source: vbox/trunk/src/libs/xpcom18a4/xpcom/components/xcDll.cpp@ 102005

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/* nsDll
 *
 * Abstraction of a Dll. Stores modifiedTime and size for easy detection of
 * change in dll.
 *
 * dp Suresh <[email protected]>
 */

#include "xcDll.h"
#include "nsDebug.h"
#include "nsIComponentManager.h"
#include "nsIComponentLoaderManager.h"
#include "nsIModule.h"
#include "nsILocalFile.h"
#include "nsDirectoryServiceDefs.h"
#include "nsDirectoryServiceUtils.h"
#include "nsCOMPtr.h"
#include "nsCRT.h"
#include "nsString.h"
#include "nsModule.h"
#ifdef DEBUG
#if defined(XP_MACOSX)
#include <signal.h>
#endif
#endif /* defined(DEBUG) */

#include "nsTraceRefcntImpl.h"

#include "nsNativeComponentLoader.h"
#ifdef VBOX_USE_IPRT_IN_XPCOM
# include "nsMemory.h"
#endif

nsDll::nsDll(nsIFile *dllSpec, nsNativeComponentLoader *loader)
    : m_dllSpec(do_QueryInterface(dllSpec)),
      m_hMod(NIL_RTLDRMOD),
      m_moduleObject(NULL),
      m_loader(loader),
      m_markForUnload(PR_FALSE)
{
    NS_ASSERTION(loader, "Null loader when creating a nsDLL");
}

nsDll::~nsDll(void)
{
    /** @todo r=aeichner Does this need fixing at all? */
    //#if DEBUG_dougt
    // The dll gets deleted when the dllStore is destroyed. This happens on
    // app shutdown. At that point, unloading dlls can cause crashes if we have
    // - dll dependencies
    // - callbacks
    // - static dtors
    // Hence turn it back on after all the above have been removed.
    //Unload();
    //#endif
}

void
nsDll::GetDisplayPath(nsACString& aLeafName)
{
    m_dllSpec->GetNativeLeafName(aLeafName);

    if (aLeafName.IsEmpty())
        aLeafName.AssignLiteral("unknown!");
}

PRBool
nsDll::HasChanged()
{
    nsCOMPtr<nsIComponentLoaderManager> manager = do_QueryInterface(m_loader->mCompMgr);
    if (!manager)
        return PR_TRUE;

    // If mod date has changed, then dll has changed
    PRInt64 currentDate;
    nsresult rv = m_dllSpec->GetLastModifiedTime(&currentDate);
    if (NS_FAILED(rv))
        return PR_TRUE;
    PRBool changed = PR_TRUE;
    manager->HasFileChanged(m_dllSpec, nsnull, currentDate, &changed);
    return changed;
}

PRBool nsDll::Load(void)
{
    /* Already loaded? Nothing to do. */
    if (m_hMod != NIL_RTLDRMOD)
        return PR_TRUE;

    if (m_dllSpec)
    {
#ifdef NS_BUILD_REFCNT_LOGGING
        nsTraceRefcntImpl::SetActivityIsLegal(PR_FALSE);
#endif

        // Load any library dependencies
        //   The Component Loader Manager may hold onto some extra data
        //   set by either the native component loader or the native
        //   component.  We assume that this data is a space delimited
        //   listing of dependent libraries which are required to be
        //   loaded prior to us loading the given component.  Once, the
        //   component is loaded into memory, we can release our hold
        //   on the dependent libraries with the assumption that the
        //   component library holds a reference via the OS so loader.
        nsCOMPtr<nsIComponentLoaderManager> manager = do_QueryInterface(m_loader->mCompMgr);
        if (!manager)
            return PR_TRUE;

        nsXPIDLCString extraData;
        manager->GetOptionalData(m_dllSpec, nsnull, getter_Copies(extraData));

        nsVoidArray dependentLibArray;

        // if there was any extra data, treat it as a listing of dependent libs
        if (extraData != nsnull)
        {
            // all dependent libraries are suppose to be in the "gre" directory.
            // note that the gre directory is the same as the "bin" directory,
            // when there isn't a real "gre" found.

            nsXPIDLCString path;
            nsCOMPtr<nsIFile> file;
            NS_GetSpecialDirectory(NS_GRE_DIR, getter_AddRefs(file));

            if (!file)
                return NS_ERROR_FAILURE;

            // we are talking about a file in the GRE dir.  Lets append something
            // stupid right now, so that later we can just set the leaf name.
            file->AppendNative(NS_LITERAL_CSTRING("dummy"));

            char *buffer = (char *)nsMemory::Clone(extraData, strlen(extraData) + 1);
            if (!buffer)
                return NS_ERROR_OUT_OF_MEMORY;

            char* newStr;
            char *token = nsCRT::strtok(buffer, " ", &newStr);
            while (token!=nsnull)
            {
                nsCStringKey key(token);
                if (m_loader->mLoadedDependentLibs.Get(&key)) {
                    token = nsCRT::strtok(newStr, " ", &newStr);
                    continue;
                }

                m_loader->mLoadedDependentLibs.Put(&key, (void*)1);

                nsXPIDLCString libpath;
                file->SetNativeLeafName(nsDependentCString(token));
                file->GetNativePath(path);
                if (!path)
                    return NS_ERROR_FAILURE;

                // Load this dependent library with the global flag and stash
                // the result for later so that we can unload it.
                const char *pszFilename = NULL;

