diff options
Diffstat (limited to 'unix/tclUnixInit.c')
| -rw-r--r-- | unix/tclUnixInit.c | 259 |
1 files changed, 1 insertions, 258 deletions
diff --git a/unix/tclUnixInit.c b/unix/tclUnixInit.c index 4c8427d..0b3cdc9 100644 --- a/unix/tclUnixInit.c +++ b/unix/tclUnixInit.c @@ -7,7 +7,7 @@ * Copyright (c) 1999 by Scriptics Corporation. * All rights reserved. * - * RCS: @(#) $Id: tclUnixInit.c,v 1.83 2008/04/27 22:21:35 dkf Exp $ + * RCS: @(#) $Id: tclUnixInit.c,v 1.84 2008/07/13 09:03:41 msofer Exp $ */ #include "tclInt.h" @@ -38,64 +38,6 @@ #endif /* - * Define TCL_NO_STACK_CHECK in the compiler options if you want to revert to - * the old behavior of never checking the stack. - */ - -/* - * Define this if you want to see a lot of output regarding stack checking. - */ - -#undef TCL_DEBUG_STACK_CHECK - -/* - * Values used to compute how much space is really available for Tcl's use for - * the stack. - * - * The getrlimit() function is documented to return the maximum stack size in - * bytes. However, with threads enabled, the pthread library on some platforms - * does bad things to the stack size limits. First, the limits cannot be - * changed. Second, they appear to be sometimes reported incorrectly. - * - * The defines below may need to be adjusted if more platforms have this - * broken behavior with threads enabled. - */ - -#ifndef TCL_MAGIC_STACK_DIVISOR -#define TCL_MAGIC_STACK_DIVISOR 1 -#endif -#ifndef TCL_RESERVED_STACK_PAGES -#define TCL_RESERVED_STACK_PAGES 8 -#endif - -/* - * Thread specific data for stack checking. - */ - -#ifndef TCL_NO_STACK_CHECK -typedef struct ThreadSpecificData { - int *outerVarPtr; /* The "outermost" stack frame pointer for - * this thread. */ - int *stackBound; /* The current stack boundary */ -} ThreadSpecificData; -static Tcl_ThreadDataKey dataKey; -#ifdef TCL_CROSS_COMPILE -static int stackGrowsDown = -1; -static int StackGrowsDown(int *parent); -#elif defined(TCL_STACK_GROWS_UP) -#define stackGrowsDown 0 -#else -#define stackGrowsDown 1 -#endif -#endif /* TCL_NO_STACK_CHECK */ - -#ifdef TCL_DEBUG_STACK_CHECK -#define STACK_DEBUG(args) printf args -#else -#define STACK_DEBUG(args) (void)0 -#endif /* TCL_DEBUG_STACK_CHECK */ - -/* * Tcl tries to use standard and homebrew methods to guess the right encoding * on the platform. However, there is always a final fallback, and this value * is it. Make sure it is a real Tcl encoding. @@ -327,9 +269,6 @@ static const LocaleTable localeTable[] = { {"zh_tw.big5", "big5"}, }; -#ifndef TCL_NO_STACK_CHECK -static int GetStackSize(size_t *stackSizePtr); -#endif /* TCL_NO_STACK_CHECK */ #ifdef HAVE_COREFOUNDATION static int MacOSXGetLibraryPath(Tcl_Interp *interp, int maxPathLen, char *tclLibPath); @@ -1008,202 +947,6 @@ TclpFindVariable( return result; } -#ifndef TCL_NO_STACK_CHECK -/* - *---------------------------------------------------------------------- - * - * TclpGetCStackParams -- - * - * Determine the stack params for the current thread: in which - * direction does the stack grow, and what is the stack lower (resp. - * upper) bound for safe invocation of a new command? This is used to - * cache the values needed for an efficient computation of - * TclpCheckStackSpace() when the interp is known. - * - * Results: - * Returns 1 if the stack grows down, in which case a stack lower bound - * is stored at stackBoundPtr. If the stack grows up, 0 is returned and - * an upper bound is stored at stackBoundPtr. If a bound cannot be - * determined NULL is stored at stackBoundPtr. - * - *---------------------------------------------------------------------- - */ - -int -TclpGetCStackParams( - int **stackBoundPtr) -{ - int result = TCL_OK; - size_t stackSize = 0; /* The size of the current stack. */ - ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey); - /* Most variables are actually in a - * thread-specific data block to minimise the - * impact on the stack. */ -#ifdef TCL_CROSS_COMPILE - if (stackGrowsDown == -1) { - /* - * Not initialised! - */ - - stackGrowsDown = StackGrowsDown(&result); - } -#endif - - /* - * The