Fri, 25 Apr 2014 07:40:33 +0200
8040140: System.nanoTime() is slow and non-monotonic on OS X
Reviewed-by: sspitsyn, shade, dholmes, acorn
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 */
25 #ifndef OS_BSD_VM_OS_BSD_HPP
26 #define OS_BSD_VM_OS_BSD_HPP
28 // Bsd_OS defines the interface to Bsd operating systems
30 // Information about the protection of the page at address '0' on this os.
31 static bool zero_page_read_protected() { return true; }
33 /* pthread_getattr_np comes with BsdThreads-0.9-7 on RedHat 7.1 */
34 typedef int (*pthread_getattr_func_type) (pthread_t, pthread_attr_t *);
36 #ifdef __APPLE__
37 // Mac OS X doesn't support clock_gettime. Stub out the type, it is
38 // unused
39 typedef int clockid_t;
40 #endif
42 class Bsd {
43 friend class os;
45 // For signal-chaining
46 #define MAXSIGNUM 32
47 static struct sigaction sigact[MAXSIGNUM]; // saved preinstalled sigactions
48 static unsigned int sigs; // mask of signals that have
49 // preinstalled signal handlers
50 static bool libjsig_is_loaded; // libjsig that interposes sigaction(),
51 // __sigaction(), signal() is loaded
52 static struct sigaction *(*get_signal_action)(int);
53 static struct sigaction *get_preinstalled_handler(int);
54 static void save_preinstalled_handler(int, struct sigaction&);
56 static void check_signal_handler(int sig);
58 // For signal flags diagnostics
59 static int sigflags[MAXSIGNUM];
61 #ifdef __APPLE__
62 // mach_absolute_time
63 static mach_timebase_info_data_t _timebase_info;
64 static volatile uint64_t _max_abstime;
65 #else
66 static int (*_clock_gettime)(clockid_t, struct timespec *);
67 #endif
69 static GrowableArray<int>* _cpu_to_node;
71 protected:
73 static julong _physical_memory;
74 static pthread_t _main_thread;
75 static int _page_size;
77 static julong available_memory();
78 static julong physical_memory() { return _physical_memory; }
79 static void initialize_system_info();
81 static bool supports_variable_stack_size();
83 static void rebuild_cpu_to_node_map();
84 static GrowableArray<int>* cpu_to_node() { return _cpu_to_node; }
86 static bool hugetlbfs_sanity_check(bool warn, size_t page_size);
88 public:
90 static void init_thread_fpu_state();
91 static pthread_t main_thread(void) { return _main_thread; }
93 static void hotspot_sigmask(Thread* thread);
95 static bool is_initial_thread(void);
96 static pid_t gettid();
98 static int page_size(void) { return _page_size; }
99 static void set_page_size(int val) { _page_size = val; }
101 static address ucontext_get_pc(ucontext_t* uc);
102 static intptr_t* ucontext_get_sp(ucontext_t* uc);
103 static intptr_t* ucontext_get_fp(ucontext_t* uc);
105 // For Analyzer Forte AsyncGetCallTrace profiling support:
106 //
107 // This interface should be declared in os_bsd_i486.hpp, but
108 // that file provides extensions to the os class and not the
109 // Bsd class.
110 static ExtendedPC fetch_frame_from_ucontext(Thread* thread, ucontext_t* uc,
111 intptr_t** ret_sp, intptr_t** ret_fp);
113 // This boolean allows users to forward their own non-matching signals
114 // to JVM_handle_bsd_signal, harmlessly.