                // if the depend library path starts with a / we are
                // going to assume that it is a full path and should
                // be loaded without prepending the gre diretory
                // location.  We could have short circuited the
                // SetNativeLeafName above, but this is clearer and
                // the common case is a relative path.
                if (token[0] == '/')
                    pszFilename = token;
                else
                    pszFilename = path;

                RTLDRMOD hMod = NIL_RTLDRMOD;
                RTERRINFOSTATIC ErrInfo;
                RTErrInfoInitStatic(&ErrInfo);

                int vrc = RTLdrLoadEx(pszFilename, &hMod, RTLDRLOAD_FLAGS_LOCAL, &ErrInfo.Core);
                // if we couldn't load the dependent library.  We did the best we
                // can.  Now just let us fail later if this really was a required
                // dependency.
                if (RT_SUCCESS(vrc))
                    dependentLibArray.AppendElement((void*)hMod);

                token = nsCRT::strtok(newStr, " ", &newStr);
            }
            nsMemory::Free(buffer);
        }

        // load the component
        nsCOMPtr<nsILocalFile> lf(do_QueryInterface(m_dllSpec));
        NS_ASSERTION(lf, "nsIFile here must implement a nsILocalFile");
        lf->Load(&m_hMod);

        // Unload any of library dependencies we loaded earlier. The assumption
        // here is that the component will have a "internal" reference count to
        // the dependency library we just loaded.
        // XXX should we unload later - or even at all?
        if (extraData != nsnull)
        {
            PRInt32 arrayCount = dependentLibArray.Count();
            for (PRInt32 index = 0; index < arrayCount; index++)
                RTLdrClose((RTLDRMOD)dependentLibArray.ElementAt(index));
        }

#ifdef NS_BUILD_REFCNT_LOGGING
        nsTraceRefcntImpl::SetActivityIsLegal(PR_TRUE);
        if (m_hMod != NIL_RTLDRMOD)
        {
            // Inform refcnt tracer of new library so that calls through the
            // new library can be traced.
            nsXPIDLCString displayPath;
            GetDisplayPath(displayPath);
            nsTraceRefcntImpl::LoadLibrarySymbols(displayPath.get(), m_hMod);
        }
#endif
    }

    return ((m_hMod == NIL_RTLDRMOD) ? PR_FALSE : PR_TRUE);
}

PRBool nsDll::Unload(void)
{
    if (m_hMod == NULL)
        return PR_FALSE;

    // Shutdown the dll
    Shutdown();

#ifdef NS_BUILD_REFCNT_LOGGING
    nsTraceRefcntImpl::SetActivityIsLegal(PR_FALSE);
#endif
    int vrc = RTLdrClose(m_hMod);
#ifdef NS_BUILD_REFCNT_LOGGING
    nsTraceRefcntImpl::SetActivityIsLegal(PR_TRUE);
#endif

    if (RT_SUCCESS(vrc))
    {
        m_hMod = NIL_RTLDRMOD;
        return PR_TRUE;
    }

    return PR_FALSE;
}

void * nsDll::FindSymbol(const char *symbol)
{
    if (symbol == NULL)
        return NULL;

    // If not already loaded, load it now.
    if (Load() != PR_TRUE)
        return NULL;

    void *pvSym = NULL;
    int vrc = RTLdrGetSymbol(m_hMod, symbol, &pvSym);
    RT_NOREF(vrc);

    return pvSym;
}


// Component dll specific functions
nsresult nsDll::GetDllSpec(nsIFile **fsobj)
{
    NS_ASSERTION(m_dllSpec, "m_dllSpec NULL");
    NS_ASSERTION(fsobj, "xcDll::GetModule : Null argument" );

    *fsobj = m_dllSpec;
    NS_ADDREF(*fsobj);
    return NS_OK;
}

nsresult nsDll::GetModule(nsISupports *servMgr, nsIModule **cobj)
{
    // using the backpointer of the loader.
    nsIComponentManager* compMgr = m_loader->mCompMgr;
    NS_ASSERTION(compMgr, "Global Component Manager is null" );
    if (!compMgr) return NS_ERROR_UNEXPECTED;

    NS_ASSERTION(cobj, "xcDll::GetModule : Null argument" );

    if (m_moduleObject)
    {
        NS_ADDREF(m_moduleObject);
        *cobj = m_moduleObject;
        return NS_OK;
    }

    // If not already loaded, load it now.
    if (Load() != PR_TRUE) return NS_ERROR_FAILURE;

    // We need a nsIFile for location
    if (!m_dllSpec)
    {
        return NS_ERROR_FAILURE;
    }

    nsGetModuleProc proc =
      (nsGetModuleProc) FindSymbol(NS_GET_MODULE_SYMBOL);

    if (proc == NULL)
        return NS_ERROR_FACTORY_NOT_LOADED;

    nsresult rv = (*proc) (compMgr, m_dllSpec, &m_moduleObject);
    if (NS_SUCCEEDED(rv))
    {
        NS_ADDREF(m_moduleObject);
        *cobj = m_moduleObject;
    }
    return rv;
}

nsresult nsDll::Shutdown(void)
{
    // Release the module object if we got one
    nsrefcnt refcnt;
    if (m_moduleObject)
    {
        NS_RELEASE2(m_moduleObject, refcnt);
        NS_ASSERTION(refcnt == 0, "Dll moduleObject refcount non zero");
    }

    return NS_OK;

}