xref: /libuv/test/test-queue-foreach-delete.c (revision 011a1ac1)
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21 
22 #include "uv.h"
23 #include "task.h"
24 
25 #include <string.h>
26 
27 
28 /*
29  * The idea behind the test is as follows.
30  * Certain handle types are stored in a queue internally.
31  * Extra care should be taken for removal of a handle from the queue while iterating over the queue.
32  * (i.e., uv__queue_remove() called within uv__queue_foreach())
33  * This usually happens when someone closes or stops a handle from within its callback.
34  * So we need to check that we haven't screwed the queue on close/stop.
35  * To do so we do the following (for each handle type):
36  *  1. Create and start 3 handles (#0, #1, and #2).
37  *
38  *     The queue after the start() calls:
39  *     ..=> [queue head] <=> [handle] <=> [handle #1] <=> [handle] <=..
40  *
41  *  2. Trigger handles to fire (for uv_idle_t, uv_prepare_t, and uv_check_t there is nothing to do).
42  *
43  *  3. In the callback for the first-executed handle (#0 or #2 depending on handle type)
44  *     stop the handle and the next one (#1).
45  *     (for uv_idle_t, uv_prepare_t, and uv_check_t callbacks are executed in the reverse order as they are start()'ed,
46  *     so callback for handle #2 will be called first)
47  *
48  *     The queue after the stop() calls:
49  *                                correct foreach "next"  |
50  *                                                       \/
51  *     ..=> [queue head] <==============================> [handle] <=..
52  *          [          ] <-  [handle] <=> [handle #1]  -> [      ]
53  *                                       /\
54  *                  wrong foreach "next"  |
55  *
56  *  4. The callback for handle #1 shouldn't be called because the handle #1 is stopped in the previous step.
57  *     However, if uv__queue_remove() is not handled properly within uv__queue_foreach(), the callback _will_
58  *     be called.
59  */
60 
61 static const unsigned first_handle_number_idle     = 2;
62 static const unsigned first_handle_number_prepare  = 2;
63 static const unsigned first_handle_number_check    = 2;
64 #ifdef __linux__
65 static const unsigned first_handle_number_fs_event = 0;
66 #endif
67 
68 
69 #define DEFINE_GLOBALS_AND_CBS(name, ...)                                     \
70   static uv_##name##_t (name)[3];                                             \
71   static unsigned name##_cb_calls[3];                                         \
72                                                                               \
73   static void name##2_cb(__VA_ARGS__) {                                       \
74     ASSERT_PTR_EQ(handle, &(name)[2]);                                        \
75     if (first_handle_number_##name == 2) {                                    \
76       uv_close((uv_handle_t*)&(name)[2], NULL);                               \
77       uv_close((uv_handle_t*)&(name)[1], NULL);                               \
78     }                                                                         \
79     name##_cb_calls[2]++;                                                     \
80   }                                                                           \
81                                                                               \
82   static void name##1_cb(__VA_ARGS__) {                                       \
83     ASSERT_PTR_EQ(handle, &(name)[1]);                                        \
84     ASSERT(0 && "Shouldn't be called" && (&name[0]));                         \
85   }                                                                           \
86                                                                               \
87   static void name##0_cb(__VA_ARGS__) {                                       \
88     ASSERT_PTR_EQ(handle, &(name)[0]);                                        \
89     if (first_handle_number_##name == 0) {                                    \
90       uv_close((uv_handle_t*)&(name)[0], NULL);                               \
91       uv_close((uv_handle_t*)&(name)[1], NULL);                               \
92     }                                                                         \
