Changed nsAutoMonitor to nsAutoCMonitor (cached monitors).

xpcom/ds/nsBuffer.cpp

@@ -85,7 +85,7 @@ nsBuffer::Create(nsISupports *aOuter, REFNSIID aIID, void **aResult)
 nsresult
 nsBuffer::PushWriteSegment()
 {
-    nsAutoMonitor mon(this);        // protect mSegments
+    nsAutoCMonitor mon(this);        // protect mSegments
 
     if (mBufferSize >= mMaxSize) {
         if (mObserver) {
@@ -118,7 +118,7 @@ nsresult
 nsBuffer::PopReadSegment()
 {
     nsresult rv;
-    nsAutoMonitor mon(this);        // protect mSegments
+    nsAutoCMonitor mon(this);        // protect mSegments
 
     PRCList* header = (PRCList*)mSegments.next;
     char* segment = (char*)header;

xpcom/tests/TestBuffers.cpp

@@ -34,7 +34,7 @@ public:
 
     NS_IMETHOD Run() {
         nsresult rv;
-        nsAutoMonitor mon(this);
+        nsAutoCMonitor mon(this);
 
         char buf[100];
         PRUint32 readCnt;
@@ -128,7 +128,7 @@ WriteMessages(nsIBuffer* buffer)
             return rv;
         }
         if (cnt == 0) {
-            nsAutoMonitor mon(reader);
+            nsAutoCMonitor mon(reader);
             mon.Notify();       // wake up reader
             mon.Wait();         // and wait for reader to read all
         }
@@ -142,7 +142,7 @@ WriteMessages(nsIBuffer* buffer)
     PR_FREEIF(mem);
     {
         reader->SetEOF();
-        nsAutoMonitor mon(reader);
+        nsAutoCMonitor mon(reader);
         mon.Notify();       // wake up reader
     }
 

xpcom/threads/nsAutoLock.h

@@ -130,14 +130,69 @@ public:
 
 class nsAutoMonitor {
 public:
-    nsAutoMonitor(void* lockObject)
+    nsAutoMonitor(PRMonitor* mon)
+        : mMonitor(mon)
+    {
+        NS_ASSERTION(mMonitor, "null lock object");
+        PR_EnterMonitor(mMonitor);
+    }
+
+    ~nsAutoMonitor() {
+        PR_ExitMonitor(mMonitor);
+    }
+
+    nsresult Wait(PRIntervalTime interval = PR_INTERVAL_NO_TIMEOUT) {
+        return PR_Wait(mMonitor, interval) == PR_SUCCESS
+            ? NS_OK : NS_ERROR_FAILURE;
+    }
+
+    nsresult Notify() {
+        return PR_Notify(mMonitor) == PR_SUCCESS
+            ? NS_OK : NS_ERROR_FAILURE;
+    }
+
+    nsresult NotifyAll() {
+        return PR_NotifyAll(mMonitor) == PR_SUCCESS
+            ? NS_OK : NS_ERROR_FAILURE;
+    }
+
+private:
+    PRMonitor* mMonitor;
+
+    // Not meant to be implemented. This makes it a compiler error to
+    // construct or assign an nsAutoLock object incorrectly.
+    nsAutoMonitor(void) {}
+    nsAutoMonitor(nsAutoMonitor& aMon) {}
+    nsAutoMonitor& operator =(nsAutoMonitor& aMon) {
+        return *this;
+    }
+
+    // Not meant to be implemented. This makes it a compiler error to
+    // attempt to create an nsAutoLock object on the heap.
+    static void* operator new(size_t size) {
+        return nsnull;
+    }
+    static void operator delete(void* memory) {}
+};
+
+////////////////////////////////////////////////////////////////////////////////
+// Once again, this time with a cache...
+// (Using this avoids the need to allocate a PRMonitor, which may be useful when
+// a large number of objects of the same class need associated monitors.)
+
+#include "prcmon.h"
+#include "nsError.h"
+
+class nsAutoCMonitor {
+public:
+    nsAutoCMonitor(void* lockObject)
         : mLockObject(lockObject)
     {
         NS_ASSERTION(lockObject, "null lock object");
         PR_CEnterMonitor(mLockObject);
     }
 
-    ~nsAutoMonitor() {
+    ~nsAutoCMonitor() {
         PR_CExitMonitor(mLockObject);
     }
 
@@ -161,9 +216,9 @@ private:
 
     // Not meant to be implemented. This makes it a compiler error to
     // construct or assign an nsAutoLock object incorrectly.
-    nsAutoMonitor(void) {}
-    nsAutoMonitor(nsAutoMonitor& aMon) {}
-    nsAutoMonitor& operator =(nsAutoMonitor& aMon) {
+    nsAutoCMonitor(void) {}
+    nsAutoCMonitor(nsAutoCMonitor& aMon) {}
+    nsAutoCMonitor& operator =(nsAutoCMonitor& aMon) {
         return *this;
     }