+++ /dev/null
-/*
- * Console control handler support.
- *
- */
-#include "Rts.h"
-#include <windows.h>
-#include "ConsoleHandler.h"
-#include "SchedAPI.h"
-#include "Schedule.h"
-#include "RtsUtils.h"
-#include "RtsFlags.h"
-#include "AsyncIO.h"
-#include "RtsSignals.h"
-
-extern int stg_InstallConsoleEvent(int action, StgStablePtr *handler);
-
-static BOOL WINAPI shutdown_handler(DWORD dwCtrlType);
-static BOOL WINAPI generic_handler(DWORD dwCtrlType);
-
-static rtsBool deliver_event = rtsTrue;
-static StgInt console_handler = STG_SIG_DFL;
-
-static HANDLE hConsoleEvent = INVALID_HANDLE_VALUE;
-
-#define N_PENDING_EVENTS 16
-StgInt stg_pending_events = 0; /* number of undelivered events */
-DWORD stg_pending_buf[N_PENDING_EVENTS]; /* their associated event numbers. */
-
-/*
- * Function: initUserSignals()
- *
- * Initialize the console handling substrate.
- */
-void
-initUserSignals(void)
-{
- stg_pending_events = 0;
- console_handler = STG_SIG_DFL;
- if (hConsoleEvent == INVALID_HANDLE_VALUE) {
- hConsoleEvent =
- CreateEvent ( NULL, /* default security attributes */
- TRUE, /* manual-reset event */
- FALSE, /* initially non-signalled */
- NULL); /* no name */
- }
- return;
-}
-
-/*
- * Function: shutdown_handler()
- *
- * Local function that performs the default handling of Ctrl+C kind
- * events; gently shutting down the RTS
- *
- * To repeat Signals.c remark -- user code may choose to override the
- * default handler. Which is fine, assuming they put back the default
- * handler when/if they de-install the custom handler.
- *
- */
-static BOOL WINAPI shutdown_handler(DWORD dwCtrlType)
-{
- switch (dwCtrlType) {
-
- case CTRL_CLOSE_EVENT:
- /* see generic_handler() comment re: this event */
- return FALSE;
- case CTRL_C_EVENT:
- case CTRL_BREAK_EVENT:
-
- // If we're already trying to interrupt the RTS, terminate with
- // extreme prejudice. So the first ^C tries to exit the program
- // cleanly, and the second one just kills it.
- if (sched_state >= SCHED_INTERRUPTING) {
- stg_exit(EXIT_INTERRUPTED);
- } else {
- interruptStgRts();
- /* Cheesy pulsing of an event to wake up a waiting RTS thread, if any */
- abandonRequestWait();
- resetAbandonRequestWait();
- }
- return TRUE;
-
- /* shutdown + logoff events are not handled here. */
- default:
- return FALSE;
- }
-}
-
-
-/*
- * Function: initDefaultHandlers()
- *
- * Install any default signal/console handlers. Currently we install a
- * Ctrl+C handler that shuts down the RTS in an orderly manner.
- */
-void initDefaultHandlers(void)
-{
- if ( !SetConsoleCtrlHandler(shutdown_handler, TRUE) ) {
- errorBelch("warning: failed to install default console handler");
- }
-}
-
-
-/*
- * Function: blockUserSignals()
- *
- * Temporarily block the delivery of further console events. Needed to
- * avoid race conditions when GCing the stack of outstanding handlers or
- * when emptying the stack by running the handlers.
- *
- */
-void
-blockUserSignals(void)
-{
- deliver_event = rtsFalse;
-}
-
-
-/*
- * Function: unblockUserSignals()
- *
- * The inverse of blockUserSignals(); re-enable the deliver of console events.
- */
-void
-unblockUserSignals(void)
-{
- deliver_event = rtsTrue;
-}
-
-
-/*
- * Function: awaitUserSignals()
- *
- * Wait for the next console event. Currently a NOP (returns immediately.)
- */
-void awaitUserSignals(void)
-{
- return;
-}
-
-
-/*
- * Function: startSignalHandlers()
- *
- * Run the handlers associated with the stacked up console events. Console
- * event delivery is blocked for the duration of this call.
- */
-void startSignalHandlers(Capability *cap)
-{
- StgStablePtr handler;
-
- if (console_handler < 0) {
- return;
- }
-
- blockUserSignals();
- ACQUIRE_LOCK(&sched_mutex);
-
- handler = deRefStablePtr((StgStablePtr)console_handler);
- while (stg_pending_events > 0) {
- stg_pending_events--;
- scheduleThread(cap,
- createIOThread(cap,
- RtsFlags.GcFlags.initialStkSize,
- rts_apply(cap,
- (StgClosure *)handler,
- rts_mkInt(cap,
- stg_pending_buf[stg_pending_events]))));
- }
-
- RELEASE_LOCK(&sched_mutex);
- unblockUserSignals();
-}
-
-/*
- * Function: markSignalHandlers()
- *
- * Evacuate the handler stack. _Assumes_ that console event delivery
- * has already been blocked.
