--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/runtime/os.cpp Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,1108 @@
+/*
+ * Copyright 1997-2007 Sun Microsystems, Inc. All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ */
+
+# include "incls/_precompiled.incl"
+# include "incls/_os.cpp.incl"
+
+# include <signal.h>
+
+OSThread* os::_starting_thread = NULL;
+address os::_polling_page = NULL;
+volatile int32_t* os::_mem_serialize_page = NULL;
+uintptr_t os::_serialize_page_mask = 0;
+long os::_rand_seed = 1;
+int os::_processor_count = 0;
+volatile jlong os::_global_time = 0;
+volatile int os::_global_time_lock = 0;
+bool os::_use_global_time = false;
+size_t os::_page_sizes[os::page_sizes_max];
+
+#ifndef PRODUCT
+int os::num_mallocs = 0; // # of calls to malloc/realloc
+size_t os::alloc_bytes = 0; // # of bytes allocated
+int os::num_frees = 0; // # of calls to free
+#endif
+
+// Atomic read of a jlong is assured by a seqlock; see update_global_time()
+jlong os::read_global_time() {
+#ifdef _LP64
+ return _global_time;
+#else
+ volatile int lock;
+ volatile jlong current_time;
+ int ctr = 0;
+
+ for (;;) {
+ lock = _global_time_lock;
+
+ // spin while locked
+ while ((lock & 0x1) != 0) {
+ ++ctr;
+ if ((ctr & 0xFFF) == 0) {
+ // Guarantee writer progress. Can't use yield; yield is advisory
+ // and has almost no effect on some platforms. Don't need a state
+ // transition - the park call will return promptly.
+ assert(Thread::current() != NULL, "TLS not initialized");
+ assert(Thread::current()->_ParkEvent != NULL, "sync not initialized");
+ Thread::current()->_ParkEvent->park(1);
+ }
+ lock = _global_time_lock;
+ }
+
+ OrderAccess::loadload();
+ current_time = _global_time;
+ OrderAccess::loadload();
+
+ // ratify seqlock value
+ if (lock == _global_time_lock) {
+ return current_time;
+ }
+ }
+#endif
+}
+
+//
+// NOTE - Assumes only one writer thread!
+//
+// We use a seqlock to guarantee that jlong _global_time is updated
+// atomically on 32-bit platforms. A locked value is indicated by
+// the lock variable LSB == 1. Readers will initially read the lock
+// value, spinning until the LSB == 0. They then speculatively read
+// the global time value, then re-read the lock value to ensure that
+// it hasn't changed. If the lock value has changed, the entire read
+// sequence is retried.
+//
+// Writers simply set the LSB = 1 (i.e. increment the variable),
+// update the global time, then release the lock and bump the version
+// number (i.e. increment the variable again.) In this case we don't
+// even need a CAS since we ensure there's only one writer.
+//
+void os::update_global_time() {
+#ifdef _LP64
+ _global_time = timeofday();
+#else
+ assert((_global_time_lock & 0x1) == 0, "multiple writers?");
+ jlong current_time = timeofday();
+ _global_time_lock++; // lock
+ OrderAccess::storestore();
+ _global_time = current_time;
+ OrderAccess::storestore();
+ _global_time_lock++; // unlock
+#endif
+}
+
+// Fill in buffer with current local time as an ISO-8601 string.
+// E.g., yyyy-mm-ddThh:mm:ss-zzzz.
+// Returns buffer, or NULL if it failed.
+// This would mostly be a call to
+// strftime(...., "%Y-%m-%d" "T" "%H:%M:%S" "%z", ....)
+// except that on Windows the %z behaves badly, so we do it ourselves.
+// Also, people wanted milliseconds on there,
+// and strftime doesn't do milliseconds.
+char* os::iso8601_time(char* buffer, size_t buffer_length) {
+ // Output will be of the form "YYYY-MM-DDThh:mm:ss.mmm+zzzz\0"
+ // 1 2
+ // 12345678901234567890123456789
+ static const char* iso8601_format =
+ "%04d-%02d-%02dT%02d:%02d:%02d.%03d%c%02d%02d";
+ static const size_t needed_buffer = 29;
+
+ // Sanity check the arguments
+ if (buffer == NULL) {
+ assert(false, "NULL buffer");
+ return NULL;
+ }
+ if (buffer_length < needed_buffer) {
+ assert(false, "buffer_length too small");
+ return NULL;
+ }
+ // Get the current time
+ jlong milliseconds_since_19700101 = timeofday();
+ const int milliseconds_per_microsecond = 1000;
+ const time_t seconds_since_19700101 =
+ milliseconds_since_19700101 / milliseconds_per_microsecond;
+ const int milliseconds_after_second =
+ milliseconds_since_19700101 % milliseconds_per_microsecond;
+ // Convert the time value to a tm and timezone variable
+ const struct tm *time_struct_temp = localtime(&seconds_since_19700101);
+ if (time_struct_temp == NULL) {
+ assert(false, "Failed localtime");
+ return NULL;
+ }
+ // Save the results of localtime
+ const struct tm time_struct = *time_struct_temp;
+ const time_t zone = timezone;
+
+ // If daylight savings time is in effect,
+ // we are 1 hour East of our time zone
+ const time_t seconds_per_minute = 60;
+ const time_t minutes_per_hour = 60;
+ const time_t seconds_per_hour = seconds_per_minute * minutes_per_hour;
+ time_t UTC_to_local = zone;
+ if (time_struct.tm_isdst > 0) {
+ UTC_to_local = UTC_to_local - seconds_per_hour;
+ }
+ // Compute the time zone offset.
