// @(#)root/base:$Name: $:$Id: TMapFile.cxx,v 1.10 2002/05/18 08:21:58 brun Exp $
// Author: Fons Rademakers 08/07/97
/*************************************************************************
* Copyright (C) 1995-2000, Rene Brun and Fons Rademakers. *
* All rights reserved. *
* *
* For the licensing terms see $ROOTSYS/LICENSE. *
* For the list of contributors see $ROOTSYS/README/CREDITS. *
*************************************************************************/
#ifdef WIN32
#pragma optimize("",off)
#endif
//////////////////////////////////////////////////////////////////////////
// //
// TMapFile //
// //
// This class implements a shared memory region mapped to a file. //
// Objects can be placed into this shared memory area using the Add() //
// member function. To actually place a copy of the object is shared //
// memory call Update() also whenever the mapped object(s) change(s) //
// call Update() to put a fresh copy in the shared memory. This extra //
// step is necessary since it is not possible to share objects with //
// virtual pointers between processes (the vtbl ptr points to the //
// originators unique address space and can not be used by the //
// consumer process(es)). Consumer processes can map the memory region //
// from this file and access the objects stored in it via the Get() //
// method (which returns a copy of the object stored in the shared //
// memory with correct vtbl ptr set). Only objects of classes with a //
// Streamer() member function defined can be shared. //
// //
// I know the current implementation is not ideal (you need to copy to //
// and from the shared memory file) but the main problem is with the //
// class' virtual_table pointer. This pointer points to a table unique //
// for every process. Therefore, different options are: //
// 1) One could allocate an object directly in shared memory in the //
// producer, but the consumer still has to copy the object from //
// shared memory into a local object which has the correct vtbl //
// pointer for that process (copy ctor's can be used for creating //
// the local copy). //
// 2) Another possibility is to only allow objects without virtual //
// functions in shared memory (like simple C structs), or to //
// forbid (how?) the consumer from calling any virtual functions //
// of the objects in shared memory. //
// 3) A last option is to copy the object internals to shared memory //
// and copy them again from there. This is what is done in the //
// TMapFile (using the object Streamer() to make a deep copy). //
// Option 1) saves one copy, but requires solid copy ctor's (along the //
// full inheritance chain) to rebuild the object in the consumer. Most //
// classes don't provide these copy ctor's, especially not when objects //
// contain collections, etc. 2) is too limiting or dangerous (calling //
// accidentally a virtual function will segv). So since we have a //
// robust Streamer mechanism I opted for 3). //
// //
//////////////////////////////////////////////////////////////////////////
#ifdef WIN32
# include <windows.h>
# include <process.h>
# ifdef GetObject
# undef GetObject
# endif
# define HAVE_SEMOP
# ifdef CreateSemaphore
# undef CreateSemaphore
# endif
# ifdef AcquireSemaphore
# undef AcquireSemaphore;
# endif
# ifdef ReleaseSemaphore
# undef ReleaseSemaphore
# endif
# ifdef DeleteSemaphore
# undef DeleteSemaphore
# endif
#else
# define INVALID_HANDLE_VALUE -1
#endif
#include <fcntl.h>
#include <errno.h>
#include "TMapFile.h"
#include "TKeyMapFile.h"
#include "TDirectory.h"
#include "TBrowser.h"
#include "TString.h"
#include "TSystem.h"
#include "TClass.h"
#include "TMath.h"
#if defined(R__UNIX) && !defined(R__MACOSX)
#define HAVE_SEMOP
#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/sem.h>
#if defined(R__HPUX) || (defined (R__ALPHA) && !defined(R__FBSD)) || \
defined (R__SOLARIS) || defined(R__AIX) || defined(R__HIUX) || \
defined (R__MKLINUX) || __GLIBC_MINOR__ > 0
union semun {
int val; // value for SETVAL
struct semid_ds *buf; // buffer for IPC_STAT & IPC_SET
ushort *array; // array for GETALL & SETALL
};
#endif
#if defined(R__LINUX) || defined(R__LYNXOS) || defined(R__HURD)
# define SEM_A 0200 // alter permission
# define SEM_R 0400 // read permission
#endif
#endif
Long_t TMapFile::fgMapAddress = 0;
void *TMapFile::fgMmallocDesc = 0;
void *gMmallocDesc = 0;
//______________________________________________________________________________
TMapRec::TMapRec(const char *name, const TObject *obj, Int_t size, void *buf)
{
fName = StrDup(name);
fClassName = 0;
fObject = (TObject*)obj;
fBuffer = buf;
fBufSize = size;
fNext = 0;
}
//______________________________________________________________________________
TMapRec::~TMapRec()
{
delete [] fName;
delete [] fClassName;
}
//______________________________________________________________________________
TObject *TMapRec::GetObject() const
{
// This method returns a pointer to the original object. NOTE: this pointer
// is only valid in the process that produces the shared memory file. In a
// consumer process this pointer is illegal! Be careful.
