os_linux.hpp revision 4275:9058789475af 
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 */
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
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 *dll_load_inner(const char *name);
99
100  static void init_thread_fpu_state();
101  static int  get_fpu_control_word();
102  static void set_fpu_control_word(int fpu_control);
103  static pthread_t main_thread(void)                                { return _main_thread; }
104  // returns kernel thread id (similar to LWP id on Solaris), which can be
105  // used to access /proc
106  static pid_t gettid();
107  static void set_createThread_lock(Mutex* lk)                      { _createThread_lock = lk; }
108  static Mutex* createThread_lock(void)                             { return _createThread_lock; }
109  static void hotspot_sigmask(Thread* thread);
110
111  static address   initial_thread_stack_bottom(void)                { return _initial_thread_stack_bottom; }
112  static uintptr_t initial_thread_stack_size(void)                  { return _initial_thread_stack_size; }
113  static bool is_initial_thread(void);
114
115  static int page_size(void)                                        { return _page_size; }
116  static void set_page_size(int val)                                { _page_size = val; }
117
118  static address   ucontext_get_pc(ucontext_t* uc);
119  static intptr_t* ucontext_get_sp(ucontext_t* uc);
120  static intptr_t* ucontext_get_fp(ucontext_t* uc);
121
122  // For Analyzer Forte AsyncGetCallTrace profiling support:
123  //
124  // This interface should be declared in os_linux_i486.hpp, but
125  // that file provides extensions to the os class and not the
126  // Linux class.
127  static ExtendedPC fetch_frame_from_ucontext(Thread* thread, ucontext_t* uc,
128    intptr_t** ret_sp, intptr_t** ret_fp);
129
130  // This boolean allows users to forward their own non-matching signals
131  // to JVM_handle_linux_signal, harmlessly.
132  static bool signal_handlers_are_installed;
133
134  static int get_our_sigflags(int);
135  static void set_our_sigflags(int, int);
136  static void signal_sets_init();
137  static void install_signal_handlers();
138  static void set_signal_handler(int, bool);
139  static bool is_sig_ignored(int sig);
140
141  static sigset_t* unblocked_signals();
142  static sigset_t* vm_signals();
143  static sigset_t* allowdebug_blocked_signals();
144
145  // For signal-chaining
146  static struct sigaction *get_chained_signal_action(int sig);
147  static bool chained_handler(int sig, siginfo_t* siginfo, void* context);
148
149  // GNU libc and libpthread version strings
150  static const char *glibc_version()          { return _glibc_version; }
151  static const char *libpthread_version()     { return _libpthread_version; }
152
153  // NPTL or LinuxThreads?
154  static bool is_LinuxThreads()               { return !_is_NPTL; }
155  static bool is_NPTL()                       { return _is_NPTL;  }
156
157  // NPTL is always floating stack. LinuxThreads could be using floating
158  // stack or fixed stack.
159  static bool is_floating_stack()             { return _is_floating_stack; }
160
161  static void libpthread_init();
162  static bool libnuma_init();
163  static void* libnuma_dlsym(void* handle, const char* name);
164  // Minimum stack size a thread can be created with (allowing
165  // the VM to completely create the thread and enter user code)
166  static size_t min_stack_allowed;
167
168  // Return default stack size or guard size for the specified thread type
169  static size_t default_stack_size(os::ThreadType thr_type);
170  static size_t default_guard_size(os::ThreadType thr_type);
171
172  static void capture_initial_stack(size_t max_size);
173
174  // Stack overflow handling
175  static bool manually_expand_stack(JavaThread * t, address addr);
176  static int max_register_window_saves_before_flushing();
177
178  // Real-time clock functions
179  static void clock_init(void);
180
181  // fast POSIX clocks support
182  static void fast_thread_clock_init(void);
183
184  static inline bool supports_monotonic_clock() {
185    return _clock_gettime != NULL;
186  }
187
188  static int clock_gettime(clockid_t clock_id, struct timespec *tp) {
189    return _clock_gettime ? _clock_gettime(clock_id, tp) : -1;
190  }
191
192  static int pthread_getcpuclockid(pthread_t tid, clockid_t *clock_id) {
193    return _pthread_getcpuclockid ? _pthread_getcpuclockid(tid, clock_id) : -1;
194  }
195
196  static bool supports_fast_thread_cpu_time() {
197    return _supports_fast_thread_cpu_time;
198  }
199
200  static jlong fast_thread_cpu_time(clockid_t clockid);
201
202  // Stack repair handling
203
204  // none present
205
206  // LinuxThreads work-around for 6292965
207  static int safe_cond_timedwait(pthread_cond_t *_cond, pthread_mutex_t *_mutex, const struct timespec *_abstime);
208
209
210  // Linux suspend/resume support - this helper is a shadow of its former
211  // self now that low-level suspension is barely used, and old workarounds
212  // for LinuxThreads are no longer needed.
