Magic-Mirror/gecko-dev
1
0
Fork 0
mirror of https://github.com/mozilla/gecko-dev.git synced 2024-10-11 04:15:43 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

Fix for PDT+ bug 27496 "DNS Service is not threadsafe on Windows". Added locks around WSAAsyncGetHostByName to protect against the possibility of the call completing before it returns. The lookup object could get deleted before the results were assigned to it.

Browse Source
This commit is contained in:
gordon%netscape.com 2000-02-27 23:06:00 +00:00
parent 90533efa40
commit 3149a5f199
1 changed files with 17 additions and 21 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

38
netwerk/dns/src/nsDnsService.cpp
View File

@ -90,7 +90,7 @@ public:
nsresult FinishHostEntry(void);
nsresult CallOnFound(void);
const char * HostName(void) { return mHostName; }
nsresult InitiateDNSLookup(nsDNSService * dnsService);
nsresult InitiateDNSLookup(void);
protected:
// Input when creating a nsDNSLookup
@ -274,14 +274,14 @@ nsDNSLookup::CallOnFound(void)
nsresult
nsDNSLookup::InitiateDNSLookup(nsDNSService * dnsService)
nsDNSLookup::InitiateDNSLookup(void)
{
nsresult rv = NS_OK;
#if defined(XP_MAC)
OSErr err;
err = OTInetStringToAddress(dnsService->mServiceRef, (char *)mHostName, (InetHostInfo *)&mInetHostInfo);
err = OTInetStringToAddress(gService->mServiceRef, (char *)mHostName, (InetHostInfo *)&mInetHostInfo);
if (err != noErr)
rv = NS_ERROR_UNEXPECTED;
#endif /* XP_MAC */
@ -290,8 +290,8 @@ nsDNSLookup::InitiateDNSLookup(nsDNSService * dnsService)
mMsgID = gService->AllocMsgID();
if (mMsgID == 0)
return NS_ERROR_UNEXPECTED;
mLookupHandle = WSAAsyncGetHostByName(dnsService->mDNSWindow, mMsgID,
PR_Lock(gService->mThreadLock); // protect against lookup completing before WSAAsyncGetHostByName returns, better to refcount lookup
mLookupHandle = WSAAsyncGetHostByName(gService->mDNSWindow, mMsgID,
mHostName, (char *)&mHostEntry.hostEnt, PR_NETDB_BUF_SIZE);
// check for error conditions
if (mLookupHandle == nsnull) {
@ -304,6 +304,7 @@ nsDNSLookup::InitiateDNSLookup(nsDNSService * dnsService)
// the first two calls made to WSAAsyncGetHostByName), to avoid using the handle on
// those systems. For more info, see bug 23709.
}
PR_Unlock(gService->mThreadLock);
#endif /* XP_PC */
#ifdef XP_UNIX
@ -315,7 +316,8 @@ nsDNSLookup::InitiateDNSLookup(nsDNSService * dnsService)
mResult = rv;
CallOnFound();
delete this;
if (PR_SUCCESS == status)
delete this; // nsDNSLookup deleted by nsDNSService::Lookup() in failure case
#endif /* XP_UNIX */
return rv;
@ -358,9 +360,7 @@ nsDNSEventProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
LRESULT result = nsnull;
int error = nsnull;
nsDNSService * dnsService = (nsDNSService *)GetWindowLong(hWnd, GWL_USERDATA);
if ((dnsService != nsnull) && (uMsg >= WM_USER) && (uMsg < WM_USER+128)) {
if ((uMsg >= WM_USER) && (uMsg < WM_USER+128)) {
// dns lookup complete - get error code
error = WSAGETASYNCERROR(lParam);
@ -370,10 +370,10 @@ nsDNSEventProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
PRBool rv;
// find matching lookup element
PR_Lock(dnsService->mThreadLock); // so we don't collide with thread calling Lookup()
index = dnsService->mCompletionQueue.Count();
PR_Lock(gService->mThreadLock); // so we don't collide with thread calling Lookup()
index = gService->mCompletionQueue.Count();
while (index) {
lookup = (nsDNSLookup *)dnsService->mCompletionQueue.ElementAt(index-1);
lookup = (nsDNSLookup *)gService->mCompletionQueue.ElementAt(index-1);
if (lookup->mMsgID == uMsg) {
break;
}
@ -381,7 +381,7 @@ nsDNSEventProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
}
if (lookup && (lookup->mMsgID == uMsg)) {
rv = dnsService->mCompletionQueue.RemoveElement(lookup);
rv = gService->mCompletionQueue.RemoveElement(lookup);
NS_ASSERTION(rv == PR_TRUE, "error removing dns lookup element.");
lookup->mComplete = PR_TRUE;
@ -389,15 +389,15 @@ nsDNSEventProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
lookup->mResult = NS_ERROR_UNKNOWN_HOST;
(void)lookup->CallOnFound();
dnsService->FreeMsgID(lookup->mMsgID);
gService->FreeMsgID(lookup->mMsgID);
delete lookup; // until we implement the dns cache
}
result = 0;
PR_Unlock(dnsService->mThreadLock);
PR_Unlock(gService->mThreadLock);
}
else if (uMsg == WM_DNS_SHUTDOWN) {
// dispose DNS EventHandler Window
(void) DestroyWindow(dnsService->mDNSWindow);
(void) DestroyWindow(gService->mDNSWindow);
PostQuitMessage(0);
result = 0;
}
@ -592,8 +592,6 @@ nsDNSService::InitDNSThread(void)
mDNSWindow = CreateWindow(windowClass, "Mozilla:DNSWindow",
0, 0, 0, 10, 10, NULL, NULL, NULL, NULL);
(void) SetWindowLong(mDNSWindow, GWL_USERDATA, (long)this);
// sync with Create thread
PRMonitor * monitor;
PRStatus status;
@ -810,16 +808,14 @@ nsDNSService::Lookup(nsISupports* clientContext,
(void)listener->OnStartLookup(clientContext, hostName);
// initiate async lookup
rv = lookup->InitiateDNSLookup(this);
rv = lookup->InitiateDNSLookup();
if (rv != NS_OK) {
#if defined(XP_PC)
PR_Lock(mThreadLock);
mCompletionQueue.RemoveElement(lookup);
PR_Unlock(mThreadLock);
#endif
#if !defined(XP_UNIX)
delete lookup;
#endif
}
return rv;
}