return fObject;
}
ClassImp(TMapFile)
//______________________________________________________________________________
TMapFile::TMapFile()
{
// Default ctor. Does not much except setting some basic values.
fFd = -1;
fMmallocDesc = 0;
fFirst = 0;
}
//______________________________________________________________________________
TMapFile::TMapFile(const char *name, const char *title, Option_t *option,
Int_t size, TMapFile *&newMapFile)
{
// Create a memory mapped file. This opens a file (to which the
// memory will be mapped) and attaches a memory region to it.
// Option can be either: "NEW", "CREATE", "RECREATE", "UPDATE" or
// "READ" (see TFile). The default open mode is "READ". The size
// argument specifies the maximum size of shared memory file in bytes.
// This protected ctor is called via the static Create() method.
#ifndef WIN32
fFd = -1;
fSemaphore = -1;
#else
fFd = (Int_t) INVALID_HANDLE_VALUE;
fSemaphore = (Int_t) INVALID_HANDLE_VALUE;
#endif
fMmallocDesc = 0;
fSize = size;
fFirst = 0;
fOffset = 0;
fVersion = gROOT->GetVersionInt();
fTitle = StrDup(title);
fOption = StrDup(option);
fDirectory = 0;
fBrowseList = 0;
fGetting = 0;
fWritten = 0;
fSumBuffer = 0;
fSum2Buffer = 0;
char *cleanup = 0;
Bool_t create = kFALSE;
Bool_t recreate, update, read;
{
TString opt = option;
if (!opt.CompareTo("NEW", TString::kIgnoreCase) ||
!opt.CompareTo("CREATE", TString::kIgnoreCase))
create = kTRUE;
recreate = opt.CompareTo("RECREATE", TString::kIgnoreCase)
? kFALSE : kTRUE;
update = opt.CompareTo("UPDATE", TString::kIgnoreCase)
? kFALSE : kTRUE;
read = opt.CompareTo("READ", TString::kIgnoreCase)
? kFALSE : kTRUE;
if (!create && !recreate && !update && !read) {
read = kTRUE;
delete [] fOption;
fOption = StrDup("READ");
}
}
const char *fname;
if ((fname = gSystem->ExpandPathName(name))) {
fName = StrDup(fname);
delete [] (char*)fname;
fname = fName;
} else {
Error("TMapFile", "error expanding path %s", fname);
goto zombie;
}
if (recreate) {
if (!gSystem->AccessPathName(fname, kFileExists))
gSystem->Unlink(fname);
recreate = kFALSE;
create = kTRUE;
delete [] fOption;
fOption = StrDup("CREATE");
}
if (create && !gSystem->AccessPathName(fname, kFileExists)) {
Error("TMapFile", "file %s already exists", fname);
goto zombie;
}
if (update) {
if (gSystem->AccessPathName(fname, kFileExists)) {
update = kFALSE;
create = kTRUE;
}
if (update && gSystem->AccessPathName(fname, kWritePermission)) {
Error("TMapFile", "no write permission, could not open file %s", fname);
goto zombie;
}
}
if (read) {
if (gSystem->AccessPathName(fname, kFileExists)) {
Error("TMapFile", "file %s does not exist", fname);
goto zombie;
}
if (gSystem->AccessPathName(fname, kReadPermission)) {
Error("TMapFile", "no read permission, could not open file %s", fname);
goto zombie;
}
}
// Open file to which memory will be mapped
if (create || update) {
#ifndef WIN32
fFd = open(fname, O_RDWR | O_CREAT, 0644);
#else
fFd = (Int_t) CreateFile(fname, // pointer to name of the file
GENERIC_WRITE | GENERIC_READ, // access (read-write) mode
FILE_SHARE_WRITE | FILE_SHARE_READ, // share mode
NULL, // pointer to security attributes
OPEN_ALWAYS, // how to create
FILE_ATTRIBUTE_TEMPORARY, // file attributes
(HANDLE) NULL); // handle to file with attributes to copy
#endif
if (fFd == (Int_t)INVALID_HANDLE_VALUE) {
