зеркало из https://github.com/mozilla/gecko-dev.git
Bug 1478124: Part 2 - Factor out common GetService code. r=froydnj
The current implementations of GetService are slightly different for contract IDs than they are for CIDs, but I'm pretty sure that's unintentional. This patch factors out the common parts of the two implementations, which should prevent them from diverging in the future, and avoids the need to make the same changes in multiple places in the following patches. Differential Revision: https://phabricator.services.mozilla.com/D15032 --HG-- extra : rebase_source : 591d854d604dc7597dbfe5438bfbd0af98224c5b
This commit is contained in:
Kris Maglione
Родитель
f1f3101eb5
Коммит
d3b05e8dad
|
|
@ -48,7 +48,9 @@
|
|||
#include "nsIMutableArray.h"
|
||||
#include "nsArrayEnumerator.h"
|
||||
#include "nsStringEnumerator.h"
|
||||
#include "mozilla/DebugOnly.h"
|
||||
#include "mozilla/FileUtils.h"
|
||||
#include "mozilla/ScopeExit.h"
|
||||
#include "mozilla/URLPreloader.h"
|
||||
#include "mozilla/UniquePtr.h"
|
||||
#include "nsDataHashtable.h"
|
||||
|
|
@ -1155,6 +1157,104 @@ PRThread* nsComponentManagerImpl::GetPendingServiceThread(
|
|||
return nullptr;
|
||||
}
|
||||
|
||||
nsresult
|
||||
nsComponentManagerImpl::GetServiceLocked(MutexLock& aLock, nsFactoryEntry& aEntry,
|
||||
const nsIID& aIID, void** aResult) {
|
||||
if (aEntry.mServiceObject) {
|
||||
aLock.Unlock();
|
||||
return aEntry.mServiceObject->QueryInterface(aIID, aResult);
|
||||
}
|
||||
|
||||
PRThread* currentPRThread = PR_GetCurrentThread();
|
||||
MOZ_ASSERT(currentPRThread, "This should never be null!");
|
||||
|
||||
// Needed to optimize the event loop below.
|
||||
nsIThread* currentThread = nullptr;
|
||||
|
||||
PRThread* pendingPRThread;
|
||||
while ((pendingPRThread = GetPendingServiceThread(*aEntry.mCIDEntry->cid))) {
|
||||
if (pendingPRThread == currentPRThread) {
|
||||
NS_ERROR("Recursive GetService!");
|
||||
return NS_ERROR_NOT_AVAILABLE;
|
||||
}
|
||||
|
||||
SafeMutexAutoUnlock unlockPending(mLock);
|
||||
|
||||
// If the current thread doesn't have an associated nsThread, then it's a
|
||||
// thread that doesn't have an event loop to process, so we'll just try
|
||||
// to yield to another thread in an attempt to make progress.
|
||||
if (!nsThreadManager::get().IsNSThread()) {
|
||||
PR_Sleep(PR_INTERVAL_NO_WAIT);
|
||||
continue;
|
||||
}
|
||||
|
||||
if (!currentThread) {
|
||||
currentThread = NS_GetCurrentThread();
|
||||
MOZ_ASSERT(currentThread, "This should never be null!");
|
||||
}
|
||||
|
||||
// This will process a single event or yield the thread if no event is
|
||||
// pending.
|
||||
if (!NS_ProcessNextEvent(currentThread, false)) {
|
||||
PR_Sleep(PR_INTERVAL_NO_WAIT);
|
||||
}
|
||||
}
|
||||
|
||||
// It's still possible that the other thread failed to create the
|
||||
// service so we're not guaranteed to have an entry or service yet.
|
||||
if (aEntry.mServiceObject) {
|
||||
aLock.Unlock();
|
||||
return aEntry.mServiceObject->QueryInterface(aIID, aResult);
|
||||
}
|
||||
|
||||
DebugOnly<PendingServiceInfo*> newInfo =
|
||||
AddPendingService(*aEntry.mCIDEntry->cid, currentPRThread);
|
||||
NS_ASSERTION(newInfo, "Failed to add info to the array!");
|
||||
|
||||
// We need to not be holding the service manager's lock while calling
|
||||
// CreateInstance, because it invokes user code which could try to re-enter
|
||||
// the service manager:
|
||||
|
||||
nsCOMPtr<nsISupports> service;
|
||||
auto cleanup = MakeScopeExit([&]() {
|
||||
// `service` must be released after the lock is released, so if we fail and
|
||||
// still have a reference, release the lock before relasing it.