+ // localtime(3C) sets timezone to the difference (in seconds)
+ // between UTC and and local time.
+ // ISO 8601 says we need the difference between local time and UTC,
+ // we change the sign of the localtime(3C) result.
+ const time_t local_to_UTC = -(UTC_to_local);
+ // Then we have to figure out if if we are ahead (+) or behind (-) UTC.
+ char sign_local_to_UTC = '+';
+ time_t abs_local_to_UTC = local_to_UTC;
+ if (local_to_UTC < 0) {
+ sign_local_to_UTC = '-';
+ abs_local_to_UTC = -(abs_local_to_UTC);
+ }
+ // Convert time zone offset seconds to hours and minutes.
+ const time_t zone_hours = (abs_local_to_UTC / seconds_per_hour);
+ const time_t zone_min =
+ ((abs_local_to_UTC % seconds_per_hour) / seconds_per_minute);
+
+ // Print an ISO 8601 date and time stamp into the buffer
+ const int year = 1900 + time_struct.tm_year;
+ const int month = 1 + time_struct.tm_mon;
+ const int printed = jio_snprintf(buffer, buffer_length, iso8601_format,
+ year,
+ month,
+ time_struct.tm_mday,
+ time_struct.tm_hour,
+ time_struct.tm_min,
+ time_struct.tm_sec,
+ milliseconds_after_second,
+ sign_local_to_UTC,
+ zone_hours,
+ zone_min);
+ if (printed == 0) {
+ assert(false, "Failed jio_printf");
+ return NULL;
+ }
+ return buffer;
+}
+
+OSReturn os::set_priority(Thread* thread, ThreadPriority p) {
+#ifdef ASSERT
+ if (!(!thread->is_Java_thread() ||
+ Thread::current() == thread ||
+ Threads_lock->owned_by_self()
+ || thread->is_Compiler_thread()
+ )) {
+ assert(false, "possibility of dangling Thread pointer");
+ }
+#endif
+
+ if (p >= MinPriority && p <= MaxPriority) {
+ int priority = java_to_os_priority[p];
+ return set_native_priority(thread, priority);
+ } else {
+ assert(false, "Should not happen");
+ return OS_ERR;
+ }
+}
+
+
+OSReturn os::get_priority(const Thread* const thread, ThreadPriority& priority) {
+ int p;
+ int os_prio;
+ OSReturn ret = get_native_priority(thread, &os_prio);
+ if (ret != OS_OK) return ret;
+
+ for (p = MaxPriority; p > MinPriority && java_to_os_priority[p] > os_prio; p--) ;
+ priority = (ThreadPriority)p;
+ return OS_OK;
+}
+
+
+// --------------------- sun.misc.Signal (optional) ---------------------
+
+
+// SIGBREAK is sent by the keyboard to query the VM state
+#ifndef SIGBREAK
+#define SIGBREAK SIGQUIT
+#endif
+
+// sigexitnum_pd is a platform-specific special signal used for terminating the Signal thread.
+
+
+static void signal_thread_entry(JavaThread* thread, TRAPS) {
+ os::set_priority(thread, NearMaxPriority);
+ while (true) {
+ int sig;
+ {
+ // FIXME : Currently we have not decieded what should be the status
+ // for this java thread blocked here. Once we decide about
+ // that we should fix this.
+ sig = os::signal_wait();
+ }
+ if (sig == os::sigexitnum_pd()) {
+ // Terminate the signal thread
+ return;
+ }
+
+ switch (sig) {
+ case SIGBREAK: {
+ // Check if the signal is a trigger to start the Attach Listener - in that
+ // case don't print stack traces.
+ if (!DisableAttachMechanism && AttachListener::is_init_trigger()) {
+ continue;
+ }
+ // Print stack traces
+ // Any SIGBREAK operations added here should make sure to flush
+ // the output stream (e.g. tty->flush()) after output. See 4803766.
+ // Each module also prints an extra carriage return after its output.
