Re: [PATCH v1] test-drop-caches: simplify delay loading of NtSetSystemInformation

From: Duy Nguyen <pclouds@gmail.com>
Date: Apr 30, 2018, 14:57 UTC
Message-ID: <CACsJy8CY1fNY9OPq9nisDC3X93QXjntre-vFgQ0OeuO=B0YV=Q@mail.gmail.com>
In-Reply-To: <20180430142555.23260-1-benpeart@microsoft.com>

On Mon, Apr 30, 2018 at 4:26 PM, Ben Peart <Ben.Peart@microsoft.com> wrote:

Show 22 quoted lines

> Take advantage of the recent addition of support for lazy loading functions
> on Windows to simplfy the loading of NtSetSystemInformation.
>
> Signed-off-by: Ben Peart <benpeart@microsoft.com>
> ---
>
> Notes:
>     Base Ref: master
>     Web-Diff: https://github.com/benpeart/git/commit/6e6ce4a788
>     Checkout: git fetch https://github.com/benpeart/git test-drop-caches-v1 && git checkout 6e6ce4a788
>
>  t/helper/test-drop-caches.c | 16 ++++------------
>  1 file changed, 4 insertions(+), 12 deletions(-)
>
> diff --git a/t/helper/test-drop-caches.c b/t/helper/test-drop-caches.c
> index 838760898b..dd41da1a2c 100644
> --- a/t/helper/test-drop-caches.c
> +++ b/t/helper/test-drop-caches.c
> @@ -1,5 +1,6 @@
>  #include "test-tool.h"
>  #include "git-compat-util.h"
> +#include "lazyload.h"

This is in compat/win32, should it be inside the "if defined (GIT_WINDOWS_NATIVE)" block instead of here?

Show 44 quoted lines

>
>  #if defined(GIT_WINDOWS_NATIVE)
>
> @@ -82,8 +83,6 @@ static int cmd_dropcaches(void)
>  {
>         HANDLE hProcess = GetCurrentProcess();
>         HANDLE hToken;
> -       HMODULE ntdll;
> -       DWORD(WINAPI *NtSetSystemInformation)(INT, PVOID, ULONG);
>         SYSTEM_MEMORY_LIST_COMMAND command;
>         int status;
>
> @@ -95,14 +94,9 @@ static int cmd_dropcaches(void)
>
>         CloseHandle(hToken);
>
> -       ntdll = LoadLibrary("ntdll.dll");
> -       if (!ntdll)
> -               return error("Can't load ntdll.dll, wrong Windows version?");
> -
> -       NtSetSystemInformation =
> -               (DWORD(WINAPI *)(INT, PVOID, ULONG))GetProcAddress(ntdll, "NtSetSystemInformation");
> -       if (!NtSetSystemInformation)
> -               return error("Can't get function addresses, wrong Windows version?");
> +       DECLARE_PROC_ADDR(ntdll.dll, DWORD, NtSetSystemInformation, INT, PVOID, ULONG);
> +       if (!INIT_PROC_ADDR(NtSetSystemInformation))
> +               return error("Could not find NtSetSystemInformation() function");
>
>         command = MemoryPurgeStandbyList;
>         status = NtSetSystemInformation(
> @@ -115,8 +109,6 @@ static int cmd_dropcaches(void)
>         else if (status != STATUS_SUCCESS)
>                 error("Unable to execute the memory list command %d", status);
>
> -       FreeLibrary(ntdll);
> -
>         return status;
>  }
>
>
> base-commit: 1f1cddd558b54bb0ce19c8ace353fd07b758510d
> --
> 2.17.0.windows.1
>

-- 
Duy