85 lines
2.0 KiB
C
85 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 "runtime.h"
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#include "go-alloc.h"
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#include "go-panic.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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G *g;
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Defer *n;
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g = runtime_g ();
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n = runtime_newdefer ();
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n->next = g->_defer;
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n->frame = frame;
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n->_panic = g->_panic;
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n->pfn = (uintptr) pfn;
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n->arg = arg;
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n->retaddr = 0;
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n->makefunccanrecover = 0;
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n->special = 0;
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g->_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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G *g;
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g = runtime_g ();
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while (g->_defer != NULL && g->_defer->frame == frame)
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{
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Defer *d;
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void (*pfn) (void *);
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d = g->_defer;
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pfn = (void (*) (void *)) d->pfn;
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d->pfn = 0;
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if (pfn != NULL)
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(*pfn) (d->arg);
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g->_defer = d->next;
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/* This may be called by a cgo callback routine to defer the
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call to syscall.CgocallBackDone, in which case we will not
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have a memory context. Don't try to free anything in that
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case--the GC will release it later. */
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if (runtime_m () != NULL)
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runtime_freedefer (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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G *g;
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g = runtime_g ();
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if (g->_defer != NULL)
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g->_defer->retaddr = (uintptr) __builtin_extract_return_addr (retaddr);
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return 0;
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}
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