mirror of
https://github.com/mozilla/gecko-dev.git
synced 2024-11-30 16:22:00 +00:00
348 lines
9.8 KiB
C++
348 lines
9.8 KiB
C++
/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
|
|
* vim: sw=4 ts=4 et :
|
|
* This Source Code Form is subject to the terms of the Mozilla Public
|
|
* License, v. 2.0. If a copy of the MPL was not distributed with this
|
|
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
|
|
|
|
|
|
#ifndef mozilla_BlockingResourceBase_h
|
|
#define mozilla_BlockingResourceBase_h
|
|
|
|
#include "prlog.h"
|
|
|
|
#include "nscore.h"
|
|
#include "nsDebug.h"
|
|
#include "nsError.h"
|
|
#include "nsTraceRefcnt.h"
|
|
|
|
#ifdef DEBUG
|
|
#include "prinit.h"
|
|
#include "prthread.h"
|
|
|
|
#include "nsStringGlue.h"
|
|
|
|
#include "mozilla/DeadlockDetector.h"
|
|
#include "nsXPCOM.h"
|
|
#endif
|
|
|
|
//
|
|
// This header is not meant to be included by client code.
|
|
//
|
|
|
|
namespace mozilla {
|
|
|
|
|
|
/**
|
|
* BlockingResourceBase
|
|
* Base class of resources that might block clients trying to acquire them.
|
|
* Does debugging and deadlock detection in DEBUG builds.
|
|
**/
|
|
class NS_COM_GLUE BlockingResourceBase
|
|
{
|
|
public:
|
|
// Needs to be kept in sync with kResourceTypeNames.
|
|
enum BlockingResourceType { eMutex, eReentrantMonitor, eCondVar };
|
|
|
|
/**
|
|
* kResourceTypeName
|
|
* Human-readable version of BlockingResourceType enum.
|
|
*/
|
|
static const char* const kResourceTypeName[];
|
|
|
|
|
|
#ifdef DEBUG
|
|
|
|
private:
|
|
// forward declaration for the following typedef
|
|
struct DeadlockDetectorEntry;
|
|
|
|
// ``DDT'' = ``Deadlock Detector Type''
|
|
typedef DeadlockDetector<DeadlockDetectorEntry> DDT;
|
|
|
|
/**
|
|
* DeadlockDetectorEntry
|
|
* We free BlockingResources, but we never free entries in the
|
|
* deadlock detector. This struct outlives its BlockingResource
|
|
* and preserves all the state needed to print subsequent
|
|
* error messages.
|
|
*
|
|
* These objects are owned by the deadlock detector.
|
|
*/
|
|
struct DeadlockDetectorEntry
|
|
{
|
|
DeadlockDetectorEntry(const char* aName,
|
|
BlockingResourceType aType) :
|
|
mName(aName),
|
|
mType(aType),
|
|
mAcquisitionContext(CallStack::kNone)
|
|
{
|
|
NS_ABORT_IF_FALSE(mName, "Name must be nonnull");
|
|
}
|
|
|
|
/**
|
|
* Print
|
|
* Write a description of this blocking resource to |out|. If
|
|
* the resource appears to be currently acquired, the current
|
|
* acquisition context is printed and true is returned.
|
|
* Otherwise, we print the context from |aFirstSeen|, the
|
|
* first acquisition from which the code calling |Print()|
|
|
* became interested in us, and return false. |Print()| can
|
|
* be forced to print the context from |aFirstSeen| regardless
|
|
* by passing |aPrintFirstSeenCx=true|.
|
|
*
|
|
* *NOT* thread safe. Reads |mAcquisitionContext| without
|
|
* synchronization, but this will not cause correctness
|
|
* problems.
|
|
*
|
|
* FIXME bug 456272: hack alert: because we can't write call
|
|
* contexts into strings, all info is written to stderr, but
|
|
* only some info is written into |out|
|
|
*/
|
|
bool Print(const DDT::ResourceAcquisition& aFirstSeen,
|
|
nsACString& out,
|
|
bool aPrintFirstSeenCx=false) const;
|
|
|
|
/**
|
|
* mName
|
|
* A descriptive name for this resource. Used in error
|
|
* messages etc.