+ VM_PrintThreads op;
+ VMThread::execute(&op);
+ VM_PrintJNI jni_op;
+ VMThread::execute(&jni_op);
+ VM_FindDeadlocks op1(tty);
+ VMThread::execute(&op1);
+ Universe::print_heap_at_SIGBREAK();
+ if (PrintClassHistogram) {
+ VM_GC_HeapInspection op1(gclog_or_tty, true /* force full GC before heap inspection */);
+ VMThread::execute(&op1);
+ }
+ if (JvmtiExport::should_post_data_dump()) {
+ JvmtiExport::post_data_dump();
+ }
+ break;
+ }
+ default: {
+ // Dispatch the signal to java
+ HandleMark hm(THREAD);
+ klassOop k = SystemDictionary::resolve_or_null(vmSymbolHandles::sun_misc_Signal(), THREAD);
+ KlassHandle klass (THREAD, k);
+ if (klass.not_null()) {
+ JavaValue result(T_VOID);
+ JavaCallArguments args;
+ args.push_int(sig);
+ JavaCalls::call_static(
+ &result,
+ klass,
+ vmSymbolHandles::dispatch_name(),
+ vmSymbolHandles::int_void_signature(),
+ &args,
+ THREAD
+ );
+ }
+ if (HAS_PENDING_EXCEPTION) {
+ // tty is initialized early so we don't expect it to be null, but
+ // if it is we can't risk doing an initialization that might
+ // trigger additional out-of-memory conditions
+ if (tty != NULL) {
+ char klass_name[256];
+ char tmp_sig_name[16];
+ const char* sig_name = "UNKNOWN";
+ instanceKlass::cast(PENDING_EXCEPTION->klass())->
+ name()->as_klass_external_name(klass_name, 256);
+ if (os::exception_name(sig, tmp_sig_name, 16) != NULL)
+ sig_name = tmp_sig_name;
+ warning("Exception %s occurred dispatching signal %s to handler"
+ "- the VM may need to be forcibly terminated",
+ klass_name, sig_name );
+ }
+ CLEAR_PENDING_EXCEPTION;
+ }
+ }
+ }
+ }
+}
+
+
+void os::signal_init() {
+ if (!ReduceSignalUsage) {
+ // Setup JavaThread for processing signals
+ EXCEPTION_MARK;
+ klassOop k = SystemDictionary::resolve_or_fail(vmSymbolHandles::java_lang_Thread(), true, CHECK);
+ instanceKlassHandle klass (THREAD, k);
+ instanceHandle thread_oop = klass->allocate_instance_handle(CHECK);
+
+ const char thread_name[] = "Signal Dispatcher";
+ Handle string = java_lang_String::create_from_str(thread_name, CHECK);
+
+ // Initialize thread_oop to put it into the system threadGroup
+ Handle thread_group (THREAD, Universe::system_thread_group());
+ JavaValue result(T_VOID);
+ JavaCalls::call_special(&result, thread_oop,
+ klass,
+ vmSymbolHandles::object_initializer_name(),
+ vmSymbolHandles::threadgroup_string_void_signature(),
+ thread_group,
+ string,
+ CHECK);
+
+ KlassHandle group(THREAD, SystemDictionary::threadGroup_klass());
+ JavaCalls::call_special(&result,
+ thread_group,
+ group,
+ vmSymbolHandles::add_method_name(),
+ vmSymbolHandles::thread_void_signature(),
+ thread_oop, // ARG 1
+ CHECK);
+
+ os::signal_init_pd();
+
+ { MutexLocker mu(Threads_lock);
+ JavaThread* signal_thread = new JavaThread(&signal_thread_entry);
+
+ // At this point it may be possible that no osthread was created for the
+ // JavaThread due to lack of memory. We would have to throw an exception
+ // in that case. However, since this must work and we do not allow
+ // exceptions anyway, check and abort if this fails.
+ if (signal_thread == NULL || signal_thread->osthread() == NULL) {
+ vm_exit_during_initialization("java.lang.OutOfMemoryError",
+ "unable to create new native thread");
+ }
+
+ java_lang_Thread::set_thread(thread_oop(), signal_thread);
+ java_lang_Thread::set_priority(thread_oop(), NearMaxPriority);
+ java_lang_Thread::set_daemon(thread_oop());
+
+ signal_thread->set_threadObj(thread_oop());
+ Threads::add(signal_thread);
+ Thread::start(signal_thread);
+ }
+ // Handle ^BREAK
+ os::signal(SIGBREAK, os::user_handler());
+ }
+}
+
+
+void os::terminate_signal_thread() {
+ if (!ReduceSignalUsage)
+ signal_notify(sigexitnum_pd());
+}
+
+
+// --------------------- loading libraries ---------------------
+
+typedef jint (JNICALL *JNI_OnLoad_t)(JavaVM *, void *);
+extern struct JavaVM_ main_vm;
+
+static void* _native_java_library = NULL;
+
+void* os::native_java_library() {
+ if (_native_java_library == NULL) {
+ char buffer[JVM_MAXPATHLEN];
+ char ebuf[1024];
+
+ // Try to load verify dll first. In 1.3 java dll depends on it and is not always
+ // able to find it when the loading executable is outside the JDK.
+ // In order to keep working with 1.2 we ignore any loading errors.