SysError("TMapFile", "file %s can not be opened", fname);
goto zombie;
}
fWritable = kTRUE;
} else {
#ifndef WIN32
fFd = open(fname, O_RDONLY);
#else
fFd = (Int_t) CreateFile(fname, // pointer to name of the file
GENERIC_READ, // access (read-write) mode
FILE_SHARE_WRITE | FILE_SHARE_READ, // share mode
NULL, // pointer to security attributes
OPEN_EXISTING, // how to create
FILE_ATTRIBUTE_TEMPORARY, // file attributes
(HANDLE) NULL); // handle to file with attributes to copy
#endif
if (fFd == (Int_t)INVALID_HANDLE_VALUE) {
SysError("TMapFile", "file %s can not be opened for reading", fname);
goto zombie;
}
fWritable = kFALSE;
}
// Attach memory region to file.
void *mapto;
TMapFile *mapfil;
if (((mapto = MapToAddress()) == (void *)-1) ||
#ifndef WIN32
((fMmallocDesc = mmalloc_attach(fFd, mapto, fSize)) == 0)) {
#else
((fMmallocDesc = mmalloc_attach((HANDLE) fFd, mapto, fSize)) == 0)) {
#endif
if (mapto == (void *)-1) {
Error("TMapFile", "no memory mapped file capability available\n"
"Use rootn.exe or link application against \"-lNew\"");
} else {
if (fMmallocDesc == 0 && fWritable)
Error("TMapFile", "mapped file not in mmalloc format or\n"
"already open in RW mode by another process");
if (fMmallocDesc == 0 && !fWritable)
Error("TMapFile", "mapped file not in mmalloc format");
}
#ifndef WIN32
close(fFd);
#else
CloseHandle((HANDLE) fFd);
#endif
fFd = -1;
if (create)
gSystem->Unlink(fname);
goto zombie;
} else if ((mapfil = (TMapFile *) mmalloc_getkey(fMmallocDesc, 0)) != 0) {
// File contains mmalloc heap. If we are in write mode and mapped
// file already connected in write mode switch to read-only mode.
// Check if ROOT versions are compatible.
// If so update mapped version of TMapFile to reflect current
// situation (only if not opened in READ mode).
if (mapfil->fVersion != fVersion) {
Error("TMapFile", "map file %s (%d) incompatible with current ROOT version (%d)",
fname, mapfil->fVersion, fVersion);
mmalloc_detach(fMmallocDesc);
#ifndef WIN32
close(fFd);
#else
CloseHandle((HANDLE) fFd);
#endif
fFd = -1;
fMmallocDesc = 0;
goto zombie;
}
if (mapfil->fWritable && fWritable) {
Warning("TMapFile", "map file already open in write mode, opening in read-only mode");
fWritable = kFALSE;
}
fBaseAddr = mapfil->fBaseAddr;
fSize = mapfil->fSize;
if (fWritable) {
// create new TMapFile object in mapped heap to get correct vtbl ptr
CreateSemaphore();
gMmallocDesc = fMmallocDesc;
TMapFile *mf = new TMapFile(*mapfil);
mf->fFd = fFd;
mf->fWritable = kTRUE;
cleanup = mf->fOption;
mf->fOption = StrDup(fOption);
mf->fSemaphore = fSemaphore;
#ifdef WIN32
mf->CreateSemaphore(fSemaphore);
#endif
mmalloc_setkey(fMmallocDesc, 0, mf);
gMmallocDesc = 0;
mapfil = mf;
} else {
gMmallocDesc = 0; // make sure we are in sbrk heap
fOffset = ((struct mdesc *) fMmallocDesc)->offset;
TMapFile *mf = new TMapFile(*mapfil, fOffset);
delete [] mf->fOption;
mf->fFd = fFd;
mf->fOption = StrDup("READ");
mf->fMmallocDesc = fMmallocDesc;
mf->fWritable = kFALSE;
mapfil = mf;
}
// store shadow mapfile (it contains the real fFd in case map
// is not writable)
fVersion = -1; // make this the shadow map file
gROOT->GetListOfMappedFiles()->AddLast(this);
} else {
// New file. If the file is writable create a new copy of the
// TMapFile which will now be allocated on the memory mapped heap.