|
||||
if (service) {
|
||||
aLock.Unlock();
|
||||
service = nullptr;
|
||||
}
|
||||
});
|
||||
|
||||
nsresult rv;
|
||||
{
|
||||
SafeMutexAutoUnlock unlock(mLock);
|
||||
rv = CreateInstance(*aEntry.mCIDEntry->cid, nullptr, aIID, getter_AddRefs(service));
|
||||
}
|
||||
if (NS_SUCCEEDED(rv) && !service) {
|
||||
NS_ERROR("Factory did not return an object but returned success");
|
||||
return NS_ERROR_SERVICE_NOT_AVAILABLE;
|
||||
}
|
||||
|
||||
#ifdef DEBUG
|
||||
pendingPRThread = GetPendingServiceThread(*aEntry.mCIDEntry->cid);
|
||||
MOZ_ASSERT(pendingPRThread == currentPRThread,
|
||||
"Pending service array has been changed!");
|
||||
#endif
|
||||
RemovePendingService(*aEntry.mCIDEntry->cid);
|
||||
|
||||
if (NS_FAILED(rv)) {
|
||||
return rv;
|
||||
}
|
||||
|
||||
NS_ASSERTION(!aEntry.mServiceObject, "Created two instances of a service!");
|
||||
|
||||
aEntry.mServiceObject = service.forget();
|
||||
|
||||
aLock.Unlock();
|
||||
*aResult = do_AddRef(aEntry.mServiceObject).take();
|
||||
return NS_OK;
|
||||
}
|
||||
|
||||
NS_IMETHODIMP
|
||||
nsComponentManagerImpl::GetService(const nsCID& aClass, const nsIID& aIID,
|
||||
void** aResult) {
|
||||
|
|
@ -1175,9 +1275,6 @@ nsComponentManagerImpl::GetService(const nsCID& aClass, const nsIID& aIID,
|
|||
return NS_ERROR_UNEXPECTED;
|
||||
}
|
||||
|
||||
// `service` must be released after the lock is released, so it must be
|
||||
// declared before the lock in this C++ block.
|
||||
nsCOMPtr<nsISupports> service;
|
||||
MutexLock lock(mLock);
|
||||
|
||||
nsFactoryEntry* entry = mFactories.Get(&aClass);
|
||||
|
|
@ -1185,86 +1282,7 @@ nsComponentManagerImpl::GetService(const nsCID& aClass, const nsIID& aIID,
|
|||
return NS_ERROR_FACTORY_NOT_REGISTERED;
|
||||
}
|
||||
|
||||
if (entry->mServiceObject) {
|
||||
lock.Unlock();
|
||||
return entry->mServiceObject->QueryInterface(aIID, aResult);
|
||||
}
|
||||
|
||||
PRThread* currentPRThread = PR_GetCurrentThread();
|
||||
MOZ_ASSERT(currentPRThread, "This should never be null!");
|
||||
|
||||
// Needed to optimize the event loop below.
|
||||
nsIThread* currentThread = nullptr;
|
||||
|
||||
PRThread* pendingPRThread;
|
||||
while ((pendingPRThread = GetPendingServiceThread(aClass))) {
|
||||
if (pendingPRThread == currentPRThread) {
|
||||
NS_ERROR("Recursive GetService!");
|
||||
return NS_ERROR_NOT_AVAILABLE;
|
||||
}
|
||||
|
||||
SafeMutexAutoUnlock unlockPending(mLock);
|
||||
|
||||
if (!currentThread) {
|
||||
currentThread = NS_GetCurrentThread();
|
||||
MOZ_ASSERT(currentThread, "This should never be null!");
|
||||
}
|
||||
|
||||
// This will process a single event or yield the thread if no event is
|
||||
// pending.
|
||||
if (!NS_ProcessNextEvent(currentThread, false)) {
|
||||
PR_Sleep(PR_INTERVAL_NO_WAIT);
|
||||
}
|
||||
}
|
||||
|
||||
// It's still possible that the other thread failed to create the
|
||||
// service so we're not guaranteed to have an entry or service yet.
