os_linux.hpp revision 4561:b4081e9714ec 
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  static const int _vm_default_page_size;
74
75  static julong available_memory();
76  static julong physical_memory() { return _physical_memory; }
77  static void initialize_system_info();
78
79  static void set_glibc_version(const char *s)      { _glibc_version = s; }
80  static void set_libpthread_version(const char *s) { _libpthread_version = s; }
81
82  static bool supports_variable_stack_size();
83
84  static void set_is_NPTL()                   { _is_NPTL = true;  }
85  static void set_is_LinuxThreads()           { _is_NPTL = false; }
86  static void set_is_floating_stack()         { _is_floating_stack = true; }
87
88  static void rebuild_cpu_to_node_map();
89  static GrowableArray<int>* cpu_to_node()    { return _cpu_to_node; }
90
91  static bool hugetlbfs_sanity_check(bool warn, size_t page_size);
92
93  static void print_full_memory_info(outputStream* st);
94  static void print_distro_info(outputStream* st);
95  static void print_libversion_info(outputStream* st);
96
97 public:
98  static bool _stack_is_executable;
99  static void *dlopen_helper(const char *name, char *ebuf, int ebuflen);
100  static void *dll_load_in_vmthread(const char *name, char *ebuf, int ebuflen);
101
102  static void init_thread_fpu_state();
103  static int  get_fpu_control_word();
104  static void set_fpu_control_word(int fpu_control);
105  static pthread_t main_thread(void)                                { return _main_thread; }
106  // returns kernel thread id (similar to LWP id on Solaris), which can be
107  // used to access /proc
108  static pid_t gettid();
109  static void set_createThread_lock(Mutex* lk)                      { _createThread_lock = lk; }
110  static Mutex* createThread_lock(void)                             { return _createThread_lock; }
111  static void hotspot_sigmask(Thread* thread);
112
113  static address   initial_thread_stack_bottom(void)                { return _initial_thread_stack_bottom; }
114  static uintptr_t initial_thread_stack_size(void)                  { return _initial_thread_stack_size; }
115  static bool is_initial_thread(void);
116
117  static int page_size(void)                                        { return _page_size; }
118  static void set_page_size(int val)                                { _page_size = val; }
119
120  static int vm_default_page_size(void)                             { return _vm_default_page_size; }
121
122  static address   ucontext_get_pc(ucontext_t* uc);
123  static intptr_t* ucontext_get_sp(ucontext_t* uc);
124  static intptr_t* ucontext_get_fp(ucontext_t* uc);
125
126  // For Analyzer Forte AsyncGetCallTrace profiling support:
127  //
128  // This interface should be declared in os_linux_i486.hpp, but
129  // that file provides extensions to the os class and not the
130  // Linux class.
131  static ExtendedPC fetch_frame_from_ucontext(Thread* thread, ucontext_t* uc,
132    intptr_t** ret_sp, intptr_t** ret_fp);
133
134  // This boolean allows users to forward their own non-matching signals
135  // to JVM_handle_linux_signal, harmlessly.
136  static bool signal_handlers_are_installed;
137
138  static int get_our_sigflags(int);
139  static void set_our_sigflags(int, int);
140  static void signal_sets_init();
141  static void install_signal_handlers();
142  static void set_signal_handler(int, bool);
143  static bool is_sig_ignored(int sig);
144
145  static sigset_t* unblocked_signals();
146  static sigset_t* vm_signals();
147  static sigset_t* allowdebug_blocked_signals();
148
149  // For signal-chaining
150  static struct sigaction *get_chained_signal_action(int sig);
151  static bool chained_handler(int sig, siginfo_t* siginfo, void* context);
152
153  // GNU libc and libpthread version strings
154  static const char *glibc_version()          { return _glibc_version; }
155  static const char *libpthread_version()     { return _libpthread_version; }
156
157  // NPTL or LinuxThreads?
