1 /*
2 * Copyright (c) 1999, 2013, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #ifndef OS_LINUX_VM_OS_LINUX_HPP
26 #define OS_LINUX_VM_OS_LINUX_HPP
27
28 // Linux_OS defines the interface to Linux operating systems
29
30 /* pthread_getattr_np comes with LinuxThreads-0.9-7 on RedHat 7.1 */
31 typedef int (*pthread_getattr_func_type) (pthread_t, pthread_attr_t *);
32
33 class Linux {
34 friend class os;
35
36 // For signal-chaining
37 #define MAXSIGNUM 32
38 static struct sigaction sigact[MAXSIGNUM]; // saved preinstalled sigactions
39 static unsigned int sigs; // mask of signals that have
40 // preinstalled signal handlers
41 static bool libjsig_is_loaded; // libjsig that interposes sigaction(),
42 // __sigaction(), signal() is loaded
43 static struct sigaction *(*get_signal_action)(int);
44 static struct sigaction *get_preinstalled_handler(int);
45 static void save_preinstalled_handler(int, struct sigaction&);
46
47 static void check_signal_handler(int sig);
48
49 // For signal flags diagnostics
50 static int sigflags[MAXSIGNUM];
51
52 static int (*_clock_gettime)(clockid_t, struct timespec *);
53 static int (*_pthread_getcpuclockid)(pthread_t, clockid_t *);
54
55 static address _initial_thread_stack_bottom;
56 static uintptr_t _initial_thread_stack_size;
57
58 static const char *_glibc_version;
59 static const char *_libpthread_version;
60
61 static bool _is_floating_stack;
62 static bool _is_NPTL;
63 static bool _supports_fast_thread_cpu_time;
64
65 static GrowableArray<int>* _cpu_to_node;
66
67 protected:
68
69 static julong _physical_memory;
70 static pthread_t _main_thread;
71 static Mutex* _createThread_lock;
72 static int _page_size;
73
74 static julong available_memory();
75 static julong physical_memory() { return _physical_memory; }
76 static void initialize_system_info();
77
78 static void set_glibc_version(const char *s) { _glibc_version = s; }
79 static void set_libpthread_version(const char *s) { _libpthread_version = s; }
80
81 static bool supports_variable_stack_size();
82
83 static void set_is_NPTL() { _is_NPTL = true; }
84 static void set_is_LinuxThreads() { _is_NPTL = false; }
85 static void set_is_floating_stack() { _is_floating_stack = true; }
86
87 static void rebuild_cpu_to_node_map();
88 static GrowableArray<int>* cpu_to_node() { return _cpu_to_node; }
89
90 static bool hugetlbfs_sanity_check(bool warn, size_t page_size);
91
92 static void print_full_memory_info(outputStream* st);
93 static void print_distro_info(outputStream* st);
94 static void print_libversion_info(outputStream* st);
95
96 public:
97 static bool _stack_is_executable;
98 static void *dlopen_helper(const char *name, char *ebuf, int ebuflen);
99 static void *dll_load_in_vmthread(const char *name, char *ebuf, int ebuflen);
100
101 static void init_thread_fpu_state();
102 static int get_fpu_control_word();
103 static void set_fpu_control_word(int fpu_control);
104 static pthread_t main_thread(void) { return _main_thread; }
105 // returns kernel thread id (similar to LWP id on Solaris), which can be
106 // used to access /proc
107 static pid_t gettid();
108 static void set_createThread_lock(Mutex* lk) { _createThread_lock = lk; }
109 static Mutex* createThread_lock(void) { return _createThread_lock; }
110 static void hotspot_sigmask(Thread* thread);
111
112 static address initial_thread_stack_bottom(void) { return _initial_thread_stack_bottom; }
113 static uintptr_t initial_thread_stack_size(void) { return _initial_thread_stack_size; }
114 static bool is_initial_thread(void);
115
116 static int page_size(void) { return _page_size; }
117 static void set_page_size(int val) { _page_size = val; }
118
119 static address ucontext_get_pc(ucontext_t* uc);
120 static intptr_t* ucontext_get_sp(ucontext_t* uc);
121 static intptr_t* ucontext_get_fp(ucontext_t* uc);
122
123 // For Analyzer Forte AsyncGetCallTrace profiling support:
124 //
125 // This interface should be declared in os_linux_i486.hpp, but
126 // that file provides extensions to the os class and not the
127 // Linux class.
