add windows platform to ydb github export

6 files changed, 2190 insertions, 0 deletions

diff --git a/contrib/libs/postgresql/src/backend/port/win32/crashdump.c b/contrib/libs/postgresql/src/backend/port/win32/crashdump.c
new file mode 100644
index 0000000000..45b6696ba1
--- /dev/null
+++ b/contrib/libs/postgresql/src/backend/port/win32/crashdump.c
@@ -0,0 +1,183 @@
+/*-------------------------------------------------------------------------
+ *
+ * crashdump.c
+ *		   Automatic crash dump creation for PostgreSQL on Windows
+ *
+ * The crashdump feature traps unhandled win32 exceptions produced by the
+ * backend, and tries to produce a Windows MiniDump crash
+ * dump for later debugging and analysis. The machine performing the dump
+ * doesn't need any special debugging tools; the user only needs to send
+ * the dump to somebody who has the same version of PostgreSQL and has debugging
+ * tools.
+ *
+ * crashdump module originally by Craig Ringer <ringerc@ringerc.id.au>
+ *
+ * LIMITATIONS
+ * ===========
+ * This *won't* work in hard OOM situations or stack overflows.
+ *
+ * For those, it'd be necessary to take a much more complicated approach where
+ * the handler switches to a new stack (if it can) and forks a helper process
+ * to debug it self.
+ *
+ * POSSIBLE FUTURE WORK
+ * ====================
+ * For bonus points, the crash dump format permits embedding of user-supplied
+ * data. If there's anything else that should always be supplied with a crash
+ * dump (postgresql.conf? Last few lines of a log file?), it could potentially
+ * be added, though at the cost of a greater chance of the crash dump failing.
+ *
+ *
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
+ *
+ * IDENTIFICATION
+ *	  src/backend/port/win32/crashdump.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#include "postgres.h"
+
+#define WIN32_LEAN_AND_MEAN
+
+/*
+ * Some versions of the MS SDK contain "typedef enum { ... } ;" which the MS
+ * compiler quite sanely complains about. Well done, Microsoft.
+ * This pragma disables the warning just while we include the header.
+ * The pragma is known to work with all (as at the time of writing) supported
+ * versions of MSVC.
+ */
+#ifdef _MSC_VER
+#pragma warning(push)
+#pragma warning(disable : 4091)
+#endif
+#include <dbghelp.h>
+#ifdef _MSC_VER
+#pragma warning(pop)
+#endif
+
+/*
+ * Much of the following code is based on CodeProject and MSDN examples,
+ * particularly
+ * http://www.codeproject.com/KB/debug/postmortemdebug_standalone1.aspx
+ *
+ * Useful MSDN articles:
+ *
+ * http://msdn.microsoft.com/en-us/library/ff805116(v=VS.85).aspx
+ * http://msdn.microsoft.com/en-us/library/ms679294(VS.85).aspx
+ *
+ * Other useful articles on working with minidumps:
+ * http://www.debuginfo.com/articles/effminidumps.html
+ */
+
+typedef BOOL (WINAPI * MINIDUMPWRITEDUMP) (HANDLE hProcess, DWORD dwPid, HANDLE hFile, MINIDUMP_TYPE DumpType,
+										   CONST PMINIDUMP_EXCEPTION_INFORMATION ExceptionParam,
+										   CONST PMINIDUMP_USER_STREAM_INFORMATION UserStreamParam,
+										   CONST PMINIDUMP_CALLBACK_INFORMATION CallbackParam
+);
+
+
+/*
+ * This function is the exception handler passed to SetUnhandledExceptionFilter.
+ * It's invoked only if there's an unhandled exception. The handler will use
+ * dbghelp.dll to generate a crash dump, then resume the normal unhandled
+ * exception process, which will generally exit with an error message from
+ * the runtime.
+ *
+ * This function is run under the unhandled exception handler, effectively
+ * in a crash context, so it should be careful with memory and avoid using
+ * any PostgreSQL functions.
+ */
+static LONG WINAPI
+crashDumpHandler(struct _EXCEPTION_POINTERS *pExceptionInfo)
+{
+	/*
+	 * We only write crash dumps if the "crashdumps" directory within the
+	 * postgres data directory exists.
+	 */
+	DWORD		attribs = GetFileAttributesA("crashdumps");
+
+	if (attribs != INVALID_FILE_ATTRIBUTES && (attribs & FILE_ATTRIBUTE_DIRECTORY))
+	{
+		/* 'crashdumps' exists and is a directory. Try to write a dump' */
+		HMODULE		hDll = NULL;
+		MINIDUMPWRITEDUMP pDump = NULL;
+		MINIDUMP_TYPE dumpType;
+		char		dumpPath[_MAX_PATH];
+		HANDLE		selfProcHandle = GetCurrentProcess();
+		DWORD		selfPid = GetProcessId(selfProcHandle);
+		HANDLE		dumpFile;
+		DWORD		systemTicks;
+		struct _MINIDUMP_EXCEPTION_INFORMATION ExInfo;
+
+		ExInfo.ThreadId = GetCurrentThreadId();
+		ExInfo.ExceptionPointers = pExceptionInfo;
+		ExInfo.ClientPointers = FALSE;
+
+		/* Load the dbghelp.dll library and functions */
+		hDll = LoadLibrary("dbghelp.dll");
+		if (hDll == NULL)
+		{
+			write_stderr("could not load dbghelp.dll, cannot write crash dump\n");
+			return EXCEPTION_CONTINUE_SEARCH;
+		}
+
+		pDump = (MINIDUMPWRITEDUMP) (pg_funcptr_t) GetProcAddress(hDll, "MiniDumpWriteDump");
+
+		if (pDump == NULL)
+		{
+			write_stderr("could not load required functions in dbghelp.dll, cannot write crash dump\n");
+			return EXCEPTION_CONTINUE_SEARCH;
+		}
+
+		/*
+		 * Dump as much as we can, except shared memory, code segments, and
+		 * memory mapped files. Exactly what we can dump depends on the
+		 * version of dbghelp.dll, see:
+		 * http://msdn.microsoft.com/en-us/library/ms680519(v=VS.85).aspx
+		 */
+		dumpType = MiniDumpNormal | MiniDumpWithHandleData |
+			MiniDumpWithDataSegs;
+
+		if (GetProcAddress(hDll, "EnumDirTree") != NULL)
+		{
+			/* If this function exists, we have version 5.2 or newer */
+			dumpType |= MiniDumpWithIndirectlyReferencedMemory |
+				MiniDumpWithPrivateReadWriteMemory;
+		}
+
+		systemTicks = GetTickCount();
+		snprintf(dumpPath, _MAX_PATH,
+				 "crashdumps\\postgres-pid%0i-%0i.mdmp",
+				 (int) selfPid, (int) systemTicks);
+		dumpPath[_MAX_PATH - 1] = '\0';
+
+		dumpFile = CreateFile(dumpPath, GENERIC_WRITE, FILE_SHARE_WRITE,
+							  NULL, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL,
+							  NULL);
+		if (dumpFile == INVALID_HANDLE_VALUE)
+		{
+			write_stderr("could not open crash dump file \"%s\" for writing: error code %lu\n",
+						 dumpPath, GetLastError());
+			return EXCEPTION_CONTINUE_SEARCH;
+		}
+
+		if ((*pDump) (selfProcHandle, selfPid, dumpFile, dumpType, &ExInfo,
+					  NULL, NULL))
+			write_stderr("wrote crash dump to file \"%s\"\n", dumpPath);
+		else
+			write_stderr("could not write crash dump to file \"%s\": error code %lu\n",
+						 dumpPath, GetLastError());
+
+		CloseHandle(dumpFile);
+	}
+
+	return EXCEPTION_CONTINUE_SEARCH;
+}
+
+
+void
+pgwin32_install_crashdump_handler(void)
+{
+	SetUnhandledExceptionFilter(crashDumpHandler);
+}
diff --git a/contrib/libs/postgresql/src/backend/port/win32/signal.c b/contrib/libs/postgresql/src/backend/port/win32/signal.c
new file mode 100644
index 0000000000..580a517f3f
--- /dev/null
+++ b/contrib/libs/postgresql/src/backend/port/win32/signal.c
@@ -0,0 +1,344 @@
+/*-------------------------------------------------------------------------
+ *
+ * signal.c
+ *	  Microsoft Windows Win32 Signal Emulation Functions
+ *
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
+ *
+ * IDENTIFICATION
+ *	  src/backend/port/win32/signal.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#include "postgres.h"
+
+#include "libpq/pqsignal.h"
+
+/*
+ * These are exported for use by the UNBLOCKED_SIGNAL_QUEUE() macro.
+ * pg_signal_queue must be volatile since it is changed by the signal
+ * handling thread and inspected without any lock by the main thread.
+ * pg_signal_mask is only changed by main thread so shouldn't need it.
+ */
+volatile int pg_signal_queue;
+int			pg_signal_mask;
+
+HANDLE		pgwin32_signal_event;
+HANDLE		pgwin32_initial_signal_pipe = INVALID_HANDLE_VALUE;
+
+/*
+ * pg_signal_crit_sec is used to protect only pg_signal_queue. That is the only
+ * variable that can be accessed from the signal sending threads!
+ */
+static CRITICAL_SECTION pg_signal_crit_sec;
+
+/* Note that array elements 0 are unused since they correspond to signal 0 */
+static pqsigfunc pg_signal_array[PG_SIGNAL_COUNT];
+static pqsigfunc pg_signal_defaults[PG_SIGNAL_COUNT];
+
+
+/* Signal handling thread functions */
+static DWORD WINAPI pg_signal_thread(LPVOID param);
+static BOOL WINAPI pg_console_handler(DWORD dwCtrlType);
+
+
+/*
+ * pg_usleep --- delay the specified number of microseconds, but
+ * stop waiting if a signal arrives.
