dlls/ole32/git.c

   1 /*
   2  * Implementation of the StdGlobalInterfaceTable object
   3  *
   4  * The GlobalInterfaceTable (GIT) object is used to marshal interfaces between
   5  * threading apartments (contexts). When you want to pass an interface but not
   6  * as a parameter, it wouldn't get marshalled automatically, so you can use this
   7  * object to insert the interface into a table, and you get back a cookie.
   8  * Then when it's retrieved, it'll be unmarshalled into the right apartment.
   9  *
  10  * Copyright 2003 Mike Hearn <mike@theoretic.com>
  11  *
  12  * This library is free software; you can redistribute it and/or
  13  * modify it under the terms of the GNU Lesser General Public
  14  * License as published by the Free Software Foundation; either
  15  * version 2.1 of the License, or (at your option) any later version.
  16  *
  17  * This library is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  20  * Lesser General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU Lesser General Public
  23  * License along with this library; if not, write to the Free Software
  24  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  25  */
  26
  27 #include "config.h"
  28
  29 #include <assert.h>
  30 #include <stdlib.h>
  31 #include <stdio.h>
  32 #include <string.h>
  33
  34 #include "windef.h"
  35 #include "objbase.h"
  36 #include "ole2.h"
  37 #include "winbase.h"
  38 #include "winerror.h"
  39 #include "winternl.h"
  40
  41 #include "compobj_private.h"
  42
  43 #include "wine/debug.h"
  44
  45 WINE_DEFAULT_DEBUG_CHANNEL(ole);
  46
  47 /****************************************************************************
  48  * StdGlobalInterfaceTable definition
  49  *
  50  * This class implements IGlobalInterfaceTable and is a process-wide singleton
  51  * used for marshalling interfaces between threading apartments using cookies.
  52  */
  53
  54 /* Each entry in the linked list of GIT entries */
  55 typedef struct StdGITEntry
  56 {
  57   DWORD cookie;
  58   IID iid;      /* IID of the interface */
  59   IStream* stream; /* Holds the marshalled interface */
  60
  61   struct StdGITEntry* next;
  62   struct StdGITEntry* prev;
  63 } StdGITEntry;
  64
  65 /* Class data */
  66 typedef struct StdGlobalInterfaceTableImpl
  67 {
  68   ICOM_VFIELD(IGlobalInterfaceTable);
  69
  70   ULONG ref;
  71   struct StdGITEntry* firstEntry;
  72   struct StdGITEntry* lastEntry;
  73   ULONG nextCookie;
  74
  75 } StdGlobalInterfaceTableImpl;
  76
  77
  78 /* IUnknown */
  79 static HRESULT WINAPI StdGlobalInterfaceTable_QueryInterface(IGlobalInterfaceTable* iface, REFIID riid, void** ppvObject);
  80 static ULONG   WINAPI StdGlobalInterfaceTable_AddRef(IGlobalInterfaceTable* iface);
  81 static ULONG   WINAPI StdGlobalInterfaceTable_Release(IGlobalInterfaceTable* iface);
  82 /* IGlobalInterfaceTable */
  83 static HRESULT WINAPI StdGlobalInterfaceTable_RegisterInterfaceInGlobal(IGlobalInterfaceTable* iface, IUnknown* pUnk, REFIID riid, DWORD* pdwCookie);
  84 static HRESULT WINAPI StdGlobalInterfaceTable_RevokeInterfaceFromGlobal(IGlobalInterfaceTable* iface, DWORD dwCookie);
  85 static HRESULT WINAPI StdGlobalInterfaceTable_GetInterfaceFromGlobal(IGlobalInterfaceTable* iface, DWORD dwCookie, REFIID riid, void **ppv);
  86
  87 /* Virtual function table */
  88 static ICOM_VTABLE(IGlobalInterfaceTable) StdGlobalInterfaceTableImpl_Vtbl =
  89 {
  90   ICOM_MSVTABLE_COMPAT_DummyRTTIVALUE
  91   StdGlobalInterfaceTable_QueryInterface,
  92   StdGlobalInterfaceTable_AddRef,
  93   StdGlobalInterfaceTable_Release,
  94   StdGlobalInterfaceTable_RegisterInterfaceInGlobal,
  95   StdGlobalInterfaceTable_RevokeInterfaceFromGlobal,
  96   StdGlobalInterfaceTable_GetInterfaceFromGlobal
  97 };
  98
  99 /***
 100  * Let's go! Here is the constructor and destructor for the class.
