Add executive resource synchronization functions

xtoskrnl/ex/data.cc

@@ -32,3 +32,12 @@ LIST_ENTRY EX::LookasideList::PoolLookasideListHead;
 
 /* Tracks dynamic system lookaside lists */
 LIST_ENTRY EX::LookasideList::SystemLookasideListHead;
+
+/* Specifies the default timeout interval for resource wait operations */
+LARGE_INTEGER EX::Resources::ResourcesTimeOut;
+
+/* Tracks all initialized structures currently active in the system */
+LIST_ENTRY EX::Resources::SystemResourcesList;
+
+/* The global spinlock that protects the system resources list */
+KSPIN_LOCK EX::Resources::SystemResourcesLock;

xtoskrnl/ex/resource.cc

@@ -0,0 +1,169 @@
+/**
+ * PROJECT:         ExectOS
+ * COPYRIGHT:       See COPYING.md in the top level directory
+ * FILE:            xtoskrnl/ex/resource.cc
+ * DESCRIPTION:     Exclusive resource synchronization support
+ * DEVELOPERS:      Aiken Harris <harraiken91@gmail.com>
+ */
+
+#include <xtos.hh>
+
+
+/**
+ * Deletes a system resource and frees its associated memory allocations.
+ *
+ * @param Resource
+ *        Supplies a pointer to the resource to be deleted.
+ *
+ * @return This routine returns a status code indicating the success or failure of the operation.
+ *
+ * @since XT 1.0
+ */
+XTAPI
+XTSTATUS
+EX::Resources::DeleteResource(IN PERESOURCE Resource)
+{
+    /* Start a guarded code block */
+    {
+        /* Raise runlevel to DISPATCH level and acquire system resources lock */
+        KE::RaiseRunLevel RunLevel(DISPATCH_LEVEL);
+        KE::QueuedSpinLockGuard Guard(&SystemResourcesLock);
+
+        /* Remove the resource from the system resource list */
+        RTL::LinkedList::RemoveEntryList(&Resource->SystemResourcesList);
+    }
+
+    /* Check if exclusive waiters event exists */
+    if(Resource->ExclusiveWaiters)
+    {
+        /* Free the exclusive waiters event */
+        MM::Allocator::FreePool(Resource->ExclusiveWaiters);
+    }
+
+    /* Check if owner table exists */
+    if(Resource->OwnerTable)
+    {
+        /* Free the owner table */
+        MM::Allocator::FreePool(Resource->OwnerTable);
+    }
+
+    /* Check if shared waiters semaphore exists */
+    if(Resource->SharedWaiters)
+    {
+        /* Free the shared waiters semaphore */
+        MM::Allocator::FreePool(Resource->SharedWaiters);
+    }
+
+    /* Return success */
+    return STATUS_SUCCESS;
+}
+
+/**
+ * Initializes a system resource object.
+ *
+ * @param Resource
+ *        Supplies a pointer to the resource structure to be initialized.
+ *
+ * @return This routine returns a status code indicating the success or failure of the operation.
+ *
+ * @since XT 1.0
+ */
+XTAPI
+XTSTATUS
+EX::Resources::InitializeResource(IN PERESOURCE Resource)
+{
+    /* Clear the entire resource structure */
+    RTL::Memory::ZeroMemory(Resource, sizeof(ERESOURCE));
+
+    /* Initialize the spinlock used for managing this resource */
+    KE::SpinLock::InitializeSpinLock(&Resource->SpinLock);
+
+    /* Raise runlevel to DISPATCH level and acquire the global system resources lock */
+    KE::RaiseRunLevel RunLevel(DISPATCH_LEVEL);
+    KE::QueuedSpinLockGuard Guard(&SystemResourcesLock);
+
+    /* Insert the resource into the global tracking list */
+    RTL::LinkedList::InsertTailList(&SystemResourcesList, &Resource->SystemResourcesList);
+
+    /* Return success */
+    return STATUS_SUCCESS;
+}
+
+/**
+ * Initializes the global system resource structures and synchronization primitives.
+ *
+ * @return This routine does not return any value.
+ *
+ * @since XT 1.0
+ */
+XTAPI
+VOID
+EX::Resources::InitializeSystemResources(VOID)
+{
+    /* Set the default timeout for resource operations to 4 seconds relative to now */
+    ResourcesTimeOut.QuadPart = -40000000LL;
+
+    /* Initialize the global system resources list and its protecting spinlock */
+    RTL::LinkedList::InitializeListHead(&SystemResourcesList);
+    KE::SpinLock::InitializeSpinLock(&SystemResourcesLock);
+}
+
+/**
+ * Reinitializes an existing resource object, resetting its state and synchronization primitives.
+ *
+ * @param Resource
+ *        Supplies a pointer to the resource structure to be reinitialized.
+ *
+ * @return This routine returns a status code indicating the success or failure of the operation.
+ *
+ * @since XT 1.0
+ */
+XTAPI
+XTSTATUS
+EX::Resources::ReinitializeResource(IN PERESOURCE Resource)
+{
+    ULONG Index;
+
+    /* Zero the active count and flags */
+    Resource->ActiveCount = 0;
+    Resource->ActiveEntries = 0;
+    Resource->Flag = 0;
+
+    /* Zero the contention count and counters */
+    Resource->ContentionCount = 0;
+    Resource->NumberOfSharedWaiters = 0;
+    Resource->NumberOfExclusiveWaiters = 0;
+
+    /* Zero the owner entry */
+    Resource->OwnerEntry.OwnerThread = 0;
+    Resource->OwnerEntry.TableSize = 0;
+
+    /* Check if exclusive waiters event exists */
+    if(Resource->ExclusiveWaiters)
+    {
+        /* Reinitialize the event */
+        KE::Event::InitializeEvent(Resource->ExclusiveWaiters, SynchronizationEvent, FALSE);
+    }
+
+    /* Check if owner table exists */
+    if(Resource->OwnerTable)
+    {
+        /* Iterate over the owner table */
+        for(Index = 1; Index < Resource->OwnerTable->TableSize; Index++)
+        {
+            /* Zero the owner table */
+            Resource->OwnerTable[Index].OwnerCount = 0;
+            Resource->OwnerTable[Index].OwnerThread = 0;
+        }
+    }
+
+    /* Check if shared waiters semaphore exists */
+    if(Resource->SharedWaiters)
+    {
+        /* Reinitialize the semaphore */
+        KE::Semaphore::InitializeSemaphore(Resource->SharedWaiters, 0, MAXLONG);
+    }
+
+    /* Return success */
+    return STATUS_SUCCESS;
+}