Update the copyright notice format

[mirror_edk2.git] / EdkCompatibilityPkg / Foundation / Library / Dxe / EfiDriverLib / Lock.c

/*++\r
\r
Copyright (c) 2004, Intel Corporation. All rights reserved.<BR>\r
This program and the accompanying materials                          \r
are licensed and made available under the terms and conditions of the BSD License         \r
which accompanies this distribution.  The full text of the license may be found at        \r
http://opensource.org/licenses/bsd-license.php                                            \r
                                                                                          \r
THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,                     \r
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.             \r
\r
Module Name:\r
\r
  Lock.c\r
\r
Abstract:\r
\r
  Support for locking lib services.\r
\r
--*/\r
\r
#include "Tiano.h"\r
#include "EfiDriverLib.h"\r
\r
VOID\r
EfiInitializeLock (\r
  IN OUT EFI_LOCK *Lock,\r
  IN EFI_TPL      Priority\r
  )\r
/*++\r
\r
Routine Description:\r
\r
  Initialize a basic mutual exclusion lock.   Each lock\r
  provides mutual exclusion access at it's task priority\r
  level.  Since there is no-premption (at any TPL) or\r
  multiprocessor support, acquiring the lock only consists\r
  of raising to the locks TPL.\r
\r
  Note on a check build ASSERT()s are used to ensure proper\r
  lock usage.\r
    \r
Arguments:\r
\r
  Lock        - The EFI_LOCK structure to initialize\r
\r
  Priority    - The task priority level of the lock\r
\r
    \r
Returns:\r
\r
  An initialized Efi Lock structure.\r
\r
--*/\r
{\r
  Lock->Tpl       = Priority;\r
  Lock->OwnerTpl  = 0;\r
  Lock->Lock      = 0;\r
}\r
\r
EFI_STATUS\r
EfiAcquireLockOrFail (\r
  IN EFI_LOCK  *Lock\r
  )\r
/*++\r
\r
Routine Description:\r
\r
  Initialize a basic mutual exclusion lock.   Each lock\r
  provides mutual exclusion access at it's task priority\r
  level.  Since there is no-premption (at any TPL) or\r
  multiprocessor support, acquiring the lock only consists\r
  of raising to the locks TPL.\r
    \r
Arguments:\r
\r
  Lock        - The EFI_LOCK structure to initialize\r
   \r
Returns:\r
\r
  EFI_SUCCESS       - Lock Owned.\r
  EFI_ACCESS_DENIED - Reentrant Lock Acquisition, Lock not Owned.\r
\r
--*/\r
{\r
  if (Lock->Lock != 0) {\r
    //\r
    // Lock is already owned, so bail out\r
    //\r
    return EFI_ACCESS_DENIED;\r
  }\r
\r
  Lock->OwnerTpl = gBS->RaiseTPL (Lock->Tpl);\r
\r
  Lock->Lock += 1;\r
  return EFI_SUCCESS;\r
}\r
\r
VOID\r
EfiAcquireLock (\r
  IN EFI_LOCK  *Lock\r
  )\r
/*++\r
\r
Routine Description:\r
\r
  Raising to the task priority level of the mutual exclusion\r
  lock, and then acquires ownership of the lock.\r
    \r
Arguments:\r
\r
  Lock - The lock to acquire\r
    \r
Returns:\r
\r
  Lock owned\r
\r
--*/\r
{\r
  EFI_STATUS  Status;\r
\r
  Status = EfiAcquireLockOrFail (Lock);\r
\r
  //\r
  // Lock was already locked.\r
  //\r
  ASSERT_EFI_ERROR (Status);\r
}\r
\r
VOID\r
EfiReleaseLock (\r
  IN EFI_LOCK  *Lock\r
  )\r
/*++\r
\r
Routine Description:\r
\r
    Releases ownership of the mutual exclusion lock, and\r
    restores the previous task priority level.\r
    \r
Arguments:\r
\r
    Lock - The lock to release\r
    \r
Returns:\r
\r
    Lock unowned\r
\r
--*/\r
{\r
  EFI_TPL Tpl;\r
\r
  Tpl = Lock->OwnerTpl;\r
\r
  ASSERT (Lock->Lock == 1);\r
  Lock->Lock -= 1;\r
\r
  gBS->RestoreTPL (Tpl);\r
}\r