+ *
+ * This replaces the non-signal-aware version provided by src/port/pgsleep.c.
+ */
+void
+pg_usleep(long microsec)
+{
+	Assert(pgwin32_signal_event != NULL);
+	if (WaitForSingleObject(pgwin32_signal_event,
+							(microsec < 500 ? 1 : (microsec + 500) / 1000))
+		== WAIT_OBJECT_0)
+	{
+		pgwin32_dispatch_queued_signals();
+		errno = EINTR;
+		return;
+	}
+}
+
+
+/* Initialization */
+void
+pgwin32_signal_initialize(void)
+{
+	int			i;
+	HANDLE		signal_thread_handle;
+
+	InitializeCriticalSection(&pg_signal_crit_sec);
+
+	for (i = 0; i < PG_SIGNAL_COUNT; i++)
+	{
+		pg_signal_array[i] = SIG_DFL;
+		pg_signal_defaults[i] = SIG_IGN;
+	}
+	pg_signal_mask = 0;
+	pg_signal_queue = 0;
+
+	/* Create the global event handle used to flag signals */
+	pgwin32_signal_event = CreateEvent(NULL, TRUE, FALSE, NULL);
+	if (pgwin32_signal_event == NULL)
+		ereport(FATAL,
+				(errmsg_internal("could not create signal event: error code %lu", GetLastError())));
+
+	/* Create thread for handling signals */
+	signal_thread_handle = CreateThread(NULL, 0, pg_signal_thread, NULL, 0, NULL);
+	if (signal_thread_handle == NULL)
+		ereport(FATAL,
+				(errmsg_internal("could not create signal handler thread")));
+
+	/* Create console control handle to pick up Ctrl-C etc */
+	if (!SetConsoleCtrlHandler(pg_console_handler, TRUE))
+		ereport(FATAL,
+				(errmsg_internal("could not set console control handler")));
+}
+
+/*
+ * Dispatch all signals currently queued and not blocked
+ * Blocked signals are ignored, and will be fired at the time of
+ * the pqsigsetmask() call.
+ */
+void
+pgwin32_dispatch_queued_signals(void)
+{
+	int			exec_mask;
+
+	Assert(pgwin32_signal_event != NULL);
+	EnterCriticalSection(&pg_signal_crit_sec);
+	while ((exec_mask = UNBLOCKED_SIGNAL_QUEUE()) != 0)
+	{
+		/* One or more unblocked signals queued for execution */
+		int			i;
+
+		for (i = 1; i < PG_SIGNAL_COUNT; i++)
+		{
+			if (exec_mask & sigmask(i))
+			{
+				/* Execute this signal */
+				pqsigfunc	sig = pg_signal_array[i];
+
+				if (sig == SIG_DFL)
+					sig = pg_signal_defaults[i];
+				pg_signal_queue &= ~sigmask(i);
+				if (sig != SIG_ERR && sig != SIG_IGN && sig != SIG_DFL)
+				{
+					LeaveCriticalSection(&pg_signal_crit_sec);
+					sig(i);
+					EnterCriticalSection(&pg_signal_crit_sec);
+					break;		/* Restart outer loop, in case signal mask or
+								 * queue has been modified inside signal
+								 * handler */
+				}
+			}
+		}
+	}
+	ResetEvent(pgwin32_signal_event);
+	LeaveCriticalSection(&pg_signal_crit_sec);
+}
+
+/* signal masking. Only called on main thread, no sync required */
+int
+pqsigsetmask(int mask)
+{
+	int			prevmask;
+
+	prevmask = pg_signal_mask;
+	pg_signal_mask = mask;
+
+	/*
+	 * Dispatch any signals queued up right away, in case we have unblocked
+	 * one or more signals previously queued
+	 */
+	pgwin32_dispatch_queued_signals();
+
+	return prevmask;
+}
+
+
+/*
+ * Unix-like signal handler installation
+ *
+ * Only called on main thread, no sync required
+ */
+pqsigfunc
+pqsignal(int signum, pqsigfunc handler)
+{
+	pqsigfunc	prevfunc;
+
+	if (signum >= PG_SIGNAL_COUNT || signum < 0)
+		return SIG_ERR;
+	prevfunc = pg_signal_array[signum];
+	pg_signal_array[signum] = handler;
+	return prevfunc;
+}
+
+/* Create the signal listener pipe for specified PID */
+HANDLE
+pgwin32_create_signal_listener(pid_t pid)
+{
+	char		pipename[128];
+	HANDLE		pipe;
+
+	snprintf(pipename, sizeof(pipename), "\\\\.\\pipe\\pgsignal_%u", (int) pid);
+
+	pipe = CreateNamedPipe(pipename, PIPE_ACCESS_DUPLEX,
+						   PIPE_TYPE_MESSAGE | PIPE_READMODE_MESSAGE | PIPE_WAIT,
+						   PIPE_UNLIMITED_INSTANCES, 16, 16, 1000, NULL);
+
+	if (pipe == INVALID_HANDLE_VALUE)
+		ereport(ERROR,
+				(errmsg("could not create signal listener pipe for PID %d: error code %lu",
+						(int) pid, GetLastError())));
+
+	return pipe;
+}
+
+
+/*
+ * All functions below execute on the signal handler thread
+ * and must be synchronized as such!
+ * NOTE! The only global variable that can be used is
+ * pg_signal_queue!
+ */
+
+
+/*
+ * Queue a signal for the main thread, by setting the flag bit and event.
+ */
+void
+pg_queue_signal(int signum)
+{
+	Assert(pgwin32_signal_event != NULL);
+	if (signum >= PG_SIGNAL_COUNT || signum <= 0)
+		return;					/* ignore any bad signal number */
+
+	EnterCriticalSection(&pg_signal_crit_sec);
+	pg_signal_queue |= sigmask(signum);
+	LeaveCriticalSection(&pg_signal_crit_sec);
+
+	SetEvent(pgwin32_signal_event);
+}
+
+/* Signal handling thread */
+static DWORD WINAPI
+pg_signal_thread(LPVOID param)
+{
+	char		pipename[128];
+	HANDLE		pipe = pgwin32_initial_signal_pipe;
+
+	/* Set up pipe name, in case we have to re-create the pipe. */
+	snprintf(pipename, sizeof(pipename), "\\\\.\\pipe\\pgsignal_%lu", GetCurrentProcessId());
+
+	for (;;)
+	{
+		BOOL		fConnected;
+
+		/* Create a new pipe instance if we don't have one. */
+		if (pipe == INVALID_HANDLE_VALUE)
+		{
+			pipe = CreateNamedPipe(pipename, PIPE_ACCESS_DUPLEX,
+								   PIPE_TYPE_MESSAGE | PIPE_READMODE_MESSAGE | PIPE_WAIT,
+								   PIPE_UNLIMITED_INSTANCES, 16, 16, 1000, NULL);
+
+			if (pipe == INVALID_HANDLE_VALUE)
+			{
+				write_stderr("could not create signal listener pipe: error code %lu; retrying\n", GetLastError());
+				SleepEx(500, FALSE);
+				continue;
+			}
+		}
+
+		/*
+		 * Wait for a client to connect.  If something connects before we
+		 * reach here, we'll get back a "failure" with ERROR_PIPE_CONNECTED,
+		 * which is actually a success (way to go, Microsoft).
+		 */
+		fConnected = ConnectNamedPipe(pipe, NULL) ? TRUE : (GetLastError() == ERROR_PIPE_CONNECTED);
+		if (fConnected)
+		{
+			/*
+			 * We have a connection from a would-be signal sender. Process it.
+			 */
+			BYTE		sigNum;
+			DWORD		bytes;
+
+			if (ReadFile(pipe, &sigNum, 1, &bytes, NULL) &&
+				bytes == 1)
+			{
+				/*
+				 * Queue the signal before responding to the client.  In this
+				 * way, it's guaranteed that once kill() has returned in the
+				 * signal sender, the next CHECK_FOR_INTERRUPTS() in the
+				 * signal recipient will see the signal.  (This is a stronger
+				 * guarantee than POSIX makes; maybe we don't need it?  But
+				 * without it, we've seen timing bugs on Windows that do not
+				 * manifest on any known Unix.)
+				 */
+				pg_queue_signal(sigNum);
+
+				/*
+				 * Write something back to the client, allowing its
+				 * CallNamedPipe() call to terminate.
+				 */
+				WriteFile(pipe, &sigNum, 1, &bytes, NULL);	/* Don't care if it
+															 * works or not */
+
+				/*
+				 * We must wait for the client to read the data before we can
+				 * disconnect, else the data will be lost.  (If the WriteFile
+				 * call failed, there'll be nothing in the buffer, so this
+				 * shouldn't block.)
+				 */
+				FlushFileBuffers(pipe);
+			}
+			else
+			{
+				/*
+				 * If we fail to read a byte from the client, assume it's the
+				 * client's problem and do nothing.  Perhaps it'd be better to
+				 * force a pipe close and reopen?
+				 */
+			}
+
+			/* Disconnect from client so that we can re-use the pipe. */
+			DisconnectNamedPipe(pipe);
+		}
+		else
+		{
+			/*
+			 * Connection failed.  Cleanup and try again.
+			 *
+			 * This should never happen.  If it does, there's a window where
+			 * we'll miss signals until we manage to re-create the pipe.