if (!fWritable) {
Error("TMapFile", "map file is not writable");
mmalloc_detach(fMmallocDesc);
#ifndef WIN32
close(fFd);
#else
CloseHandle((HANDLE) fFd);
#endif
fFd = -1;
fMmallocDesc = 0;
goto zombie;
}
fBaseAddr = (ULong_t)((struct mdesc *) fMmallocDesc)->base;
CreateSemaphore();
gMmallocDesc = fMmallocDesc;
mapfil = new TMapFile(*this);
mmalloc_setkey(fMmallocDesc, 0, mapfil);
gMmallocDesc = 0;
// store shadow mapfile
fVersion = -1; // make this the shadow map file
gROOT->GetListOfMappedFiles()->AddLast(this);
}
mapfil->InitDirectory();
gROOT->GetListOfMappedFiles()->AddFirst(mapfil);
delete [] cleanup;
newMapFile = mapfil;
return;
zombie:
// error in file opening occured, make this object a zombie
MakeZombie();
newMapFile = this;
gMmallocDesc = 0;
}
//______________________________________________________________________________
TMapFile::TMapFile(const TMapFile &f, Long_t offset) : TObject(f)
{
// Private copy ctor. Used by the the ctor to create a new version
// of TMapFile in the memory mapped heap. It's main purpose is to
// correctly create the string data members.
fFd = f.fFd;
fVersion = f.fVersion;
fName = StrDup((char *)((long)f.fName + offset));
fTitle = StrDup((char *)((long)f.fTitle + offset));
fOption = StrDup((char *)((long)f.fOption + offset));
fMmallocDesc = f.fMmallocDesc;
fBaseAddr = f.fBaseAddr;
fSize = f.fSize;
fFirst = f.fFirst;
fLast = f.fLast;
fWritable = f.fWritable;
fSemaphore = f.fSemaphore;
fOffset = offset;
fDirectory = 0;
fBrowseList = 0;
fGetting = 0;
fWritten = f.fWritten;
fSumBuffer = f.fSumBuffer;
fSum2Buffer = f.fSum2Buffer;
#ifdef WIN32
CreateSemaphore(fSemaphore);
#endif
}
//______________________________________________________________________________
TMapFile::~TMapFile()
{
// TMapFiles may not be deleted, since we want to keep the complete
// TMapFile object in the mapped file for later re-use. To enforce this
// the delete operator has been made private. Use Close() to properly
// terminate a TMapFile (also done via the TROOT dtor).
if (fDirectory == gDirectory) gDirectory = gROOT;
delete fDirectory; fDirectory = 0;
if (fBrowseList) fBrowseList->Delete();
delete fBrowseList; fBrowseList = 0;
// if shadow map file we are done here
if (fVersion == -1)
return;
// Writable mapfile is allocated in mapped memory. This object should
// not be deleted by ::operator delete(), because it is needed if we
// want to connect later to the file again.
if (fWritable)
TObject::SetDtorOnly(this);
Close("dtor");
fgMmallocDesc = fMmallocDesc;
}
//______________________________________________________________________________
void TMapFile::InitDirectory()
{
// Create the directory associated to this mapfile
gDirectory = 0;
fDirectory = new TDirectory();
fDirectory->SetName(GetName());
fDirectory->SetTitle(GetTitle());
fDirectory->Build();
fDirectory->SetMother(this);
gDirectory = fDirectory;
}
//______________________________________________________________________________
void TMapFile::Add(const TObject *obj, const char *name)
{
// Add an object to the list of objects to be stored in shared memory.