|
||||
if (entry->mServiceObject) {
|
||||
lock.Unlock();
|
||||
return entry->mServiceObject->QueryInterface(aIID, aResult);
|
||||
}
|
||||
|
||||
#ifdef DEBUG
|
||||
PendingServiceInfo* newInfo =
|
||||
#endif
|
||||
AddPendingService(aClass, currentPRThread);
|
||||
NS_ASSERTION(newInfo, "Failed to add info to the array!");
|
||||
|
||||
// We need to not be holding the service manager's lock while calling
|
||||
// CreateInstance, because it invokes user code which could try to re-enter
|
||||
// the service manager:
|
||||
|
||||
nsresult rv;
|
||||
{
|
||||
SafeMutexAutoUnlock unlock(mLock);
|
||||
rv = CreateInstance(aClass, nullptr, aIID, getter_AddRefs(service));
|
||||
}
|
||||
if (NS_SUCCEEDED(rv) && !service) {
|
||||
NS_ERROR("Factory did not return an object but returned success");
|
||||
return NS_ERROR_SERVICE_NOT_AVAILABLE;
|
||||
}
|
||||
|
||||
#ifdef DEBUG
|
||||
pendingPRThread = GetPendingServiceThread(aClass);
|
||||
MOZ_ASSERT(pendingPRThread == currentPRThread,
|
||||
"Pending service array has been changed!");
|
||||
#endif
|
||||
RemovePendingService(aClass);
|
||||
|
||||
if (NS_FAILED(rv)) {
|
||||
return rv;
|
||||
}
|
||||
|
||||
NS_ASSERTION(!entry->mServiceObject, "Created two instances of a service!");
|
||||
|
||||
entry->mServiceObject = service.forget();
|
||||
|
||||
lock.Unlock();
|
||||
nsISupports** sresult = reinterpret_cast<nsISupports**>(aResult);
|
||||
*sresult = entry->mServiceObject;
|
||||
(*sresult)->AddRef();
|
||||
|
||||
return NS_OK;
|
||||
return GetServiceLocked(lock, *entry, aIID, aResult);
|
||||
}
|
||||
|
||||
NS_IMETHODIMP
|
||||
|
|
@ -1369,9 +1387,6 @@ nsComponentManagerImpl::GetServiceByContractID(const char* aContractID,
|
|||
return NS_ERROR_UNEXPECTED;
|
||||
}
|
||||
|
||||
// `service` must be released after the lock is released, so it must be
|
||||
// declared before the lock in this C++ block.
|
||||
nsCOMPtr<nsISupports> service;
|
||||
MutexLock lock(mLock);
|
||||
|
||||
nsFactoryEntry* entry = mContractIDs.Get(nsDependentCString(aContractID));
|
||||
|
|
@ -1379,102 +1394,7 @@ nsComponentManagerImpl::GetServiceByContractID(const char* aContractID,
|
|||
return NS_ERROR_FACTORY_NOT_REGISTERED;
|
||||
}
|
||||
|
||||
if (entry->mServiceObject) {
|
||||
// We need to not be holding the service manager's monitor while calling
|
||||
// QueryInterface, because it invokes user code which could try to re-enter
|
||||
// the service manager, or try to grab some other lock/monitor/condvar
|
||||
// and deadlock, e.g. bug 282743.
|
||||
// `entry` is valid until XPCOM shutdown, so we can safely use it after
|
||||
// exiting the lock.
|
||||
lock.Unlock();
|
||||
return entry->mServiceObject->QueryInterface(aIID, aResult);
|
||||
}
|
||||
|
||||
PRThread* currentPRThread = PR_GetCurrentThread();
|
||||
MOZ_ASSERT(currentPRThread, "This should never be null!");
|
||||
|
||||
// Needed to optimize the event loop below.
|
||||
nsIThread* currentThread = nullptr;
|
||||
|
||||
PRThread* pendingPRThread;
|
||||
while ((pendingPRThread = GetPendingServiceThread(*entry->mCIDEntry->cid))) {
|
||||
if (pendingPRThread == currentPRThread) {
|
||||
NS_ERROR("Recursive GetService!");
|
||||
return NS_ERROR_NOT_AVAILABLE;
|
||||
}
|
||||
|
||||
SafeMutexAutoUnlock unlockPending(mLock);
|
||||
|
||||
// If the current thread doesn't have an associated nsThread, then it's a
|
||||
// thread that doesn't have an event loop to process, so we'll just try
|
||||
// to yield to another thread in an attempt to make progress.
