82 lines
2.9 KiB
C
82 lines
2.9 KiB
C
// ke_event.c - synchronisation events
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#include <stdbool.h>
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#include <ke_event.h>
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#include <ke_thread.h>
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#include <ke_sched.h>
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#include <ke_irql.h>
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#include <ke_apc.h>
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#include <ob_object.h>
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static void KiEventDestroy(OBJECT* obj) { (void)obj; }
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__declspec(dllexport) KSTATUS KeEventCreate(EVENT_TYPE type, uint32_t initialState, EVENT **out) {
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if (!out) return STATUS_INVALID_PARAMETER;
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EVENT* e = (EVENT *)ObAllocateObject(ObjectTypeEvent, sizeof(EVENT));
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if (!e) return STATUS_NO_MEMORY;
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e->Header.Destroy = KiEventDestroy;
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e->Lock = (SPINLOCK)SPINLOCK_INIT;
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e->Type = type;
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e->Signaled = initialState ? 1 : 0;
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LIST_INIT(&e->WaitList);
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*out = e;
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return STATUS_SUCCESS;
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}
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__declspec(dllexport) void KeSignalEvent(EVENT* event) {
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if (!event) return;
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uintptr_t flags = KeAcquireSpinlock(&event->Lock);
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if (event->Type == EventManualReset) {
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event->Signaled = 1;
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while (!LIST_IS_EMPTY(&event->WaitList)) {
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LIST_ENTRY* node = ListPopHead(&event->WaitList);
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THREAD* t = CONTAINING_RECORD(node, THREAD, SchedulerLink);
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KeReleaseSpinlock(&event->Lock, flags);
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KeUnblockThreadWithStatus(t, STATUS_SUCCESS);
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flags = KeAcquireSpinlock(&event->Lock);
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}
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} else {
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if (!LIST_IS_EMPTY(&event->WaitList)) {
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// Auto-reset handoff: transfer the signal directly to exactly one
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// waiter. Do not leave Signaled=1, because a later waiter can steal
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// the disk/APC completion before the selected thread resumes.
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event->Signaled = 0;
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LIST_ENTRY* node = ListPopHead(&event->WaitList);
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THREAD* t = CONTAINING_RECORD(node, THREAD, SchedulerLink);
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KeReleaseSpinlock(&event->Lock, flags);
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KeUnblockThreadWithStatus(t, STATUS_SUCCESS);
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return;
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}
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event->Signaled = 1;
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}
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KeReleaseSpinlock(&event->Lock, flags);
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}
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__declspec(dllexport) void KeClearEvent(EVENT* event) {
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if (!event) return;
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uintptr_t flags = KeAcquireSpinlock(&event->Lock);
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event->Signaled = 0;
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KeReleaseSpinlock(&event->Lock, flags);
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}
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__declspec(dllexport) KSTATUS KeWaitForEvent(EVENT* event, uint8_t alertable) {
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if (!event) return STATUS_INVALID_PARAMETER;
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if (!KeCanWait()) return STATUS_INVALID_IRQL;
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if (alertable && KeAreKernelApcsDisabled()) return STATUS_INVALID_PARAMETER;
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THREAD* self = KeGetCurrentThread();
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uintptr_t flags = KeAcquireSpinlock(&event->Lock);
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if (event->Signaled) {
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if (event->Type == EventAutoReset) event->Signaled = 0;
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KeReleaseSpinlock(&event->Lock, flags);
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return STATUS_SUCCESS;
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}
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KePrepareBlockThread(self, &event->Header, alertable);
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ListInsertTail(&event->WaitList, &self->SchedulerLink);
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KeSetThreadWaitList(self, &event->WaitList);
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KeReleaseSpinlock(&event->Lock, flags);
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return KeCommitBlockThread(self, alertable);
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}
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