115 static bool signal_handlers_are_installed;
117 static int get_our_sigflags(int);
118 static void set_our_sigflags(int, int);
119 static void signal_sets_init();
120 static void install_signal_handlers();
121 static void set_signal_handler(int, bool);
122 static bool is_sig_ignored(int sig);
124 static sigset_t* unblocked_signals();
125 static sigset_t* vm_signals();
126 static sigset_t* allowdebug_blocked_signals();
128 // For signal-chaining
129 static struct sigaction *get_chained_signal_action(int sig);
130 static bool chained_handler(int sig, siginfo_t* siginfo, void* context);
132 // Minimum stack size a thread can be created with (allowing
133 // the VM to completely create the thread and enter user code)
134 static size_t min_stack_allowed;
136 // Return default stack size or guard size for the specified thread type
137 static size_t default_stack_size(os::ThreadType thr_type);
138 static size_t default_guard_size(os::ThreadType thr_type);
140 // Real-time clock functions
141 static void clock_init(void);
143 static inline bool supports_monotonic_clock() {
144 #ifdef __APPLE__
145 return true;
146 #else
147 return _clock_gettime != NULL;
148 #endif
149 }
151 // Stack repair handling
153 // none present
155 // BsdThreads work-around for 6292965
156 static int safe_cond_timedwait(pthread_cond_t *_cond, pthread_mutex_t *_mutex, const struct timespec *_abstime);
158 private:
159 typedef int (*sched_getcpu_func_t)(void);
160 typedef int (*numa_node_to_cpus_func_t)(int node, unsigned long *buffer, int bufferlen);
161 typedef int (*numa_max_node_func_t)(void);
162 typedef int (*numa_available_func_t)(void);
163 typedef int (*numa_tonode_memory_func_t)(void *start, size_t size, int node);
164 typedef void (*numa_interleave_memory_func_t)(void *start, size_t size, unsigned long *nodemask);
166 static sched_getcpu_func_t _sched_getcpu;
167 static numa_node_to_cpus_func_t _numa_node_to_cpus;
168 static numa_max_node_func_t _numa_max_node;
169 static numa_available_func_t _numa_available;
170 static numa_tonode_memory_func_t _numa_tonode_memory;
171 static numa_interleave_memory_func_t _numa_interleave_memory;
172 static unsigned long* _numa_all_nodes;
174 static void set_sched_getcpu(sched_getcpu_func_t func) { _sched_getcpu = func; }
175 static void set_numa_node_to_cpus(numa_node_to_cpus_func_t func) { _numa_node_to_cpus = func; }
176 static void set_numa_max_node(numa_max_node_func_t func) { _numa_max_node = func; }
177 static void set_numa_available(numa_available_func_t func) { _numa_available = func; }
178 static void set_numa_tonode_memory(numa_tonode_memory_func_t func) { _numa_tonode_memory = func; }
179 static void set_numa_interleave_memory(numa_interleave_memory_func_t func) { _numa_interleave_memory = func; }
180 static void set_numa_all_nodes(unsigned long* ptr) { _numa_all_nodes = ptr; }
181 public:
182 static int sched_getcpu() { return _sched_getcpu != NULL ? _sched_getcpu() : -1; }
183 static int numa_node_to_cpus(int node, unsigned long *buffer, int bufferlen) {
184 return _numa_node_to_cpus != NULL ? _numa_node_to_cpus(node, buffer, bufferlen) : -1;
185 }
186 static int numa_max_node() { return _numa_max_node != NULL ? _numa_max_node() : -1; }
187 static int numa_available() { return _numa_available != NULL ? _numa_available() : -1; }
188 static int numa_tonode_memory(void *start, size_t size, int node) {
189 return _numa_tonode_memory != NULL ? _numa_tonode_memory(start, size, node) : -1;
190 }
191 static void numa_interleave_memory(void *start, size_t size) {
192 if (_numa_interleave_memory != NULL && _numa_all_nodes != NULL) {
193 _numa_interleave_memory(start, size, _numa_all_nodes);
194 }
195 }
196 static int get_node_by_cpu(int cpu_id);
197 };
200 class PlatformEvent : public CHeapObj<mtInternal> {
201 private:
202 double CachePad [4] ; // increase odds that _mutex is sole occupant of cache line
203 volatile int _Event ;
204 volatile int _nParked ;
205 pthread_mutex_t _mutex [1] ;
206 pthread_cond_t _cond [1] ;
207 double PostPad [2] ;
208 Thread * _Assoc ;
210 public: // TODO-FIXME: make dtor private
211 ~PlatformEvent() { guarantee (0, "invariant") ; }
213 public:
214 PlatformEvent() {
215 int status;
216 status = pthread_cond_init (_cond, NULL);
217 assert_status(status == 0, status, "cond_init");
218 status = pthread_mutex_init (_mutex, NULL);
219 assert_status(status == 0, status, "mutex_init");
220 _Event = 0 ;
221 _nParked = 0 ;
222 _Assoc = NULL ;
223 }
225 // Use caution with reset() and fired() -- they may require MEMBARs
226 void reset() { _Event = 0 ; }
227 int fired() { return _Event; }
228 void park () ;
229 void unpark () ;
230 int TryPark () ;
231 int park (jlong millis) ;
232 void SetAssociation (Thread * a) { _Assoc = a ; }
233 };
235 class PlatformParker : public CHeapObj<mtInternal> {
236 protected:
237 pthread_mutex_t _mutex [1] ;
238 pthread_cond_t _cond [1] ;
240 public: // TODO-FIXME: make dtor private
241 ~PlatformParker() { guarantee (0, "invariant") ; }
243 public:
244 PlatformParker() {
245 int status;
246 status = pthread_cond_init (_cond, NULL);
247 assert_status(status == 0, status, "cond_init");
248 status = pthread_mutex_init (_mutex, NULL);
249 assert_status(status == 0, status, "mutex_init");
250 }
251 };
253 #endif // OS_BSD_VM_OS_BSD_HPP