os_linux.hpp revision 1879:f95d63e2154a 
1/*
2 * Copyright (c) 1999, 2010, 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 */
31typedef int (*pthread_getattr_func_type) (pthread_t, pthread_attr_t *);
32
33class 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 public:
90  static void init_thread_fpu_state();
91  static int  get_fpu_control_word();
92  static void set_fpu_control_word(int fpu_control);
93  static pthread_t main_thread(void)                                { return _main_thread; }
94  // returns kernel thread id (similar to LWP id on Solaris), which can be
95  // used to access /proc
96  static pid_t gettid();
97  static void set_createThread_lock(Mutex* lk)                      { _createThread_lock = lk; }
98  static Mutex* createThread_lock(void)                             { return _createThread_lock; }
99  static void hotspot_sigmask(Thread* thread);
100
101  static address   initial_thread_stack_bottom(void)                { return _initial_thread_stack_bottom; }
102  static uintptr_t initial_thread_stack_size(void)                  { return _initial_thread_stack_size; }
103  static bool is_initial_thread(void);
104
105  static int page_size(void)                                        { return _page_size; }
106  static void set_page_size(int val)                                { _page_size = val; }
107
108  static address   ucontext_get_pc(ucontext_t* uc);
109  static intptr_t* ucontext_get_sp(ucontext_t* uc);
110  static intptr_t* ucontext_get_fp(ucontext_t* uc);
111
112  // For Analyzer Forte AsyncGetCallTrace profiling support:
113  //
114  // This interface should be declared in os_linux_i486.hpp, but
115  // that file provides extensions to the os class and not the
116  // Linux class.
117  static ExtendedPC fetch_frame_from_ucontext(Thread* thread, ucontext_t* uc,
118    intptr_t** ret_sp, intptr_t** ret_fp);
119
120  // This boolean allows users to forward their own non-matching signals
121  // to JVM_handle_linux_signal, harmlessly.
122  static bool signal_handlers_are_installed;
123
124  static int get_our_sigflags(int);
125  static void set_our_sigflags(int, int);
126  static void signal_sets_init();
127  static void install_signal_handlers();
128  static void set_signal_handler(int, bool);
129  static bool is_sig_ignored(int sig);
130
131  static sigset_t* unblocked_signals();
132  static sigset_t* vm_signals();
133  static sigset_t* allowdebug_blocked_signals();
134
135  // For signal-chaining
136  static struct sigaction *get_chained_signal_action(int sig);
137  static bool chained_handler(int sig, siginfo_t* siginfo, void* context);
138
139  // GNU libc and libpthread version strings
140  static const char *glibc_version()          { return _glibc_version; }
141  static const char *libpthread_version()     { return _libpthread_version; }
142
143  // NPTL or LinuxThreads?
144  static bool is_LinuxThreads()               { return !_is_NPTL; }
145  static bool is_NPTL()                       { return _is_NPTL;  }
146
147  // NPTL is always floating stack. LinuxThreads could be using floating
148  // stack or fixed stack.
149  static bool is_floating_stack()             { return _is_floating_stack; }
150
151  static void libpthread_init();
152  static bool libnuma_init();
153  static void* libnuma_dlsym(void* handle, const char* name);
154  // Minimum stack size a thread can be created with (allowing
155  // the VM to completely create the thread and enter user code)
156  static size_t min_stack_allowed;
157
158  // Return default stack size or guard size for the specified thread type
159  static size_t default_stack_size(os::ThreadType thr_type);
160  static size_t default_guard_size(os::ThreadType thr_type);
161
162  static void capture_initial_stack(size_t max_size);
163
164  // Stack overflow handling
165  static bool manually_expand_stack(JavaThread * t, address addr);
166  static int max_register_window_saves_before_flushing();
167
168  // Real-time clock functions
169  static void clock_init(void);
170
171  // fast POSIX clocks support
172  static void fast_thread_clock_init(void);
173
174  static bool supports_monotonic_clock() {
175    return _clock_gettime != NULL;
176  }
177
178  static int clock_gettime(clockid_t clock_id, struct timespec *tp) {
179    return _clock_gettime ? _clock_gettime(clock_id, tp) : -1;
180  }
181
182  static int pthread_getcpuclockid(pthread_t tid, clockid_t *clock_id) {
183    return _pthread_getcpuclockid ? _pthread_getcpuclockid(tid, clock_id) : -1;
184  }
185
186  static bool supports_fast_thread_cpu_time() {
187    return _supports_fast_thread_cpu_time;
188  }
189
190  static jlong fast_thread_cpu_time(clockid_t clockid);
191
192  // Stack repair handling
193
194  // none present
195
196  // LinuxThreads work-around for 6292965
197  static int safe_cond_timedwait(pthread_cond_t *_cond, pthread_mutex_t *_mutex, const struct timespec *_abstime);
198
199
200  // Linux suspend/resume support - this helper is a shadow of its former
201  // self now that low-level suspension is barely used, and old workarounds
202  // for LinuxThreads are no longer needed.