158  static bool is_LinuxThreads()               { return !_is_NPTL; }
159  static bool is_NPTL()                       { return _is_NPTL;  }
160
161  // NPTL is always floating stack. LinuxThreads could be using floating
162  // stack or fixed stack.
163  static bool is_floating_stack()             { return _is_floating_stack; }
164
165  static void libpthread_init();
166  static bool libnuma_init();
167  static void* libnuma_dlsym(void* handle, const char* name);
168  // Minimum stack size a thread can be created with (allowing
169  // the VM to completely create the thread and enter user code)
170  static size_t min_stack_allowed;
171
172  // Return default stack size or guard size for the specified thread type
173  static size_t default_stack_size(os::ThreadType thr_type);
174  static size_t default_guard_size(os::ThreadType thr_type);
175
176  static void capture_initial_stack(size_t max_size);
177
178  // Stack overflow handling
179  static bool manually_expand_stack(JavaThread * t, address addr);
180  static int max_register_window_saves_before_flushing();
181
182  // Real-time clock functions
183  static void clock_init(void);
184
185  // fast POSIX clocks support
186  static void fast_thread_clock_init(void);
187
188  static inline bool supports_monotonic_clock() {
189    return _clock_gettime != NULL;
190  }
191
192  static int clock_gettime(clockid_t clock_id, struct timespec *tp) {
193    return _clock_gettime ? _clock_gettime(clock_id, tp) : -1;
194  }
195
196  static int pthread_getcpuclockid(pthread_t tid, clockid_t *clock_id) {
197    return _pthread_getcpuclockid ? _pthread_getcpuclockid(tid, clock_id) : -1;
198  }
199
200  static bool supports_fast_thread_cpu_time() {
201    return _supports_fast_thread_cpu_time;
202  }
203
204  static jlong fast_thread_cpu_time(clockid_t clockid);
205
206  // Stack repair handling
207
208  // none present
209
210  // LinuxThreads work-around for 6292965
211  static int safe_cond_timedwait(pthread_cond_t *_cond, pthread_mutex_t *_mutex, const struct timespec *_abstime);
212
213
214  // Linux suspend/resume support - this helper is a shadow of its former
215  // self now that low-level suspension is barely used, and old workarounds
216  // for LinuxThreads are no longer needed.
217  class SuspendResume {
218  private:
219    volatile int  _suspend_action;
220    volatile jint _state;
221  public:
222    // values for suspend_action:
223    enum {
224      SR_NONE              = 0x00,
225      SR_SUSPEND           = 0x01,  // suspend request
226      SR_CONTINUE          = 0x02,  // resume request
227      SR_SUSPENDED         = 0x20   // values for _state: + SR_NONE
228    };
229
230    SuspendResume() { _suspend_action = SR_NONE; _state = SR_NONE; }
231
232    int suspend_action() const     { return _suspend_action; }
233    void set_suspend_action(int x) { _suspend_action = x;    }
234
235    // atomic updates for _state
236    inline void set_suspended();
237    inline void clear_suspended();
238    bool is_suspended()            { return _state & SR_SUSPENDED;       }
239
240  };
241
242private:
243  typedef int (*sched_getcpu_func_t)(void);
244  typedef int (*numa_node_to_cpus_func_t)(int node, unsigned long *buffer, int bufferlen);
245  typedef int (*numa_max_node_func_t)(void);
246  typedef int (*numa_available_func_t)(void);
247  typedef int (*numa_tonode_memory_func_t)(void *start, size_t size, int node);
248  typedef void (*numa_interleave_memory_func_t)(void *start, size_t size, unsigned long *nodemask);
249
250  static sched_getcpu_func_t _sched_getcpu;
251  static numa_node_to_cpus_func_t _numa_node_to_cpus;