+			 * However, just trying to use the same pipe again is probably not
+			 * going to work, so we have little choice.
+			 */
+			CloseHandle(pipe);
+			pipe = INVALID_HANDLE_VALUE;
+		}
+	}
+	return 0;
+}
+
+
+/* Console control handler will execute on a thread created
+   by the OS at the time of invocation */
+static BOOL WINAPI
+pg_console_handler(DWORD dwCtrlType)
+{
+	if (dwCtrlType == CTRL_C_EVENT ||
+		dwCtrlType == CTRL_BREAK_EVENT ||
+		dwCtrlType == CTRL_CLOSE_EVENT ||
+		dwCtrlType == CTRL_SHUTDOWN_EVENT)
+	{
+		pg_queue_signal(SIGINT);
+		return TRUE;
+	}
+	return FALSE;
+}
diff --git a/contrib/libs/postgresql/src/backend/port/win32/socket.c b/contrib/libs/postgresql/src/backend/port/win32/socket.c
new file mode 100644
index 0000000000..af151e8470
--- /dev/null
+++ b/contrib/libs/postgresql/src/backend/port/win32/socket.c
@@ -0,0 +1,700 @@
+/*-------------------------------------------------------------------------
+ *
+ * socket.c
+ *	  Microsoft Windows Win32 Socket Functions
+ *
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
+ *
+ * IDENTIFICATION
+ *	  src/backend/port/win32/socket.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#include "postgres.h"
+
+/*
+ * Indicate if pgwin32_recv() and pgwin32_send() should operate
+ * in non-blocking mode.
+ *
+ * Since the socket emulation layer always sets the actual socket to
+ * non-blocking mode in order to be able to deliver signals, we must
+ * specify this in a separate flag if we actually need non-blocking
+ * operation.
+ *
+ * This flag changes the behaviour *globally* for all socket operations,
+ * so it should only be set for very short periods of time.
+ */
+int			pgwin32_noblock = 0;
+
+/* Undef the macros defined in win32.h, so we can access system functions */
+#undef socket
+#undef bind
+#undef listen
+#undef accept
+#undef connect
+#undef select
+#undef recv
+#undef send
+
+/*
+ * Blocking socket functions implemented so they listen on both
+ * the socket and the signal event, required for signal handling.
+ */
+
+/*
+ * Convert the last socket error code into errno
+ *
+ * Note: where there is a direct correspondence between a WSAxxx error code
+ * and a Berkeley error symbol, this mapping is actually a no-op, because
+ * in win32.h we redefine the network-related Berkeley error symbols to have
+ * the values of their WSAxxx counterparts.  The point of the switch is
+ * mostly to translate near-miss error codes into something that's sensible
+ * in the Berkeley universe.
+ */
+static void
+TranslateSocketError(void)
+{
+	switch (WSAGetLastError())
+	{
+		case WSAEINVAL:
+		case WSANOTINITIALISED:
+		case WSAEINVALIDPROVIDER:
+		case WSAEINVALIDPROCTABLE:
+		case WSAEDESTADDRREQ:
+			errno = EINVAL;
+			break;
+		case WSAEINPROGRESS:
+			errno = EINPROGRESS;
+			break;
+		case WSAEFAULT:
+			errno = EFAULT;
+			break;
+		case WSAEISCONN:
+			errno = EISCONN;
+			break;
+		case WSAEMSGSIZE:
+			errno = EMSGSIZE;
+			break;
+		case WSAEAFNOSUPPORT:
+			errno = EAFNOSUPPORT;
+			break;
+		case WSAEMFILE:
+			errno = EMFILE;
+			break;
+		case WSAENOBUFS:
+			errno = ENOBUFS;
+			break;
+		case WSAEPROTONOSUPPORT:
+		case WSAEPROTOTYPE:
+		case WSAESOCKTNOSUPPORT:
+			errno = EPROTONOSUPPORT;
+			break;
+		case WSAECONNABORTED:
+			errno = ECONNABORTED;
+			break;
+		case WSAECONNREFUSED:
+			errno = ECONNREFUSED;
+			break;
+		case WSAECONNRESET:
+			errno = ECONNRESET;
+			break;
+		case WSAEINTR:
+			errno = EINTR;
+			break;
+		case WSAENOTSOCK:
+			errno = ENOTSOCK;
+			break;
+		case WSAEOPNOTSUPP:
+			errno = EOPNOTSUPP;
+			break;
+		case WSAEWOULDBLOCK:
+			errno = EWOULDBLOCK;
+			break;
+		case WSAEACCES:
+			errno = EACCES;
+			break;
+		case WSAEADDRINUSE:
+			errno = EADDRINUSE;
+			break;
+		case WSAEADDRNOTAVAIL:
+			errno = EADDRNOTAVAIL;
+			break;
+		case WSAEHOSTDOWN:
+			errno = EHOSTDOWN;
+			break;
+		case WSAEHOSTUNREACH:
+		case WSAHOST_NOT_FOUND:
+			errno = EHOSTUNREACH;
+			break;
+		case WSAENETDOWN:
+			errno = ENETDOWN;
+			break;
+		case WSAENETUNREACH:
+			errno = ENETUNREACH;
+			break;
+		case WSAENETRESET:
+			errno = ENETRESET;
+			break;
+		case WSAENOTCONN:
+		case WSAESHUTDOWN:
+		case WSAEDISCON:
+			errno = ENOTCONN;
+			break;
+		default:
+			ereport(NOTICE,
+					(errmsg_internal("unrecognized win32 socket error code: %d", WSAGetLastError())));
+			errno = EINVAL;
+	}
+}
+
+static int
+pgwin32_poll_signals(void)
+{
+	if (UNBLOCKED_SIGNAL_QUEUE())
+	{
+		pgwin32_dispatch_queued_signals();
+		errno = EINTR;
+		return 1;
+	}
+	return 0;
+}
+
+static int
+isDataGram(SOCKET s)
+{
+	int			type;
+	int			typelen = sizeof(type);
+
+	if (getsockopt(s, SOL_SOCKET, SO_TYPE, (char *) &type, &typelen))
+		return 1;
+
+	return (type == SOCK_DGRAM) ? 1 : 0;
+}
+
+int
+pgwin32_waitforsinglesocket(SOCKET s, int what, int timeout)
+{
+	static HANDLE waitevent = INVALID_HANDLE_VALUE;
+	static SOCKET current_socket = INVALID_SOCKET;
+	static int	isUDP = 0;
+	HANDLE		events[2];
+	int			r;
+
+	/* Create an event object just once and use it on all future calls */
+	if (waitevent == INVALID_HANDLE_VALUE)
+	{
+		waitevent = CreateEvent(NULL, TRUE, FALSE, NULL);
+
+		if (waitevent == INVALID_HANDLE_VALUE)
+			ereport(ERROR,
+					(errmsg_internal("could not create socket waiting event: error code %lu", GetLastError())));
+	}
+	else if (!ResetEvent(waitevent))
+		ereport(ERROR,
+				(errmsg_internal("could not reset socket waiting event: error code %lu", GetLastError())));
+
+	/*
+	 * Track whether socket is UDP or not.  (NB: most likely, this is both
+	 * useless and wrong; there is no reason to think that the behavior of
+	 * WSAEventSelect is different for TCP and UDP.)
+	 */
+	if (current_socket != s)
+		isUDP = isDataGram(s);
+	current_socket = s;
+
+	/*
+	 * Attach event to socket.  NOTE: we must detach it again before
+	 * returning, since other bits of code may try to attach other events to
+	 * the socket.
+	 */
+	if (WSAEventSelect(s, waitevent, what) != 0)
+	{
+		TranslateSocketError();
+		return 0;
+	}
+
+	events[0] = pgwin32_signal_event;
+	events[1] = waitevent;
+
+	/*
+	 * Just a workaround of unknown locking problem with writing in UDP socket
+	 * under high load: Client's pgsql backend sleeps infinitely in
+	 * WaitForMultipleObjectsEx, pgstat process sleeps in pgwin32_select().
+	 * So, we will wait with small timeout(0.1 sec) and if socket is still
+	 * blocked, try WSASend (see comments in pgwin32_select) and wait again.