 101  *
 102  */
 103
 104 /** This function constructs the GIT. It should only be called once **/
 105 void* StdGlobalInterfaceTable_Construct() {
 106   StdGlobalInterfaceTableImpl* newGIT;
 107
 108   newGIT = HeapAlloc(GetProcessHeap(), 0, sizeof(StdGlobalInterfaceTableImpl));
 109   if (newGIT == 0) return newGIT;
 110
 111   newGIT->lpVtbl = &StdGlobalInterfaceTableImpl_Vtbl;
 112   newGIT->ref = 0;      /* Initialise the reference count */
 113   newGIT->firstEntry = NULL; /* we start with an empty table   */
 114   newGIT->lastEntry  = NULL;
 115   newGIT->nextCookie = 0xf100; /* that's where windows starts, so that's where we start */
 116   TRACE("Created the GIT at %p\n", newGIT);
 117
 118   return (void*)newGIT;
 119 }
 120
 121 /** This destroys it again. It should revoke all the held interfaces first **/
 122 void StdGlobalInterfaceTable_Destroy(void* self) {
 123   TRACE("(%p)\n", self);
 124   FIXME("Revoke held interfaces here\n");
 125
 126   HeapFree(GetProcessHeap(), 0, self);
 127 }
 128
 129 /***
 130  * A helper function to traverse the list and find the entry that matches the cookie.
 131  * Returns NULL if not found
 132  */
 133 StdGITEntry* StdGlobalInterfaceTable_FindEntry(IGlobalInterfaceTable* iface, DWORD cookie) {
 134   StdGlobalInterfaceTableImpl* const self = (StdGlobalInterfaceTableImpl*) iface;
 135   StdGITEntry* e;
 136
 137   TRACE("iface=%p, cookie=0x%x\n", iface, (UINT)cookie);
 138
 139   e = self->firstEntry;
 140   while (e != NULL) {
 141     if (e->cookie == cookie) return e;
 142     e = e->next;
 143   }
 144   return NULL;
 145 }
 146
 147 /***
 148  * Here's the boring boilerplate stuff for IUnknown
 149  */
 150
 151 HRESULT WINAPI StdGlobalInterfaceTable_QueryInterface(IGlobalInterfaceTable* iface, REFIID riid, void** ppvObject) {
 152   StdGlobalInterfaceTableImpl* const self = (StdGlobalInterfaceTableImpl*) iface;
 153
 154   /* Make sure silly coders can't crash us */
 155   if (ppvObject == 0) return E_INVALIDARG;
 156
 157   *ppvObject = 0; /* assume we don't have the interface */
 158
 159   /* Do we implement that interface? */
 160   if (IsEqualIID(&IID_IUnknown, riid)) {
 161     *ppvObject = (IGlobalInterfaceTable*) self;
 162   } else if (IsEqualIID(&IID_IGlobalInterfaceTable, riid)) {
 163     *ppvObject = (IGlobalInterfaceTable*) self;
 164   } else return E_NOINTERFACE;
 165
 166   /* Now inc the refcount */
 167   /* we don't use refcounts for now: StdGlobalInterfaceTable_AddRef(iface); */
 168   return S_OK;
 169 }
 170
 171 ULONG WINAPI StdGlobalInterfaceTable_AddRef(IGlobalInterfaceTable* iface) {
 172   StdGlobalInterfaceTableImpl* const self = (StdGlobalInterfaceTableImpl*) iface;
 173
 174   self->ref++;
 175   return self->ref;
 176 }
 177
 178 ULONG WINAPI StdGlobalInterfaceTable_Release(IGlobalInterfaceTable* iface) {
 179   StdGlobalInterfaceTableImpl* const self = (StdGlobalInterfaceTableImpl*) iface;
 180
 181   self->ref--;