- */
-void markSignalHandlers (evac_fn evac)
-{
- if (console_handler >= 0) {
- StgPtr p = deRefStablePtr((StgStablePtr)console_handler);
- evac((StgClosure**)(void *)&p);
- }
-}
-
-
-/*
- * Function: generic_handler()
- *
- * Local function which handles incoming console event (done in a sep OS thread),
- * recording the event in stg_pending_events.
- */
-static BOOL WINAPI generic_handler(DWORD dwCtrlType)
-{
- ACQUIRE_LOCK(&sched_mutex);
-
- /* Ultra-simple -- up the counter + signal a switch. */
- switch(dwCtrlType) {
- case CTRL_CLOSE_EVENT:
- /* Don't support the delivery of this event; if we
- * indicate that we've handled it here and the Haskell handler
- * doesn't take proper action (e.g., terminate the OS process),
- * the user of the app will be unable to kill/close it. Not
- * good, so disable the delivery for now.
- */
- return FALSE;
- default:
- if (!deliver_event) return TRUE;
-
- if ( stg_pending_events < N_PENDING_EVENTS ) {
- stg_pending_buf[stg_pending_events] = dwCtrlType;
- stg_pending_events++;
- }
- /* Cheesy pulsing of an event to wake up a waiting RTS thread, if any */
- abandonRequestWait();
- resetAbandonRequestWait();
- return TRUE;
- }
-
- RELEASE_LOCK(&sched_mutex);
-}
-
-
-/*
- * Function: rts_InstallConsoleEvent()
- *
- * Install/remove a console event handler.
- */
-int
-rts_InstallConsoleEvent(int action, StgStablePtr *handler)
-{
- StgInt previous_hdlr = console_handler;
-
- switch (action) {
- case STG_SIG_IGN:
- console_handler = STG_SIG_IGN;
- if ( !SetConsoleCtrlHandler(NULL, TRUE) ) {
- errorBelch("warning: unable to ignore console events");
- }
- break;
- case STG_SIG_DFL:
- console_handler = STG_SIG_IGN;
- if ( !SetConsoleCtrlHandler(NULL, FALSE) ) {
- errorBelch("warning: unable to restore default console event handling");
- }
- break;
- case STG_SIG_HAN:
- console_handler = (StgInt)*handler;
- if ( previous_hdlr < 0 ) {
- /* Only install generic_handler() once */
- if ( !SetConsoleCtrlHandler(generic_handler, TRUE) ) {
- errorBelch("warning: unable to install console event handler");
- }
- }
- break;
- }
-
- if (previous_hdlr == STG_SIG_DFL ||
- previous_hdlr == STG_SIG_IGN) {
- return previous_hdlr;
- } else {
- *handler = (StgStablePtr)previous_hdlr;
- return STG_SIG_HAN;
- }
-}
-
-/*
- * Function: rts_HandledConsoleEvent()
- *
- * Signal that a Haskell console event handler has completed its run.
- * The explicit notification that a Haskell handler has completed is
- * required to better handle the delivery of Ctrl-C/Break events whilst
- * an async worker thread is handling a read request on stdin. The
- * Win32 console implementation will abort such a read request when Ctrl-C
- * is delivered. That leaves the worker thread in a bind: should it
- * abandon the request (the Haskell thread reading from stdin has been
- * thrown an exception to signal the delivery of Ctrl-C & hence have
- * aborted the I/O request) or simply ignore the aborted read and retry?
- * (the Haskell thread reading from stdin isn't concerned with the
- * delivery and handling of Ctrl-C.) With both scenarios being
- * possible, the worker thread needs to be told -- that is, did the
- * console event handler cause the IO request to be abandoned?
- *
- */
-void
-rts_ConsoleHandlerDone(int ev)
-{
- if ( (DWORD)ev == CTRL_BREAK_EVENT ||
- (DWORD)ev == CTRL_C_EVENT ) {
- /* only these two cause stdin system calls to abort.. */
- SetEvent(hConsoleEvent); /* event is manual-reset */
- Sleep(0); /* yield */
- ResetEvent(hConsoleEvent); /* turn it back off again */
- }
-}
-
-/*
- * Function: rts_waitConsoleHandlerCompletion()
- *
- * Esoteric entry point used by worker thread that got woken
- * up as part Ctrl-C delivery.
- */
-int
-rts_waitConsoleHandlerCompletion()
-{
- /* As long as the worker doesn't need to do a multiple wait,
- * let's keep this HANDLE private to this 'module'.
- */
- return (WaitForSingleObject(hConsoleEvent, INFINITE) == WAIT_OBJECT_0);
-}
projects / ghc-hetmet.git / blobdiff