+	 */
+	if ((what & FD_WRITE) && isUDP)
+	{
+		for (;;)
+		{
+			r = WaitForMultipleObjectsEx(2, events, FALSE, 100, TRUE);
+
+			if (r == WAIT_TIMEOUT)
+			{
+				char		c;
+				WSABUF		buf;
+				DWORD		sent;
+
+				buf.buf = &c;
+				buf.len = 0;
+
+				r = WSASend(s, &buf, 1, &sent, 0, NULL, NULL);
+				if (r == 0)		/* Completed - means things are fine! */
+				{
+					WSAEventSelect(s, NULL, 0);
+					return 1;
+				}
+				else if (WSAGetLastError() != WSAEWOULDBLOCK)
+				{
+					TranslateSocketError();
+					WSAEventSelect(s, NULL, 0);
+					return 0;
+				}
+			}
+			else
+				break;
+		}
+	}
+	else
+		r = WaitForMultipleObjectsEx(2, events, FALSE, timeout, TRUE);
+
+	WSAEventSelect(s, NULL, 0);
+
+	if (r == WAIT_OBJECT_0 || r == WAIT_IO_COMPLETION)
+	{
+		pgwin32_dispatch_queued_signals();
+		errno = EINTR;
+		return 0;
+	}
+	if (r == WAIT_OBJECT_0 + 1)
+		return 1;
+	if (r == WAIT_TIMEOUT)
+	{
+		errno = EWOULDBLOCK;
+		return 0;
+	}
+	ereport(ERROR,
+			(errmsg_internal("unrecognized return value from WaitForMultipleObjects: %d (error code %lu)", r, GetLastError())));
+	return 0;
+}
+
+/*
+ * Create a socket, setting it to overlapped and non-blocking
+ */
+SOCKET
+pgwin32_socket(int af, int type, int protocol)
+{
+	SOCKET		s;
+	unsigned long on = 1;
+
+	s = WSASocket(af, type, protocol, NULL, 0, WSA_FLAG_OVERLAPPED);
+	if (s == INVALID_SOCKET)
+	{
+		TranslateSocketError();
+		return INVALID_SOCKET;
+	}
+
+	if (ioctlsocket(s, FIONBIO, &on))
+	{
+		TranslateSocketError();
+		return INVALID_SOCKET;
+	}
+	errno = 0;
+
+	return s;
+}
+
+int
+pgwin32_bind(SOCKET s, struct sockaddr *addr, int addrlen)
+{
+	int			res;
+
+	res = bind(s, addr, addrlen);
+	if (res < 0)
+		TranslateSocketError();
+	return res;
+}
+
+int
+pgwin32_listen(SOCKET s, int backlog)
+{
+	int			res;
+
+	res = listen(s, backlog);
+	if (res < 0)
+		TranslateSocketError();
+	return res;
+}
+
+SOCKET
+pgwin32_accept(SOCKET s, struct sockaddr *addr, int *addrlen)
+{
+	SOCKET		rs;
+
+	/*
+	 * Poll for signals, but don't return with EINTR, since we don't handle
+	 * that in pqcomm.c
+	 */
+	pgwin32_poll_signals();
+
+	rs = WSAAccept(s, addr, addrlen, NULL, 0);
+	if (rs == INVALID_SOCKET)
+	{
+		TranslateSocketError();
+		return INVALID_SOCKET;
+	}
+	return rs;
+}
+
+
+/* No signal delivery during connect. */
+int
+pgwin32_connect(SOCKET s, const struct sockaddr *addr, int addrlen)
+{
+	int			r;
+
+	r = WSAConnect(s, addr, addrlen, NULL, NULL, NULL, NULL);
+	if (r == 0)
+		return 0;
+
+	if (WSAGetLastError() != WSAEWOULDBLOCK)
+	{
+		TranslateSocketError();
+		return -1;
+	}
+
+	while (pgwin32_waitforsinglesocket(s, FD_CONNECT, INFINITE) == 0)
+	{
+		/* Loop endlessly as long as we are just delivering signals */
+	}
+
+	return 0;
+}
+
+int
+pgwin32_recv(SOCKET s, char *buf, int len, int f)
+{
+	WSABUF		wbuf;
+	int			r;
+	DWORD		b;
+	DWORD		flags = f;
+	int			n;
+
+	if (pgwin32_poll_signals())
+		return -1;
+
+	wbuf.len = len;
+	wbuf.buf = buf;
+
+	r = WSARecv(s, &wbuf, 1, &b, &flags, NULL, NULL);
+	if (r != SOCKET_ERROR)
+		return b;				/* success */
+
+	if (WSAGetLastError() != WSAEWOULDBLOCK)
+	{
+		TranslateSocketError();
+		return -1;
+	}
+
+	if (pgwin32_noblock)
+	{
+		/*
+		 * No data received, and we are in "emulated non-blocking mode", so
+		 * return indicating that we'd block if we were to continue.
+		 */
+		errno = EWOULDBLOCK;
+		return -1;
+	}
+
+	/* We're in blocking mode, so wait for data */
+
+	for (n = 0; n < 5; n++)
+	{
+		if (pgwin32_waitforsinglesocket(s, FD_READ | FD_CLOSE | FD_ACCEPT,
+										INFINITE) == 0)
+			return -1;			/* errno already set */
+
+		r = WSARecv(s, &wbuf, 1, &b, &flags, NULL, NULL);
+		if (r != SOCKET_ERROR)
+			return b;			/* success */
+		if (WSAGetLastError() != WSAEWOULDBLOCK)
+		{
+			TranslateSocketError();
+			return -1;
+		}
+
+		/*
+		 * There seem to be cases on win2k (at least) where WSARecv can return
+		 * WSAEWOULDBLOCK even when pgwin32_waitforsinglesocket claims the
+		 * socket is readable.  In this case, just sleep for a moment and try
+		 * again.  We try up to 5 times - if it fails more than that it's not
+		 * likely to ever come back.
+		 */
+		pg_usleep(10000);
+	}
+	ereport(NOTICE,
+			(errmsg_internal("could not read from ready socket (after retries)")));
+	errno = EWOULDBLOCK;
+	return -1;
+}
+
+/*
+ * The second argument to send() is defined by SUS to be a "const void *"
+ * and so we use the same signature here to keep compilers happy when
+ * handling callers.
+ *
+ * But the buf member of a WSABUF struct is defined as "char *", so we cast
+ * the second argument to that here when assigning it, also to keep compilers
+ * happy.
+ */
+
+int
+pgwin32_send(SOCKET s, const void *buf, int len, int flags)
+{
+	WSABUF		wbuf;
+	int			r;
+	DWORD		b;
+
+	if (pgwin32_poll_signals())
+		return -1;
+
+	wbuf.len = len;
+	wbuf.buf = (char *) buf;
+
+	/*
+	 * Readiness of socket to send data to UDP socket may be not true: socket
+	 * can become busy again! So loop until send or error occurs.
+	 */
+	for (;;)
+	{
+		r = WSASend(s, &wbuf, 1, &b, flags, NULL, NULL);
+		if (r != SOCKET_ERROR && b > 0)
+			/* Write succeeded right away */
+			return b;
+
+		if (r == SOCKET_ERROR &&
+			WSAGetLastError() != WSAEWOULDBLOCK)
+		{
+			TranslateSocketError();
+			return -1;
+		}
+
+		if (pgwin32_noblock)
+		{
+			/*
+			 * No data sent, and we are in "emulated non-blocking mode", so
+			 * return indicating that we'd block if we were to continue.
+			 */
+			errno = EWOULDBLOCK;
+			return -1;
+		}
+
+		/* No error, zero bytes (win2000+) or error+WSAEWOULDBLOCK (<=nt4) */
+
+		if (pgwin32_waitforsinglesocket(s, FD_WRITE | FD_CLOSE, INFINITE) == 0)
+			return -1;
+	}
+
+	return -1;
+}
+
+
+/*
+ * Wait for activity on one or more sockets.
+ * While waiting, allow signals to run
+ *
+ * NOTE! Currently does not implement exceptfds check,
+ * since it is not used in postgresql!
+ */
+int
+pgwin32_select(int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds, const struct timeval *timeout)
+{
+	WSAEVENT	events[FD_SETSIZE * 2]; /* worst case is readfds totally
+										 * different from writefds, so
+										 * 2*FD_SETSIZE sockets */
+	SOCKET		sockets[FD_SETSIZE * 2];
+	int			numevents = 0;
+	int			i;
+	int			r;
+	DWORD		timeoutval = WSA_INFINITE;
+	FD_SET		outreadfds;
+	FD_SET		outwritefds;
+	int			nummatches = 0;
+
+	Assert(exceptfds == NULL);
+
+	if (pgwin32_poll_signals())
+		return -1;
+
+	FD_ZERO(&outreadfds);
+	FD_ZERO(&outwritefds);
+
+	/*
+	 * Windows does not guarantee to log an FD_WRITE network event indicating
+	 * that more data can be sent unless the previous send() failed with
+	 * WSAEWOULDBLOCK.  While our caller might well have made such a call, we
+	 * cannot assume that here.  Therefore, if waiting for write-ready, force
+	 * the issue by doing a dummy send().  If the dummy send() succeeds,
+	 * assume that the socket is in fact write-ready, and return immediately.
+	 * Also, if it fails with something other than WSAEWOULDBLOCK, return a
+	 * write-ready indication to let our caller deal with the error condition.
+	 */
+	if (writefds != NULL)
+	{
+		for (i = 0; i < writefds->fd_count; i++)
+		{
+			char		c;
+			WSABUF		buf;
+			DWORD		sent;
+
+			buf.buf = &c;
+			buf.len = 0;
+
+			r = WSASend(writefds->fd_array[i], &buf, 1, &sent, 0, NULL, NULL);
+			if (r == 0 || WSAGetLastError() != WSAEWOULDBLOCK)
+				FD_SET(writefds->fd_array[i], &outwritefds);
+		}
+
+		/* If we found any write-ready sockets, just return them immediately */
+		if (outwritefds.fd_count > 0)
+		{
+			memcpy(writefds, &outwritefds, sizeof(fd_set));
+			if (readfds)
+				FD_ZERO(readfds);
+			return outwritefds.fd_count;
+		}
+	}
+
+
+	/* Now set up for an actual select */
+
+	if (timeout != NULL)
+	{
+		/* timeoutval is in milliseconds */
+		timeoutval = timeout->tv_sec * 1000 + timeout->tv_usec / 1000;
+	}
+
+	if (readfds != NULL)
+	{
+		for (i = 0; i < readfds->fd_count; i++)
+		{
+			events[numevents] = WSACreateEvent();
+			sockets[numevents] = readfds->fd_array[i];
+			numevents++;
+		}
+	}
+	if (writefds != NULL)
+	{
+		for (i = 0; i < writefds->fd_count; i++)
+		{
+			if (!readfds ||
+				!FD_ISSET(writefds->fd_array[i], readfds))
+			{
+				/* If the socket is not in the read list */
+				events[numevents] = WSACreateEvent();
+				sockets[numevents] = writefds->fd_array[i];
+				numevents++;
+			}
+		}
+	}
+
+	for (i = 0; i < numevents; i++)
+	{
+		int			flags = 0;
+
+		if (readfds && FD_ISSET(sockets[i], readfds))
+			flags |= FD_READ | FD_ACCEPT | FD_CLOSE;
+
+		if (writefds && FD_ISSET(sockets[i], writefds))
+			flags |= FD_WRITE | FD_CLOSE;
+
+		if (WSAEventSelect(sockets[i], events[i], flags) != 0)
+		{
+			TranslateSocketError();
+			/* release already-assigned event objects */
+			while (--i >= 0)
+				WSAEventSelect(sockets[i], NULL, 0);
+			for (i = 0; i < numevents; i++)
+				WSACloseEvent(events[i]);
+			return -1;
+		}
+	}
+
+	events[numevents] = pgwin32_signal_event;
+	r = WaitForMultipleObjectsEx(numevents + 1, events, FALSE, timeoutval, TRUE);
+	if (r != WAIT_TIMEOUT && r != WAIT_IO_COMPLETION && r != (WAIT_OBJECT_0 + numevents))
+	{
+		/*
+		 * We scan all events, even those not signaled, in case more than one
+		 * event has been tagged but Wait.. can only return one.