252  static numa_max_node_func_t _numa_max_node;
253  static numa_available_func_t _numa_available;
254  static numa_tonode_memory_func_t _numa_tonode_memory;
255  static numa_interleave_memory_func_t _numa_interleave_memory;
256  static unsigned long* _numa_all_nodes;
257
258  static void set_sched_getcpu(sched_getcpu_func_t func) { _sched_getcpu = func; }
259  static void set_numa_node_to_cpus(numa_node_to_cpus_func_t func) { _numa_node_to_cpus = func; }
260  static void set_numa_max_node(numa_max_node_func_t func) { _numa_max_node = func; }
261  static void set_numa_available(numa_available_func_t func) { _numa_available = func; }
262  static void set_numa_tonode_memory(numa_tonode_memory_func_t func) { _numa_tonode_memory = func; }
263  static void set_numa_interleave_memory(numa_interleave_memory_func_t func) { _numa_interleave_memory = func; }
264  static void set_numa_all_nodes(unsigned long* ptr) { _numa_all_nodes = ptr; }
265  static int sched_getcpu_syscall(void);
266public:
267  static int sched_getcpu()  { return _sched_getcpu != NULL ? _sched_getcpu() : -1; }
268  static int numa_node_to_cpus(int node, unsigned long *buffer, int bufferlen) {
269    return _numa_node_to_cpus != NULL ? _numa_node_to_cpus(node, buffer, bufferlen) : -1;
270  }
271  static int numa_max_node() { return _numa_max_node != NULL ? _numa_max_node() : -1; }
272  static int numa_available() { return _numa_available != NULL ? _numa_available() : -1; }
273  static int numa_tonode_memory(void *start, size_t size, int node) {
274    return _numa_tonode_memory != NULL ? _numa_tonode_memory(start, size, node) : -1;
275  }
276  static void numa_interleave_memory(void *start, size_t size) {
277    if (_numa_interleave_memory != NULL && _numa_all_nodes != NULL) {
278      _numa_interleave_memory(start, size, _numa_all_nodes);
279    }
280  }
281  static int get_node_by_cpu(int cpu_id);
282};
283
284
285class PlatformEvent : public CHeapObj<mtInternal> {
286  private:
287    double CachePad [4] ;   // increase odds that _mutex is sole occupant of cache line
288    volatile int _Event ;
289    volatile int _nParked ;
290    pthread_mutex_t _mutex  [1] ;
291    pthread_cond_t  _cond   [1] ;
292    double PostPad  [2] ;
293    Thread * _Assoc ;
294
295  public:       // TODO-FIXME: make dtor private
296    ~PlatformEvent() { guarantee (0, "invariant") ; }
297
298  public:
299    PlatformEvent() {
300      int status;
301      status = pthread_cond_init (_cond, NULL);
302      assert_status(status == 0, status, "cond_init");
303      status = pthread_mutex_init (_mutex, NULL);
304      assert_status(status == 0, status, "mutex_init");
305      _Event   = 0 ;
306      _nParked = 0 ;
307      _Assoc   = NULL ;
308    }
309
310    // Use caution with reset() and fired() -- they may require MEMBARs
311    void reset() { _Event = 0 ; }
312    int  fired() { return _Event; }
313    void park () ;
314    void unpark () ;
315    int  TryPark () ;
316    int  park (jlong millis) ;
317    void SetAssociation (Thread * a) { _Assoc = a ; }
318} ;
319
320class PlatformParker : public CHeapObj<mtInternal> {
321  protected:
322    pthread_mutex_t _mutex [1] ;
323    pthread_cond_t  _cond  [1] ;
324
325  public:       // TODO-FIXME: make dtor private
326    ~PlatformParker() { guarantee (0, "invariant") ; }
327
328  public:
329    PlatformParker() {
330      int status;
331      status = pthread_cond_init (_cond, NULL);
332      assert_status(status == 0, status, "cond_init");
333      status = pthread_mutex_init (_mutex, NULL);
334      assert_status(status == 0, status, "mutex_init");
335    }
336} ;
337
338#endif // OS_LINUX_VM_OS_LINUX_HPP
339