+ hpi::dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(), "verify");
+ hpi::dll_load(buffer, ebuf, sizeof(ebuf));
+
+ // Load java dll
+ hpi::dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(), "java");
+ _native_java_library = hpi::dll_load(buffer, ebuf, sizeof(ebuf));
+ if (_native_java_library == NULL) {
+ vm_exit_during_initialization("Unable to load native library", ebuf);
+ }
+ // The JNI_OnLoad handling is normally done by method load in java.lang.ClassLoader$NativeLibrary,
+ // but the VM loads the base library explicitly so we have to check for JNI_OnLoad as well
+ const char *onLoadSymbols[] = JNI_ONLOAD_SYMBOLS;
+ JNI_OnLoad_t JNI_OnLoad = CAST_TO_FN_PTR(JNI_OnLoad_t, hpi::dll_lookup(_native_java_library, onLoadSymbols[0]));
+ if (JNI_OnLoad != NULL) {
+ JavaThread* thread = JavaThread::current();
+ ThreadToNativeFromVM ttn(thread);
+ HandleMark hm(thread);
+ jint ver = (*JNI_OnLoad)(&main_vm, NULL);
+ if (!Threads::is_supported_jni_version_including_1_1(ver)) {
+ vm_exit_during_initialization("Unsupported JNI version");
+ }
+ }
+ }
+ return _native_java_library;
+}
+
+// --------------------- heap allocation utilities ---------------------
+
+char *os::strdup(const char *str) {
+ size_t size = strlen(str);
+ char *dup_str = (char *)malloc(size + 1);
+ if (dup_str == NULL) return NULL;
+ strcpy(dup_str, str);
+ return dup_str;
+}
+
+
+
+#ifdef ASSERT
+#define space_before (MallocCushion + sizeof(double))
+#define space_after MallocCushion
+#define size_addr_from_base(p) (size_t*)(p + space_before - sizeof(size_t))
+#define size_addr_from_obj(p) ((size_t*)p - 1)
+// MallocCushion: size of extra cushion allocated around objects with +UseMallocOnly
+// NB: cannot be debug variable, because these aren't set from the command line until
+// *after* the first few allocs already happened
+#define MallocCushion 16
+#else
+#define space_before 0
+#define space_after 0
+#define size_addr_from_base(p) should not use w/o ASSERT
+#define size_addr_from_obj(p) should not use w/o ASSERT
+#define MallocCushion 0
+#endif
+#define paranoid 0 /* only set to 1 if you suspect checking code has bug */
+
+#ifdef ASSERT
+inline size_t get_size(void* obj) {
+ size_t size = *size_addr_from_obj(obj);
+ if (size < 0 )
+ fatal2("free: size field of object #%p was overwritten (%lu)", obj, size);
+ return size;
+}
+
+u_char* find_cushion_backwards(u_char* start) {
+ u_char* p = start;
+ while (p[ 0] != badResourceValue || p[-1] != badResourceValue ||
+ p[-2] != badResourceValue || p[-3] != badResourceValue) p--;
+ // ok, we have four consecutive marker bytes; find start
+ u_char* q = p - 4;
+ while (*q == badResourceValue) q--;
+ return q + 1;
+}
+
+u_char* find_cushion_forwards(u_char* start) {
+ u_char* p = start;
+ while (p[0] != badResourceValue || p[1] != badResourceValue ||
+ p[2] != badResourceValue || p[3] != badResourceValue) p++;
+ // ok, we have four consecutive marker bytes; find end of cushion
+ u_char* q = p + 4;
+ while (*q == badResourceValue) q++;
+ return q - MallocCushion;
+}
+
+void print_neighbor_blocks(void* ptr) {
+ // find block allocated before ptr (not entirely crash-proof)
+ if (MallocCushion < 4) {
+ tty->print_cr("### cannot find previous block (MallocCushion < 4)");
+ return;
+ }
+ u_char* start_of_this_block = (u_char*)ptr - space_before;
+ u_char* end_of_prev_block_data = start_of_this_block - space_after -1;
+ // look for cushion in front of prev. block
+ u_char* start_of_prev_block = find_cushion_backwards(end_of_prev_block_data);
+ ptrdiff_t size = *size_addr_from_base(start_of_prev_block);
+ u_char* obj = start_of_prev_block + space_before;
+ if (size <= 0 ) {
+ // start is bad; mayhave been confused by OS data inbetween objects
+ // search one more backwards
+ start_of_prev_block = find_cushion_backwards(start_of_prev_block);
+ size = *size_addr_from_base(start_of_prev_block);
+ obj = start_of_prev_block + space_before;
+ }
+
+ if (start_of_prev_block + space_before + size + space_after == start_of_this_block) {
+ tty->print_cr("### previous object: %p (%ld bytes)", obj, size);
+ } else {
+ tty->print_cr("### previous object (not sure if correct): %p (%ld bytes)", obj, size);
+ }
+
+ // now find successor block
+ u_char* start_of_next_block = (u_char*)ptr + *size_addr_from_obj(ptr) + space_after;
+ start_of_next_block = find_cushion_forwards(start_of_next_block);
+ u_char* next_obj = start_of_next_block + space_before;
+ ptrdiff_t next_size = *size_addr_from_base(start_of_next_block);
+ if (start_of_next_block[0] == badResourceValue &&
+ start_of_next_block[1] == badResourceValue &&
+ start_of_next_block[2] == badResourceValue &&
+ start_of_next_block[3] == badResourceValue) {
+ tty->print_cr("### next object: %p (%ld bytes)", next_obj, next_size);
+ } else {
+ tty->print_cr("### next object (not sure if correct): %p (%ld bytes)", next_obj, next_size);
+ }
+}
+
+
+void report_heap_error(void* memblock, void* bad, const char* where) {
+ tty->print_cr("## nof_mallocs = %d, nof_frees = %d", os::num_mallocs, os::num_frees);
+ tty->print_cr("## memory stomp: byte at %p %s object %p", bad, where, memblock);
+ print_neighbor_blocks(memblock);
+ fatal("memory stomping error");
+}
+
+void verify_block(void* memblock) {
+ size_t size = get_size(memblock);
+ if (MallocCushion) {
+ u_char* ptr = (u_char*)memblock - space_before;
+ for (int i = 0; i < MallocCushion; i++) {
+ if (ptr[i] != badResourceValue) {
+ report_heap_error(memblock, ptr+i, "in front of");
+ }
+ }
+ u_char* end = (u_char*)memblock + size + space_after;
+ for (int j = -MallocCushion; j < 0; j++) {
+ if (end[j] != badResourceValue) {
+ report_heap_error(memblock, end+j, "after");
+ }
+ }
+ }
+}
+#endif
+
+void* os::malloc(size_t size) {
+ NOT_PRODUCT(num_mallocs++);
+ NOT_PRODUCT(alloc_bytes += size);
+
+ if (size == 0) {
+ // return a valid pointer if size is zero
+ // if NULL is returned the calling functions assume out of memory.
