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ntoskrnl
ex
00001 /*
00002  * COPYRIGHT:       See COPYING in the top level directory
00003  * PROJECT:         ReactOS Kernel
00004  * FILE:            ntoskrnl/ex/evtpair.c
00005  * PURPOSE:         Support for event pairs
00006  * PROGRAMMERS:     Alex Ionescu (alex@relsoft.net)
00007  *                  Thomas Weidenmueller
00008  */
00009 
00010 /* INCLUDES *****************************************************************/
00011 
00012 #include <ntoskrnl.h>
00013 #define NDEBUG
00014 #include <debug.h>
00015 
00016 #if defined (ALLOC_PRAGMA)
00017 #pragma alloc_text(INIT, ExpInitializeEventPairImplementation)
00018 #endif
00019 
00020 /* GLOBALS *******************************************************************/
00021 
00022 POBJECT_TYPE ExEventPairObjectType = NULL;
00023 
00024 GENERIC_MAPPING ExEventPairMapping =
00025 {
00026     STANDARD_RIGHTS_READ,
00027     STANDARD_RIGHTS_WRITE,
00028     STANDARD_RIGHTS_EXECUTE | SYNCHRONIZE,
00029     EVENT_PAIR_ALL_ACCESS
00030 };
00031 
00032 /* FUNCTIONS *****************************************************************/
00033 
00034 VOID
00035 INIT_FUNCTION
00036 NTAPI
00037 ExpInitializeEventPairImplementation(VOID)
00038 {
00039     OBJECT_TYPE_INITIALIZER ObjectTypeInitializer;
00040     UNICODE_STRING Name;
00041     DPRINT("Creating Event Pair Object Type\n");
00042 
00043     /* Create the Event Pair Object Type */
00044     RtlZeroMemory(&ObjectTypeInitializer, sizeof(ObjectTypeInitializer));
00045     RtlInitUnicodeString(&Name, L"EventPair");
00046     ObjectTypeInitializer.Length = sizeof(ObjectTypeInitializer);
00047     ObjectTypeInitializer.DefaultNonPagedPoolCharge = sizeof(KEVENT_PAIR);
00048     ObjectTypeInitializer.GenericMapping = ExEventPairMapping;
00049     ObjectTypeInitializer.PoolType = NonPagedPool;
00050     ObjectTypeInitializer.ValidAccessMask = EVENT_PAIR_ALL_ACCESS;
00051     ObjectTypeInitializer.UseDefaultObject = TRUE;
00052     ObCreateObjectType(&Name, &ObjectTypeInitializer, NULL, &ExEventPairObjectType);
00053 }
00054 
00055 NTSTATUS
00056 NTAPI
00057 NtCreateEventPair(OUT PHANDLE EventPairHandle,
00058                   IN ACCESS_MASK DesiredAccess,
00059                   IN POBJECT_ATTRIBUTES ObjectAttributes)
00060 {
00061     PKEVENT_PAIR EventPair;
00062     HANDLE hEventPair;
00063     KPROCESSOR_MODE PreviousMode = ExGetPreviousMode();
00064     NTSTATUS Status;
00065     PAGED_CODE();
00066     DPRINT("NtCreateEventPair: 0x%p\n", EventPairHandle);
00067 
00068     /* Check if we were called from user-mode */
00069     if (PreviousMode != KernelMode)
00070     {
00071         /* Enter SEH Block */
00072         _SEH2_TRY
00073         {
00074             /* Check handle pointer */
00075             ProbeForWriteHandle(EventPairHandle);
00076         }
00077         _SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
00078         {
00079             /* Return the exception code */
00080             _SEH2_YIELD(return _SEH2_GetExceptionCode());
00081         }
00082         _SEH2_END;
00083     }
00084 
00085     /* Create the Object */
00086     DPRINT("Creating EventPair\n");
00087     Status = ObCreateObject(PreviousMode,
00088                             ExEventPairObjectType,
00089                             ObjectAttributes,
00090                             PreviousMode,
00091                             NULL,
00092                             sizeof(KEVENT_PAIR),
00093                             0,
00094                             0,
00095                             (PVOID*)&EventPair);
00096 
00097     /* Check for Success */
00098     if (NT_SUCCESS(Status))
00099     {
00100         /* Initalize the Event */
00101         DPRINT("Initializing EventPair\n");
00102         KeInitializeEventPair(EventPair);
00103 
00104         /* Insert it */
00105         Status = ObInsertObject((PVOID)EventPair,
00106                                  NULL,
00107                                  DesiredAccess,
00108                                  0,
00109                                  NULL,
00110                                  &hEventPair);
00111 
00112         /* Check for success */
00113         if (NT_SUCCESS(Status))
00114         {
00115             /* Enter SEH */
00116             _SEH2_TRY
00117             {
00118                 /* Return the handle */
00119                 *EventPairHandle = hEventPair;
00120             }
00121             _SEH2_EXCEPT(ExSystemExceptionFilter())
00122             {
00123                 /* Get the exception code */
00124                 Status = _SEH2_GetExceptionCode();
00125             }
00126             _SEH2_END;
00127         }
00128     }
00129 