128 static ExtendedPC fetch_frame_from_ucontext(Thread* thread, ucontext_t* uc,
129 intptr_t** ret_sp, intptr_t** ret_fp);
130
131 // This boolean allows users to forward their own non-matching signals
132 // to JVM_handle_linux_signal, harmlessly.
133 static bool signal_handlers_are_installed;
134
135 static int get_our_sigflags(int);
136 static void set_our_sigflags(int, int);
137 static void signal_sets_init();
138 static void install_signal_handlers();
139 static void set_signal_handler(int, bool);
140 static bool is_sig_ignored(int sig);
141
142 static sigset_t* unblocked_signals();
143 static sigset_t* vm_signals();
144 static sigset_t* allowdebug_blocked_signals();
145
146 // For signal-chaining
147 static struct sigaction *get_chained_signal_action(int sig);
148 static bool chained_handler(int sig, siginfo_t* siginfo, void* context);
149
150 // GNU libc and libpthread version strings
151 static const char *glibc_version() { return _glibc_version; }
152 static const char *libpthread_version() { return _libpthread_version; }
153
154 // NPTL or LinuxThreads?
155 static bool is_LinuxThreads() { return !_is_NPTL; }
156 static bool is_NPTL() { return _is_NPTL; }
157
158 // NPTL is always floating stack. LinuxThreads could be using floating
159 // stack or fixed stack.
160 static bool is_floating_stack() { return _is_floating_stack; }
161
162 static void libpthread_init();
163 static bool libnuma_init();
164 static void* libnuma_dlsym(void* handle, const char* name);
165 // Minimum stack size a thread can be created with (allowing
166 // the VM to completely create the thread and enter user code)
167 static size_t min_stack_allowed;
168
169 // Return default stack size or guard size for the specified thread type
170 static size_t default_stack_size(os::ThreadType thr_type);
171 static size_t default_guard_size(os::ThreadType thr_type);
172
173 static void capture_initial_stack(size_t max_size);
174
175 // Stack overflow handling
176 static bool manually_expand_stack(JavaThread * t, address addr);
177 static int max_register_window_saves_before_flushing();
178
179 // Real-time clock functions
180 static void clock_init(void);
181
182 // fast POSIX clocks support
183 static void fast_thread_clock_init(void);
184
185 static inline bool supports_monotonic_clock() {
186 return _clock_gettime != NULL;
187 }
188
189 static int clock_gettime(clockid_t clock_id, struct timespec *tp) {
190 return _clock_gettime ? _clock_gettime(clock_id, tp) : -1;
191 }
192
193 static int pthread_getcpuclockid(pthread_t tid, clockid_t *clock_id) {
194 return _pthread_getcpuclockid ? _pthread_getcpuclockid(tid, clock_id) : -1;
195 }
196
197 static bool supports_fast_thread_cpu_time() {
198 return _supports_fast_thread_cpu_time;
199 }
200
201 static jlong fast_thread_cpu_time(clockid_t clockid);
202
203 // Stack repair handling
204
205 // none present
206
207 // LinuxThreads work-around for 6292965
208 static int safe_cond_timedwait(pthread_cond_t *_cond, pthread_mutex_t *_mutex, const struct timespec *_abstime);
209
210
211 // Linux suspend/resume support - this helper is a shadow of its former
212 // self now that low-level suspension is barely used, and old workarounds
213 // for LinuxThreads are no longer needed.