+ size = 1;
+ }
+
+ NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
+ u_char* ptr = (u_char*)::malloc(size + space_before + space_after);
+#ifdef ASSERT
+ if (ptr == NULL) return NULL;
+ if (MallocCushion) {
+ for (u_char* p = ptr; p < ptr + MallocCushion; p++) *p = (u_char)badResourceValue;
+ u_char* end = ptr + space_before + size;
+ for (u_char* pq = ptr+MallocCushion; pq < end; pq++) *pq = (u_char)uninitBlockPad;
+ for (u_char* q = end; q < end + MallocCushion; q++) *q = (u_char)badResourceValue;
+ }
+ // put size just before data
+ *size_addr_from_base(ptr) = size;
+#endif
+ u_char* memblock = ptr + space_before;
+ if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
+ tty->print_cr("os::malloc caught, %lu bytes --> %p", size, memblock);
+ breakpoint();
+ }
+ debug_only(if (paranoid) verify_block(memblock));
+ if (PrintMalloc && tty != NULL) tty->print_cr("os::malloc %lu bytes --> %p", size, memblock);
+ return memblock;
+}
+
+
+void* os::realloc(void *memblock, size_t size) {
+ NOT_PRODUCT(num_mallocs++);
+ NOT_PRODUCT(alloc_bytes += size);
+#ifndef ASSERT
+ return ::realloc(memblock, size);
+#else
+ if (memblock == NULL) {
+ return os::malloc(size);
+ }
+ if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
+ tty->print_cr("os::realloc caught %p", memblock);
+ breakpoint();
+ }
+ verify_block(memblock);
+ NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
+ if (size == 0) return NULL;
+ // always move the block
+ void* ptr = malloc(size);
+ if (PrintMalloc) tty->print_cr("os::remalloc %lu bytes, %p --> %p", size, memblock, ptr);
+ // Copy to new memory if malloc didn't fail
+ if ( ptr != NULL ) {
+ memcpy(ptr, memblock, MIN2(size, get_size(memblock)));
+ if (paranoid) verify_block(ptr);
+ if ((intptr_t)ptr == (intptr_t)MallocCatchPtr) {
+ tty->print_cr("os::realloc caught, %lu bytes --> %p", size, ptr);
+ breakpoint();
+ }
+ free(memblock);
+ }
+ return ptr;
+#endif
+}
+
+
+void os::free(void *memblock) {
+ NOT_PRODUCT(num_frees++);
+#ifdef ASSERT
+ if (memblock == NULL) return;
+ if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
+ if (tty != NULL) tty->print_cr("os::free caught %p", memblock);
+ breakpoint();
+ }
+ verify_block(memblock);
+ if (PrintMalloc && tty != NULL)
+ // tty->print_cr("os::free %p", memblock);
+ fprintf(stderr, "os::free %p\n", memblock);
+ NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
+ // Added by detlefs.
+ if (MallocCushion) {
+ u_char* ptr = (u_char*)memblock - space_before;
+ for (u_char* p = ptr; p < ptr + MallocCushion; p++) {
+ guarantee(*p == badResourceValue,
+ "Thing freed should be malloc result.");
+ *p = (u_char)freeBlockPad;
+ }
+ size_t size = get_size(memblock);
+ u_char* end = ptr + space_before + size;
+ for (u_char* q = end; q < end + MallocCushion; q++) {
+ guarantee(*q == badResourceValue,
+ "Thing freed should be malloc result.");
+ *q = (u_char)freeBlockPad;
+ }
+ }
+#endif
+ ::free((char*)memblock - space_before);
+}
+
+void os::init_random(long initval) {
+ _rand_seed = initval;
+}
+
+
+long os::random() {
+ /* standard, well-known linear congruential random generator with
+ * next_rand = (16807*seed) mod (2**31-1)
+ * see
+ * (1) "Random Number Generators: Good Ones Are Hard to Find",
+ * S.K. Park and K.W. Miller, Communications of the ACM 31:10 (Oct 1988),
+ * (2) "Two Fast Implementations of the 'Minimal Standard' Random
+ * Number Generator", David G. Carta, Comm. ACM 33, 1 (Jan 1990), pp. 87-88.
+ */
+ const long a = 16807;
+ const unsigned long m = 2147483647;
+ const long q = m / a; assert(q == 127773, "weird math");
+ const long r = m % a; assert(r == 2836, "weird math");
+
+ // compute az=2^31p+q
+ unsigned long lo = a * (long)(_rand_seed & 0xFFFF);
+ unsigned long hi = a * (long)((unsigned long)_rand_seed >> 16);
+ lo += (hi & 0x7FFF) << 16;
+
+ // if q overflowed, ignore the overflow and increment q
+ if (lo > m) {
+ lo &= m;
+ ++lo;
+ }
+ lo += hi >> 15;
+
+ // if (p+q) overflowed, ignore the overflow and increment (p+q)
+ if (lo > m) {
+ lo &= m;
+ ++lo;
+ }
+ return (_rand_seed = lo);
+}
+
+// The INITIALIZED state is distinguished from the SUSPENDED state because the
+// conditions in which a thread is first started are different from those in which
+// a suspension is resumed. These differences make it hard for us to apply the
+// tougher checks when starting threads that we want to do when resuming them.