00130     /* Return Status */
00131     return Status;
00132 }
00133 
00134 NTSTATUS
00135 NTAPI
00136 NtOpenEventPair(OUT PHANDLE EventPairHandle,
00137                 IN ACCESS_MASK DesiredAccess,
00138                 IN POBJECT_ATTRIBUTES ObjectAttributes)
00139 {
00140     HANDLE hEventPair;
00141     KPROCESSOR_MODE PreviousMode = ExGetPreviousMode();
00142     NTSTATUS Status;
00143     PAGED_CODE();
00144 
00145     /* Check if we were called from user-mode */
00146     if (PreviousMode != KernelMode)
00147     {
00148         /* Enter SEH Block */
00149         _SEH2_TRY
00150         {
00151             /* Check handle pointer */
00152             ProbeForWriteHandle(EventPairHandle);
00153         }
00154         _SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
00155         {
00156             /* Return the exception code */
00157             _SEH2_YIELD(return _SEH2_GetExceptionCode());
00158         }
00159         _SEH2_END;
00160     }
00161 
00162     /* Open the Object */
00163     Status = ObOpenObjectByName(ObjectAttributes,
00164                                 ExEventPairObjectType,
00165                                 PreviousMode,
00166                                 NULL,
00167                                 DesiredAccess,
00168                                 NULL,
00169                                 &hEventPair);
00170 
00171     /* Check for success */
00172     if (NT_SUCCESS(Status))
00173     {
00174         /* Enter SEH */
00175         _SEH2_TRY
00176         {
00177             /* Return the handle */
00178             *EventPairHandle = hEventPair;
00179         }
00180         _SEH2_EXCEPT(ExSystemExceptionFilter())
00181         {
00182             /* Get the exception code */
00183             Status = _SEH2_GetExceptionCode();
00184         }
00185         _SEH2_END;
00186     }
00187 
00188     /* Return status */
00189     return Status;
00190 }
00191 
00192 NTSTATUS
00193 NTAPI
00194 NtSetHighEventPair(IN HANDLE EventPairHandle)
00195 {
00196     PKEVENT_PAIR EventPair;
00197     KPROCESSOR_MODE PreviousMode = ExGetPreviousMode();
00198     NTSTATUS Status;
00199     PAGED_CODE();
00200     DPRINT("NtSetHighEventPair(EventPairHandle 0x%p)\n", EventPairHandle);
00201 
00202     /* Open the Object */
00203     Status = ObReferenceObjectByHandle(EventPairHandle,
00204                                        SYNCHRONIZE,
00205                                        ExEventPairObjectType,
00206                                        PreviousMode,
00207                                        (PVOID*)&EventPair,
00208                                        NULL);
00209 
00210     /* Check for Success */
00211     if(NT_SUCCESS(Status))
00212     {
00213         /* Set the Event */
00214         KeSetEvent(&EventPair->HighEvent, EVENT_INCREMENT, FALSE);
00215 
00216         /* Dereference Object */
00217         ObDereferenceObject(EventPair);
00218     }
00219 
00220     /* Return status */
00221     return Status;
00222 }
00223 
00224 NTSTATUS
00225 NTAPI
00226 NtSetHighWaitLowEventPair(IN HANDLE EventPairHandle)
00227 {
00228     PKEVENT_PAIR EventPair;
00229     KPROCESSOR_MODE PreviousMode = ExGetPreviousMode();
00230     NTSTATUS Status;
00231     PAGED_CODE();
00232     DPRINT("NtSetHighWaitLowEventPair(Handle 0x%p)\n", EventPairHandle);
00233 
00234     /* Open the Object */
00235     Status = ObReferenceObjectByHandle(EventPairHandle,
00236                                        SYNCHRONIZE,
00237                                        ExEventPairObjectType,
00238                                        PreviousMode,
00239                                        (PVOID*)&EventPair,
00240                                        NULL);
00241 
00242     /* Check for Success */
00243     if(NT_SUCCESS(Status))
00244     {
00245         /* Set the Event */
00246         KeSetEvent(&EventPair->HighEvent, EVENT_INCREMENT, FALSE);
00247 
00248         /* Wait for the Other one */
00249         KeWaitForSingleObject(&EventPair->LowEvent,
00250                               WrEventPair,
00251                               PreviousMode,
00252                               FALSE,
00253                               NULL);
00254 
00255         /* Dereference Object */
00256         ObDereferenceObject(EventPair);
00257     }
00258 
00259     /* Return status */
00260     return Status;
00261 }
00262 
00263 NTSTATUS
00264 NTAPI
00265 NtSetLowEventPair(IN HANDLE EventPairHandle)
00266 {
00267     PKEVENT_PAIR EventPair;
00268     KPROCESSOR_MODE PreviousMode = ExGetPreviousMode();
00269     NTSTATUS Status;
00270     PAGED_CODE();
00271     DPRINT1("NtSetHighEventPair(EventPairHandle 0x%p)\n", EventPairHandle);
00272 
00273     /* Open the Object */