203  class SuspendResume {
204  private:
205    volatile int _suspend_action;
206    // values for suspend_action:
207    #define SR_NONE               (0x00)
208    #define SR_SUSPEND            (0x01)  // suspend request
209    #define SR_CONTINUE           (0x02)  // resume request
210
211    volatile jint _state;
212    // values for _state: + SR_NONE
213    #define SR_SUSPENDED          (0x20)
214  public:
215    SuspendResume() { _suspend_action = SR_NONE; _state = SR_NONE; }
216
217    int suspend_action() const     { return _suspend_action; }
218    void set_suspend_action(int x) { _suspend_action = x;    }
219
220    // atomic updates for _state
221    void set_suspended()           {
222      jint temp, temp2;
223      do {
224        temp = _state;
225        temp2 = Atomic::cmpxchg(temp | SR_SUSPENDED, &_state, temp);
226      } while (temp2 != temp);
227    }
228    void clear_suspended()        {
229      jint temp, temp2;
230      do {
231        temp = _state;
232        temp2 = Atomic::cmpxchg(temp & ~SR_SUSPENDED, &_state, temp);
233      } while (temp2 != temp);
234    }
235    bool is_suspended()            { return _state & SR_SUSPENDED;       }
236
237    #undef SR_SUSPENDED
238  };
239
240private:
241  typedef int (*sched_getcpu_func_t)(void);
242  typedef int (*numa_node_to_cpus_func_t)(int node, unsigned long *buffer, int bufferlen);
243  typedef int (*numa_max_node_func_t)(void);
244  typedef int (*numa_available_func_t)(void);
245  typedef int (*numa_tonode_memory_func_t)(void *start, size_t size, int node);
246  typedef void (*numa_interleave_memory_func_t)(void *start, size_t size, unsigned long *nodemask);
247
248  static sched_getcpu_func_t _sched_getcpu;
249  static numa_node_to_cpus_func_t _numa_node_to_cpus;
250  static numa_max_node_func_t _numa_max_node;
251  static numa_available_func_t _numa_available;
252  static numa_tonode_memory_func_t _numa_tonode_memory;
253  static numa_interleave_memory_func_t _numa_interleave_memory;
254  static unsigned long* _numa_all_nodes;
255
256  static void set_sched_getcpu(sched_getcpu_func_t func) { _sched_getcpu = func; }
257  static void set_numa_node_to_cpus(numa_node_to_cpus_func_t func) { _numa_node_to_cpus = func; }
258  static void set_numa_max_node(numa_max_node_func_t func) { _numa_max_node = func; }
259  static void set_numa_available(numa_available_func_t func) { _numa_available = func; }
260  static void set_numa_tonode_memory(numa_tonode_memory_func_t func) { _numa_tonode_memory = func; }
261  static void set_numa_interleave_memory(numa_interleave_memory_func_t func) { _numa_interleave_memory = func; }
262  static void set_numa_all_nodes(unsigned long* ptr) { _numa_all_nodes = ptr; }
263public:
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
282class PlatformEvent : public CHeapObj {
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
317class PlatformParker : public CHeapObj {
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
336