+// However, when start_thread is called as a result of Thread.start, on a Java
+// thread, the operation is synchronized on the Java Thread object. So there
+// cannot be a race to start the thread and hence for the thread to exit while
+// we are working on it. Non-Java threads that start Java threads either have
+// to do so in a context in which races are impossible, or should do appropriate
+// locking.
+
+void os::start_thread(Thread* thread) {
+ // guard suspend/resume
+ MutexLockerEx ml(thread->SR_lock(), Mutex::_no_safepoint_check_flag);
+ OSThread* osthread = thread->osthread();
+ osthread->set_state(RUNNABLE);
+ pd_start_thread(thread);
+}
+
+//---------------------------------------------------------------------------
+// Helper functions for fatal error handler
+
+void os::print_hex_dump(outputStream* st, address start, address end, int unitsize) {
+ assert(unitsize == 1 || unitsize == 2 || unitsize == 4 || unitsize == 8, "just checking");
+
+ int cols = 0;
+ int cols_per_line = 0;
+ switch (unitsize) {
+ case 1: cols_per_line = 16; break;
+ case 2: cols_per_line = 8; break;
+ case 4: cols_per_line = 4; break;
+ case 8: cols_per_line = 2; break;
+ default: return;
+ }
+
+ address p = start;
+ st->print(PTR_FORMAT ": ", start);
+ while (p < end) {
+ switch (unitsize) {
+ case 1: st->print("%02x", *(u1*)p); break;
+ case 2: st->print("%04x", *(u2*)p); break;
+ case 4: st->print("%08x", *(u4*)p); break;
+ case 8: st->print("%016" FORMAT64_MODIFIER "x", *(u8*)p); break;
+ }
+ p += unitsize;
+ cols++;
+ if (cols >= cols_per_line && p < end) {
+ cols = 0;
+ st->cr();
+ st->print(PTR_FORMAT ": ", p);
+ } else {
+ st->print(" ");
+ }
+ }
+ st->cr();
+}
+
+void os::print_environment_variables(outputStream* st, const char** env_list,
+ char* buffer, int len) {
+ if (env_list) {
+ st->print_cr("Environment Variables:");
+
+ for (int i = 0; env_list[i] != NULL; i++) {
+ if (getenv(env_list[i], buffer, len)) {
+ st->print(env_list[i]);
+ st->print("=");
+ st->print_cr(buffer);
+ }
+ }
+ }
+}
+
+void os::print_cpu_info(outputStream* st) {
+ // cpu
+ st->print("CPU:");
+ st->print("total %d", os::processor_count());
+ // It's not safe to query number of active processors after crash
+ // st->print("(active %d)", os::active_processor_count());
+ st->print(" %s", VM_Version::cpu_features());
+ st->cr();
+}
+
+void os::print_date_and_time(outputStream *st) {
+ time_t tloc;
+ (void)time(&tloc);
+ st->print("time: %s", ctime(&tloc)); // ctime adds newline.
+
+ double t = os::elapsedTime();
+ // NOTE: It tends to crash after a SEGV if we want to printf("%f",...) in
+ // Linux. Must be a bug in glibc ? Workaround is to round "t" to int
+ // before printf. We lost some precision, but who cares?
+ st->print_cr("elapsed time: %d seconds", (int)t);
+}
+
+
+// Looks like all platforms except IA64 can use the same function to check
+// if C stack is walkable beyond current frame. The check for fp() is not
+// necessary on Sparc, but it's harmless.
+bool os::is_first_C_frame(frame* fr) {
+#ifdef IA64
+ // In order to walk native frames on Itanium, we need to access the unwind
+ // table, which is inside ELF. We don't want to parse ELF after fatal error,
+ // so return true for IA64. If we need to support C stack walking on IA64,
+ // this function needs to be moved to CPU specific files, as fp() on IA64
+ // is register stack, which grows towards higher memory address.
+ return true;
+#endif
+
+ // Load up sp, fp, sender sp and sender fp, check for reasonable values.
+ // Check usp first, because if that's bad the other accessors may fault
+ // on some architectures. Ditto ufp second, etc.
+ uintptr_t fp_align_mask = (uintptr_t)(sizeof(address)-1);
+ // sp on amd can be 32 bit aligned.
+ uintptr_t sp_align_mask = (uintptr_t)(sizeof(int)-1);
+
+ uintptr_t usp = (uintptr_t)fr->sp();
+ if ((usp & sp_align_mask) != 0) return true;
+
+ uintptr_t ufp = (uintptr_t)fr->fp();
+ if ((ufp & fp_align_mask) != 0) return true;
+
+ uintptr_t old_sp = (uintptr_t)fr->sender_sp();
+ if ((old_sp & sp_align_mask) != 0) return true;
+ if (old_sp == 0 || old_sp == (uintptr_t)-1) return true;
+
+ uintptr_t old_fp = (uintptr_t)fr->link();
+ if ((old_fp & fp_align_mask) != 0) return true;
+ if (old_fp == 0 || old_fp == (uintptr_t)-1 || old_fp == ufp) return true;
+
+ // stack grows downwards; if old_fp is below current fp or if the stack
+ // frame is too large, either the stack is corrupted or fp is not saved
+ // on stack (i.e. on x86, ebp may be used as general register). The stack
+ // is not walkable beyond current frame.
