76 lines
2.0 KiB
C
76 lines
2.0 KiB
C
/* go-defer.c -- manage the defer stack.
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Copyright 2009 The Go Authors. All rights reserved.
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Use of this source code is governed by a BSD-style
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license that can be found in the LICENSE file. */
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#include <stddef.h>
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#include "go-alloc.h"
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#include "go-panic.h"
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#include "go-defer.h"
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/* This function is called each time we need to defer a call. */
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void
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__go_defer (_Bool *frame, void (*pfn) (void *), void *arg)
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{
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struct __go_defer_stack *n;
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if (__go_panic_defer == NULL)
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__go_panic_defer = ((struct __go_panic_defer_struct *)
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__go_alloc (sizeof (struct __go_panic_defer_struct)));
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n = (struct __go_defer_stack *) __go_alloc (sizeof (struct __go_defer_stack));
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n->__next = __go_panic_defer->__defer;
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n->__frame = frame;
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n->__panic = __go_panic_defer->__panic;
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n->__pfn = pfn;
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n->__arg = arg;
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n->__retaddr = NULL;
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__go_panic_defer->__defer = n;
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}
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/* This function is called when we want to undefer the stack. */
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void
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__go_undefer (_Bool *frame)
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{
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if (__go_panic_defer == NULL)
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return;
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while (__go_panic_defer->__defer != NULL
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&& __go_panic_defer->__defer->__frame == frame)
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{
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struct __go_defer_stack *d;
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void (*pfn) (void *);
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d = __go_panic_defer->__defer;
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pfn = d->__pfn;
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d->__pfn = NULL;
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if (pfn != NULL)
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(*pfn) (d->__arg);
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__go_panic_defer->__defer = d->__next;
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__go_free (d);
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/* Since we are executing a defer function here, we know we are
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returning from the calling function. If the calling
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function, or one of its callees, paniced, then the defer
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functions would be executed by __go_panic. */
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*frame = 1;
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}
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}
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/* This function is called to record the address to which the deferred
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function returns. This may in turn be checked by __go_can_recover.
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The frontend relies on this function returning false. */
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_Bool
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__go_set_defer_retaddr (void *retaddr)
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{
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if (__go_panic_defer != NULL && __go_panic_defer->__defer != NULL)
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__go_panic_defer->__defer->__retaddr = retaddr;
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return 0;
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}
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