Tcl Source Code

2013-08-01  Harald Oehlmann  <[email protected]>

	* tclUnixNotify.c Tcl_InitNotifier: Bug [a0bc856dcd]
	  Start notifier thread again if we were forked, to solve Rivet bug
	  55153.

2013-07-05  Kevin B. Kenny  <[email protected]>

	* library/tzdata/Africa/Casablanca:
	* library/tzdata/America/Asuncion:
	* library/tzdata/Antarctica/Macquarie:
	* library/tzdata/Asia/Gaza:
	* library/tzdata/Asia/Hebron:

# This file contains a collection of tests for the procedures in the file
# tclUnixNotify.c.  Sourcing this file into Tcl runs the tests and
# generates output for errors.  No output means no errors were found.
#
# Copyright (c) 1995-1997 Sun Microsystems, Inc.
# Copyright (c) 1998-1999 by Scriptics Corporation.
#
# See the file "license.terms" for information on usage and redistribution
# of this file, and for a DISCLAIMER OF ALL WARRANTIES.

package require tcltest 2
namespace import -force ::tcltest::*

testConstraint testfork [llength [info commands testfork]]

# Test if the notifier thread is well initialized in a forked interpreter
# by Tcl_InitNotifier
test unixforkevent-1.1 {fork and test writeable event} \
    -constraints testfork \
    -body {
	set myFolder [makeDirectory unixtestfork]
	set pid [testfork]
	if {$pid == 0} {
	    # we are the forked process
	    set result initialized
	    set h [open [file join $myFolder test.txt] w]
	    fileevent $h writable\
		    "set result writable;\
		    after cancel [after 1000 {set result timeout}]"
	    vwait result
	    close $h
	    makeFile $result result.txt $myFolder
	    exit
	}
	# we are the original process
	while {![file readable [file join $myFolder result.txt]]} {}
	viewFile result.txt $myFolder
    } \
    -result {writable} \
    -cleanup { 
	catch { removeFolder $myFolder }
    }

::tcltest::cleanupTests
return

    Tcl_Condition waitCV;	/* Any other thread alerts a notifier that an
				 * event is ready to be processed by signaling
				 * this condition variable. */
#endif /* __CYGWIN__ */
    int eventReady;		/* True if an event is ready to be processed.
				 * Used as condition flag together with waitCV
				 * above. */
#endif /* TCL_THREADS */
} ThreadSpecificData;

static Tcl_ThreadDataKey dataKey;

#ifdef TCL_THREADS
/*
 * The following static indicates the number of threads that have initialized
 * notifiers.
 *
 * You must hold the notifierMutex lock before accessing this variable.
 */

static int notifierCount = 0;

/*
 * The following static stores the process ID of the initialized notifier
 * thread. If it changes, we have passed a fork and we should start a new
 * notifier thread.
 *
 * You must hold the notifierMutex lock before accessing this variable.
 */
static pid_t processIDInitialized = 0;

/*
 * The following variable points to the head of a doubly-linked list of
 * ThreadSpecificData structures for all threads that are currently waiting on
 * an event.
 *
 * You must hold the notifierMutex lock before accessing this list.
 */

/*
 * This is the thread ID of the notifier thread that does select.
 */

static Tcl_ThreadId notifierThread;

#endif /* TCL_THREADS */

/*
 * Static routines defined in this file.
 */

#ifdef TCL_THREADS
static void	NotifierThreadProc(ClientData clientData);
#ifdef HAVE_PTHREAD_ATFORK
static int	atForkInit = 0;
static void	AtForkPrepare(void);
static void	AtForkParent(void);
static void	AtForkChild(void);
#endif /* HAVE_PTHREAD_ATFORK */
#endif /* TCL_THREADS */
static int	FileHandlerEventProc(Tcl_Event *evPtr, int flags);

/*
 *----------------------------------------------------------------------
 *
 * Tcl_InitNotifier --
 *

    tsdPtr->eventReady = 0;

    /*
     * Start the Notifier thread if necessary.
     */

    Tcl_MutexLock(&notifierMutex);
#ifdef HAVE_PTHREAD_ATFORK
    /*
     * Install pthread_atfork handlers to reinitialize the notifier in the
     * child of a fork.
     */

    if (!atForkInit) {
	int result = pthread_atfork(AtForkPrepare, AtForkParent, AtForkChild);

	if (result) {
	    Tcl_Panic("Tcl_InitNotifier: pthread_atfork failed");
	}
	atForkInit = 1;
    }
#endif
    /*
     * Check if my process id changed, e.g. I was forked
     * In this case, restart the notifier thread and close the
     * pipe to the original notifier thread
     */
    if (notifierCount > 0 && processIDInitialized != getpid()) {
	notifierCount = 0;
	processIDInitialized = 0;
	close(triggerPipe);
	triggerPipe = -1;
    }
    if (notifierCount == 0) {
	if (TclpThreadCreate(&notifierThread, NotifierThreadProc, NULL,
		TCL_THREAD_STACK_DEFAULT, TCL_THREAD_JOINABLE) != TCL_OK) {
	    Tcl_Panic("Tcl_InitNotifier: unable to start notifier thread");
	}
    processIDInitialized = getpid();
    }
    notifierCount++;

    /*
     * Wait for the notifier pipe to be created.
     */

    while (triggerPipe < 0) {
	Tcl_ConditionWait(&notifierCV, &notifierMutex, NULL);
    }

    Tcl_MutexUnlock(&notifierMutex);
#endif /* TCL_THREADS */
    return (ClientData) tsdPtr;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_FinalizeNotifier --

    Tcl_MutexLock(&notifierMutex);
    triggerPipe = -1;
    Tcl_ConditionNotify(&notifierCV);
    Tcl_MutexUnlock(&notifierMutex);

    TclpThreadExit (0);
}

#ifdef HAVE_PTHREAD_ATFORK
/*
 *----------------------------------------------------------------------
 *
 * AtForkPrepare --
 *
 *	Lock the notifier in preparation for a fork.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

static void
AtForkPrepare(void)
{
}

/*
 *----------------------------------------------------------------------
 *
 * AtForkParent --
 *
 *	Unlock the notifier in the parent after a fork.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

static void
AtForkParent(void)
{
}

/*
 *----------------------------------------------------------------------
 *
 * AtForkChild --
 *
 *	Unlock and reinstall the notifier in the child after a fork.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

static void
AtForkChild(void)
{
    notifierMutex = NULL;
    notifierCV = NULL;
    Tcl_InitNotifier();
}
#endif /* HAVE_PTHREAD_ATFORK */

#endif /* TCL_THREADS */

#endif /* HAVE_COREFOUNDATION */

/*
 * Local Variables:
 * mode: c
 * c-basic-offset: 4
 * fill-column: 78
 * End:
 */