+		 */
+		WSANETWORKEVENTS resEvents;
+
+		for (i = 0; i < numevents; i++)
+		{
+			ZeroMemory(&resEvents, sizeof(resEvents));
+			if (WSAEnumNetworkEvents(sockets[i], events[i], &resEvents) != 0)
+				elog(ERROR, "failed to enumerate network events: error code %d",
+					 WSAGetLastError());
+			/* Read activity? */
+			if (readfds && FD_ISSET(sockets[i], readfds))
+			{
+				if ((resEvents.lNetworkEvents & FD_READ) ||
+					(resEvents.lNetworkEvents & FD_ACCEPT) ||
+					(resEvents.lNetworkEvents & FD_CLOSE))
+				{
+					FD_SET(sockets[i], &outreadfds);
+
+					nummatches++;
+				}
+			}
+			/* Write activity? */
+			if (writefds && FD_ISSET(sockets[i], writefds))
+			{
+				if ((resEvents.lNetworkEvents & FD_WRITE) ||
+					(resEvents.lNetworkEvents & FD_CLOSE))
+				{
+					FD_SET(sockets[i], &outwritefds);
+
+					nummatches++;
+				}
+			}
+		}
+	}
+
+	/* Clean up all the event objects */
+	for (i = 0; i < numevents; i++)
+	{
+		WSAEventSelect(sockets[i], NULL, 0);
+		WSACloseEvent(events[i]);
+	}
+
+	if (r == WSA_WAIT_TIMEOUT)
+	{
+		if (readfds)
+			FD_ZERO(readfds);
+		if (writefds)
+			FD_ZERO(writefds);
+		return 0;
+	}
+
+	/* Signal-like events. */
+	if (r == WAIT_OBJECT_0 + numevents || r == WAIT_IO_COMPLETION)
+	{
+		pgwin32_dispatch_queued_signals();
+		errno = EINTR;
+		if (readfds)
+			FD_ZERO(readfds);
+		if (writefds)
+			FD_ZERO(writefds);
+		return -1;
+	}
+
+	/* Overwrite socket sets with our resulting values */
+	if (readfds)
+		memcpy(readfds, &outreadfds, sizeof(fd_set));
+	if (writefds)
+		memcpy(writefds, &outwritefds, sizeof(fd_set));
+	return nummatches;
+}
diff --git a/contrib/libs/postgresql/src/backend/port/win32/timer.c b/contrib/libs/postgresql/src/backend/port/win32/timer.c
new file mode 100644
index 0000000000..53fdae9468
--- /dev/null
+++ b/contrib/libs/postgresql/src/backend/port/win32/timer.c
@@ -0,0 +1,121 @@
+/*-------------------------------------------------------------------------
+ *
+ * timer.c
+ *	  Microsoft Windows Win32 Timer Implementation
+ *
+ *	  Limitations of this implementation:
+ *
+ *	  - Does not support interval timer (value->it_interval)
+ *	  - Only supports ITIMER_REAL
+ *
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
+ *
+ * IDENTIFICATION
+ *	  src/backend/port/win32/timer.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#include "postgres.h"
+
+
+/* Communication area for inter-thread communication */
+typedef struct timerCA
+{
+	struct itimerval value;
+	HANDLE		event;
+	CRITICAL_SECTION crit_sec;
+} timerCA;
+
+static timerCA timerCommArea;
+static HANDLE timerThreadHandle = INVALID_HANDLE_VALUE;
+
+
+/* Timer management thread */
+static DWORD WINAPI
+pg_timer_thread(LPVOID param)
+{
+	DWORD		waittime;
+
+	Assert(param == NULL);
+
+	waittime = INFINITE;
+
+	for (;;)
+	{
+		int			r;
+
+		r = WaitForSingleObjectEx(timerCommArea.event, waittime, FALSE);
+		if (r == WAIT_OBJECT_0)
+		{
+			/* Event signaled from main thread, change the timer */
+			EnterCriticalSection(&timerCommArea.crit_sec);
+			if (timerCommArea.value.it_value.tv_sec == 0 &&
+				timerCommArea.value.it_value.tv_usec == 0)
+				waittime = INFINITE;	/* Cancel the interrupt */
+			else
+			{
+				/* WaitForSingleObjectEx() uses milliseconds, round up */
+				waittime = (timerCommArea.value.it_value.tv_usec + 999) / 1000 +
+					timerCommArea.value.it_value.tv_sec * 1000;
+			}
+			ResetEvent(timerCommArea.event);
+			LeaveCriticalSection(&timerCommArea.crit_sec);
+		}
+		else if (r == WAIT_TIMEOUT)
+		{
+			/* Timeout expired, signal SIGALRM and turn it off */
+			pg_queue_signal(SIGALRM);
+			waittime = INFINITE;
+		}
+		else
+		{
+			/* Should never happen */
+			Assert(false);
+		}
+	}
+
+	return 0;
+}
+
+/*
+ * Win32 setitimer emulation by creating a persistent thread
+ * to handle the timer setting and notification upon timeout.
+ */
+int
+setitimer(int which, const struct itimerval *value, struct itimerval *ovalue)
+{
+	Assert(value != NULL);
+	Assert(value->it_interval.tv_sec == 0 && value->it_interval.tv_usec == 0);
+	Assert(which == ITIMER_REAL);
+
+	if (timerThreadHandle == INVALID_HANDLE_VALUE)
+	{
+		/* First call in this backend, create event and the timer thread */
+		timerCommArea.event = CreateEvent(NULL, TRUE, FALSE, NULL);
+		if (timerCommArea.event == NULL)
+			ereport(FATAL,
+					(errmsg_internal("could not create timer event: error code %lu",
+									 GetLastError())));
+
+		MemSet(&timerCommArea.value, 0, sizeof(struct itimerval));
+
+		InitializeCriticalSection(&timerCommArea.crit_sec);
+
+		timerThreadHandle = CreateThread(NULL, 0, pg_timer_thread, NULL, 0, NULL);
+		if (timerThreadHandle == INVALID_HANDLE_VALUE)
+			ereport(FATAL,
+					(errmsg_internal("could not create timer thread: error code %lu",
+									 GetLastError())));
+	}
+
+	/* Request the timer thread to change settings */
+	EnterCriticalSection(&timerCommArea.crit_sec);
+	if (ovalue)
+		*ovalue = timerCommArea.value;
+	timerCommArea.value = *value;
+	LeaveCriticalSection(&timerCommArea.crit_sec);
+	SetEvent(timerCommArea.event);
+
+	return 0;
+}
diff --git a/contrib/libs/postgresql/src/backend/port/win32_sema.c b/contrib/libs/postgresql/src/backend/port/win32_sema.c
new file mode 100644
index 0000000000..858b88adae
--- /dev/null
+++ b/contrib/libs/postgresql/src/backend/port/win32_sema.c
@@ -0,0 +1,235 @@
+/*-------------------------------------------------------------------------
+ *
+ * win32_sema.c
+ *	  Microsoft Windows Win32 Semaphores Emulation
+ *
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
+ *
+ * IDENTIFICATION
+ *	  src/backend/port/win32_sema.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#include "postgres.h"
+
+#include "miscadmin.h"
+#include "storage/ipc.h"
+#include "storage/pg_sema.h"
+
+static HANDLE *mySemSet;		/* IDs of sema sets acquired so far */
+static int	numSems;			/* number of sema sets acquired so far */
+static int	maxSems;			/* allocated size of mySemaSet array */
+
+static void ReleaseSemaphores(int code, Datum arg);
+
+
+/*
+ * Report amount of shared memory needed for semaphores
+ */
+Size
+PGSemaphoreShmemSize(int maxSemas)
+{
+	/* No shared memory needed on Windows */
+	return 0;
+}
+
+/*
+ * PGReserveSemaphores --- initialize semaphore support
+ *
+ * In the Win32 implementation, we acquire semaphores on-demand; the
+ * maxSemas parameter is just used to size the array that keeps track of
+ * acquired semas for subsequent releasing.  We use anonymous semaphores
+ * so the semaphores are automatically freed when the last referencing
+ * process exits.
