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