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1 // Copyright (C) 2013 The Android Open Source Project
2 // All rights reserved.
3 //
4 // Redistribution and use in source and binary forms, with or without
5 // modification, are permitted provided that the following conditions
6 // are met:
7 // 1. Redistributions of source code must retain the above copyright
8 //    notice, this list of conditions and the following disclaimer.
9 // 2. Redistributions in binary form must reproduce the above copyright
10 //    notice, this list of conditions and the following disclaimer in the
11 //    documentation and/or other materials provided with the distribution.
12 // 3. Neither the name of the project nor the names of its contributors
13 //    may be used to endorse or promote products derived from this software
14 //    without specific prior written permission.
15 //
16 // THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
17 // ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 // IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 // ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
20 // FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 // DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 // OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 // HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 // LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 // OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 // SUCH DAMAGE.
27 
28 // A test used to check that __cxa_get_globals() does not use malloc.
29 // This will do the following:
30 //
31 //  - Lazily load libtest_malloc_lockup.so, which includes a copy of
32 //    GAbi++ linked with malloc() / free() functions that exit() with
33 //    an error if called.
34 //
35 //  - Create a large number of concurrent threads, and have each one
36 //    call the library's 'get_globals' function, which returns the
37 //    result of __cxa_get_globals() linked against the special mallocs,
38 //    then store the value in a global array.
39 //
40 //  - Tell all the threads to stop, wait for them to complete.
41 //
42 //  - Look at the values stored in the global arrays. They should not be NULL
43 //    (to indicate succesful allocation), and all different (each one should
44 //    correspond to a thread-specific instance of __cxa_eh_globals).
45 //
46 //  - Unload the library.
47 //
48 
49 #include <dlfcn.h>
50 #include <errno.h>
51 #include <pthread.h>
52 #include <stdio.h>
53 #include <stdlib.h>
54 #include <string.h>
55 
56 typedef void* (*get_globals_fn)();
57 
58 static get_globals_fn g_get_globals;
59 
60 // Number of threads to create. Must be > 4096 to really check slab allocation.
61 static const size_t kMaxThreads = 5000;
62 
63 static pthread_t g_threads[kMaxThreads];
64 static void* g_thread_objects[kMaxThreads];
65 
66 static pthread_mutex_t g_lock = PTHREAD_MUTEX_INITIALIZER;
67 static pthread_cond_t g_cond_exit = PTHREAD_COND_INITIALIZER;
68 static pthread_cond_t g_cond_counter = PTHREAD_COND_INITIALIZER;
69 static unsigned g_thread_count = 0;
70 static bool g_can_exit = false;
71 
72 // Thread routine, just call 'get_globals' and store the result in our global
73 // array, then wait for an event from the main thread. This guarantees that
74 // no thread exits before another one starts, and thus that allocation slots
75 // are not reused.
my_thread(void * param)76 static void* my_thread(void* param) {
77   // Get thread-specific object pointer, store it in global array.
78   int id = (int)(intptr_t)param;
79   g_thread_objects[id] = (*g_get_globals)();
80 
81   // Increment global thread counter and tell the main thread about this.
82   pthread_mutex_lock(&g_lock);
83   g_thread_count += 1;
84   pthread_cond_signal(&g_cond_counter);
85 
86   // The thread object will be automatically released/recycled when the thread
87   // exits. Wait here until signaled by the main thread to avoid this.
88   while (!g_can_exit)
89     pthread_cond_wait(&g_cond_exit, &g_lock);
90   pthread_mutex_unlock(&g_lock);
91 
92   return NULL;
93 }
94 
main(void)95 int main(void) {
96   // Load the library.
97   void* lib = dlopen("libtest_malloc_lockup.so", RTLD_NOW);
98   if (!lib) {
99     fprintf(stderr, "ERROR: Can't find library: %s\n", strerror(errno));
100     return 1;
101   }
102 
103   // Extract 'get_globals' function address.
104   g_get_globals = reinterpret_cast<get_globals_fn>(dlsym(lib, "get_globals"));
105   if (!g_get_globals) {
106     fprintf(stderr, "ERROR: Could not find 'get_globals' function: %s\n",
107             dlerror());
108     dlclose(lib);
109     return 1;
110   }
111 
112   // Use a smaller stack per thread to be able to create lots of them.
113   pthread_attr_t attr;
114   pthread_attr_init(&attr);
115   pthread_attr_setstacksize(&attr, 16384);
116 
117   // Start as many threads as needed.
118   printf("Creating %d threads\n", kMaxThreads);
119   for (size_t n = 0; n < kMaxThreads; ++n) {
120     int ret = pthread_create(&g_threads[n], &attr, my_thread, (void*)n);
121     if (ret != 0) {
122       fprintf(stderr, "ERROR: Thread #%d creation error: %s\n",
123               n + 1, strerror(errno));
124       return 2;
125     }
126   }
127 
128   // Wait until they all ran, then tell them to exit.
129   printf("Waiting for all threads to run\n");
130   pthread_mutex_lock(&g_lock);
131   while (g_thread_count < kMaxThreads)
132     pthread_cond_wait(&g_cond_counter, &g_lock);
133 
134   printf("Waking up threads\n");
135   g_can_exit = true;
136   pthread_cond_broadcast(&g_cond_exit);
137   pthread_mutex_unlock(&g_lock);
138 
139   // Wait for them to complete.
140   printf("Waiting for all threads to complete\n");
141   for (size_t n = 0; n < kMaxThreads; ++n) {
142     void* dummy;
143     pthread_join(g_threads[n], &dummy);
144   }
145 
146   // Verify that the thread objects are all non-NULL and different.
147   printf("Checking results\n");
148   size_t failures = 0;
149   const size_t kMaxFailures = 16;
150   for (size_t n = 0; n < kMaxThreads; ++n) {
151     void* obj = g_thread_objects[n];
152     if (obj == NULL) {
153       if (++failures < kMaxFailures)
154         printf("Thread %d got a NULL object!\n", n + 1);
155     } else {
156       for (size_t m = n + 1; m < kMaxThreads; ++m) {
157         if (g_thread_objects[m] == obj) {
158           if (++failures < kMaxFailures)
159             printf("Thread %d has same object as thread %d (%p)\n",
160                    n + 1, m + 1, obj);
161         }
162       }
163     }
164   }
165 
166   // We're done.
167   dlclose(lib);
168   if (failures > 0) {
169     fprintf(stderr, "%d failures detected!\n", failures);
170     return 1;
171   }
172 
173   printf("All OK!\n");
174   return 0;
175 }
176