t/helper/test-drop-caches.c

   1 #include "test-tool.h"
   2 #include "git-compat-util.h"
   3
   4 #if defined(GIT_WINDOWS_NATIVE)
   5
   6 static int cmd_sync(void)
   7 {
   8         char Buffer[MAX_PATH];
   9         DWORD dwRet;
  10         char szVolumeAccessPath[] = "\\\\.\\X:";
  11         HANDLE hVolWrite;
  12         int success = 0;
  13
  14         dwRet = GetCurrentDirectory(MAX_PATH, Buffer);
  15         if ((0 == dwRet) || (dwRet > MAX_PATH))
  16                 return error("Error getting current directory");
  17
  18         if ((Buffer[0] < 'A') || (Buffer[0] > 'Z'))
  19                 return error("Invalid drive letter '%c'", Buffer[0]);
  20
  21         szVolumeAccessPath[4] = Buffer[0];
  22         hVolWrite = CreateFile(szVolumeAccessPath, GENERIC_READ | GENERIC_WRITE,
  23                 FILE_SHARE_READ | FILE_SHARE_WRITE, NULL, OPEN_EXISTING, 0, NULL);
  24         if (INVALID_HANDLE_VALUE == hVolWrite)
  25                 return error("Unable to open volume for writing, need admin access");
  26
  27         success = FlushFileBuffers(hVolWrite);
  28         if (!success)
  29                 error("Unable to flush volume");
  30
  31         CloseHandle(hVolWrite);
  32
  33         return !success;
  34 }
  35
  36 #define STATUS_SUCCESS                  (0x00000000L)
  37 #define STATUS_PRIVILEGE_NOT_HELD       (0xC0000061L)
  38
  39 typedef enum _SYSTEM_INFORMATION_CLASS {
  40         SystemMemoryListInformation = 80,
  41 } SYSTEM_INFORMATION_CLASS;
  42
  43 typedef enum _SYSTEM_MEMORY_LIST_COMMAND {
  44         MemoryCaptureAccessedBits,
  45         MemoryCaptureAndResetAccessedBits,
  46         MemoryEmptyWorkingSets,
  47         MemoryFlushModifiedList,
  48         MemoryPurgeStandbyList,
  49         MemoryPurgeLowPriorityStandbyList,
  50         MemoryCommandMax
  51 } SYSTEM_MEMORY_LIST_COMMAND;
  52
  53 static BOOL GetPrivilege(HANDLE TokenHandle, LPCSTR lpName, int flags)
  54 {
  55         BOOL bResult;
  56         DWORD dwBufferLength;
  57         LUID luid;
  58         TOKEN_PRIVILEGES tpPreviousState;
  59         TOKEN_PRIVILEGES tpNewState;
  60
  61         dwBufferLength = 16;
  62         bResult = LookupPrivilegeValueA(0, lpName, &luid);
  63         if (bResult) {
  64                 tpNewState.PrivilegeCount = 1;
  65                 tpNewState.Privileges[0].Luid = luid;
  66                 tpNewState.Privileges[0].Attributes = 0;
  67                 bResult = AdjustTokenPrivileges(TokenHandle, 0, &tpNewState,
  68                         (DWORD)((LPBYTE)&(tpNewState.Privileges[1]) - (LPBYTE)&tpNewState),
  69                         &tpPreviousState, &dwBufferLength);
  70                 if (bResult) {
  71                         tpPreviousState.PrivilegeCount = 1;
  72                         tpPreviousState.Privileges[0].Luid = luid;
  73                         tpPreviousState.Privileges[0].Attributes = flags != 0 ? 2 : 0;
  74                         bResult = AdjustTokenPrivileges(TokenHandle, 0, &tpPreviousState,
  75                                 dwBufferLength, 0, 0);
  76                 }
  77         }
  78         return bResult;
  79 }
  80
  81 static int cmd_dropcaches(void)
  82 {
  83         HANDLE hProcess = GetCurrentProcess();
  84         HANDLE hToken;
  85         HMODULE ntdll;
  86         DWORD(WINAPI *NtSetSystemInformation)(INT, PVOID, ULONG);
  87         SYSTEM_MEMORY_LIST_COMMAND command;
  88         int status;
  89
  90         if (!OpenProcessToken(hProcess, TOKEN_QUERY | TOKEN_ADJUST_PRIVILEGES, &hToken))
  91                 return error("Can't open current process token");
  92
  93         if (!GetPrivilege(hToken, "SeProfileSingleProcessPrivilege", 1))
  94                 return error("Can't get SeProfileSingleProcessPrivilege");
  95
  96         CloseHandle(hToken);
  97
  98         ntdll = LoadLibrary("ntdll.dll");
  99         if (!ntdll)
 100                 return error("Can't load ntdll.dll, wrong Windows version?");
 101
 102         NtSetSystemInformation =
 103                 (DWORD(WINAPI *)(INT, PVOID, ULONG))GetProcAddress(ntdll, "NtSetSystemInformation");
 104         if (!NtSetSystemInformation)
 105                 return error("Can't get function addresses, wrong Windows version?");
 106
 107         command = MemoryPurgeStandbyList;
 108         status = NtSetSystemInformation(
 109                 SystemMemoryListInformation,
 110                 &command,
 111                 sizeof(SYSTEM_MEMORY_LIST_COMMAND)
 112         );
 113         if (status == STATUS_PRIVILEGE_NOT_HELD)
 114                 error("Insufficient privileges to purge the standby list, need admin access");
 115         else if (status != STATUS_SUCCESS)
 116                 error("Unable to execute the memory list command %d", status);
 117
 118         FreeLibrary(ntdll);
 119
 120         return status;
 121 }
 122
 123 #elif defined(__linux__)
 124
 125 static int cmd_sync(void)
 126 {
 127         return system("sync");
 128 }
 129
 130 static int cmd_dropcaches(void)
 131 {
 132         return system("echo 3 | sudo tee /proc/sys/vm/drop_caches");
 133 }
 134
 135 #elif defined(__APPLE__)
 136
 137 static int cmd_sync(void)
 138 {
 139         return system("sync");
 140 }
 141
 142 static int cmd_dropcaches(void)
 143 {
 144         return system("sudo purge");
 145 }
 146
 147 #else
 148
 149 static int cmd_sync(void)
 150 {
 151         return 0;
 152 }
 153
 154 static int cmd_dropcaches(void)
 155 {
 156         return error("drop caches not implemented on this platform");
 157 }
 158
 159 #endif
 160
 161 int cmd__drop_caches(int argc, const char **argv)
 162 {
 163         cmd_sync();
 164         return cmd_dropcaches();
 165 }