+ if (old_fp < ufp) return true;
+ if (old_fp - ufp > 64 * K) return true;
+
+ return false;
+}
+
+#ifdef ASSERT
+extern "C" void test_random() {
+ const double m = 2147483647;
+ double mean = 0.0, variance = 0.0, t;
+ long reps = 10000;
+ unsigned long seed = 1;
+
+ tty->print_cr("seed %ld for %ld repeats...", seed, reps);
+ os::init_random(seed);
+ long num;
+ for (int k = 0; k < reps; k++) {
+ num = os::random();
+ double u = (double)num / m;
+ assert(u >= 0.0 && u <= 1.0, "bad random number!");
+
+ // calculate mean and variance of the random sequence
+ mean += u;
+ variance += (u*u);
+ }
+ mean /= reps;
+ variance /= (reps - 1);
+
+ assert(num == 1043618065, "bad seed");
+ tty->print_cr("mean of the 1st 10000 numbers: %f", mean);
+ tty->print_cr("variance of the 1st 10000 numbers: %f", variance);
+ const double eps = 0.0001;
+ t = fabsd(mean - 0.5018);
+ assert(t < eps, "bad mean");
+ t = (variance - 0.3355) < 0.0 ? -(variance - 0.3355) : variance - 0.3355;
+ assert(t < eps, "bad variance");
+}
+#endif
+
+
+// Set up the boot classpath.
+
+char* os::format_boot_path(const char* format_string,
+ const char* home,
+ int home_len,
+ char fileSep,
+ char pathSep) {
+ assert((fileSep == '/' && pathSep == ':') ||
+ (fileSep == '\\' && pathSep == ';'), "unexpected seperator chars");
+
+ // Scan the format string to determine the length of the actual
+ // boot classpath, and handle platform dependencies as well.
+ int formatted_path_len = 0;
+ const char* p;
+ for (p = format_string; *p != 0; ++p) {
+ if (*p == '%') formatted_path_len += home_len - 1;
+ ++formatted_path_len;
+ }
+
+ char* formatted_path = NEW_C_HEAP_ARRAY(char, formatted_path_len + 1);
+ if (formatted_path == NULL) {
+ return NULL;
+ }
+
+ // Create boot classpath from format, substituting separator chars and
+ // java home directory.
+ char* q = formatted_path;
+ for (p = format_string; *p != 0; ++p) {
+ switch (*p) {
+ case '%':
+ strcpy(q, home);
+ q += home_len;
+ break;
+ case '/':
+ *q++ = fileSep;
+ break;
+ case ':':
+ *q++ = pathSep;
+ break;
+ default:
+ *q++ = *p;
+ }
+ }
+ *q = '\0';
+
+ assert((q - formatted_path) == formatted_path_len, "formatted_path size botched");
+ return formatted_path;
+}
+
+
+bool os::set_boot_path(char fileSep, char pathSep) {
+
+ const char* home = Arguments::get_java_home();
+ int home_len = (int)strlen(home);
+
+ static const char* meta_index_dir_format = "%/lib/";
+ static const char* meta_index_format = "%/lib/meta-index";
+ char* meta_index = format_boot_path(meta_index_format, home, home_len, fileSep, pathSep);
+ if (meta_index == NULL) return false;
+ char* meta_index_dir = format_boot_path(meta_index_dir_format, home, home_len, fileSep, pathSep);
+ if (meta_index_dir == NULL) return false;
+ Arguments::set_meta_index_path(meta_index, meta_index_dir);
+
+ // Any modification to the JAR-file list, for the boot classpath must be
+ // aligned with install/install/make/common/Pack.gmk. Note: boot class
+ // path class JARs, are stripped for StackMapTable to reduce download size.
+ static const char classpath_format[] =
+ "%/lib/resources.jar:"
+ "%/lib/rt.jar:"
+ "%/lib/sunrsasign.jar:"
+ "%/lib/jsse.jar:"
+ "%/lib/jce.jar:"
+ "%/lib/charsets.jar:"
+ "%/classes";
+ char* sysclasspath = format_boot_path(classpath_format, home, home_len, fileSep, pathSep);
+ if (sysclasspath == NULL) return false;
+ Arguments::set_sysclasspath(sysclasspath);
+
+ return true;
+}
+
+
+void os::set_memory_serialize_page(address page) {
+ int count = log2_intptr(sizeof(class JavaThread)) - log2_intptr(64);
+ _mem_serialize_page = (volatile int32_t *)page;
+ // We initialize the serialization page shift count here
+ // We assume a cache line size of 64 bytes
+ assert(SerializePageShiftCount == count,
+ "thread size changed, fix SerializePageShiftCount constant");
+ set_serialize_page_mask((uintptr_t)(vm_page_size() - sizeof(int32_t)));
+}
+
+// This method is called from signal handler when SIGSEGV occurs while the current
+// thread tries to store to the "read-only" memory serialize page during state
+// transition.
+void os::block_on_serialize_page_trap() {
+ if (TraceSafepoint) {
+ tty->print_cr("Block until the serialize page permission restored");
+ }
+ // When VMThread is holding the SerializePage_lock during modifying the
+ // access permission of the memory serialize page, the following call
+ // will block until the permission of that page is restored to rw.
