Magic-Mirror/gecko-dev
1
0
Fork 0
mirror of https://github.com/mozilla/gecko-dev.git synced 2024-10-10 11:55:49 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

working around broken usage of XPCOM for bug 256911 "bind lifetime of

Browse Source 
child stubs to that of the master stub" (based on similar patch by
Javier Pedemonte for nsJavaXPTCStub.cpp)
This commit is contained in:
darin%meer.net 2004-09-09 22:57:24 +00:00
parent ddff876c72
commit 145aa32a94
1 changed files with 53 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

62
ipc/ipcd/extensions/dconnect/src/ipcDConnectService.cpp
View File

@ -909,10 +909,11 @@ DConnectStub::~DConnectStub()
if (NS_FAILED(rv))
NS_WARNING("failed to send RELEASE event");
if (mMaster)
if (!mMaster)
{
mMaster->mChildren.RemoveElement(this);
NS_RELEASE(mMaster);
// delete each child stub
for (PRInt32 i=0; i<mChildren.Count(); ++i)
delete (DConnectStub *) mChildren[i];
}
}
@ -952,8 +953,35 @@ DConnectStub::FindStubSupportingIID(const nsID &iid)
return nsnull;
}
NS_IMPL_ADDREF(DConnectStub)
NS_IMPL_RELEASE(DConnectStub)
NS_IMETHODIMP_(nsrefcnt)
DConnectStub::AddRef()
{
if (mMaster)
return mMaster->AddRef();
NS_ASSERT_OWNINGTHREAD("DConnectStub");
++mRefCnt;
NS_LOG_ADDREF(this, mRefCnt, "DConnectStub", sizeof(*this));
return mRefCnt;
}
NS_IMETHODIMP_(nsrefcnt)
DConnectStub::Release()
{
if (mMaster)
return mMaster->Release();
NS_ASSERT_OWNINGTHREAD("DConnectStub");
--mRefCnt;
NS_LOG_RELEASE(this, mRefCnt, "DConnectStub");
if (mRefCnt == 0)
{
mRefCnt = 1; /* stabilize */
delete this;
return 0;
} \
return mRefCnt;
}
NS_IMETHODIMP
DConnectStub::QueryInterface(const nsID &aIID, void **aInstancePtr)
@ -1015,10 +1043,26 @@ DConnectStub::QueryInterface(const nsID &aIID, void **aInstancePtr)
stub = (DConnectStub *) result;
// add stub to the master's list of children, so we can preserve
// symmetry in future QI calls. each child owns his master, but
// the master only keeps weak references to its children. the
// children are responsible for removing themselves as they die.
NS_ADDREF(master);
// symmetry in future QI calls. the master will delete each child
// when it is destroyed. the refcount of each child is bound to
// the refcount of the master. this is done to deal with code
// like this:
//
// nsCOMPtr<nsIBar> bar = ...;
// nsIFoo *foo;
// {
// nsCOMPtr<nsIFoo> temp = do_QueryInterface(bar);
// foo = temp;
// }
// foo->DoStuff();
//
// while this code is not valid XPCOM (since it is using |foo|
// after having called Release on it), such code is unfortunately
// very common in the mozilla codebase. the assumption this code
// is making is that so long as |bar| is alive, it should be valid
// to access |foo| even if the code doesn't own a strong reference
// to |foo|! clearly wrong, but we need to support it anyways.
stub->mMaster = master;
master->mChildren.AppendElement(stub);