Libc-498.tar.gz

[apple/libc.git] / i386 / gen / getmcontext.c

diff --git a/i386/gen/getmcontext.c b/i386/gen/getmcontext.c
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+/*
+ * Copyright (c) 2007 Apple Inc. All rights reserved.
+ *
+ * @APPLE_LICENSE_HEADER_START@
+ * 
+ * This file contains Original Code and/or Modifications of Original Code
+ * as defined in and that are subject to the Apple Public Source License
+ * Version 2.0 (the 'License'). You may not use this file except in
+ * compliance with the License. Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this
+ * file.
+ * 
+ * The Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
+ * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
+ * limitations under the License.
+ * 
+ * @APPLE_LICENSE_HEADER_END@
+ */
+
+#if defined(__i386__)
+
+#define _XOPEN_SOURCE 600L
+
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <pthread.h>
+#include <signal.h>
+#include <ucontext.h>
+
+extern size_t pthread_get_stacksize_np(pthread_t);
+extern void *pthread_get_stackaddr_np(pthread_t);
+#ifdef __DYNAMIC__
+extern int __in_sigtramp;
+#endif /* __DYNAMIC_ */
+
+__private_extern__ mcontext_t
+getmcontext(ucontext_t *uctx, void *sp)
+{
+       pthread_t self = pthread_self();
+       mcontext_t mctx = (mcontext_t)&uctx->__mcontext_data;
+       size_t stacksize = pthread_get_stacksize_np(self);
+       stack_t stack;
+
+       uctx->uc_stack.ss_sp = sp;
+       uctx->uc_stack.ss_flags = 0;
+
+       if (0 == sigaltstack(NULL, &stack)) {
+               if (stack.ss_flags & SS_ONSTACK) {
+                       uctx->uc_stack = stack;
+                       stacksize = stack.ss_size;
+               }
+       }
+
+       if (stacksize == 0) {   /* main thread doesn't have pthread stack size */
+               rlim_t rlim;
+               if (0 == getrlimit(RLIMIT_STACK, &rlim))
+                       stacksize = rlim;
+       }
+
+       uctx->uc_stack.ss_size = stacksize;
+
+       if (uctx->uc_mcontext != mctx) {
+               uctx->uc_mcontext = mctx;
+
+#ifdef __DYNAMIC__
+               uctx->uc_link = (ucontext_t*)__in_sigtramp; /* non-zero if in signal handler */
+#else  /* !__DYNAMIC__ */
+               uctx->uc_link = 0;
+#endif /* __DYNAMIC__ */
+
+       }
+
+       sigprocmask(0, NULL, &uctx->uc_sigmask);
+       return mctx;
+}
+
+#endif /* __i386__ */