// To place the object actually into shared memory call Update().
if (!fWritable || !fMmallocDesc) return;
Bool_t lock = fGetting != obj ? kTRUE : kFALSE;
if (lock)
AcquireSemaphore();
gMmallocDesc = fMmallocDesc;
const char *n;
if (name && *name)
n = name;
else
n = obj->GetName();
if (Remove(n, kFALSE))
; //Warning("Add", "replaced object with same name %s", n);
TMapRec *mr = new TMapRec(n, obj, 0, 0);
if (!fFirst) {
fFirst = mr;
fLast = mr;
} else {
fLast->fNext = mr;
fLast = mr;
}
gMmallocDesc = 0;
if (lock)
ReleaseSemaphore();
}
//______________________________________________________________________________
void TMapFile::Update(TObject *obj)
{
// Update an object (or all objects, if obj == 0) in shared memory.
if (!fWritable || !fMmallocDesc) return;
AcquireSemaphore();
gMmallocDesc = fMmallocDesc;
Bool_t all = (obj == 0) ? kTRUE : kFALSE;
TMapRec *mr = fFirst;
while (mr) {
if (all || mr->fObject == obj) {
TBuffer *b;
if (!mr->fBufSize) {
b = new TBuffer(TBuffer::kWrite, GetBestBuffer());
mr->fClassName = StrDup(mr->fObject->ClassName());
} else
b = new TBuffer(TBuffer::kWrite, mr->fBufSize, mr->fBuffer);
b->MapObject(mr->fObject); //register obj in map to handle self reference
mr->fObject->Streamer(*b);
mr->fBufSize = b->BufferSize();
mr->fBuffer = b->Buffer();
SumBuffer(b->Length());
b->DetachBuffer();
delete b;
}
mr = mr->fNext;
}
gMmallocDesc = 0;
ReleaseSemaphore();
}
//______________________________________________________________________________
TObject *TMapFile::Remove(TObject *obj, Bool_t lock)
{
// Remove object from shared memory. Returns pointer to removed
// object if successful, 0 otherwise.
if (!fWritable || !fMmallocDesc) return 0;
if (lock)
AcquireSemaphore();
TObject *retObj = 0;
TMapRec *prev = 0, *mr = fFirst;
while (mr) {
if (mr->fObject == obj) {
if (mr == fFirst) {
fFirst = mr->fNext;
if (mr == fLast)
fLast = 0;
} else {
prev->fNext = mr->fNext;
if (mr == fLast)
fLast = prev;
}
retObj = obj;
delete mr;
break;
}
prev = mr;
mr = mr->fNext;
}
if (lock)
ReleaseSemaphore();
return retObj;
}
//______________________________________________________________________________
TObject *TMapFile::Remove(const char *name, Bool_t lock)
{
// Remove object by name from shared memory. Returns pointer to removed
// object if successful, 0 otherwise.
if (!fWritable || !fMmallocDesc) return 0;
if (lock)
AcquireSemaphore();
TObject *retObj = 0;
TMapRec *prev = 0, *mr = fFirst;
while (mr) {
if (!strcmp(mr->fName, name)) {
if (mr == fFirst) {
fFirst = mr->fNext;
if (mr == fLast)
fLast = 0;
} else {
prev->fNext = mr->fNext;
if (mr == fLast)
fLast = prev;
}
retObj = mr->fObject;
delete mr;
break;
}
prev = mr;
mr = mr->fNext;
}
if (lock)
ReleaseSemaphore();
return retObj;
}
//______________________________________________________________________________
void TMapFile::RemoveAll()
{
// Remove all objects from shared memory.
if (!fWritable || !fMmallocDesc) return;
AcquireSemaphore();
TMapRec *mr = fFirst;
while (mr) {
TMapRec *t = mr;
mr = mr->fNext;
delete t;
}
fFirst = fLast = 0;
ReleaseSemaphore();
}
//______________________________________________________________________________
TObject *TMapFile::Get(const char *name, TObject *delObj)
{
// Return pointer to object retrieved from shared memory. The object must
// be deleted after use. If delObj is a pointer to a previously allocated
// object it will be deleted. Returns 0 in case object with the given
// name does not exist.