first time through in a thread: record the "outermost" stack - * frame and inquire with the OS about the stack size. - */ - - if (tsdPtr->outerVarPtr == NULL) { - tsdPtr->outerVarPtr = &result; - result = GetStackSize(&stackSize); - if (result != TCL_OK) { - /* Can't check, assume it always succeeds */ -#ifdef TCL_CROSS_COMPILE - stackGrowsDown = 1; -#endif - tsdPtr->stackBound = NULL; - goto done; - } - } - - if (stackSize || (tsdPtr->stackBound && - ((stackGrowsDown && (&result < tsdPtr->stackBound)) || - (!stackGrowsDown && (&result > tsdPtr->stackBound))))) { - /* - * Either the thread's first pass or stack failure: set the params - */ - - if (!stackSize) { - /* - * Stack failure: if we didn't already blow up, we are within the - * safety area. Recheck with the OS in case the stack was grown. - */ - result = GetStackSize(&stackSize); - if (result != TCL_OK) { - /* Can't check, assume it always succeeds */ -#ifdef TCL_CROSS_COMPILE - stackGrowsDown = 1; -#endif - tsdPtr->stackBound = NULL; - goto done; - } - } - - if (stackGrowsDown) { - tsdPtr->stackBound = (int *) ((char *)tsdPtr->outerVarPtr - - stackSize); - } else { - tsdPtr->stackBound = (int *) ((char *)tsdPtr->outerVarPtr + - stackSize); - } - } - - done: - *stackBoundPtr = tsdPtr->stackBound; - return stackGrowsDown; -} - -#ifdef TCL_CROSS_COMPILE -int -StackGrowsDown( - int *parent) -{ - int here; - return (&here < parent); -} -#endif - -/* - *---------------------------------------------------------------------- - * - * GetStackSize -- - * - * Discover what the stack size for the current thread/process actually - * is. Expects to only ever be called once per thread and then only at a - * point when there is a reasonable amount of space left on the current - * stack; TclpCheckStackSpace is called sufficiently frequently that that - * is true. - * - * Results: - * TCL_OK if the stack space was discovered, TCL_BREAK if the stack space - * was undiscoverable in a way that stack checks should fail, and - * TCL_CONTINUE if the stack space was undiscoverable in a way that stack - * checks should succeed. - * - * Side effects: - * None - * - *---------------------------------------------------------------------- - */ - -static int -GetStackSize( - size_t *stackSizePtr) -{ - size_t rawStackSize; - struct rlimit rLimit; /* The result from getrlimit(). */ - -#ifdef TCL_THREADS - rawStackSize = TclpThreadGetStackSize(); - if (rawStackSize == (size_t) -1) { - /* - * Some kind of confirmed error in TclpThreadGetStackSize?! Fall back - * to whatever getrlimit can determine. - */ - STACK_DEBUG(("stack checks: TclpThreadGetStackSize failed in \n")); - } - if (rawStackSize > 0) { - goto finalSanityCheck; - } - - /* - * If we have zero or an error, try the system limits instead. After all, - * the pthread documentation states that threads should always be bound by - * the system stack size limit in any case. - */ -#endif /* TCL_THREADS */ - - if (getrlimit(RLIMIT_STACK, &rLimit) != 0) { - /* - * getrlimit() failed, just fail the whole thing. - */ - STACK_DEBUG(("skipping stack checks with failure: getrlimit failed\n")); - return TCL_BREAK; - } - if (rLimit.rlim_cur == RLIM_INFINITY) { - /* - * Limit is "infinite"; there is no stack limit. - */ - STACK_DEBUG(("skipping stack checks with success: infinite limit\n")); - return TCL_CONTINUE; - } - rawStackSize = rLimit.rlim_cur; - - /* - * Final sanity check on the determined stack size. If we fail this, - * assume there are bogus values about and that we can't actually figure - * out what the stack size really is. - */ - -#ifdef TCL_THREADS /* Stop warning... */ - finalSanityCheck: -#endif - if (rawStackSize <= 0) { - STACK_DEBUG(("skipping stack checks with success\n")); - return TCL_CONTINUE; - } - - /* - * Calculate a stack size with a safety margin. - */ - - *stackSizePtr = (rawStackSize / TCL_MAGIC_STACK_DIVISOR) - - (getpagesize() * TCL_RESERVED_STACK_PAGES); - - return TCL_OK; -} -#endif /* TCL_NO_STACK_CHECK */ /* *---------------------------------------------------------------------- |