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求助：DS18B20单片机控温，导入学习板后没反应
我写的DS18B20程序，可参考
#include reg52.h
#include intrins.h
#include stdio.h
#define uchar unsigned char
#define uint unsigned int
*** it xssj=P1^0; //显示数据
*** it xssz=P1^1; //显示时钟
*** it control=P1^3;
*** it DQ = P1^4;
bit flag;
uint Temperature;
uint temp[9];
uchar temp_buff[9]; //存储读取的字节，read scratchpad为9字节，read rom ID为8字节
uchar id_buff[8];
uchar *p;
uchar crc_data;
uint Temperature_h;
uint Temperature_l;
uchar code Crcontrolable [256]={
0, 94, 188, 226, 97, 63, 221, 131, 194, 156, 126, 32, 163, 253, 31, 65,
157, 195, 33, 127, 252, 162, 64, 30, 95, 1, 227, 189, 62, 96, 130, 220,
35, 125, 159, 193, 66, 28, 254, 160, 225, 191, 93, 3, 128, 222, 60, 98,
190, 224, 2, 92, 223, 129, 99, 61, 124, 34, 192, 158, 29, 67, 161, 255,
70, 24, 250, 164, 39, 121, 155, 197, 132, 218, 56, 102, 229, 187, 89, 7,
219, 133, 103, 57, 186, 228, 6, 88, 25, 71, 165, 251, 120, 38, 196, 154,
101, 59, 217, 135, 4, 90, 184, 230, 167, 249, 27, 69, 198, 152, 122, 36,
248, 166, 68, 26, 153, 199, 37, 123, 58, 100, 134, 216, 91, 5, 231, 185,
140, 210, 48, 110, 237, 179, 81, 15, 78, 16, 242, 172, 47, 113, 147, 205,
17, 79, 173, 243, 112, 46, 204, 146, 211, 141, 111, 49, 178, 236, 14, 80,
175, 241, 19, 77, 206, 144, 114, 44, 109, 51, 209, 143, 12, 82, 176, 238,
50, 108, 142, 208, 83, 13, 239, 177, 240, 174, 76, 18, 145, 207, 45, 115,
202, 148, 118, 40, 171, 245, 23, 73, 8, 86, 180, 234, 105, 55, 213, 139,
87, 9, 235, 181, 54, 104, 138, 212, 149, 203, 41, 119, 244, 170, 72, 22,
233, 183, 85, 11, 136, 214, 52, 106, 43, 117, 151, 201, 74, 20, 246, 168,
116, 42, 200, 150, 21, 75, 169, 247, 182, 232, 10, 84, 215, 137, 107, 53};
//uchar code tab[16]={0xc0,0xf9,0xa4,0xb0,0x99,0x92,0x82,0xf8,0x80,0x90,0x88,0x83,0xc6,0xa1,0x86,0x8e};//共阳极0-F代码
uchar code tab[18]={0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f,0x77,0x7c,0x39,0x5e,0x79,0x71,0,0x40};//共阴极0-F代码
void delay1ms(int t)
{
int i,j,k=0;
for(k=0;kt;k++)
{for(j=0;j=25;j++)
{for(i=0;i255;i++){;}}}
}
/************************************************************
*Funcontrolion:延时处理
*parameter:
*Return:
*Modify:
*************************************************************/
void TempDelay (uchar us)
{
while(us--);
}
/************************************************************
*Funcontrolion:18B20初始化
*parameter:
*Return:
*Modify:
*************************************************************/
void Init18b20 (void)
{
DQ=1;
_nop_();
DQ=0;
TempDelay(86); //delay 530 uS//80
_nop_();
DQ=1;
TempDelay(14); //delay 100 uS//14
_nop_();
_nop_();
_nop_();
if(DQ==0)
{
flag = 1; //detecontrol 1820 success!
TempDelay(20); //delay 530 uS//80
}
else
{
flag = 0; //detecontrol 1820 fail!