|
||||
if (!nsThreadManager::get().IsNSThread()) {
|
||||
PR_Sleep(PR_INTERVAL_NO_WAIT);
|
||||
continue;
|
||||
}
|
||||
|
||||
if (!currentThread) {
|
||||
currentThread = NS_GetCurrentThread();
|
||||
MOZ_ASSERT(currentThread, "This should never be null!");
|
||||
}
|
||||
|
||||
// This will process a single event or yield the thread if no event is
|
||||
// pending.
|
||||
if (!NS_ProcessNextEvent(currentThread, false)) {
|
||||
PR_Sleep(PR_INTERVAL_NO_WAIT);
|
||||
}
|
||||
}
|
||||
|
||||
if (currentThread && entry->mServiceObject) {
|
||||
// If we have a currentThread then we must have waited on another thread
|
||||
// to create the service. Grab it now if that succeeded.
|
||||
lock.Unlock();
|
||||
return entry->mServiceObject->QueryInterface(aIID, aResult);
|
||||
}
|
||||
|
||||
#ifdef DEBUG
|
||||
PendingServiceInfo* newInfo =
|
||||
#endif
|
||||
AddPendingService(*entry->mCIDEntry->cid, currentPRThread);
|
||||
NS_ASSERTION(newInfo, "Failed to add info to the array!");
|
||||
|
||||
// We need to not be holding the service manager's lock while calling
|
||||
// CreateInstance, because it invokes user code which could try to re-enter
|
||||
// the service manager:
|
||||
|
||||
nsresult rv;
|
||||
{
|
||||
SafeMutexAutoUnlock unlock(mLock);
|
||||
rv = CreateInstanceByContractID(aContractID, nullptr, aIID,
|
||||
getter_AddRefs(service));
|
||||
}
|
||||
if (NS_SUCCEEDED(rv) && !service) {
|
||||
NS_ERROR("Factory did not return an object but returned success");
|
||||
return NS_ERROR_SERVICE_NOT_AVAILABLE;
|
||||
}
|
||||
|
||||
#ifdef DEBUG
|
||||
pendingPRThread = GetPendingServiceThread(*entry->mCIDEntry->cid);
|
||||
MOZ_ASSERT(pendingPRThread == currentPRThread,
|
||||
"Pending service array has been changed!");
|
||||
#endif
|
||||
RemovePendingService(*entry->mCIDEntry->cid);
|
||||
|
||||
if (NS_FAILED(rv)) {
|
||||
return rv;
|
||||
}
|
||||
|
||||
NS_ASSERTION(!entry->mServiceObject, "Created two instances of a service!");
|
||||
|
||||
entry->mServiceObject = service.forget();
|
||||
|
||||
lock.Unlock();
|
||||
|
||||
nsISupports** sresult = reinterpret_cast<nsISupports**>(aResult);
|
||||
*sresult = entry->mServiceObject;
|
||||
(*sresult)->AddRef();
|
||||
|
||||
return NS_OK;
|
||||
return GetServiceLocked(lock, *entry, aIID, aResult);
|
||||
}
|
||||
|
||||
NS_IMETHODIMP
|
||||
|
|
|
|||
|
|
@ -52,6 +52,10 @@ struct PRThread;
|
|||
|
||||
extern const mozilla::Module kXPCOMModule;
|
||||
|
||||
namespace {
|
||||
class MutexLock;
|
||||
}
|
||||
|
||||
/**
|
||||
* This is a wrapper around mozilla::Mutex which provides runtime
|
||||
* checking for a deadlock where the same thread tries to lock a mutex while
|
||||
|
|
@ -262,6 +266,9 @@ class nsComponentManagerImpl final : public nsIComponentManager,
|
|||
|
||||
private:
|
||||
~nsComponentManagerImpl();
|
||||
|
||||
nsresult GetServiceLocked(MutexLock& aLock, nsFactoryEntry& aEntry,
|
||||
const nsIID& aIID, void** aResult);
|
||||
};
|
||||
|
||||
#define NS_MAX_FILENAME_LEN 1024
|
||||
|
|
|
|||
Загрузка…
Ссылка в новой задаче