93     name##_cb_calls[0]++;                                                     \
94   }                                                                           \
95                                                                               \
96   static const uv_##name##_cb name##_cbs[] = {                                \
97     name##0_cb,                                                               \
98     name##1_cb,                                                               \
99     name##2_cb,                                                               \
100   };
101 
102 #define INIT_AND_START(name, loop)                                            \
103   do {                                                                        \
104     size_t i;                                                                 \
105     for (i = 0; i < ARRAY_SIZE(name); i++) {                                  \
106       int r;                                                                  \
107       r = uv_##name##_init((loop), &(name)[i]);                               \
108       ASSERT_OK(r);                                                           \
109                                                                               \
110       r = uv_##name##_start(&(name)[i], name##_cbs[i]);                       \
111       ASSERT_OK(r);                                                           \
112     }                                                                         \
113   } while (0)
114 
115 #define END_ASSERTS(name)                                                     \
116   do {                                                                        \
117     ASSERT_EQ(1, name##_cb_calls[0]);                                         \
118     ASSERT_OK(name##_cb_calls[1]);                                            \
119     ASSERT_EQ(1, name##_cb_calls[2]);                                         \
120   } while (0)
121 
122 DEFINE_GLOBALS_AND_CBS(idle, uv_idle_t* handle)
123 DEFINE_GLOBALS_AND_CBS(prepare, uv_prepare_t* handle)
124 DEFINE_GLOBALS_AND_CBS(check, uv_check_t* handle)
125 
126 #ifdef __linux__
127 DEFINE_GLOBALS_AND_CBS(fs_event,
128                        uv_fs_event_t* handle,
129                        const char* filename,
130                        int events,
131                        int status)
132 
133 static const char watched_dir[] = ".";
134 static uv_timer_t timer;
135 static unsigned helper_timer_cb_calls;
136 
137 
init_and_start_fs_events(uv_loop_t * loop)138 static void init_and_start_fs_events(uv_loop_t* loop) {
139   size_t i;
140   for (i = 0; i < ARRAY_SIZE(fs_event); i++) {
141     int r;
142     r = uv_fs_event_init(loop, &fs_event[i]);
143     ASSERT_OK(r);
144 
145     r = uv_fs_event_start(&fs_event[i],
146                           (uv_fs_event_cb)fs_event_cbs[i],
147                           watched_dir,
148                           0);
149     ASSERT_OK(r);
150   }
151 }
152 
helper_timer_cb(uv_timer_t * thandle)153 static void helper_timer_cb(uv_timer_t* thandle) {
154   int r;
155   uv_fs_t fs_req;
156 
157   /* fire all fs_events */
158   r = uv_fs_utime(thandle->loop, &fs_req, watched_dir, 0, 0, NULL);
159   ASSERT_OK(r);
160   ASSERT_OK(fs_req.result);
161   ASSERT_EQ(fs_req.fs_type, UV_FS_UTIME);
162   ASSERT_OK(strcmp(fs_req.path, watched_dir));
163   uv_fs_req_cleanup(&fs_req);
164 
165   helper_timer_cb_calls++;
166 }
167 #endif
168 
169 
TEST_IMPL(queue_foreach_delete)170 TEST_IMPL(queue_foreach_delete) {
171   uv_loop_t* loop;
172   int r;
173 
174   loop = uv_default_loop();
175 
176   INIT_AND_START(idle,    loop);
177   INIT_AND_START(prepare, loop);
178   INIT_AND_START(check,   loop);
179 
180 #ifdef __linux__
181   init_and_start_fs_events(loop);
182 
183   /* helper timer to trigger async and fs_event callbacks */
184   r = uv_timer_init(loop, &timer);
185   ASSERT_OK(r);
186 
187   r = uv_timer_start(&timer, helper_timer_cb, 0, 0);
188   ASSERT_OK(r);
189 #endif
190 
191   r = uv_run(loop, UV_RUN_NOWAIT);
192   ASSERT_EQ(1, r);
193 
194   END_ASSERTS(idle);
195   END_ASSERTS(prepare);
196   END_ASSERTS(check);
197 
198 #ifdef __linux__
199   ASSERT_EQ(1, helper_timer_cb_calls);
200 #endif
201 
202   MAKE_VALGRIND_HAPPY(loop);
203 
204   return 0;
205 }
206