|
|
*/
|
|
const char* mName;
|
|
/**
|
|
* mType
|
|
* The more specific type of this resource. Used to implement
|
|
* special semantics (e.g., reentrancy of monitors).
|
|
**/
|
|
BlockingResourceType mType;
|
|
/**
|
|
* mAcquisitionContext
|
|
* The calling context from which this resource was acquired, or
|
|
* |CallStack::kNone| if it is currently free (or freed).
|
|
*/
|
|
CallStack mAcquisitionContext;
|
|
};
|
|
|
|
protected:
|
|
/**
|
|
* BlockingResourceBase
|
|
* Initialize this blocking resource. Also hooks the resource into
|
|
* instrumentation code.
|
|
*
|
|
* Thread safe.
|
|
*
|
|
* @param aName A meaningful, unique name that can be used in
|
|
* error messages, et al.
|
|
* @param aType The specific type of |this|, if any.
|
|
**/
|
|
BlockingResourceBase(const char* aName, BlockingResourceType aType);
|
|
|
|
~BlockingResourceBase();
|
|
|
|
/**
|
|
* CheckAcquire
|
|
*
|
|
* Thread safe.
|
|
*
|
|
* @param aCallContext the client's calling context from which the
|
|
* original acquisition request was made.
|
|
**/
|
|
void CheckAcquire(const CallStack& aCallContext);
|
|
|
|
/**
|
|
* Acquire
|
|
*
|
|
* *NOT* thread safe. Requires ownership of underlying resource.
|
|
*
|
|
* @param aCallContext the client's calling context from which the
|
|
* original acquisition request was made.
|
|
**/
|
|
void Acquire(const CallStack& aCallContext); //NS_NEEDS_RESOURCE(this)
|
|
|
|
/**
|
|
* Release
|
|
* Remove this resource from the current thread's acquisition chain.
|
|
* The resource does not have to be at the front of the chain, although
|
|
* it is confusing to release resources in a different order than they
|
|
* are acquired. This generates a warning.
|
|
*
|
|
* *NOT* thread safe. Requires ownership of underlying resource.
|
|
**/
|
|
void Release(); //NS_NEEDS_RESOURCE(this)
|
|
|
|
/**
|
|
* PrintCycle
|
|
* Append to |out| detailed information about the circular
|
|
* dependency in |cycle|. Returns true if it *appears* that this
|
|
* cycle may represent an imminent deadlock, but this is merely a
|
|
* heuristic; the value returned may be a false positive or false
|
|
* negative.
|
|
*
|
|
* *NOT* thread safe. Calls |Print()|.
|
|
*
|
|
* FIXME bug 456272 hack alert: because we can't write call
|
|
* contexts into strings, all info is written to stderr, but only
|
|
* some info is written into |out|
|
|
*/
|
|
static bool PrintCycle(const DDT::ResourceAcquisitionArray* cycle,
|
|
nsACString& out);
|
|
|
|
/**
|
|
* ResourceChainFront
|
|
*
|
|
* Thread safe.
|
|
*
|
|
* @return the front of the resource acquisition chain, i.e., the last
|
|
* resource acquired.
|
|
*/
|
|
static BlockingResourceBase* ResourceChainFront()
|
|
{
|
|
return (BlockingResourceBase*)
|
|
PR_GetThreadPrivate(sResourceAcqnChainFrontTPI);
|
|
}
|
|
|
|
/**
|
|
* ResourceChainPrev
|
|
*
|
|
* *NOT* thread safe. Requires ownership of underlying resource.
|
|
*/
|
|
static BlockingResourceBase*
|
|
ResourceChainPrev(const BlockingResourceBase* aResource)
|
|
{
|
|
return aResource->mChainPrev;
|
|
} //NS_NEEDS_RESOURCE(this)
|
|
|
|
/**
|
|
* ResourceChainAppend
|
|
* Set |this| to the front of the resource acquisition chain, and link
|
|
* |this| to |aPrev|.
|
|
*
|
|
* *NOT* thread safe. Requires ownership of underlying resource.
|
|
*/
|
|
void ResourceChainAppend(BlockingResourceBase* aPrev)
|
|
{
|
|
mChainPrev = aPrev;
|
|
PR_SetThreadPrivate(sResourceAcqnChainFrontTPI, this);
|
|
} //NS_NEEDS_RESOURCE(this)
|
|
|
|
/**
|
|
* ResourceChainRemove
|
|
* Remove |this| from the front of the resource acquisition chain.
