1 files changed, 169 insertions, 0 deletions

diff --git a/private/ntos/ex/callperf.c b/private/ntos/ex/callperf.c
new file mode 100644
index 000000000..7caad7b31
--- /dev/null
+++ b/private/ntos/ex/callperf.c
@@ -0,0 +1,169 @@
+/*++
+
+Copyright (c) 1994  Microsoft Corporation
+
+Module Name:
+
+    callperf.c
+
+Abstract:
+
+   This module implements the functions necessary to collect call data.
+
+Author:
+
+    David N. Cutler (davec) 22-May-1994
+
+Environment:
+
+    Kernel mode only.
+
+Revision History:
+
+--*/
+
+#include "exp.h"
+
+VOID
+ExInitializeCallData (
+    IN PCALL_PERFORMANCE_DATA CallData
+    )
+
+/*++
+
+Routine Description:
+
+    This function initializes a call performance data structure.
+
+Arguments:
+
+    CallData - Supplies a pointer to the call performance data structure
+        that is initialized.
+
+Return Value:
+
+    None.
+
+--*/
+
+{
+
+    ULONG Index;
+
+    //
+    // Initialize the spinlock and listheads for the call performance
+    // data structure.
+    //
+
+    KeInitializeSpinLock(&CallData->SpinLock);
+    for (Index = 0; Index < CALL_HASH_TABLE_SIZE; Index += 1) {
+        InitializeListHead(&CallData->HashTable[Index]);
+    }
+}
+
+VOID
+ExRecordCallerInHashTable (
+    IN PCALL_PERFORMANCE_DATA CallData,
+    IN PVOID CallersAddress,
+    IN PVOID CallersCaller
+    )
+
+/*++
+
+Routine Description:
+
+    This function records call data in the specified call performance
+    data structure.
+
+Arguments:
+
+    CallData - Supplies a pointer to the call performance data structure
+        in which the call data is recorded.
+
+    CallersAddress - Supplies the address of the caller of a fucntion.
+
+    CallersCaller - Supplies the address of the caller of a caller of
+        a function.
+
+Return Value:
+
+    None.
+
+--*/
+
+{
+
+    PCALL_HASH_ENTRY HashEntry;
+    ULONG Hash;
+    PCALL_HASH_ENTRY MatchEntry;
+    PLIST_ENTRY NextEntry;
+    KIRQL OldIrql;
+
+    //
+    // If the initialization phase is not zero, then collect call performance
+    // data.
+    //
+
+    if (InitializationPhase != 0) {
+
+        //
+        // Acquire the call performance data structure spinlock.
+        //
+
+        ExAcquireSpinLock(&CallData->SpinLock, &OldIrql);
+
+        //
+        // Lookup the callers address in call performance data hash table. If
+        // the address does not exist in the table, then create a new entry.
+        //
+
+        Hash = (ULONG)CallersAddress ^ (ULONG)CallersCaller;
+        Hash = ((Hash > 24) ^ (Hash > 16) ^ (Hash > 8) ^ (Hash)) & (CALL_HASH_TABLE_SIZE - 1);
+        MatchEntry = NULL;
+        NextEntry = CallData->HashTable[Hash].Flink;
+        while (NextEntry != &CallData->HashTable[Hash]) {
+            HashEntry = CONTAINING_RECORD(NextEntry,
+                                          CALL_HASH_ENTRY,
+                                          ListEntry);
+
+            if ((HashEntry->CallersAddress == CallersAddress) &&
+                (HashEntry->CallersCaller == CallersCaller)) {
+                MatchEntry = HashEntry;
+                break;
+            }
+
+            NextEntry = NextEntry->Flink;
+        }
+
+        //
+        // If a matching caller address was found, then update the call site
+        // statistics. Otherwise, allocate a new hash entry and initialize
+        // call site statistics.
+        //
+
+        if (MatchEntry != NULL) {
+            MatchEntry->CallCount += 1;
+
+        } else {
+            MatchEntry = ExAllocatePoolWithTag(NonPagedPool,
+                                              sizeof(CALL_HASH_ENTRY),
+                                              'CdHe');
+
+            if (MatchEntry != NULL) {
+                MatchEntry->CallersAddress = CallersAddress;
+                MatchEntry->CallersCaller = CallersCaller;
+                MatchEntry->CallCount = 1;
+                InsertTailList(&CallData->HashTable[Hash],
+                               &MatchEntry->ListEntry);
+            }
+        }
+
+        //
+        // Release the call performance data structure spinlock.
+        //
+
+        ExReleaseSpinLock(&CallData->SpinLock, OldIrql);
+    }
+
+    return;
+}