1 files changed, 300 insertions, 0 deletions
diff --git a/src/backend/port/win32/signal.c b/src/backend/port/win32/signal.c
new file mode 100644
index 00000000000..280f10da23d
--- /dev/null
+++ b/src/backend/port/win32/signal.c
@@ -0,0 +1,300 @@
+/*-------------------------------------------------------------------------
+ *
+ * signal.c
+ *	  Microsoft Windows Win32 Signal Emulation Functions
+ *
+ * Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
+ *
+ * IDENTIFICATION
+ *	  $PostgreSQL: pgsql/src/backend/port/win32/signal.c,v 1.1 2004/04/12 16:19:18 momjian Exp $
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#include "postgres.h"
+
+#include <libpq/pqsignal.h>
+
+
+/* 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;
+static int	pg_signal_queue;
+
+#define PG_SIGNAL_COUNT 32
+static pqsigfunc pg_signal_array[PG_SIGNAL_COUNT];
+static pqsigfunc pg_signal_defaults[PG_SIGNAL_COUNT];
+static int	pg_signal_mask;
+
+DLLIMPORT HANDLE pgwin32_signal_event;
+
+
+/* Signal handling thread function */
+static DWORD WINAPI pg_signal_thread(LPVOID param);
+static BOOL WINAPI pg_console_handler(DWORD dwCtrlType);
+
+/* Sleep function that can be interrupted by signals */
+void pgwin32_backend_usleep(long microsec) {
+	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("Failed to create signal event: %i!",(int)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("Failed to create signal handler thread!")));
+
+	/* Create console control handle to pick up Ctrl-C etc */
+	if (!SetConsoleCtrlHandler(pg_console_handler, TRUE)) 
+		ereport(FATAL,
+				(errmsg_internal("Failed to 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 sigsetmask() call. */
+void
+pgwin32_dispatch_queued_signals(void)
+{
+	int			i;
+
+	EnterCriticalSection(&pg_signal_crit_sec);
+	while (pg_signal_queue & ~pg_signal_mask)
+	{
+		/* One or more unblocked signals queued for execution */
+
+		int			exec_mask = pg_signal_queue & ~pg_signal_mask;
+
+		for (i = 0; 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;
+}
+
+
+/* signal manipulation. 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;
+}
+
+/* signal sending */
+int
+pqkill(int pid, int sig)
+{
+	char		pipename[128];
+	BYTE		sigData = sig;
+	BYTE		sigRet = 0;
+	DWORD		bytes;
+
+	if (sig >= PG_SIGNAL_COUNT || sig <= 0)
+	{
+		errno = EINVAL;
+		return -1;
+	}
+	if (pid <= 0)
+	{
+		/* No support for process groups */
+		errno = EINVAL;
+		return -1;
+	}
+	wsprintf(pipename, "\\\\.\\pipe\\pgsignal_%i", pid);
+	if (!CallNamedPipe(pipename, &sigData, 1, &sigRet, 1, &bytes, 1000))
+	{
+		if (GetLastError() == ERROR_FILE_NOT_FOUND)
+			errno = ESRCH;
+		else if (GetLastError() == ERROR_ACCESS_DENIED)
+			errno = EPERM;
+		else
+			errno = EINVAL;
+		return -1;
+	}
+	if (bytes != 1 || sigRet != sig)
+	{
+		errno = ESRCH;
+		return -1;
+	}
+
+	return 0;
+}
+
+/*
+ * 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!
+ */
+
+
+void
+pg_queue_signal(int signum)
+{
+	if (signum >= PG_SIGNAL_COUNT || signum < 0)
+		return;
+
+	EnterCriticalSection(&pg_signal_crit_sec);
+	pg_signal_queue |= sigmask(signum);
+	LeaveCriticalSection(&pg_signal_crit_sec);
+
+	SetEvent(pgwin32_signal_event);
+}
+
+/* Signal dispatching thread */
+static DWORD WINAPI
+pg_signal_dispatch_thread(LPVOID param)
+{
+	HANDLE		pipe = (HANDLE) param;
+	BYTE		sigNum;
+	DWORD		bytes;
+
+	if (!ReadFile(pipe, &sigNum, 1, &bytes, NULL))
+	{
+		/* Client died before sending */
+		CloseHandle(pipe);
+		return 0;
+	}
+	if (bytes != 1)
+	{
+		/* Received <bytes> bytes over signal pipe (should be 1) */
+		CloseHandle(pipe);
+		return 0;
+	}
+	WriteFile(pipe, &sigNum, 1, &bytes, NULL);	/* Don't care if it works
+												 * or not.. */
+	FlushFileBuffers(pipe);
+	DisconnectNamedPipe(pipe);
+	CloseHandle(pipe);
+
+	pg_queue_signal(sigNum);
+	return 0;
+}
+
+/* Signal handling thread */
+static DWORD WINAPI
+pg_signal_thread(LPVOID param)
+{
+	char		pipename[128];
+	HANDLE		pipe = INVALID_HANDLE_VALUE;
+
+	wsprintf(pipename, "\\\\.\\pipe\\pgsignal_%i", GetCurrentProcessId());
+
+	for (;;)
+	{
+		BOOL		fConnected;
+		HANDLE		hThread;
+
+		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)
+		{
+			fprintf(stderr, gettext("Failed to create signal listener pipe: %i. Retrying.\n"), (int) GetLastError());
+			SleepEx(500, FALSE);
+			continue;
+		}
+
+		fConnected = ConnectNamedPipe(pipe, NULL) ? TRUE : (GetLastError() == ERROR_PIPE_CONNECTED);
+		if (fConnected)
+		{
+			hThread = CreateThread(NULL, 0,
+					  (LPTHREAD_START_ROUTINE) pg_signal_dispatch_thread,
+								   (LPVOID) pipe, 0, NULL);
+			if (hThread == INVALID_HANDLE_VALUE)
+				fprintf(stderr, gettext("Failed to create signal dispatch thread: %i\n"), (int) GetLastError());
+			else
+				CloseHandle(hThread);
+		}
+		else
+			/* Connection failed. Cleanup and try again */
+			CloseHandle(pipe);
+	}
+	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;
+}