU(_PRCPU* cpu)
+{
+    cpu->md.trackScheduling = RunningOnOSX();
+    if (cpu->md.trackScheduling) {
+        AbsoluteTime    zeroTime = {0, 0};
+        cpu->md.lastThreadSwitch = UpTime();
+        cpu->md.lastWakeUpProcess = zeroTime;
+    }
+}
+
 
 //##############################################################################
 //##############################################################################