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authorThe Android Open Source Project <initial-contribution@android.com>2009-01-20 14:03:55 -0800
committerThe Android Open Source Project <initial-contribution@android.com>2009-01-20 14:03:55 -0800
commitd37527501c85edcb3a6a7c8a0b6297d52d434897 (patch)
treef005d945ce90569b8e63cf42294ab42dddab52c2 /libc/stdlib/atexit.c
parente5cc1f386b167b9f7bfdebc7219e89aa9b71e4b2 (diff)
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auto import from //branches/cupcake/...@127101
Diffstat (limited to 'libc/stdlib/atexit.c')
-rw-r--r--libc/stdlib/atexit.c98
1 files changed, 87 insertions, 11 deletions
diff --git a/libc/stdlib/atexit.c b/libc/stdlib/atexit.c
index 97eac4a..5bf82ba 100644
--- a/libc/stdlib/atexit.c
+++ b/libc/stdlib/atexit.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: atexit.c,v 1.12 2006/02/22 07:16:32 otto Exp $ */
+/* $OpenBSD: atexit.c,v 1.14 2007/09/05 20:47:47 chl Exp $ */
/*
* Copyright (c) 2002 Daniel Hartmeier
* All rights reserved.
@@ -32,6 +32,7 @@
#include <sys/types.h>
#include <sys/mman.h>
#include <stdlib.h>
+#include <string.h>
#include <unistd.h>
#include "atexit.h"
#include "thread_private.h"
@@ -45,17 +46,22 @@ struct atexit *__atexit;
* function pointer in the first allocated page (the last one in
* the linked list) is reserved for the cleanup function.
*
- * Outside the following two functions, all pages are mprotect()'ed
+ * Outside the following functions, all pages are mprotect()'ed
* to prevent unintentional/malicious corruption.
*/
/*
- * Register a function to be performed at exit.
+ * Register a function to be performed at exit or when a shared object
+ * with the given dso handle is unloaded dynamically. Also used as
+ * the backend for atexit(). For more info on this API, see:
+ *
+ * http://www.codesourcery.com/cxx-abi/abi.html#dso-dtor
*/
int
-atexit(void (*fn)(void))
+__cxa_atexit(void (*func)(void *), void *arg, void *dso)
{
- struct atexit *p;
+ struct atexit *p = __atexit;
+ struct atexit_fn *fnp;
int pgsize = getpagesize();
int ret = -1;
@@ -71,11 +77,11 @@ atexit(void (*fn)(void))
}
if (p == NULL) {
p = mmap(NULL, pgsize, PROT_READ | PROT_WRITE,
- MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
+ MAP_ANON | MAP_PRIVATE, -1, 0);
if (p == MAP_FAILED)
goto unlock;
if (__atexit == NULL) {
- p->fns[0] = NULL;
+ memset(&p->fns[0], 0, sizeof(p->fns[0]));
p->ind = 1;
} else
p->ind = 0;
@@ -86,7 +92,10 @@ atexit(void (*fn)(void))
if (__atexit_invalid)
__atexit_invalid = 0;
}
- p->fns[p->ind++] = fn;
+ fnp = &p->fns[p->ind++];
+ fnp->fn_ptr.cxa_func = func;
+ fnp->fn_arg = arg;
+ fnp->fn_dso = dso;
if (mprotect(p, pgsize, PROT_READ))
goto unlock;
ret = 0;
@@ -96,10 +105,75 @@ unlock:
}
/*
+ * Register a function to be performed at exit.
+ */
+int
+atexit(void (*func)(void))
+{
+ return (__cxa_atexit((void (*)(void *))func, NULL, NULL));
+}
+
+/*
+ * Call all handlers registered with __cxa_atexit() for the shared
+ * object owning 'dso'.
+ * Note: if 'dso' is NULL, then all remaining handlers are called.
+ */
+void
+__cxa_finalize(void *dso)
+{
+ struct atexit *p, *q;
+ struct atexit_fn fn;
+ int n, pgsize = getpagesize();
+ static int call_depth;
+
+ if (__atexit_invalid)
+ return;
+
+ call_depth++;
+
+ for (p = __atexit; p != NULL; p = p->next) {
+ for (n = p->ind; --n >= 0;) {
+ if (p->fns[n].fn_ptr.cxa_func == NULL)
+ continue; /* already called */
+ if (dso != NULL && dso != p->fns[n].fn_dso)
+ continue; /* wrong DSO */
+
+ /*
+ * Mark handler as having been already called to avoid
+ * dupes and loops, then call the appropriate function.
+ */
+ fn = p->fns[n];
+ if (mprotect(p, pgsize, PROT_READ | PROT_WRITE) == 0) {
+ p->fns[n].fn_ptr.cxa_func = NULL;
+ mprotect(p, pgsize, PROT_READ);
+ }
+ if (dso != NULL)
+ (*fn.fn_ptr.cxa_func)(fn.fn_arg);
+ else
+ (*fn.fn_ptr.std_func)();
+ }
+ }
+
+ /*
+ * If called via exit(), unmap the pages since we have now run
+ * all the handlers. We defer this until calldepth == 0 so that
+ * we don't unmap things prematurely if called recursively.
+ */
+ if (dso == NULL && --call_depth == 0) {
+ for (p = __atexit; p != NULL; ) {
+ q = p;
+ p = p->next;
+ munmap(q, pgsize);
+ }
+ __atexit = NULL;
+ }
+}
+
+/*
* Register the cleanup function
*/
void
-__atexit_register_cleanup(void (*fn)(void))
+__atexit_register_cleanup(void (*func)(void))
{
struct atexit *p;
int pgsize = getpagesize();
@@ -112,7 +186,7 @@ __atexit_register_cleanup(void (*fn)(void))
p = p->next;
if (p == NULL) {
p = mmap(NULL, pgsize, PROT_READ | PROT_WRITE,
- MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
+ MAP_ANON | MAP_PRIVATE, -1, 0);
if (p == MAP_FAILED)
goto unlock;
p->ind = 1;
@@ -126,7 +200,9 @@ __atexit_register_cleanup(void (*fn)(void))
if (mprotect(p, pgsize, PROT_READ | PROT_WRITE))
goto unlock;
}
- p->fns[0] = fn;
+ p->fns[0].fn_ptr.std_func = func;
+ p->fns[0].fn_arg = NULL;
+ p->fns[0].fn_dso = NULL;
mprotect(p, pgsize, PROT_READ);
unlock:
_ATEXIT_UNLOCK();