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-rw-r--r--t/helper/test-drop-caches.c157
1 files changed, 157 insertions, 0 deletions
diff --git a/t/helper/test-drop-caches.c b/t/helper/test-drop-caches.c
new file mode 100644
index 0000000000..d6bcfddf13
--- /dev/null
+++ b/t/helper/test-drop-caches.c
@@ -0,0 +1,157 @@
+#include "test-tool.h"
+#include "git-compat-util.h"
+
+#if defined(GIT_WINDOWS_NATIVE)
+#include "lazyload.h"
+
+static int cmd_sync(void)
+{
+ char Buffer[MAX_PATH];
+ DWORD dwRet;
+ char szVolumeAccessPath[] = "\\\\.\\X:";
+ HANDLE hVolWrite;
+ int success = 0;
+
+ dwRet = GetCurrentDirectory(MAX_PATH, Buffer);
+ if ((0 == dwRet) || (dwRet > MAX_PATH))
+ return error("Error getting current directory");
+
+ if ((Buffer[0] < 'A') || (Buffer[0] > 'Z'))
+ return error("Invalid drive letter '%c'", Buffer[0]);
+
+ szVolumeAccessPath[4] = Buffer[0];
+ hVolWrite = CreateFile(szVolumeAccessPath, GENERIC_READ | GENERIC_WRITE,
+ FILE_SHARE_READ | FILE_SHARE_WRITE, NULL, OPEN_EXISTING, 0, NULL);
+ if (INVALID_HANDLE_VALUE == hVolWrite)
+ return error("Unable to open volume for writing, need admin access");
+
+ success = FlushFileBuffers(hVolWrite);
+ if (!success)
+ error("Unable to flush volume");
+
+ CloseHandle(hVolWrite);
+
+ return !success;
+}
+
+#define STATUS_SUCCESS (0x00000000L)
+#define STATUS_PRIVILEGE_NOT_HELD (0xC0000061L)
+
+typedef enum _SYSTEM_INFORMATION_CLASS {
+ SystemMemoryListInformation = 80,
+} SYSTEM_INFORMATION_CLASS;
+
+typedef enum _SYSTEM_MEMORY_LIST_COMMAND {
+ MemoryCaptureAccessedBits,
+ MemoryCaptureAndResetAccessedBits,
+ MemoryEmptyWorkingSets,
+ MemoryFlushModifiedList,
+ MemoryPurgeStandbyList,
+ MemoryPurgeLowPriorityStandbyList,
+ MemoryCommandMax
+} SYSTEM_MEMORY_LIST_COMMAND;
+
+static BOOL GetPrivilege(HANDLE TokenHandle, LPCSTR lpName, int flags)
+{
+ BOOL bResult;
+ DWORD dwBufferLength;
+ LUID luid;
+ TOKEN_PRIVILEGES tpPreviousState;
+ TOKEN_PRIVILEGES tpNewState;
+
+ dwBufferLength = 16;
+ bResult = LookupPrivilegeValueA(0, lpName, &luid);
+ if (bResult) {
+ tpNewState.PrivilegeCount = 1;
+ tpNewState.Privileges[0].Luid = luid;
+ tpNewState.Privileges[0].Attributes = 0;
+ bResult = AdjustTokenPrivileges(TokenHandle, 0, &tpNewState,
+ (DWORD)((LPBYTE)&(tpNewState.Privileges[1]) - (LPBYTE)&tpNewState),
+ &tpPreviousState, &dwBufferLength);
+ if (bResult) {
+ tpPreviousState.PrivilegeCount = 1;
+ tpPreviousState.Privileges[0].Luid = luid;
+ tpPreviousState.Privileges[0].Attributes = flags != 0 ? 2 : 0;
+ bResult = AdjustTokenPrivileges(TokenHandle, 0, &tpPreviousState,
+ dwBufferLength, 0, 0);
+ }
+ }
+ return bResult;
+}
+
+static int cmd_dropcaches(void)
+{
+ HANDLE hProcess = GetCurrentProcess();
+ HANDLE hToken;
+ DECLARE_PROC_ADDR(ntdll.dll, DWORD, NtSetSystemInformation, INT, PVOID, ULONG);
+ SYSTEM_MEMORY_LIST_COMMAND command;
+ int status;
+
+ if (!OpenProcessToken(hProcess, TOKEN_QUERY | TOKEN_ADJUST_PRIVILEGES, &hToken))
+ return error("Can't open current process token");
+
+ if (!GetPrivilege(hToken, "SeProfileSingleProcessPrivilege", 1))
+ return error("Can't get SeProfileSingleProcessPrivilege");
+
+ CloseHandle(hToken);
+
+ if (!INIT_PROC_ADDR(NtSetSystemInformation))
+ return error("Could not find NtSetSystemInformation() function");
+
+ command = MemoryPurgeStandbyList;
+ status = NtSetSystemInformation(
+ SystemMemoryListInformation,
+ &command,
+ sizeof(SYSTEM_MEMORY_LIST_COMMAND)
+ );
+ if (status == STATUS_PRIVILEGE_NOT_HELD)
+ error("Insufficient privileges to purge the standby list, need admin access");
+ else if (status != STATUS_SUCCESS)
+ error("Unable to execute the memory list command %d", status);
+
+ return status;
+}
+
+#elif defined(__linux__)
+
+static int cmd_sync(void)
+{
+ return system("sync");
+}
+
+static int cmd_dropcaches(void)
+{
+ return system("echo 3 | sudo tee /proc/sys/vm/drop_caches");
+}
+
+#elif defined(__APPLE__)
+
+static int cmd_sync(void)
+{
+ return system("sync");
+}
+
+static int cmd_dropcaches(void)
+{
+ return system("sudo purge");
+}
+
+#else
+
+static int cmd_sync(void)
+{
+ return 0;
+}
+
+static int cmd_dropcaches(void)
+{
+ return error("drop caches not implemented on this platform");
+}
+
+#endif
+
+int cmd__drop_caches(int argc, const char **argv)
+{
+ cmd_sync();
+ return cmd_dropcaches();
+}