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