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