+ */
+void
+PGReserveSemaphores(int maxSemas)
+{
+	mySemSet = (HANDLE *) malloc(maxSemas * sizeof(HANDLE));
+	if (mySemSet == NULL)
+		elog(PANIC, "out of memory");
+	numSems = 0;
+	maxSems = maxSemas;
+
+	on_shmem_exit(ReleaseSemaphores, 0);
+}
+
+/*
+ * Release semaphores at shutdown or shmem reinitialization
+ *
+ * (called as an on_shmem_exit callback, hence funny argument list)
+ */
+static void
+ReleaseSemaphores(int code, Datum arg)
+{
+	int			i;
+
+	for (i = 0; i < numSems; i++)
+		CloseHandle(mySemSet[i]);
+	free(mySemSet);
+}
+
+/*
+ * PGSemaphoreCreate
+ *
+ * Allocate a PGSemaphore structure with initial count 1
+ */
+PGSemaphore
+PGSemaphoreCreate(void)
+{
+	HANDLE		cur_handle;
+	SECURITY_ATTRIBUTES sec_attrs;
+
+	/* Can't do this in a backend, because static state is postmaster's */
+	Assert(!IsUnderPostmaster);
+
+	if (numSems >= maxSems)
+		elog(PANIC, "too many semaphores created");
+
+	ZeroMemory(&sec_attrs, sizeof(sec_attrs));
+	sec_attrs.nLength = sizeof(sec_attrs);
+	sec_attrs.lpSecurityDescriptor = NULL;
+	sec_attrs.bInheritHandle = TRUE;
+
+	/* We don't need a named semaphore */
+	cur_handle = CreateSemaphore(&sec_attrs, 1, 32767, NULL);
+	if (cur_handle)
+	{
+		/* Successfully done */
+		mySemSet[numSems++] = cur_handle;
+	}
+	else
+		ereport(PANIC,
+				(errmsg("could not create semaphore: error code %lu",
+						GetLastError())));
+
+	return (PGSemaphore) cur_handle;
+}
+
+/*
+ * PGSemaphoreReset
+ *
+ * Reset a previously-initialized PGSemaphore to have count 0
+ */
+void
+PGSemaphoreReset(PGSemaphore sema)
+{
+	/*
+	 * There's no direct API for this in Win32, so we have to ratchet the
+	 * semaphore down to 0 with repeated trylock's.
+	 */
+	while (PGSemaphoreTryLock(sema))
+		 /* loop */ ;
+}
+
+/*
+ * PGSemaphoreLock
+ *
+ * Lock a semaphore (decrement count), blocking if count would be < 0.
+ */
+void
+PGSemaphoreLock(PGSemaphore sema)
+{
+	HANDLE		wh[2];
+	bool		done = false;
+
+	/*
+	 * Note: pgwin32_signal_event should be first to ensure that it will be
+	 * reported when multiple events are set.  We want to guarantee that
+	 * pending signals are serviced.
+	 */
+	wh[0] = pgwin32_signal_event;
+	wh[1] = sema;
+
+	/*
+	 * As in other implementations of PGSemaphoreLock, we need to check for
+	 * cancel/die interrupts each time through the loop.  But here, there is
+	 * no hidden magic about whether the syscall will internally service a
+	 * signal --- we do that ourselves.
+	 */
+	while (!done)
+	{
+		DWORD		rc;
+
+		CHECK_FOR_INTERRUPTS();
+
+		rc = WaitForMultipleObjectsEx(2, wh, FALSE, INFINITE, TRUE);
+		switch (rc)
+		{
+			case WAIT_OBJECT_0:
+				/* Signal event is set - we have a signal to deliver */
+				pgwin32_dispatch_queued_signals();
+				break;
+			case WAIT_OBJECT_0 + 1:
+				/* We got it! */
+				done = true;
+				break;
+			case WAIT_IO_COMPLETION:
+
+				/*
+				 * The system interrupted the wait to execute an I/O
+				 * completion routine or asynchronous procedure call in this
+				 * thread.  PostgreSQL does not provoke either of these, but
+				 * atypical loaded DLLs or even other processes might do so.
+				 * Now, resume waiting.
+				 */
+				break;
+			case WAIT_FAILED:
+				ereport(FATAL,
+						(errmsg("could not lock semaphore: error code %lu",
+								GetLastError())));
+				break;
+			default:
+				elog(FATAL, "unexpected return code from WaitForMultipleObjectsEx(): %lu", rc);
+				break;
+		}
+	}
+}
+
+/*
+ * PGSemaphoreUnlock
+ *
+ * Unlock a semaphore (increment count)
+ */
+void
+PGSemaphoreUnlock(PGSemaphore sema)
+{
+	if (!ReleaseSemaphore(sema, 1, NULL))
+		ereport(FATAL,
+				(errmsg("could not unlock semaphore: error code %lu",
+						GetLastError())));
+}
+
+/*
+ * PGSemaphoreTryLock
+ *
+ * Lock a semaphore only if able to do so without blocking
+ */
+bool
+PGSemaphoreTryLock(PGSemaphore sema)
+{
+	DWORD		ret;
+
+	ret = WaitForSingleObject(sema, 0);
+
+	if (ret == WAIT_OBJECT_0)
+	{
+		/* We got it! */
+		return true;
+	}
+	else if (ret == WAIT_TIMEOUT)
+	{
+		/* Can't get it */
+		errno = EAGAIN;
+		return false;
+	}
+
+	/* Otherwise we are in trouble */
+	ereport(FATAL,
+			(errmsg("could not try-lock semaphore: error code %lu",
+					GetLastError())));
+
+	/* keep compiler quiet */
+	return false;
+}
diff --git a/contrib/libs/postgresql/src/backend/port/win32_shmem.c b/contrib/libs/postgresql/src/backend/port/win32_shmem.c
new file mode 100644
index 0000000000..d7a71992d8
--- /dev/null
+++ b/contrib/libs/postgresql/src/backend/port/win32_shmem.c
@@ -0,0 +1,607 @@
+/*-------------------------------------------------------------------------
+ *
+ * win32_shmem.c
+ *	  Implement shared memory using win32 facilities
+ *
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
+ *
+ * IDENTIFICATION
+ *	  src/backend/port/win32_shmem.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "miscadmin.h"
+#include "storage/dsm.h"
+#include "storage/ipc.h"
+#include "storage/pg_shmem.h"
+
+/*
+ * Early in a process's life, Windows asynchronously creates threads for the
+ * process's "default thread pool"
+ * (https://docs.microsoft.com/en-us/windows/desktop/ProcThread/thread-pools).
+ * Occasionally, thread creation allocates a stack after
+ * PGSharedMemoryReAttach() has released UsedShmemSegAddr and before it has
+ * mapped shared memory at UsedShmemSegAddr.  This would cause mapping to fail
+ * if the allocator preferred the just-released region for allocating the new
+ * thread stack.  We observed such failures in some Windows Server 2016
+ * configurations.  To give the system another region to prefer, reserve and
+ * release an additional, protective region immediately before reserving or
+ * releasing shared memory.  The idea is that, if the allocator handed out
+ * REGION1 pages before REGION2 pages at one occasion, it will do so whenever
+ * both regions are free.  Windows Server 2016 exhibits that behavior, and a
+ * system behaving differently would have less need to protect
+ * UsedShmemSegAddr.  The protective region must be at least large enough for
+ * one thread stack.  However, ten times as much is less than 2% of the 32-bit
+ * address space and is negligible relative to the 64-bit address space.
+ */
+#define PROTECTIVE_REGION_SIZE (10 * WIN32_STACK_RLIMIT)
+void	   *ShmemProtectiveRegion = NULL;
+
+HANDLE		UsedShmemSegID = INVALID_HANDLE_VALUE;
+void	   *UsedShmemSegAddr = NULL;
+static Size UsedShmemSegSize = 0;
+
+static bool EnableLockPagesPrivilege(int elevel);
+static void pgwin32_SharedMemoryDelete(int status, Datum shmId);
+
+/*
+ * Generate shared memory segment name. Expand the data directory, to generate
+ * an identifier unique for this data directory. Then replace all backslashes
+ * with forward slashes, since backslashes aren't permitted in global object names.
+ *
+ * Store the shared memory segment in the Global\ namespace (requires NT2 TSE or
+ * 2000, but that's all we support for other reasons as well), to make sure you can't
+ * open two postmasters in different sessions against the same data directory.
+ *
+ * XXX: What happens with junctions? It's only someone breaking things on purpose,
+ *		and this is still better than before, but we might want to do something about
+ *		that sometime in the future.
+ */
+static char *
+GetSharedMemName(void)
+{
+	char	   *retptr;
+	DWORD		bufsize;
+	DWORD		r;
+	char	   *cp;
+
+	bufsize = GetFullPathName(DataDir, 0, NULL, NULL);
+	if (bufsize == 0)
+		elog(FATAL, "could not get size for full pathname of datadir %s: error code %lu",
+			 DataDir, GetLastError());
+
+	retptr = malloc(bufsize + 18);	/* 18 for Global\PostgreSQL: */
+	if (retptr == NULL)
+		elog(FATAL, "could not allocate memory for shared memory name");
+
+	strcpy(retptr, "Global\\PostgreSQL:");
+	r = GetFullPathName(DataDir, bufsize, retptr + 18, NULL);
+	if (r == 0 || r > bufsize)
+		elog(FATAL, "could not generate full pathname for datadir %s: error code %lu",
+			 DataDir, GetLastError());
+
+	/*
+	 * XXX: Intentionally overwriting the Global\ part here. This was not the
+	 * original approach, but putting it in the actual Global\ namespace
+	 * causes permission errors in a lot of cases, so we leave it in the
+	 * default namespace for now.