}
TempDelay(20); //20
_nop_();
_nop_();
DQ = 1;
}
/************************************************************
*Funcontrolion:向18B20写入一个字节
*parameter:
*Return:
*Modify:
*************************************************************/
void WriteByte (uchar wr) //单字节写入
{
uchar i;
for (i=0;i8;i++)
{
DQ = 0;
_nop_();
DQ=wr0x01;
TempDelay(5); //delay 45 uS //5
_nop_();
_nop_();
DQ=1;
wr = 1;
}
}
/************************************************************
*Funcontrolion:读18B20的一个字节
*parameter:
*Return:
*Modify:
*************************************************************/
uchar ReadByte (void) //读取单字节
{
uchar i,u=0;
for(i=0;i8;i++)
{
DQ = 0;
u = 1;
DQ = 1;
if(DQ==1)
u |= 0x80;
TempDelay (4);
_nop_();
}
return(u);
}
/************************************************************
*Funcontrolion:读18B20
*parameter:
*Return:
*Modify:
*************************************************************/
void read_bytes (uchar j)
{
uchar i;
for(i=0;ij;i++)
{
*p = ReadByte();
p++;
}
}
/************************************************************
*Funcontrolion:CRC校验
*parameter:
*Return:
*Modify:
*************************************************************/
uchar CRC (uchar j)
{
uchar i,crc_data=0;
for(i=0;ij;i++) //查表校验
crc_data = Crcontrolable[crc_data^temp_buff[i]];
return (crc_data);
}
/************************************************************
*Funcontrolion:读取温度
*parameter:
*Return:
*Modify:
*************************************************************/
void GemTemp (void)
{
read_bytes (9);
if (CRC(9)==0) //校验正确
{
Temperature = temp_buff[1]*0x100 + temp_buff[0];
Temperature /= 16;//17.7;//16;
TempDelay(1);
}
}
/************************************************************
*Funcontrolion:内部配置
*parameter:
*Return:
*Modify:
*************************************************************/
void Config18b20 (void) //重新配置报警限定值和分辨率
{
Init18b20();
WriteByte(0x7f); //set 11 bit (0.125)
Init18b20();
WriteByte(0xcc); //skip rom
WriteByte(0x48); //保存设定值
Init18b20();
WriteByte(0xcc); //skip rom
WriteByte(0xb8); //回调设定值
}
/************************************************************
*Funcontrolion:读18B20ID
*parameter:
*Return:
*Modify:
*************************************************************/
void ReadID (void)//读取器件 id
{
Init18b20();
if(flag ==1)
{
WriteByte(0xcc);
WriteByte(0x44);
}
}
/************************************************************
*Funcontrolion:18B20ID全处理
*parameter:
*Return:
*Modify:
*************************************************************/
void TemperatuerResult(void)
{
p = id_buff;
ReadID();
Config18b20();
Init18b20 ();
WriteByte(0xcc); //skip rom
WriteByte(0x44); //Temperature convert
Init18b20 ();
WriteByte(0xcc); //skip rom
WriteByte(0xbe); //read Temperature
p = temp_buff;
GemTemp();
}
void disp(uchar i)
{
int xssjhc; //显示数据缓冲
uchar a;
xssjhc=tab[i];
for(a=0;a8;a++)
{
xssz=0;
xssj=xssjhc0x80;
xssjhc=1;
xssz=1;
}
}
void panduan()
{
if(Temperature20)
{
control=1;
}
if(Temperature19)
{
control=0;
}
}
void main()
{
while(1)
{
TemperatuerResult();
Temperature_h=Temperature/10;
Temperature_l=Temperature%10;
panduan();
disp(Temperature_h);
delay1ms(50);
disp(Temperature_l);
delay1ms(50);
