From 98bc4c37ef92368cb446dfe0be4e917ac90d8b16 Mon Sep 17 00:00:00 2001
From: "gordon%netscape.com" <gordon%netscape.com>
Date: Tue, 6 Mar 2001 03:26:13 +0000
Subject: [PATCH] [not part of build]

Fix race condition in nsCacheRequest WaitForValidation().

Force !streamBased to set storagePolicy to nsICache:STORE_IN_MEMORY when creating nsCacheSessions.

Fix ProcessRequest() to refrain from creating a descriptor for ACCESS_READ requests when no entry is found (found by pavlov).
---
 netwerk/cache/src/nsCacheRequest.h   | 14 +++++++++++---
 netwerk/cache/src/nsCacheService.cpp |  6 ++++--
 netwerk/cache/src/nsCacheSession.cpp |  1 +
 3 files changed, 16 insertions(+), 5 deletions(-)

diff --git a/netwerk/cache/src/nsCacheRequest.h b/netwerk/cache/src/nsCacheRequest.h
index abfa6f3c2ef..c5c0b19e6bf 100644
--- a/netwerk/cache/src/nsCacheRequest.h
+++ b/netwerk/cache/src/nsCacheRequest.h
@@ -54,6 +54,7 @@ private:
         SetAccessRequested(accessRequested);
         if (streamBased)  MarkStreamBased();
         SetStoragePolicy(storagePolicy);
+        MarkWaitingForValidation();
     }
     
     ~nsCacheRequest()
@@ -111,6 +112,11 @@ private:
     nsresult
     WaitForValidation(void)
     {
+        if (!WaitingForValidation()) {   // flag already cleared
+            MarkWaitingForValidation();  // set up for next time
+            return NS_OK;                // early exit;
+        }
+
         if (!mLock) {
             mLock = PR_NewLock();
             if (!mLock) return NS_ERROR_OUT_OF_MEMORY;
@@ -122,14 +128,14 @@ private:
                 return NS_ERROR_OUT_OF_MEMORY;
             }
         }
-        
         PRStatus status;
         PR_Lock(mLock);
         while (WaitingForValidation() && (status == PR_SUCCESS) ) {
             status = PR_WaitCondVar(mCondVar, PR_INTERVAL_NO_TIMEOUT);
         }
+        MarkWaitingForValidation();  // set up for next time
         PR_Unlock(mLock);
-
+        
         NS_ASSERTION(status == PR_SUCCESS, "PR_WaitCondVar() returned PR_FAILURE?");
         if (status == PR_FAILURE)
             return NS_ERROR_UNEXPECTED;
@@ -138,10 +144,12 @@ private:
     }
 
     void WakeUp(void) {
-        PR_Lock(mLock);
         DoneWaitingForValidation();
+        if (mLock) {
+        PR_Lock(mLock);
         PR_NotifyCondVar(mCondVar);
         PR_Unlock(mLock);
+        }
     }
 
     /**
diff --git a/netwerk/cache/src/nsCacheService.cpp b/netwerk/cache/src/nsCacheService.cpp
index 9d7c9e3a6c0..dcd6684601d 100644
--- a/netwerk/cache/src/nsCacheService.cpp
+++ b/netwerk/cache/src/nsCacheService.cpp
@@ -282,6 +282,7 @@ nsCacheService::ProcessRequest(nsCacheRequest * request,
             if (request->mListener) // async exits - validate, doom, or close will resume
                 return rv; 
             
+            // XXX allocate condvar for request if necessary
             PR_Unlock(mCacheServiceLock);
             rv = request->WaitForValidation();
             PR_Lock(mCacheServiceLock);
@@ -300,8 +301,9 @@ nsCacheService::ProcessRequest(nsCacheRequest * request,
     }
 
     nsCOMPtr<nsICacheEntryDescriptor> descriptor;
-
-    rv = entry->CreateDescriptor(request, accessGranted, getter_AddRefs(descriptor));
+    
+    if (NS_SUCCEEDED(rv))
+        rv = entry->CreateDescriptor(request, accessGranted, getter_AddRefs(descriptor));
 
     if (request->mListener) {  // Asynchronous
         // call listener to report error or descriptor
diff --git a/netwerk/cache/src/nsCacheSession.cpp b/netwerk/cache/src/nsCacheSession.cpp
index 5b16e959378..ab49d1ba815 100644
--- a/netwerk/cache/src/nsCacheSession.cpp
+++ b/netwerk/cache/src/nsCacheSession.cpp
@@ -38,6 +38,7 @@ nsCacheSession::nsCacheSession(const char *         clientID,
       mStreamBased(streamBased)
 {
   NS_INIT_ISUPPORTS();
+  if (!streamBased) mStoragePolicy = nsICache::STORE_IN_MEMORY;
 }
 
 nsCacheSession::~nsCacheSession()