+	 */
+	for (cp = retptr; *cp; cp++)
+		if (*cp == '\\')
+			*cp = '/';
+
+	return retptr;
+}
+
+
+/*
+ * PGSharedMemoryIsInUse
+ *
+ * Is a previously-existing shmem segment still existing and in use?
+ *
+ * The point of this exercise is to detect the case where a prior postmaster
+ * crashed, but it left child backends that are still running.  Therefore
+ * we only care about shmem segments that are associated with the intended
+ * DataDir.  This is an important consideration since accidental matches of
+ * shmem segment IDs are reasonably common.
+ */
+bool
+PGSharedMemoryIsInUse(unsigned long id1, unsigned long id2)
+{
+	char	   *szShareMem;
+	HANDLE		hmap;
+
+	szShareMem = GetSharedMemName();
+
+	hmap = OpenFileMapping(FILE_MAP_READ, FALSE, szShareMem);
+
+	free(szShareMem);
+
+	if (hmap == NULL)
+		return false;
+
+	CloseHandle(hmap);
+	return true;
+}
+
+/*
+ * EnableLockPagesPrivilege
+ *
+ * Try to acquire SeLockMemoryPrivilege so we can use large pages.
+ */
+static bool
+EnableLockPagesPrivilege(int elevel)
+{
+	HANDLE		hToken;
+	TOKEN_PRIVILEGES tp;
+	LUID		luid;
+
+	if (!OpenProcessToken(GetCurrentProcess(), TOKEN_ADJUST_PRIVILEGES | TOKEN_QUERY, &hToken))
+	{
+		ereport(elevel,
+				(errmsg("could not enable user right \"%s\": error code %lu",
+
+		/*
+		 * translator: This is a term from Windows and should be translated to
+		 * match the Windows localization.
+		 */
+						_("Lock pages in memory"),
+						GetLastError()),
+				 errdetail("Failed system call was %s.", "OpenProcessToken")));
+		return FALSE;
+	}
+
+	if (!LookupPrivilegeValue(NULL, SE_LOCK_MEMORY_NAME, &luid))
+	{
+		ereport(elevel,
+				(errmsg("could not enable user right \"%s\": error code %lu", _("Lock pages in memory"), GetLastError()),
+				 errdetail("Failed system call was %s.", "LookupPrivilegeValue")));
+		CloseHandle(hToken);
+		return FALSE;
+	}
+	tp.PrivilegeCount = 1;
+	tp.Privileges[0].Luid = luid;
+	tp.Privileges[0].Attributes = SE_PRIVILEGE_ENABLED;
+
+	if (!AdjustTokenPrivileges(hToken, FALSE, &tp, 0, NULL, NULL))
+	{
+		ereport(elevel,
+				(errmsg("could not enable user right \"%s\": error code %lu", _("Lock pages in memory"), GetLastError()),
+				 errdetail("Failed system call was %s.", "AdjustTokenPrivileges")));
+		CloseHandle(hToken);
+		return FALSE;
+	}
+
+	if (GetLastError() != ERROR_SUCCESS)
+	{
+		if (GetLastError() == ERROR_NOT_ALL_ASSIGNED)
+			ereport(elevel,
+					(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+					 errmsg("could not enable user right \"%s\"", _("Lock pages in memory")),
+					 errhint("Assign user right \"%s\" to the Windows user account which runs PostgreSQL.",
+							 _("Lock pages in memory"))));
+		else
+			ereport(elevel,
+					(errmsg("could not enable user right \"%s\": error code %lu", _("Lock pages in memory"), GetLastError()),
+					 errdetail("Failed system call was %s.", "AdjustTokenPrivileges")));
+		CloseHandle(hToken);
+		return FALSE;
+	}
+
+	CloseHandle(hToken);
+
+	return TRUE;
+}
+
+/*
+ * PGSharedMemoryCreate
+ *
+ * Create a shared memory segment of the given size and initialize its
+ * standard header.
+ */
+PGShmemHeader *
+PGSharedMemoryCreate(Size size,
+					 PGShmemHeader **shim)
+{
+	void	   *memAddress;
+	PGShmemHeader *hdr;
+	HANDLE		hmap,
+				hmap2;
+	char	   *szShareMem;
+	int			i;
+	DWORD		size_high;
+	DWORD		size_low;
+	SIZE_T		largePageSize = 0;
+	Size		orig_size = size;
+	DWORD		flProtect = PAGE_READWRITE;
+
+	ShmemProtectiveRegion = VirtualAlloc(NULL, PROTECTIVE_REGION_SIZE,
+										 MEM_RESERVE, PAGE_NOACCESS);
+	if (ShmemProtectiveRegion == NULL)
+		elog(FATAL, "could not reserve memory region: error code %lu",
+			 GetLastError());
+
+	/* Room for a header? */
+	Assert(size > MAXALIGN(sizeof(PGShmemHeader)));
+
+	szShareMem = GetSharedMemName();
+
+	UsedShmemSegAddr = NULL;
+
+	if (huge_pages == HUGE_PAGES_ON || huge_pages == HUGE_PAGES_TRY)
+	{
+		/* Does the processor support large pages? */
+		largePageSize = GetLargePageMinimum();
+		if (largePageSize == 0)
+		{
+			ereport(huge_pages == HUGE_PAGES_ON ? FATAL : DEBUG1,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("the processor does not support large pages")));
+			ereport(DEBUG1,
+					(errmsg_internal("disabling huge pages")));
+		}
+		else if (!EnableLockPagesPrivilege(huge_pages == HUGE_PAGES_ON ? FATAL : DEBUG1))
+		{
+			ereport(DEBUG1,
+					(errmsg_internal("disabling huge pages")));
+		}
+		else
+		{
+			/* Huge pages available and privilege enabled, so turn on */
+			flProtect = PAGE_READWRITE | SEC_COMMIT | SEC_LARGE_PAGES;
+
+			/* Round size up as appropriate. */
+			if (size % largePageSize != 0)
+				size += largePageSize - (size % largePageSize);
+		}
+	}
+
+retry:
+#ifdef _WIN64
+	size_high = size >> 32;
+#else
+	size_high = 0;
+#endif
+	size_low = (DWORD) size;
+
+	/*
+	 * When recycling a shared memory segment, it may take a short while
+	 * before it gets dropped from the global namespace. So re-try after
+	 * sleeping for a second, and continue retrying 10 times. (both the 1
+	 * second time and the 10 retries are completely arbitrary)
+	 */
+	for (i = 0; i < 10; i++)
+	{
+		/*
+		 * In case CreateFileMapping() doesn't set the error code to 0 on
+		 * success
+		 */
+		SetLastError(0);
+
+		hmap = CreateFileMapping(INVALID_HANDLE_VALUE,	/* Use the pagefile */
+								 NULL,	/* Default security attrs */
+								 flProtect,
+								 size_high, /* Size Upper 32 Bits	*/
+								 size_low,	/* Size Lower 32 bits */
+								 szShareMem);
+
+		if (!hmap)
+		{
+			if (GetLastError() == ERROR_NO_SYSTEM_RESOURCES &&
+				huge_pages == HUGE_PAGES_TRY &&
+				(flProtect & SEC_LARGE_PAGES) != 0)
+			{
+				elog(DEBUG1, "CreateFileMapping(%zu) with SEC_LARGE_PAGES failed, "
+					 "huge pages disabled",
+					 size);
+
+				/*
+				 * Use the original size, not the rounded-up value, when
+				 * falling back to non-huge pages.
+				 */
+				size = orig_size;
+				flProtect = PAGE_READWRITE;
+				goto retry;
+			}
+			else
+				ereport(FATAL,
+						(errmsg("could not create shared memory segment: error code %lu", GetLastError()),
+						 errdetail("Failed system call was CreateFileMapping(size=%zu, name=%s).",
+								   size, szShareMem)));
+		}
+
+		/*
+		 * If the segment already existed, CreateFileMapping() will return a
+		 * handle to the existing one and set ERROR_ALREADY_EXISTS.
+		 */
+		if (GetLastError() == ERROR_ALREADY_EXISTS)
+		{
+			CloseHandle(hmap);	/* Close the handle, since we got a valid one
+								 * to the previous segment. */
+			hmap = NULL;
+			Sleep(1000);
+			continue;
+		}
+		break;
+	}
+
+	/*
+	 * If the last call in the loop still returned ERROR_ALREADY_EXISTS, this
+	 * shared memory segment exists and we assume it belongs to somebody else.
+	 */
+	if (!hmap)
+		ereport(FATAL,
+				(errmsg("pre-existing shared memory block is still in use"),
+				 errhint("Check if there are any old server processes still running, and terminate them.")));
+
+	free(szShareMem);
+
+	/*
+	 * Make the handle inheritable
+	 */
+	if (!DuplicateHandle(GetCurrentProcess(), hmap, GetCurrentProcess(), &hmap2, 0, TRUE, DUPLICATE_SAME_ACCESS))
+		ereport(FATAL,
+				(errmsg("could not create shared memory segment: error code %lu", GetLastError()),
+				 errdetail("Failed system call was DuplicateHandle.")));
+
+	/*
+	 * Close the old, non-inheritable handle. If this fails we don't really
+	 * care.
+	 */
+	if (!CloseHandle(hmap))
+		elog(LOG, "could not close handle to shared memory: error code %lu", GetLastError());
+
+
+	/*
+	 * Get a pointer to the new shared memory segment. Map the whole segment
+	 * at once, and let the system decide on the initial address.