213  class SuspendResume {
214  private:
215    volatile int  _suspend_action;
216    volatile jint _state;
217  public:
218    // values for suspend_action:
219    enum {
220      SR_NONE              = 0x00,
221      SR_SUSPEND           = 0x01,  // suspend request
222      SR_CONTINUE          = 0x02,  // resume request
223      SR_SUSPENDED         = 0x20   // values for _state: + SR_NONE
224    };
225
226    SuspendResume() { _suspend_action = SR_NONE; _state = SR_NONE; }
227
228    int suspend_action() const     { return _suspend_action; }
229    void set_suspend_action(int x) { _suspend_action = x;    }
230
231    // atomic updates for _state
232    inline void set_suspended();
233    inline void clear_suspended();
234    bool is_suspended()            { return _state & SR_SUSPENDED;       }
235
236  };
237
238private:
239  typedef int (*sched_getcpu_func_t)(void);
240  typedef int (*numa_node_to_cpus_func_t)(int node, unsigned long *buffer, int bufferlen);
241  typedef int (*numa_max_node_func_t)(void);
242  typedef int (*numa_available_func_t)(void);
243  typedef int (*numa_tonode_memory_func_t)(void *start, size_t size, int node);
244  typedef void (*numa_interleave_memory_func_t)(void *start, size_t size, unsigned long *nodemask);
245
246  static sched_getcpu_func_t _sched_getcpu;
247  static numa_node_to_cpus_func_t _numa_node_to_cpus;
248  static numa_max_node_func_t _numa_max_node;
249  static numa_available_func_t _numa_available;
250  static numa_tonode_memory_func_t _numa_tonode_memory;
251  static numa_interleave_memory_func_t _numa_interleave_memory;
252  static unsigned long* _numa_all_nodes;
253
254  static void set_sched_getcpu(sched_getcpu_func_t func) { _sched_getcpu = func; }
255  static void set_numa_node_to_cpus(numa_node_to_cpus_func_t func) { _numa_node_to_cpus = func; }
256  static void set_numa_max_node(numa_max_node_func_t func) { _numa_max_node = func; }
257  static void set_numa_available(numa_available_func_t func) { _numa_available = func; }
258  static void set_numa_tonode_memory(numa_tonode_memory_func_t func) { _numa_tonode_memory = func; }
259  static void set_numa_interleave_memory(numa_interleave_memory_func_t func) { _numa_interleave_memory = func; }
260  static void set_numa_all_nodes(unsigned long* ptr) { _numa_all_nodes = ptr; }
261  static int sched_getcpu_syscall(void);
262public:
263  static int sched_getcpu()  { return _sched_getcpu != NULL ? _sched_getcpu() : -1; }
264  static int numa_node_to_cpus(int node, unsigned long *buffer, int bufferlen) {
265    return _numa_node_to_cpus != NULL ? _numa_node_to_cpus(node, buffer, bufferlen) : -1;
266  }
267  static int numa_max_node() { return _numa_max_node != NULL ? _numa_max_node() : -1; }
268  static int numa_available() { return _numa_available != NULL ? _numa_available() : -1; }
269  static int numa_tonode_memory(void *start, size_t size, int node) {
270    return _numa_tonode_memory != NULL ? _numa_tonode_memory(start, size, node) : -1;
271  }
272  static void numa_interleave_memory(void *start, size_t size) {
273    if (_numa_interleave_memory != NULL && _numa_all_nodes != NULL) {
274      _numa_interleave_memory(start, size, _numa_all_nodes);
275    }
276  }
277  static int get_node_by_cpu(int cpu_id);
278};
279
280
281class PlatformEvent : public CHeapObj<mtInternal> {
282  private:
283    double CachePad [4] ;   // increase odds that _mutex is sole occupant of cache line
284    volatile int _Event ;
285    volatile int _nParked ;
286    pthread_mutex_t _mutex  [1] ;
287    pthread_cond_t  _cond   [1] ;
288    double PostPad  [2] ;
289    Thread * _Assoc ;
290
291  public:       // TODO-FIXME: make dtor private
292    ~PlatformEvent() { guarantee (0, "invariant") ; }
293
294  public:
295    PlatformEvent() {
296      int status;
297      status = pthread_cond_init (_cond, NULL);
298      assert_status(status == 0, status, "cond_init");
299      status = pthread_mutex_init (_mutex, NULL);
300      assert_status(status == 0, status, "mutex_init");
301      _Event   = 0 ;
302      _nParked = 0 ;
303      _Assoc   = NULL ;
304    }
305
306    // Use caution with reset() and fired() -- they may require MEMBARs
307    void reset() { _Event = 0 ; }
308    int  fired() { return _Event; }
309    void park () ;
310    void unpark () ;
311    int  TryPark () ;
312    int  park (jlong millis) ;
313    void SetAssociation (Thread * a) { _Assoc = a ; }
314} ;
315
316class PlatformParker : public CHeapObj<mtInternal> {
317  protected:
318    pthread_mutex_t _mutex [1] ;
319    pthread_cond_t  _cond  [1] ;
320
321  public:       // TODO-FIXME: make dtor private
322    ~PlatformParker() { guarantee (0, "invariant") ; }
323
324  public:
325    PlatformParker() {
326      int status;
327      status = pthread_cond_init (_cond, NULL);
328      assert_status(status == 0, status, "cond_init");
329      status = pthread_mutex_init (_mutex, NULL);
330      assert_status(status == 0, status, "mutex_init");
331    }
332} ;
333
334#endif // OS_LINUX_VM_OS_LINUX_HPP
335