+ // Generally, it is unsafe to manipulate locks in signal handlers, but in
+ // this case, it's OK as the signal is synchronous and we know precisely when
+ // it can occur. SerializePage_lock is a transiently-held leaf lock, so
+ // lock_without_safepoint_check should be safe.
+ SerializePage_lock->lock_without_safepoint_check();
+ SerializePage_lock->unlock();
+}
+
+// Serialize all thread state variables
+void os::serialize_thread_states() {
+ // On some platforms such as Solaris & Linux, the time duration of the page
+ // permission restoration is observed to be much longer than expected due to
+ // scheduler starvation problem etc. To avoid the long synchronization
+ // time and expensive page trap spinning, 'SerializePage_lock' is used to block
+ // the mutator thread if such case is encountered. Since this method is always
+ // called by VMThread during safepoint, lock_without_safepoint_check is used
+ // instead. See bug 6546278.
+ SerializePage_lock->lock_without_safepoint_check();
+ os::protect_memory( (char *)os::get_memory_serialize_page(), os::vm_page_size() );
+ os::unguard_memory( (char *)os::get_memory_serialize_page(), os::vm_page_size() );
+ SerializePage_lock->unlock();
+}
+
+// Returns true if the current stack pointer is above the stack shadow
+// pages, false otherwise.
+
+bool os::stack_shadow_pages_available(Thread *thread, methodHandle method) {
+ assert(StackRedPages > 0 && StackYellowPages > 0,"Sanity check");
+ address sp = current_stack_pointer();
+ // Check if we have StackShadowPages above the yellow zone. This parameter
+ // is dependant on the depth of the maximum VM call stack possible from
+ // the handler for stack overflow. 'instanceof' in the stack overflow
+ // handler or a println uses at least 8k stack of VM and native code
+ // respectively.
+ const int framesize_in_bytes =
+ Interpreter::size_top_interpreter_activation(method()) * wordSize;
+ int reserved_area = ((StackShadowPages + StackRedPages + StackYellowPages)
+ * vm_page_size()) + framesize_in_bytes;
+ // The very lower end of the stack
+ address stack_limit = thread->stack_base() - thread->stack_size();
+ return (sp > (stack_limit + reserved_area));
+}
+
+size_t os::page_size_for_region(size_t region_min_size, size_t region_max_size,
+ uint min_pages)
+{
+ assert(min_pages > 0, "sanity");
+ if (UseLargePages) {
+ const size_t max_page_size = region_max_size / min_pages;
+
+ for (unsigned int i = 0; _page_sizes[i] != 0; ++i) {
+ const size_t sz = _page_sizes[i];
+ const size_t mask = sz - 1;
+ if ((region_min_size & mask) == 0 && (region_max_size & mask) == 0) {
+ // The largest page size with no fragmentation.
+ return sz;
+ }
+
+ if (sz <= max_page_size) {
+ // The largest page size that satisfies the min_pages requirement.
+ return sz;
+ }
+ }
+ }
+
+ return vm_page_size();
+}
+
+#ifndef PRODUCT
+void os::trace_page_sizes(const char* str, const size_t region_min_size,
+ const size_t region_max_size, const size_t page_size,
+ const char* base, const size_t size)
+{
+ if (TracePageSizes) {
+ tty->print_cr("%s: min=" SIZE_FORMAT " max=" SIZE_FORMAT
+ " pg_sz=" SIZE_FORMAT " base=" PTR_FORMAT
+ " size=" SIZE_FORMAT,
+ str, region_min_size, region_max_size,
+ page_size, base, size);
+ }
+}
+#endif // #ifndef PRODUCT
+
+// This is the working definition of a server class machine:
+// >= 2 physical CPU's and >=2GB of memory, with some fuzz
+// because the graphics memory (?) sometimes masks physical memory.
+// If you want to change the definition of a server class machine
+// on some OS or platform, e.g., >=4GB on Windohs platforms,
+// then you'll have to parameterize this method based on that state,
+// as was done for logical processors here, or replicate and
+// specialize this method for each platform. (Or fix os to have
+// some inheritance structure and use subclassing. Sigh.)
+// If you want some platform to always or never behave as a server
+// class machine, change the setting of AlwaysActAsServerClassMachine
+// and NeverActAsServerClassMachine in globals*.hpp.
+bool os::is_server_class_machine() {
+ // First check for the early returns
+ if (NeverActAsServerClassMachine) {
+ return false;
+ }
+ if (AlwaysActAsServerClassMachine) {
+ return true;
+ }
+ // Then actually look at the machine
+ bool result = false;
+ const unsigned int server_processors = 2;
+ const julong server_memory = 2UL * G;
+ // We seem not to get our full complement of memory.
+ // We allow some part (1/8?) of the memory to be "missing",
+ // based on the sizes of DIMMs, and maybe graphics cards.
+ const julong missing_memory = 256UL * M;
+
+ /* Is this a server class machine? */
+ if ((os::active_processor_count() >= (int)server_processors) &&
+ (os::physical_memory() >= (server_memory - missing_memory))) {
+ const unsigned int logical_processors =
+ VM_Version::logical_processors_per_package();
+ if (logical_processors > 1) {
+ const unsigned int physical_packages =
+ os::active_processor_count() / logical_processors;
+ if (physical_packages > server_processors) {
+ result = true;
+ }
+ } else {
+ result = true;
+ }
+ }
+ return result;
+}