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   ICOM_VTBL(newGIT) = &StdGlobalInterfaceTableImpl_Vtbl;
 112
 113   newGIT->ref = 0;      /* Initialise the reference count */
 114   newGIT->firstEntry = NULL; /* we start with an empty table   */
 115   newGIT->lastEntry  = NULL;
 116   newGIT->nextCookie = 0xf100; /* that's where windows starts, so that's where we start */
 117   TRACE("Created the GIT at %p\n", newGIT);
 118
 119   return (void*)newGIT;
 120 }
 121
 122 /** This destroys it again. It should revoke all the held interfaces first **/
 123 void StdGlobalInterfaceTable_Destroy(void* self) {
 124   TRACE("(%p)\n", self);
 125   FIXME("Revoke held interfaces here\n");
 126
 127   HeapFree(GetProcessHeap(), 0, self);
 128 }
 129
 130 /***
 131  * A helper function to traverse the list and find the entry that matches the cookie.
 132  * Returns NULL if not found
 133  */
 134 StdGITEntry* StdGlobalInterfaceTable_FindEntry(IGlobalInterfaceTable* iface, DWORD cookie) {
 135   StdGlobalInterfaceTableImpl* const self = (StdGlobalInterfaceTableImpl*) iface;
 136   StdGITEntry* e;
 137
 138   TRACE("iface=%p, cookie=0x%x\n", iface, (UINT)cookie);
 139
 140   e = self->firstEntry;
 141   while (e != NULL) {
 142     if (e->cookie == cookie) return e;
 143     e = e->next;
 144   }
 145   return NULL;
 146 }
 147
 148 /***
 149  * Here's the boring boilerplate stuff for IUnknown
 150  */
 151
 152 HRESULT WINAPI StdGlobalInterfaceTable_QueryInterface(IGlobalInterfaceTable* iface, REFIID riid, void** ppvObject) {
 153   StdGlobalInterfaceTableImpl* const self = (StdGlobalInterfaceTableImpl*) iface;
 154
 155   /* Make sure silly coders can't crash us */
 156   if (ppvObject == 0) return E_INVALIDARG;
 157
 158   *ppvObject = 0; /* assume we don't have the interface */
 159
 160   /* Do we implement that interface? */
 161   if (IsEqualIID(&IID_IUnknown, riid)) {
 162     *ppvObject = (IGlobalInterfaceTable*) self;
 163   } else if (IsEqualIID(&IID_IGlobalInterfaceTable, riid)) {
 164     *ppvObject = (IGlobalInterfaceTable*) self;
 165   } else return E_NOINTERFACE;
 166
 167   /* Now inc the refcount */
 168   /* we don't use refcounts for now: StdGlobalInterfaceTable_AddRef(iface); */
 169   return S_OK;
 170 }
 171
 172 ULONG WINAPI StdGlobalInterfaceTable_AddRef(IGlobalInterfaceTable* iface) {
 173   StdGlobalInterfaceTableImpl* const self = (StdGlobalInterfaceTableImpl*) iface;
 174
 175   self->ref++;
 176   return self->ref;
 177 }
 178
 179 ULONG WINAPI StdGlobalInterfaceTable_Release(IGlobalInterfaceTable* iface) {
 180   StdGlobalInterfaceTableImpl* const self = (StdGlobalInterfaceTableImpl*) iface;
 181
 182   self->ref--;
 183   if (self->ref == 0) {
 184     /* Hey ho, it's time to go, so long again 'till next weeks show! */
 185     StdGlobalInterfaceTable_Destroy(self);
 186     return 0;
 187   }
 188
 189   return self->ref;
 190 }
 191
 192 /***
 193  * Now implement the actual IGlobalInterfaceTable interface
 194  */
 195
 196 HRESULT WINAPI StdGlobalInterfaceTable_RegisterInterfaceInGlobal(IGlobalInterfaceTable* iface, IUnknown* pUnk, REFIID riid, DWORD* pdwCookie) {
 197   StdGlobalInterfaceTableImpl* const self = (StdGlobalInterfaceTableImpl*) iface;
 198   IStream* stream = NULL;
 199   HRESULT hres;
 200   StdGITEntry* entry;
 201
 202   TRACE("iface=%p, pUnk=%p, riid=%s, pdwCookie=%p\n", iface, pUnk, debugstr_guid(riid), pdwCookie);
 203
 204   if (pUnk == NULL) return E_INVALIDARG;
 205
 206   /* marshal the interface */
 207   hres = CoMarshalInterThreadInterfaceInStream(riid, pUnk, &stream);
 208   if (hres) return hres;
 209   entry = HeapAlloc(GetProcessHeap(), 0, sizeof(StdGITEntry));
 210   if (entry == NULL) return E_OUTOFMEMORY;
 211
 212   entry->iid = *riid;
 213   entry->stream = stream;
 214   entry->cookie = self->nextCookie;
 215   self->nextCookie++; /* inc the cookie count */
 216
 217   /* insert the new entry at the end of the list */
 218   entry->next = NULL;
 219   entry->prev = self->lastEntry;
 220   if (entry->prev) entry->prev->next = entry;
 221   else self->firstEntry = entry;
 222   self->lastEntry = entry;
 223
 224   /* and return the cookie */
 225   *pdwCookie = entry->cookie;
 226   return S_OK;
 227 }
 228
 229 HRESULT WINAPI StdGlobalInterfaceTable_RevokeInterfaceFromGlobal(IGlobalInterfaceTable* iface, DWORD dwCookie) {
 230   StdGlobalInterfaceTableImpl* const self = (StdGlobalInterfaceTableImpl*) iface;
 231   StdGITEntry* entry;
 232
 233   TRACE("iface=%p, dwCookie=0x%x\n", iface, (UINT)dwCookie);
 234
 235   entry = StdGlobalInterfaceTable_FindEntry(iface, dwCookie);
 236   if (entry == NULL) {
 237     TRACE("Entry not found\n");
 238     return E_INVALIDARG; /* not found */
 239   }
 240
 241   /* chop entry out of the list, and free the memory */
 242   if (entry->prev) entry->prev->next = entry->next;
 243   else self->firstEntry = entry->next;
 244   if (entry->next) entry->next->prev = entry->prev;
 245   else self->lastEntry = entry->prev;
 246   HeapFree(GetProcessHeap(), 0, entry);
 247   return S_OK;
 248 }
 249
 250 HRESULT WINAPI StdGlobalInterfaceTable_GetInterfaceFromGlobal(IGlobalInterfaceTable* iface, DWORD dwCookie, REFIID riid, void **ppv) {
 251   StdGITEntry* entry;
 252   HRESULT hres;
 253
 254   entry = StdGlobalInterfaceTable_FindEntry(iface, dwCookie);
 255   if (entry == NULL) return E_INVALIDARG;
 256   if (!IsEqualIID(&entry->iid, &riid)) return E_INVALIDARG;
 257
 258   /* unmarshal the interface */
 259   hres = CoGetInterfaceAndReleaseStream(entry->stream, riid, *ppv);
 260   if (hres) return hres;
 261
 262   return S_OK;
 263 }