214 class SuspendResume {
215 private:
216 volatile int _suspend_action;
217 volatile jint _state;
218 public:
219 // values for suspend_action:
220 enum {
221 SR_NONE = 0x00,
222 SR_SUSPEND = 0x01, // suspend request
223 SR_CONTINUE = 0x02, // resume request
224 SR_SUSPENDED = 0x20 // values for _state: + SR_NONE
225 };
226
227 SuspendResume() { _suspend_action = SR_NONE; _state = SR_NONE; }
228
229 int suspend_action() const { return _suspend_action; }
230 void set_suspend_action(int x) { _suspend_action = x; }
231
232 // atomic updates for _state
233 inline void set_suspended();
234 inline void clear_suspended();
235 bool is_suspended() { return _state & SR_SUSPENDED; }
236
237 };
238
239 private:
240 typedef int (*sched_getcpu_func_t)(void);
241 typedef int (*numa_node_to_cpus_func_t)(int node, unsigned long *buffer, int bufferlen);
242 typedef int (*numa_max_node_func_t)(void);
243 typedef int (*numa_available_func_t)(void);
244 typedef int (*numa_tonode_memory_func_t)(void *start, size_t size, int node);
245 typedef void (*numa_interleave_memory_func_t)(void *start, size_t size, unsigned long *nodemask);
246
247 static sched_getcpu_func_t _sched_getcpu;
248 static numa_node_to_cpus_func_t _numa_node_to_cpus;
249 static numa_max_node_func_t _numa_max_node;
250 static numa_available_func_t _numa_available;
251 static numa_tonode_memory_func_t _numa_tonode_memory;
252 static numa_interleave_memory_func_t _numa_interleave_memory;
253 static unsigned long* _numa_all_nodes;
254
255 static void set_sched_getcpu(sched_getcpu_func_t func) { _sched_getcpu = func; }
256 static void set_numa_node_to_cpus(numa_node_to_cpus_func_t func) { _numa_node_to_cpus = func; }
257 static void set_numa_max_node(numa_max_node_func_t func) { _numa_max_node = func; }
258 static void set_numa_available(numa_available_func_t func) { _numa_available = func; }
259 static void set_numa_tonode_memory(numa_tonode_memory_func_t func) { _numa_tonode_memory = func; }
260 static void set_numa_interleave_memory(numa_interleave_memory_func_t func) { _numa_interleave_memory = func; }
261 static void set_numa_all_nodes(unsigned long* ptr) { _numa_all_nodes = ptr; }
262 static int sched_getcpu_syscall(void);
263 public:
264 static int sched_getcpu() { return _sched_getcpu != NULL ? _sched_getcpu() : -1; }
265 static int numa_node_to_cpus(int node, unsigned long *buffer, int bufferlen) {
266 return _numa_node_to_cpus != NULL ? _numa_node_to_cpus(node, buffer, bufferlen) : -1;
267 }
268 static int numa_max_node() { return _numa_max_node != NULL ? _numa_max_node() : -1; }
269 static int numa_available() { return _numa_available != NULL ? _numa_available() : -1; }
270 static int numa_tonode_memory(void *start, size_t size, int node) {
271 return _numa_tonode_memory != NULL ? _numa_tonode_memory(start, size, node) : -1;
272 }
273 static void numa_interleave_memory(void *start, size_t size) {
274 if (_numa_interleave_memory != NULL && _numa_all_nodes != NULL) {
275 _numa_interleave_memory(start, size, _numa_all_nodes);
276 }
277 }
278 static int get_node_by_cpu(int cpu_id);
279 };
280
281
282 class PlatformEvent : public CHeapObj<mtInternal> {
283 private:
284 double CachePad [4] ; // increase odds that _mutex is sole occupant of cache line
285 volatile int _Event ;
286 volatile int _nParked ;
287 pthread_mutex_t _mutex [1] ;
288 pthread_cond_t _cond [1] ;
289 double PostPad [2] ;
290 Thread * _Assoc ;
291
292 public: // TODO-FIXME: make dtor private
293 ~PlatformEvent() { guarantee (0, "invariant") ; }
294
295 public:
296 PlatformEvent() {
297 int status;
298 status = pthread_cond_init (_cond, NULL);
299 assert_status(status == 0, status, "cond_init");
300 status = pthread_mutex_init (_mutex, NULL);
301 assert_status(status == 0, status, "mutex_init");
302 _Event = 0 ;
303 _nParked = 0 ;
304 _Assoc = NULL ;
305 }
306
307 // Use caution with reset() and fired() -- they may require MEMBARs
308 void reset() { _Event = 0 ; }
309 int fired() { return _Event; }
310 void park () ;
311 void unpark () ;
312 int TryPark () ;
313 int park (jlong millis) ;
314 void SetAssociation (Thread * a) { _Assoc = a ; }
315 } ;
316
317 class PlatformParker : public CHeapObj<mtInternal> {
318 protected:
319 pthread_mutex_t _mutex [1] ;
320 pthread_cond_t _cond [1] ;
321
322 public: // TODO-FIXME: make dtor private
323 ~PlatformParker() { guarantee (0, "invariant") ; }
324
325 public:
326 PlatformParker() {
327 int status;
328 status = pthread_cond_init (_cond, NULL);
329 assert_status(status == 0, status, "cond_init");
330 status = pthread_mutex_init (_mutex, NULL);
331 assert_status(status == 0, status, "mutex_init");
332 }
333 } ;
334
335 #endif // OS_LINUX_VM_OS_LINUX_HPP