|
|
*
|
|
* *NOT* thread safe. Requires ownership of underlying resource.
|
|
*/
|
|
void ResourceChainRemove()
|
|
{
|
|
NS_ASSERTION(this == ResourceChainFront(), "not at chain front");
|
|
PR_SetThreadPrivate(sResourceAcqnChainFrontTPI, mChainPrev);
|
|
} //NS_NEEDS_RESOURCE(this)
|
|
|
|
/**
|
|
* GetAcquisitionContext
|
|
* Return the calling context from which this resource was acquired,
|
|
* or CallStack::kNone if it's currently free.
|
|
*
|
|
* *NOT* thread safe. Requires ownership of underlying resource.
|
|
*/
|
|
CallStack
|
|
GetAcquisitionContext()
|
|
{
|
|
return mDDEntry->mAcquisitionContext;
|
|
}
|
|
|
|
/**
|
|
* SetAcquisitionContext
|
|
* Set the calling context from which this resource was acquired.
|
|
*
|
|
* *NOT* thread safe. Requires ownership of underlying resource.
|
|
*/
|
|
void
|
|
SetAcquisitionContext(CallStack aAcquisitionContext)
|
|
{
|
|
mDDEntry->mAcquisitionContext = aAcquisitionContext;
|
|
}
|
|
|
|
/**
|
|
* mChainPrev
|
|
* A series of resource acquisitions creates a chain of orders. This
|
|
* chain is implemented as a linked list; |mChainPrev| points to the
|
|
* resource most recently Acquire()'d before this one.
|
|
**/
|
|
BlockingResourceBase* mChainPrev;
|
|
|
|
private:
|
|
/**
|
|
* mDDEntry
|
|
* The key for this BlockingResourceBase in the deadlock detector.
|
|
*/
|
|
DeadlockDetectorEntry* mDDEntry;
|
|
|
|
/**
|
|
* sCallOnce
|
|
* Ensures static members are initialized only once, and in a
|
|
* thread-safe way.
|
|
*/
|
|
static PRCallOnceType sCallOnce;
|
|
|
|
/**
|
|
* sResourceAcqnChainFrontTPI
|
|
* Thread-private index to the front of each thread's resource
|
|
* acquisition chain.
|
|
*/
|
|
static unsigned sResourceAcqnChainFrontTPI;
|
|
|
|
/**
|
|
* sDeadlockDetector
|
|
* Does as named.
|
|
*/
|
|
static DDT* sDeadlockDetector;
|
|
|
|
/**
|
|
* InitStatics
|
|
* Inititialize static members of BlockingResourceBase that can't
|
|
* be statically initialized.
|
|
*
|
|
* *NOT* thread safe.
|
|
*/
|
|
static PRStatus InitStatics() {
|
|
PR_NewThreadPrivateIndex(&sResourceAcqnChainFrontTPI, 0);
|
|
sDeadlockDetector = new DDT();
|
|
if (!sDeadlockDetector)
|
|
NS_RUNTIMEABORT("can't allocate deadlock detector");
|
|
return PR_SUCCESS;
|
|
}
|
|
|
|
/**
|
|
* Shutdown
|
|
* Free static members.
|
|
*
|
|
* *NOT* thread safe.
|
|
*/
|
|
static void Shutdown() {
|
|
delete sDeadlockDetector;
|
|
sDeadlockDetector = 0;
|
|
}
|
|
|
|
# ifdef MOZILLA_INTERNAL_API
|
|
// so it can call BlockingResourceBase::Shutdown()
|
|
friend void LogTerm();
|
|
# endif // ifdef MOZILLA_INTERNAL_API
|
|
|
|
#else // non-DEBUG implementation
|
|
|
|
BlockingResourceBase(const char* aName, BlockingResourceType aType)
|
|
{
|
|
}
|
|
|
|
~BlockingResourceBase()
|
|
{
|
|
}
|
|
|
|
#endif
|
|
};
|
|
|
|
|
|
} // namespace mozilla
|
|
|
|
|
|
#endif // mozilla_BlockingResourceBase_h
|