00274     Status = ObReferenceObjectByHandle(EventPairHandle,
00275                                        SYNCHRONIZE,
00276                                        ExEventPairObjectType,
00277                                        PreviousMode,
00278                                        (PVOID*)&EventPair,
00279                                        NULL);
00280 
00281     /* Check for Success */
00282     if(NT_SUCCESS(Status))
00283     {
00284         /* Set the Event */
00285         KeSetEvent(&EventPair->LowEvent, EVENT_INCREMENT, FALSE);
00286 
00287         /* Dereference Object */
00288         ObDereferenceObject(EventPair);
00289     }
00290 
00291     /* Return status */
00292     return Status;
00293 }
00294 
00295 NTSTATUS
00296 NTAPI
00297 NtSetLowWaitHighEventPair(IN HANDLE EventPairHandle)
00298 {
00299     PKEVENT_PAIR EventPair;
00300     KPROCESSOR_MODE PreviousMode = ExGetPreviousMode();
00301     NTSTATUS Status;
00302     PAGED_CODE();
00303     DPRINT("NtSetHighWaitLowEventPair(Handle 0x%p)\n", EventPairHandle);
00304 
00305     /* Open the Object */
00306     Status = ObReferenceObjectByHandle(EventPairHandle,
00307                                        SYNCHRONIZE,
00308                                        ExEventPairObjectType,
00309                                        PreviousMode,
00310                                        (PVOID*)&EventPair,
00311                                        NULL);
00312 
00313     /* Check for Success */
00314     if(NT_SUCCESS(Status))
00315     {
00316         /* Set the Event */
00317         KeSetEvent(&EventPair->LowEvent, EVENT_INCREMENT, FALSE);
00318 
00319         /* Wait for the Other one */
00320         KeWaitForSingleObject(&EventPair->HighEvent,
00321                               WrEventPair,
00322                               PreviousMode,
00323                               FALSE,
00324                               NULL);
00325 
00326         /* Dereference Object */
00327         ObDereferenceObject(EventPair);
00328     }
00329 
00330     /* Return status */
00331     return Status;
00332 }
00333 
00334 
00335 NTSTATUS
00336 NTAPI
00337 NtWaitLowEventPair(IN HANDLE EventPairHandle)
00338 {
00339     PKEVENT_PAIR EventPair;
00340     KPROCESSOR_MODE PreviousMode = ExGetPreviousMode();
00341     NTSTATUS Status;
00342     PAGED_CODE();
00343     DPRINT("NtSetHighWaitLowEventPair(Handle 0x%p)\n", EventPairHandle);
00344 
00345     /* Open the Object */
00346     Status = ObReferenceObjectByHandle(EventPairHandle,
00347                                        SYNCHRONIZE,
00348                                        ExEventPairObjectType,
00349                                        PreviousMode,
00350                                        (PVOID*)&EventPair,
00351                                        NULL);
00352 
00353     /* Check for Success */
00354     if(NT_SUCCESS(Status))
00355     {
00356         /* Wait for the Event */
00357         KeWaitForSingleObject(&EventPair->LowEvent,
00358                               WrEventPair,
00359                               PreviousMode,
00360                               FALSE,
00361                               NULL);
00362 
00363         /* Dereference Object */
00364         ObDereferenceObject(EventPair);
00365     }
00366 
00367     /* Return status */
00368     return Status;
00369 }
00370 
00371 NTSTATUS
00372 NTAPI
00373 NtWaitHighEventPair(IN HANDLE EventPairHandle)
00374 {
00375     PKEVENT_PAIR EventPair;
00376     KPROCESSOR_MODE PreviousMode = ExGetPreviousMode();
00377     NTSTATUS Status;
00378 
00379     PAGED_CODE();
00380     DPRINT("NtSetHighWaitLowEventPair(Handle 0x%p)\n", EventPairHandle);
00381 
00382     /* Open the Object */
00383     Status = ObReferenceObjectByHandle(EventPairHandle,
00384                                        SYNCHRONIZE,
00385                                        ExEventPairObjectType,
00386                                        PreviousMode,
00387                                        (PVOID*)&EventPair,
00388                                        NULL);
00389 
00390     /* Check for Success */
00391     if(NT_SUCCESS(Status))
00392     {
00393         /* Wait for the Event */
00394         KeWaitForSingleObject(&EventPair->HighEvent,
00395                               WrEventPair,
00396                               PreviousMode,
00397                               FALSE,
00398                               NULL);
00399 
00400         /* Dereference Object */
00401         ObDereferenceObject(EventPair);
00402     }
00403 
00404     /* Return status */
00405     return Status;
00406 }
00407 
00408 /* EOF */
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