if (!fMmallocDesc) return 0;
AcquireSemaphore();
delete delObj;
TObject *obj = 0;
TMapRec *mr = GetFirst();
while (OrgAddress(mr)) {
if (!strcmp(mr->GetName(fOffset), name)) {
if (!mr->fBufSize) goto release;
TClass *cl = gROOT->GetClass(mr->GetClassName(fOffset));
if (!cl) {
Error("Get", "unknown class %s", mr->GetClassName(fOffset));
goto release;
}
obj = (TObject *)cl->New();
if (!obj) {
Error("Get", "cannot create new object of class %s", mr->GetClassName(fOffset));
goto release;
}
fGetting = obj;
TBuffer *b = new TBuffer(TBuffer::kRead, mr->fBufSize, mr->GetBuffer(fOffset));
b->MapObject(obj); //register obj in map to handle self reference
obj->Streamer(*b);
b->DetachBuffer();
delete b;
fGetting = 0;
goto release;
}
mr = mr->GetNext(fOffset);
}
release:
ReleaseSemaphore();
return obj;
}
//______________________________________________________________________________
#ifndef WIN32
void TMapFile::CreateSemaphore(int)
#else
void TMapFile::CreateSemaphore(int pid)
#endif
{
// Create semaphore used for synchronizing access to shared memory.
#ifdef HAVE_SEMOP
#ifndef WIN32
// create semaphore to synchronize access (should use read/write lock)
fSemaphore = semget(IPC_PRIVATE, 1, SEM_R|SEM_A|(SEM_R>>3)|(SEM_A>>3)|
(SEM_R>>6)|(SEM_A>>6));
// set semaphore to 1
if (fSemaphore != -1) {
union semun set;
set.val = 1;
semctl(fSemaphore, 0, SETVAL, set);
}
#else
char buffer[] ="ROOT_Semaphore_xxxxxxxx";
int lbuf = strlen(buffer);
if (!pid) fSemaphore = getpid();
fhSemaphore = (ULong_t)CreateMutex(NULL,FALSE,itoa(fSemaphore,&buffer[lbuf-8],16));
if (fhSemaphore == 0) fSemaphore = (Int_t)INVALID_HANDLE_VALUE;
#endif
#endif
}
//______________________________________________________________________________
void TMapFile::DeleteSemaphore()
{
// Delete the semaphore.
#ifdef HAVE_SEMOP
// remove semaphore
#ifndef WIN32
if (fSemaphore != -1) {
int semid = fSemaphore;
fSemaphore = -1;
union semun set;
set.val = 0;
semctl(semid, 0, IPC_RMID, set);
}
#else
if (fSemaphore != (Int_t)INVALID_HANDLE_VALUE) {
CloseHandle((HANDLE)fhSemaphore);
fhSemaphore = 0;
fSemaphore = (Int_t)INVALID_HANDLE_VALUE;
}
#endif
#endif
}
//______________________________________________________________________________
Int_t TMapFile::AcquireSemaphore()
{
// Acquire semaphore. Returns 0 if OK, -1 on error.
#ifdef HAVE_SEMOP
#ifndef WIN32
if (fSemaphore != -1) {
struct sembuf buf = { 0, -1, SEM_UNDO };
int intr = 0;
again:
if (semop(fSemaphore, &buf, 1) == -1) {
#if defined(R__FBSD)
if (TSystem::GetErrno() == EINVAL)
#else
if (TSystem::GetErrno() == EIDRM)
#endif
fSemaphore = -1;
#if !defined(R__FBSD)
if (TSystem::GetErrno() == EINTR) {
if (intr > 2)
return -1;
TSystem::ResetErrno();
intr++;
goto again;
}
#endif
}
}
#else
// Enter Critical section to "write" lock
if (fSemaphore != (Int_t)INVALID_HANDLE_VALUE)
WaitForSingleObject((HANDLE)fhSemaphore,INFINITE);
#endif
#endif
// file might have grown, update mapping on reader to new size
if (!fWritable && fMmallocDesc) {
if (mmalloc_update_mapping(fMmallocDesc) == -1)
Error("AcquireSemaphore", "cannot update mapping");
}
return 0;
}
//______________________________________________________________________________
Int_t TMapFile::ReleaseSemaphore()
{
// Release semaphore. Returns 0 if OK, -1 on error.
