MdePkg/BaseSynchronizationLib: Add InterlockedCompareExchange16

[mirror_edk2.git] / MdePkg / Library / BaseSynchronizationLib / Synchronization.c

diff --git a/MdePkg/Library/BaseSynchronizationLib/Synchronization.c b/MdePkg/Library/BaseSynchronizationLib/Synchronization.c
index 0eea40ba1622bb2dfa4a87f023b1cd2451375618..4218a265a0ec37d0668647bc5f12c5bcbbf27dda 100644 (file)
--- a/MdePkg/Library/BaseSynchronizationLib/Synchronization.c
+++ b/MdePkg/Library/BaseSynchronizationLib/Synchronization.c
@@ -276,6 +276,37 @@ InterlockedDecrement (
   return InternalSyncDecrement (Value);\r
 }\r
 \r
+/**\r
+  Performs an atomic compare exchange operation on a 16-bit unsigned integer.\r
+\r
+  Performs an atomic compare exchange operation on the 16-bit unsigned integer\r
+  specified by Value.  If Value is equal to CompareValue, then Value is set to\r
+  ExchangeValue and CompareValue is returned.  If Value is not equal to CompareValue,\r
+  then Value is returned.  The compare exchange operation must be performed using\r
+  MP safe mechanisms.\r
+\r
+  If Value is NULL, then ASSERT().\r
+\r
+  @param  Value         A pointer to the 16-bit value for the compare exchange\r
+                        operation.\r
+  @param  CompareValue  16-bit value used in compare operation.\r
+  @param  ExchangeValue 16-bit value used in exchange operation.\r
+\r
+  @return The original *Value before exchange.\r
+\r
+**/\r
+UINT16\r
+EFIAPI\r
+InterlockedCompareExchange16 (\r
+  IN OUT  UINT16                    *Value,\r
+  IN      UINT16                    CompareValue,\r
+  IN      UINT16                    ExchangeValue\r
+  )\r
+{\r
+  ASSERT (Value != NULL);\r
+  return InternalSyncCompareExchange16 (Value, CompareValue, ExchangeValue);\r
+}\r
+\r
 /**\r
   Performs an atomic compare exchange operation on a 32-bit unsigned integer.\r
 \r