+	 */
+	memAddress = MapViewOfFileEx(hmap2, FILE_MAP_WRITE | FILE_MAP_READ, 0, 0, 0, NULL);
+	if (!memAddress)
+		ereport(FATAL,
+				(errmsg("could not create shared memory segment: error code %lu", GetLastError()),
+				 errdetail("Failed system call was MapViewOfFileEx.")));
+
+
+
+	/*
+	 * OK, we created a new segment.  Mark it as created by this process. The
+	 * order of assignments here is critical so that another Postgres process
+	 * can't see the header as valid but belonging to an invalid PID!
+	 */
+	hdr = (PGShmemHeader *) memAddress;
+	hdr->creatorPID = getpid();
+	hdr->magic = PGShmemMagic;
+
+	/*
+	 * Initialize space allocation status for segment.
+	 */
+	hdr->totalsize = size;
+	hdr->freeoffset = MAXALIGN(sizeof(PGShmemHeader));
+	hdr->dsm_control = 0;
+
+	/* Save info for possible future use */
+	UsedShmemSegAddr = memAddress;
+	UsedShmemSegSize = size;
+	UsedShmemSegID = hmap2;
+
+	/* Register on-exit routine to delete the new segment */
+	on_shmem_exit(pgwin32_SharedMemoryDelete, PointerGetDatum(hmap2));
+
+	*shim = hdr;
+	return hdr;
+}
+
+/*
+ * PGSharedMemoryReAttach
+ *
+ * This is called during startup of a postmaster child process to re-attach to
+ * an already existing shared memory segment, using the handle inherited from
+ * the postmaster.
+ *
+ * ShmemProtectiveRegion, UsedShmemSegID and UsedShmemSegAddr are implicit
+ * parameters to this routine.  The caller must have already restored them to
+ * the postmaster's values.
+ */
+void
+PGSharedMemoryReAttach(void)
+{
+	PGShmemHeader *hdr;
+	void	   *origUsedShmemSegAddr = UsedShmemSegAddr;
+
+	Assert(ShmemProtectiveRegion != NULL);
+	Assert(UsedShmemSegAddr != NULL);
+	Assert(IsUnderPostmaster);
+
+	/*
+	 * Release memory region reservations made by the postmaster
+	 */
+	if (VirtualFree(ShmemProtectiveRegion, 0, MEM_RELEASE) == 0)
+		elog(FATAL, "failed to release reserved memory region (addr=%p): error code %lu",
+			 ShmemProtectiveRegion, GetLastError());
+	if (VirtualFree(UsedShmemSegAddr, 0, MEM_RELEASE) == 0)
+		elog(FATAL, "failed to release reserved memory region (addr=%p): error code %lu",
+			 UsedShmemSegAddr, GetLastError());
+
+	hdr = (PGShmemHeader *) MapViewOfFileEx(UsedShmemSegID, FILE_MAP_READ | FILE_MAP_WRITE, 0, 0, 0, UsedShmemSegAddr);
+	if (!hdr)
+		elog(FATAL, "could not reattach to shared memory (key=%p, addr=%p): error code %lu",
+			 UsedShmemSegID, UsedShmemSegAddr, GetLastError());
+	if (hdr != origUsedShmemSegAddr)
+		elog(FATAL, "reattaching to shared memory returned unexpected address (got %p, expected %p)",
+			 hdr, origUsedShmemSegAddr);
+	if (hdr->magic != PGShmemMagic)
+		elog(FATAL, "reattaching to shared memory returned non-PostgreSQL memory");
+	dsm_set_control_handle(hdr->dsm_control);
+
+	UsedShmemSegAddr = hdr;		/* probably redundant */
+}
+
+/*
+ * PGSharedMemoryNoReAttach
+ *
+ * This is called during startup of a postmaster child process when we choose
+ * *not* to re-attach to the existing shared memory segment.  We must clean up
+ * to leave things in the appropriate state.
+ *
+ * The child process startup logic might or might not call PGSharedMemoryDetach
+ * after this; make sure that it will be a no-op if called.
+ *
+ * ShmemProtectiveRegion, UsedShmemSegID and UsedShmemSegAddr are implicit
+ * parameters to this routine.  The caller must have already restored them to
+ * the postmaster's values.
+ */
+void
+PGSharedMemoryNoReAttach(void)
+{
+	Assert(ShmemProtectiveRegion != NULL);
+	Assert(UsedShmemSegAddr != NULL);
+	Assert(IsUnderPostmaster);
+
+	/*
+	 * Under Windows we will not have mapped the segment, so we don't need to
+	 * un-map it.  Just reset UsedShmemSegAddr to show we're not attached.
+	 */
+	UsedShmemSegAddr = NULL;
+
+	/*
+	 * We *must* close the inherited shmem segment handle, else Windows will
+	 * consider the existence of this process to mean it can't release the
+	 * shmem segment yet.  We can now use PGSharedMemoryDetach to do that.
+	 */
+	PGSharedMemoryDetach();
+}
+
+/*
+ * PGSharedMemoryDetach
+ *
+ * Detach from the shared memory segment, if still attached.  This is not
+ * intended to be called explicitly by the process that originally created the
+ * segment (it will have an on_shmem_exit callback registered to do that).
+ * Rather, this is for subprocesses that have inherited an attachment and want
+ * to get rid of it.
+ *
+ * ShmemProtectiveRegion, UsedShmemSegID and UsedShmemSegAddr are implicit
+ * parameters to this routine.
+ */
+void
+PGSharedMemoryDetach(void)
+{
+	/*
+	 * Releasing the protective region liberates an unimportant quantity of
+	 * address space, but be tidy.
+	 */
+	if (ShmemProtectiveRegion != NULL)
+	{
+		if (VirtualFree(ShmemProtectiveRegion, 0, MEM_RELEASE) == 0)
+			elog(LOG, "failed to release reserved memory region (addr=%p): error code %lu",
+				 ShmemProtectiveRegion, GetLastError());
+
+		ShmemProtectiveRegion = NULL;
+	}
+
+	/* Unmap the view, if it's mapped */
+	if (UsedShmemSegAddr != NULL)
+	{
+		if (!UnmapViewOfFile(UsedShmemSegAddr))
+			elog(LOG, "could not unmap view of shared memory: error code %lu",
+				 GetLastError());
+
+		UsedShmemSegAddr = NULL;
+	}
+
+	/* And close the shmem handle, if we have one */
+	if (UsedShmemSegID != INVALID_HANDLE_VALUE)
+	{
+		if (!CloseHandle(UsedShmemSegID))
+			elog(LOG, "could not close handle to shared memory: error code %lu",
+				 GetLastError());
+
+		UsedShmemSegID = INVALID_HANDLE_VALUE;
+	}
+}
+
+
+/*
+ * pgwin32_SharedMemoryDelete
+ *
+ * Detach from and delete the shared memory segment
+ * (called as an on_shmem_exit callback, hence funny argument list)
+ */
+static void
+pgwin32_SharedMemoryDelete(int status, Datum shmId)
+{
+	Assert(DatumGetPointer(shmId) == UsedShmemSegID);
+	PGSharedMemoryDetach();
+}
+
+/*
+ * pgwin32_ReserveSharedMemoryRegion(hChild)
+ *
+ * Reserve the memory region that will be used for shared memory in a child
+ * process. It is called before the child process starts, to make sure the
+ * memory is available.
+ *
+ * Once the child starts, DLLs loading in different order or threads getting
+ * scheduled differently may allocate memory which can conflict with the
+ * address space we need for our shared memory. By reserving the shared
+ * memory region before the child starts, and freeing it only just before we
+ * attempt to get access to the shared memory forces these allocations to
+ * be given different address ranges that don't conflict.
+ *
+ * NOTE! This function executes in the postmaster, and should for this
+ * reason not use elog(FATAL) since that would take down the postmaster.
+ */
+int
+pgwin32_ReserveSharedMemoryRegion(HANDLE hChild)
+{
+	void	   *address;
+
+	Assert(ShmemProtectiveRegion != NULL);
+	Assert(UsedShmemSegAddr != NULL);
+	Assert(UsedShmemSegSize != 0);
+
+	/* ShmemProtectiveRegion */
+	address = VirtualAllocEx(hChild, ShmemProtectiveRegion,
+							 PROTECTIVE_REGION_SIZE,
+							 MEM_RESERVE, PAGE_NOACCESS);
+	if (address == NULL)
+	{
+		/* Don't use FATAL since we're running in the postmaster */
+		elog(LOG, "could not reserve shared memory region (addr=%p) for child %p: error code %lu",
+			 ShmemProtectiveRegion, hChild, GetLastError());
+		return false;
+	}
+	if (address != ShmemProtectiveRegion)
+	{
+		/*
+		 * Should never happen - in theory if allocation granularity causes
+		 * strange effects it could, so check just in case.
+		 *
+		 * Don't use FATAL since we're running in the postmaster.
+		 */
+		elog(LOG, "reserved shared memory region got incorrect address %p, expected %p",
+			 address, ShmemProtectiveRegion);
+		return false;
+	}
+
+	/* UsedShmemSegAddr */
+	address = VirtualAllocEx(hChild, UsedShmemSegAddr, UsedShmemSegSize,
+							 MEM_RESERVE, PAGE_READWRITE);
+	if (address == NULL)
+	{
+		elog(LOG, "could not reserve shared memory region (addr=%p) for child %p: error code %lu",
+			 UsedShmemSegAddr, hChild, GetLastError());
+		return false;
+	}
+	if (address != UsedShmemSegAddr)
+	{
+		elog(LOG, "reserved shared memory region got incorrect address %p, expected %p",
+			 address, UsedShmemSegAddr);
+		return false;
+	}
+
+	return true;
+}