#ifdef HAVE_SEMOP
#ifndef WIN32
if (fSemaphore != -1) {
struct sembuf buf = { 0, 1, SEM_UNDO };
if (semop(fSemaphore, &buf, 1) == -1) {
#if defined(R__FBSD)
if (TSystem::GetErrno() == EINVAL)
#else
if (TSystem::GetErrno() == EIDRM)
#endif
fSemaphore = -1;
}
}
#else
if (fSemaphore != (Int_t)INVALID_HANDLE_VALUE)
ReleaseMutex((HANDLE)fhSemaphore);
#endif
#endif
return 0;
}
//______________________________________________________________________________
void TMapFile::Close(Option_t *option)
{
// Close a mapped file. First detach mapped memory then close file.
// No member functions of a TMapFile that was opened in write mode
// may be called after Close() (this includes, of course, "delete" which
// would call the dtors). The option="dtor" is only used when called
// via the ~TMapFile.
if (!fMmallocDesc) return;
TMapFile *shadow = FindShadowMapFile();
if (!shadow) {
Error("Close", "shadow map == 0, should never happen!");
return;
}
gROOT->GetListOfMappedFiles()->Remove(shadow);
gROOT->GetListOfMappedFiles()->Remove(this);
if (shadow->fWritable) {
fWritable = kFALSE;
DeleteSemaphore();
}
if (fMmallocDesc) {
if (strcmp(option, "dtor"))
mmalloc_detach(fMmallocDesc);
// If writable cannot access fMmallocDesc anymore since
// it points to the just unmapped memory region. Any further
// access to this TMapFile will cause a crash.
if (!shadow->fWritable)
fMmallocDesc = 0;
}
if (shadow->fFd != -1)
#ifndef WIN32
close(shadow->fFd);
#else
CloseHandle((HANDLE)shadow->fFd);
#endif
delete shadow;
}
//______________________________________________________________________________
TMapFile *TMapFile::FindShadowMapFile()
{
// Returns shadow map file.
TObjLink *lnk = ((TList *)gROOT->GetListOfMappedFiles())->LastLink();
while (lnk) {
TMapFile *mf = (TMapFile*)lnk->GetObject();
if (mf->fVersion == -1 && fBaseAddr == mf->fBaseAddr && fSize == mf->fSize)
return mf;
lnk = lnk->Prev();
}
return 0;
}
//______________________________________________________________________________
void TMapFile::Print(Option_t *) const
{
// Print some info about the mapped file.
Printf("Memory mapped file: %s", fName);
Printf("Title: %s", fTitle);
if (fMmallocDesc) {
Printf("Option: %s", fOption);
ULong_t size = (ULong_t)((struct mdesc *)fMmallocDesc)->top - fBaseAddr;
Printf("Mapped Memory region: 0x%lx - 0x%lx (%.2f MB)", fBaseAddr, fBaseAddr + size,
(float)size/1048576);
Printf("Current breakval: 0x%lx", (ULong_t)GetBreakval());
} else
Printf("Option: file closed");
}
//______________________________________________________________________________
Bool_t TMapFile::IsFolder() const
{
// Returns kTRUE in case object is a folder (i.e. contains browsable lists).
if (fMmallocDesc && fVersion > 0) return kTRUE;
return kFALSE;
}
//______________________________________________________________________________
void TMapFile::Browse(TBrowser *b)
{
// Browse contents of TMapFile.
if (b && fMmallocDesc) {
AcquireSemaphore();
TMapRec *mr = GetFirst();
TKeyMapFile *keymap;
if (!fBrowseList) fBrowseList = new TList();
while (OrgAddress(mr)) {
keymap = (TKeyMapFile*)fBrowseList->FindObject(mr->GetName(fOffset));
if (!keymap) {
keymap = new TKeyMapFile(mr->GetName(fOffset),mr->GetClassName(fOffset),this);
fBrowseList->Add(keymap);
}
b->Add(keymap, keymap->GetName());
mr = mr->GetNext(fOffset);
}
ReleaseSemaphore();
}
}
//______________________________________________________________________________
Bool_t TMapFile::cd(const char *path)
{
// Cd to associated directory,
if (fDirectory)
return fDirectory->cd(path);
return kFALSE;
}
//______________________________________________________________________________
void TMapFile::ls(Option_t *) const
{
// List contents of TMapFile.
