1 /*
2 * Copyright (c) 1994 by Xerox Corporation. All rights reserved.
3 * Copyright (c) 1996 by Silicon Graphics. All rights reserved.
4 * Copyright (c) 1998 by Fergus Henderson. All rights reserved.
5 * Copyright (c) 2000-2010 by Hewlett-Packard Development Company.
6 * All rights reserved.
7 *
8 * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
9 * OR IMPLIED. ANY USE IS AT YOUR OWN RISK.
10 *
11 * Permission is hereby granted to use or copy this program
12 * for any purpose, provided the above notices are retained on all copies.
13 * Permission to modify the code and to distribute modified code is granted,
14 * provided the above notices are retained, and a notice that the code was
15 * modified is included with the above copyright notice.
16 */
17 18 /*
19 * We want to make sure that `GC_thread_exit_proc()` is unconditionally
20 * invoked, even if the client is not compiled with `-fexceptions` option,
21 * but the collector is. The workaround is to put `GC_pthread_start_inner()`
22 * in its own file (this one), and undefine `__EXCEPTIONS` in the gcc case
23 * at the top of the file.
24 * FIXME: It is still unclear whether this will actually cause the
25 * `exit` handler to be invoked last when `thread_exit` is called (and
26 * if `-fexceptions` option is used).
27 */
28 29 #if !defined(DONT_UNDEF_EXCEPTIONS) && defined(__GNUC__) && defined(__linux__)
30 /*
31 * We undefine `__EXCEPTIONS` to avoid using gcc `__cleanup__` attribute.
32 * The current NPTL implementation of `pthread_cleanup_push` uses
33 * `__cleanup__` attribute when `__EXCEPTIONS` is defined (`-fexceptions`
34 * option is given). The stack unwinding and cleanup with `__cleanup__`
35 * attribute work correctly when everything is compiled with `-fexceptions`
36 * option, but it is not the requirement for this library clients to use
37 * `-fexceptions` option everywhere. With `__EXCEPTIONS` undefined, the
38 * cleanup routines are registered with `__pthread_register_cancel` thus
39 * should work anyway.
40 */
41 # undef __EXCEPTIONS
42 #endif
43 44 #include "private/pthread_support.h"
45 46 #if defined(GC_PTHREADS) && !defined(PLATFORM_THREADS) \
47 && !defined(SN_TARGET_PSP2)
48 49 /* Invoked from `GC_pthread_start()`. */
50 GC_INNER_PTHRSTART void *GC_CALLBACK
51 GC_pthread_start_inner(struct GC_stack_base *sb, void *arg)
52 {
53 void *(*start)(void *);
54 void *start_arg;
55 void *result;
56 volatile GC_thread me
57 = GC_start_rtn_prepare_thread(&start, &start_arg, sb, arg);
58 59 # ifndef NACL
60 pthread_cleanup_push(GC_thread_exit_proc, (/* no volatile */ void *)me);
61 # endif
62 result = (*start)(start_arg);
63 # if defined(DEBUG_THREADS) && !defined(GC_PTHREAD_START_STANDALONE)
64 GC_log_printf("Finishing thread %p\n", PTHREAD_TO_VPTR(pthread_self()));
65 # endif
66 me->status = result;
67 /* Note: we cannot use `GC_dirty()` instead. */
68 GC_end_stubborn_change(me);
69 70 /*
71 * Cleanup acquires the allocator lock, ensuring that we cannot exit
72 * while a collection that thinks we are alive is trying to stop us.
73 */
74 # ifdef NACL
75 GC_thread_exit_proc((/* no volatile */ void *)me);
76 # else
77 pthread_cleanup_pop(1);
78 # endif
79 return result;
80 }
81 82 #endif /* GC_PTHREADS */
83