 182   if (self->ref == 0) {
 183     /* Hey ho, it's time to go, so long again 'till next weeks show! */
 184     StdGlobalInterfaceTable_Destroy(self);
 185     return 0;
 186   }
 187
 188   return self->ref;
 189 }
 190
 191 /***
 192  * Now implement the actual IGlobalInterfaceTable interface
 193  */
 194
 195 HRESULT WINAPI StdGlobalInterfaceTable_RegisterInterfaceInGlobal(IGlobalInterfaceTable* iface, IUnknown* pUnk, REFIID riid, DWORD* pdwCookie) {
 196   StdGlobalInterfaceTableImpl* const self = (StdGlobalInterfaceTableImpl*) iface;
 197   IStream* stream = NULL;
 198   HRESULT hres;
 199   StdGITEntry* entry;
 200
 201   TRACE("iface=%p, pUnk=%p, riid=%s, pdwCookie=%p\n", iface, pUnk, debugstr_guid(riid), pdwCookie);
 202
 203   if (pUnk == NULL) return E_INVALIDARG;
 204
 205   /* marshal the interface */
 206   hres = CoMarshalInterThreadInterfaceInStream(riid, pUnk, &stream);
 207   if (hres) return hres;
 208   entry = HeapAlloc(GetProcessHeap(), 0, sizeof(StdGITEntry));
 209   if (entry == NULL) return E_OUTOFMEMORY;
 210
 211   entry->iid = *riid;
 212   entry->stream = stream;
 213   entry->cookie = self->nextCookie;
 214   self->nextCookie++; /* inc the cookie count */
 215
 216   /* insert the new entry at the end of the list */
 217   entry->next = NULL;
 218   entry->prev = self->lastEntry;
 219   if (entry->prev) entry->prev->next = entry;
 220   else self->firstEntry = entry;
 221   self->lastEntry = entry;
 222
 223   /* and return the cookie */
 224   *pdwCookie = entry->cookie;
 225   return S_OK;
 226 }
 227
 228 HRESULT WINAPI StdGlobalInterfaceTable_RevokeInterfaceFromGlobal(IGlobalInterfaceTable* iface, DWORD dwCookie) {
 229   StdGlobalInterfaceTableImpl* const self = (StdGlobalInterfaceTableImpl*) iface;
 230   StdGITEntry* entry;
 231
 232   TRACE("iface=%p, dwCookie=0x%x\n", iface, (UINT)dwCookie);
 233
 234   entry = StdGlobalInterfaceTable_FindEntry(iface, dwCookie);
 235   if (entry == NULL) {
 236     TRACE("Entry not found\n");
 237     return E_INVALIDARG; /* not found */
 238   }
 239
 240   /* chop entry out of the list, and free the memory */
 241   if (entry->prev) entry->prev->next = entry->next;
 242   else self->firstEntry = entry->next;
 243   if (entry->next) entry->next->prev = entry->prev;
 244   else self->lastEntry = entry->prev;
 245   HeapFree(GetProcessHeap(), 0, entry);
 246   return S_OK;
 247 }
 248
 249 HRESULT WINAPI StdGlobalInterfaceTable_GetInterfaceFromGlobal(IGlobalInterfaceTable* iface, DWORD dwCookie, REFIID riid, void **ppv) {
 250   StdGITEntry* entry;
 251   HRESULT hres;
 252
 253   entry = StdGlobalInterfaceTable_FindEntry(iface, dwCookie);
 254   if (entry == NULL) return E_INVALIDARG;
 255   if (!IsEqualIID(&entry->iid, &riid)) return E_INVALIDARG;
 256
 257   /* unmarshal the interface */
 258   hres = CoGetInterfaceAndReleaseStream(entry->stream, riid, *ppv);
 259   if (hres) return hres;
 260
 261   return S_OK;
 262 }