if (fMmallocDesc) {
((TMapFile*)this)->AcquireSemaphore();
Printf("%-20s %-20s %-10s", "Object", "Class", "Size");
if (!fFirst)
Printf("*** no objects stored in memory mapped file ***");
TMapRec *mr = GetFirst();
while (OrgAddress(mr)) {
Printf("%-20s %-20s %-10d", mr->GetName(fOffset),
mr->GetClassName(fOffset), mr->fBufSize);
mr = mr->GetNext(fOffset);
}
((TMapFile*)this)->ReleaseSemaphore();
}
}
//_______________________________________________________________________
void TMapFile::SumBuffer(Int_t bufsize)
{
// Increment statistics for buffer sizes of objects in this file.
fWritten++;
fSumBuffer += bufsize;
fSum2Buffer += bufsize*bufsize;
}
//______________________________________________________________________________
Int_t TMapFile::GetBestBuffer()
{
// Return the best buffer size for objects in this file.
//
// The best buffer size is estimated based on the current mean value
// and standard deviation of all objects written so far to this file.
// Returns mean value + one standard deviation.
if (!fWritten) return TBuffer::kMinimalSize;
Double_t mean = fSumBuffer/fWritten;
Double_t rms2 = TMath::Abs(fSum2Buffer/fSumBuffer - mean*mean);
return (Int_t)(mean + TMath::Sqrt(rms2));
}
//______________________________________________________________________________
TMapFile *TMapFile::Create(const char *name, Option_t *option, Int_t size,
const char *title)
{
// Create a memory mapped file. This opens a file (to which the
// memory will be mapped) and attaches a memory region to it.
// Option can be either: "NEW", "CREATE", "RECREATE", "UPDATE"
// or "READ" (see TFile). The default open mode is "READ". The size
// argument specifies the maximum size of shared memory file in bytes.
// TMapFile's can only be created via this method. Create() enforces that
// a TMapFile is always on the memory mapped heap (when "NEW", "CREATE"
// or "RECREATE" are used).
TMapFile *newMapFile;
new TMapFile(name, title, option, size, newMapFile);
return newMapFile;
}
//______________________________________________________________________________
void TMapFile::SetMapAddress(Long_t addr)
{
// Set preferred map address. Find out preferred map address as follows:
// 1) Run consumer program to find the preferred map address:
// $ root
// root [0] m = TMapFile::Create("dummy.map", "recreate", 10000000);
// root [1] m.Print()
// Memory mapped file: dummy.map
// Title:
// Option: CREATE
// Mapped Memory region: 0x40b4c000 - 0x40d95f00 (2.29 MB)
// Current breakval: 0x40b53000
// root [2] .q
// $ rm dummy.map
// Remember begin of mapped region, i.e. 0x40b4c000
//
// 2) Add to producer program, just before creating the TMapFile:
// TMapFile::SetMapAddress(0x40b4c000);
//
// Repeat this if more than one map file is being used.
//
// The above procedure allow programs using, e.g., different number of
// shared libraries (that cause the default mapping address to be
// different) to create shared memory regions in the same location
// without overwriting a shared library. The above assumes the consumer
// program is larger (i.e. has more shared memory occupied) than the
// producer. If this is not true inverse the procedure.
fgMapAddress = addr;
}
//______________________________________________________________________________
void *TMapFile::MapToAddress()
{
// Return the base address at which we would like the next TMapFile's
// mapped data to start.
//
// For now, we let the system decide (start address 0). There are
// a lot of issues to deal with here to make this work reasonably,
// including:
//
// - Avoid memory collisions with existing mapped address spaces
//
// - Reclaim address spaces when their mmalloc heaps are unmapped
//
// - When mmalloc heaps are shared between processes they have to be
// mapped at the same addresses in each
//
// Once created, a mmalloc heap that is to be mapped back in must be
// mapped at the original address. I.E. each TMapFile will expect
// to be remapped at it's original address. This becomes a problem if
// the desired address is already in use.
#ifdef HAVE_MMAP
if (TStorage::HasCustomNewDelete())
return (void *)fgMapAddress;
else
return (void *)-1;
#else
return (void *)-1;
#endif
}
//______________________________________________________________________________
void TMapFile::operator delete(void *ptr)
{
// Need special "operator delete" in which we close the shared memory.
// This has to be done after the dtor chain has been finished.
mmalloc_detach(fgMmallocDesc);
fgMmallocDesc = 0;
TObject::operator delete(ptr);
}
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