* miscfuncs.cc (DEFAULT_STACKSIZE): Remove.
(CygwinCreateThread): Simplify code by assuming that now stack-related input values are undefined. Set stack protection to PAGE_READWRITE, as is default on Windows. Add lengthy comment to explain POSIX guardpage. * thread.cc (pthread_attr::pthread_attr): Initialize stacksize as PTHREAD_DEFAULT_STACKSIZE. Initialize guardsize as PTHREAD_DEFAULT_GUARDSIZE. * thread.h (PTHREAD_DEFAULT_STACKSIZE): Define. Add comment to explain. (PTHREAD_DEFAULT_GUARDSIZE): Define.
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@@ -549,8 +549,6 @@ thread_wrapper (VOID *arg)
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ExitThread (0);
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}
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#define DEFAULT_STACKSIZE (1024 * 1024)
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HANDLE WINAPI
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CygwinCreateThread (LPTHREAD_START_ROUTINE thread_func, PVOID thread_arg,
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PVOID stackaddr, ULONG stacksize, ULONG guardsize,
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@@ -572,30 +570,19 @@ CygwinCreateThread (LPTHREAD_START_ROUTINE thread_func, PVOID thread_arg,
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wrapper_arg->func = thread_func;
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wrapper_arg->arg = thread_arg;
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/* Set stacksize. */
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real_stacksize = stacksize ?: DEFAULT_STACKSIZE;
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if (real_stacksize < PTHREAD_STACK_MIN)
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real_stacksize = PTHREAD_STACK_MIN;
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if (stackaddr)
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{
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/* If the application provided the stack, just use it. */
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wrapper_arg->stackaddr = (char *) stackaddr;
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wrapper_arg->stackbase = (char *) stackaddr + real_stacksize;
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wrapper_arg->stackbase = (char *) stackaddr + stacksize;
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}
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else
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{
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/* If not, we have to create the stack here. */
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real_stacksize = roundup2 (real_stacksize, wincap.page_size ());
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/* If no guardsize has been specified by the application, use the
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system pagesize as default. */
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real_guardsize = (guardsize != (ULONG) -1)
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? guardsize : wincap.page_size ();
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if (real_guardsize)
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real_guardsize = roundup2 (real_guardsize, wincap.page_size ());
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/* Add the guardsize to the stacksize, but only if the stacksize and
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the guardsize have been explicitely specified. */
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if (stacksize || guardsize != (ULONG) -1)
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real_stacksize += real_guardsize;
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real_stacksize = roundup2 (stacksize, wincap.page_size ());
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real_guardsize = roundup2 (guardsize, wincap.page_size ());
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/* Add the guardsize to the stacksize */
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real_stacksize += real_guardsize;
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/* Now roundup the result to the next allocation boundary. */
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real_stacksize = roundup2 (real_stacksize,
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wincap.allocation_granularity ());
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@@ -606,7 +593,7 @@ CygwinCreateThread (LPTHREAD_START_ROUTINE thread_func, PVOID thread_arg,
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the Cygwin DLL comes to mind. */
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real_stackaddr = VirtualAlloc (NULL, real_stacksize,
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MEM_RESERVE | MEM_TOP_DOWN,
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PAGE_EXECUTE_READWRITE);
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PAGE_READWRITE);
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if (!real_stackaddr)
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return NULL;
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/* Set up committed region. In contrast to the OS we commit 64K and
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@@ -615,13 +602,19 @@ CygwinCreateThread (LPTHREAD_START_ROUTINE thread_func, PVOID thread_arg,
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+ real_stacksize
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- wincap.allocation_granularity ();
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if (!VirtualAlloc (commitaddr, wincap.page_size (), MEM_COMMIT,
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PAGE_EXECUTE_READWRITE | PAGE_GUARD))
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PAGE_READWRITE | PAGE_GUARD))
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goto err;
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commitaddr += wincap.page_size ();
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if (!VirtualAlloc (commitaddr, wincap.allocation_granularity ()
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- wincap.page_size (), MEM_COMMIT,
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PAGE_EXECUTE_READWRITE))
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PAGE_READWRITE))
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goto err;
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/* If the guardsize is != 0 (which is the default), set up a POSIX
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guardpage at the end of the stack. This isn't the same as the
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Windows guardpage, which is used to convert reserved stack to
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commited stack if necessary. Rather, the POSIX guardpage consists
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of one or more memory pages with NOACCESS protection. It's supposed
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to safeguard memory areas beyond the stack against stack overflow. */
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if (real_guardsize)
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VirtualAlloc (real_stackaddr, real_guardsize, MEM_COMMIT,
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PAGE_NOACCESS);
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