michael@0: /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
michael@0: /* vim:set ts=2 sw=2 sts=2 ci et: */
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #include "mozilla/Mutex.h"
michael@0: #include "mozilla/Scoped.h"
michael@0: 
michael@0: #include <algorithm>
michael@0: #include <vector>
michael@0: 
michael@0: #include "PoisonIOInterposer.h"
michael@0: 
michael@0: // Auxiliary method to convert file descriptors to ids
michael@0: #if defined(XP_WIN32)
michael@0: #include <io.h>
michael@0: inline intptr_t FileDescriptorToID(int aFd) {
michael@0:   return _get_osfhandle(aFd);
michael@0: }
michael@0: #else
michael@0: inline intptr_t FileDescriptorToID(int aFd) {
michael@0:   return aFd;
michael@0: }
michael@0: #endif /* if not XP_WIN32 */
michael@0: 
michael@0: using namespace mozilla;
michael@0: 
michael@0: namespace {
michael@0: struct DebugFilesAutoLockTraits {
michael@0:   typedef PRLock *type;
michael@0:   const static type empty() {
michael@0:     return nullptr;
michael@0:   }
michael@0:   const static void release(type aL) {
michael@0:     PR_Unlock(aL);
michael@0:   }
michael@0: };
michael@0: 
michael@0: class DebugFilesAutoLock : public Scoped<DebugFilesAutoLockTraits> {
michael@0:   static PRLock *Lock;
michael@0: public:
michael@0:   static void Clear();
michael@0:   static PRLock *getDebugFileIDsLock() {
michael@0:     // On windows this static is not thread safe, but we know that the first
michael@0:     // call is from
michael@0:     // * An early registration of a debug FD or
michael@0:     // * The call to InitWritePoisoning.
michael@0:     // Since the early debug FDs are logs created early in the main thread
michael@0:     // and no writes are trapped before InitWritePoisoning, we are safe.
michael@0:     if (!Lock) {
michael@0:       Lock = PR_NewLock();
michael@0:     }
michael@0: 
michael@0:     // We have to use something lower level than a mutex. If we don't, we
michael@0:     // can get recursive in here when called from logging a call to free.
michael@0:     return Lock;
michael@0:   }
michael@0: 
michael@0:   DebugFilesAutoLock() :
michael@0:     Scoped<DebugFilesAutoLockTraits>(getDebugFileIDsLock()) {
michael@0:     PR_Lock(get());
michael@0:   }
michael@0: };
michael@0: 
michael@0: PRLock *DebugFilesAutoLock::Lock;
michael@0: void DebugFilesAutoLock::Clear() {
michael@0:   MOZ_ASSERT(Lock != nullptr);
michael@0:   Lock = nullptr;
michael@0: }
michael@0: 
michael@0: // Return a vector used to hold the IDs of the current debug files. On unix
michael@0: // an ID is a file descriptor. On Windows it is a file HANDLE.
michael@0: std::vector<intptr_t>* getDebugFileIDs() {
michael@0:   PR_ASSERT_CURRENT_THREAD_OWNS_LOCK(DebugFilesAutoLock::getDebugFileIDsLock());
michael@0:   // We have to use new as some write happen during static destructors
michael@0:   // so an static std::vector might be destroyed while we still need it.
michael@0:   static std::vector<intptr_t> *DebugFileIDs = new std::vector<intptr_t>();
michael@0:   return DebugFileIDs;
michael@0: }
michael@0: 
michael@0: } // anonymous namespace
michael@0: 
michael@0: namespace mozilla{
michael@0: 
michael@0: // Auxiliary Method to test if a file descriptor is registered to be ignored
michael@0: // by the poisoning IO interposer
michael@0: bool IsDebugFile(intptr_t aFileID) {
michael@0:   DebugFilesAutoLock lockedScope;
michael@0: 
michael@0:   std::vector<intptr_t> &Vec = *getDebugFileIDs();
michael@0:   return std::find(Vec.begin(), Vec.end(), aFileID) != Vec.end();
michael@0: }
michael@0: 
michael@0: // Clean-up for the registered debug files.
michael@0: // We should probably make sure all debug files are unregistered instead.
michael@0: // But as the poison IO interposer is used for late-write checks we're not
michael@0: // disabling it at any point yet. So Really no need for this.
michael@0: //
michael@0: // void ClearDebugFileRegister() {
michael@0: //   PRLock *Lock;
michael@0: //   {
michael@0: //     DebugFilesAutoLock lockedScope;
michael@0: //     delete getDebugFileIDs();
michael@0: //     Lock = DebugFilesAutoLock::getDebugFileIDsLock();
michael@0: //     DebugFilesAutoLock::Clear();
michael@0: //   }
michael@0: //   PR_DestroyLock(Lock);
michael@0: // }
michael@0: 
michael@0: } // namespace mozilla
michael@0: 
michael@0: extern "C" {
michael@0: 
michael@0:   void MozillaRegisterDebugFD(int fd) {
michael@0:     intptr_t fileId = FileDescriptorToID(fd);
michael@0:     DebugFilesAutoLock lockedScope;
michael@0:     std::vector<intptr_t> &Vec = *getDebugFileIDs();
michael@0:     MOZ_ASSERT(std::find(Vec.begin(), Vec.end(), fileId) == Vec.end());
michael@0:     Vec.push_back(fileId);
michael@0:   }
michael@0: 
michael@0:   void MozillaRegisterDebugFILE(FILE *f) {
michael@0:     int fd = fileno(f);
michael@0:     if (fd == 1 || fd == 2) {
michael@0:       return;
michael@0:     }
michael@0:     MozillaRegisterDebugFD(fd);
michael@0:   }
michael@0: 
michael@0:   void MozillaUnRegisterDebugFD(int fd) {
michael@0:     DebugFilesAutoLock lockedScope;
michael@0:     intptr_t fileId = FileDescriptorToID(fd);
michael@0:     std::vector<intptr_t> &Vec = *getDebugFileIDs();
michael@0:     std::vector<intptr_t>::iterator i =
michael@0:       std::find(Vec.begin(), Vec.end(), fileId);
michael@0:     MOZ_ASSERT(i != Vec.end());
michael@0:     Vec.erase(i);
michael@0:   }
michael@0: 
michael@0:   void MozillaUnRegisterDebugFILE(FILE *f) {
michael@0:     int fd = fileno(f);
michael@0:     if (fd == 1 || fd == 2) {
michael@0:       return;
michael@0:     }
michael@0:     fflush(f);
michael@0:     MozillaUnRegisterDebugFD(fd);
michael@0:   }
michael@0: 
michael@0: }