}
}
大家介绍点英文歌，谢了。
500首好歌任你选吧
10 Pearl Jam Alive
9 AC/DC Back In Black
8 Alice In Chains Man In The Box
7 AC/DC Hell’s Bells
6 Nirvana Come As You Are
5 Metallica The Unforgiven
4 Guns N’ Roses Paradise City
3 Metallica Enter Sandman
2 Nirvana Smells Like Teen Spirit
1 Guns N’ Roses Welcome To The Jungle
1-99
99 Ozzy O *** ourne Flying High Again
98 Soundgarden Fell On Black Days
97 Van Halen (Oh) Pretty Woman
96 Ozzy O *** ourne Bark At The Moon
95 Stone Temple Pilots Interstate Love Song
94 Aero *** ith Walk This Way
93 AC/DC T.N.T.
92 Alice In Chains Rooster
91 Pink Floyd Have A Cigar
90 Def Leppard Too Late For Love
89 Soundgarden My Wave
88 Def Leppard Rocket
87 Jimi Hendrix Are You Experienced
86 Metallica Until It Sleeps
85 3 Doors Down Kryptonite
84 Soundgarden Spoonman
83 Scorpions No One Like You
82 Metallica Wherever I May Roam
81 Nirvana Heart-Shaped Box
80 Green Day Longview
79 Lynyrd S Free Bird
78 U2 Pride (In The Name Of Love)
77 AC/DC Dirty Deeds Done Dirt Cheap
76 Led Zeppelin Immigrant Song
75 Nirvana About A Girl (Unplugged)
74 Def Leppard Bringin’ On The Heartbreak
73 Alice In Chains Would?
72 Pearl Jam Better Man
71 Aero *** ith Dude
70 Alice In Chains I Stay Away
69 Nirvana Dumb
68 Ozzy O *** ourne Shot In The Dark
67 Metallica The Unforgiven II
66 AC/DC Big Balls
65 Quiet Riot Cum On Feel The Noize
64 Nirvana All Apologies
63 Jimi Hendrix Fire
62 Pearl Jam Black
61 Jimi Hendrix Hey Joe
60 AC/DC It’s A Long Way To The Top ...
59 Black Sabbath War Pigs
58 Pink Floyd Money
57 Aero *** ith Sweet Emotion
56 Pink Floyd Run Like Hell
55 Offspring Come Out Play
54 Led Zeppelin Kashmir
53 Ozzy O *** ourne Crazy Train
52 Jimi Hendrix Foxey Lady
51 Kiss Rock Roll All Night
50 Motley Crue Girls, Girls, Girls"
49 Beastie Boys (You Gotta) Fight For Your ...
48 Pink Floyd Brain Damage/Eclipse
47 Pearl Jam Elderly Woman Behind The...
46 Red Hot Chili Peppers Soul To Squeeze
45 Stone Temple Pilots Plush
44 Led Zeppelin Black Dog
43 Jimi Hendrix Purple Haze
42 Red Hot Chili Peppers Give It Away
41 Def Leppard Armageddon It
40 Nirvana Lithium
39 Def Leppard Hysteria
38 Nirvana In Bloom
37 Van Halen Panama
36 Guns N’ Roses Mr. Brownstone
35 Pearl Jam Jeremy
34 Van Halen Hot For Teacher
33 Whitesnake Here I Go Again
32 Def Leppard Pour Some Sugar On Me
31 Pink Floyd Happiest Days/Another
30 Guns N’ Roses Sweet Child O’ Mine
29 Metallica Fade To Black
28 Guns N’ Roses November Rain
27 Led Zeppelin Rock Roll
26 Black Sabbath Iron Man
25 Pearl Jam Evenflow
24 Black Sabbath Paranoid
23 AC/DC Highway To Hell
22 Van Halen You Really Got Me
21 Van Halen Eruption
20 Led Zeppelin Whole Lotta Love
19 Metallica Master Of Puppets
18 Aero *** ith Janie’s Got A Gun
17 Metallica Nothing Else Matters
16 AC/DC You Shook Me All Night Long
15 Def Leppard Foolin’
14 AC/DC For Those About To Rock...
13 Soundgarden Black Hole Sun
12 Led Zeppelin Stairway To Heaven
11 Aero *** ith Dream On
10 Pearl Jam Alive
9 AC/DC Back In Black
8 Alice In Chains Man In The Box
7 AC/DC Hell’s Bells
6 Nirvana Come As You Are
5 Metallica The Unforgiven
4 Guns N’ Roses Paradise City
3 Metallica Enter Sandman
2 Nirvana Smells Like Teen Spirit
1 Guns N’ Roses Welcome To The Jungle
100-199
199 Pearl Jam Crazy Mary
198 Ozzy O *** ourne I Don’t Know
197 Nirvana Lake Of Fire
196 AC/DC Are Your Ready
195 Led Zeppelin Misty Mountain Hop
194 Red Hot Chili Peppers Californication
193 Metallica Harvester Of Sorrow
192 Temple Of The Dog Say Hello 2 Heaven
191 U2 Where The Streets Have No Name
190 Red Hot Chili Peppers Higher Ground
189 Soundgarden Pretty Noose
188 Kiss I Was Made For Loving You
187 Judas Priest You’ve Got Another Thing Comin’
186 Green Day Brain Stew/Jaded
185 Cult Fire Woman
184 AC/DC Who Made Who
183 Motley Crue Dr. Feelgood
182 Jimi Hendrix Manic Depression
181 Stone Temple Pilots Wicked Garden
180 Jimi Hendrix Crosstown Traffic
179 Guns N’ Roses Nightrain
178 Pink Floyd Time
177 Aero *** ith Angel
176 Nirvana The Man Who Sold The World
175 Jimi Hendrix Little Wing
174 Green Day Basket Case
173 Whitesnake Still Of The Night
172 Creed My Own Prison
171 Days Of The New Touch, Peel Stand
170 U2 Sunday Bloody Sunday
169 Black Sabbath Sweet Leaf
168 Tool Schi ***
167 Def Leppard Rock Of Ages
166 AC/DC Sin City
165 Van Halen Runnin’ With The Devil
164 Scorpions Wind Of Change
163 Led Zeppelin D’Yer Mak’er
162 Disturbed Stupify
161 Metallica For Whom The Bells Toll
160 AC/DC Moneytalks
159 Def Leppard Photograph
158 Linkin Park In The End
157 Metallica Sad But True
156 Stone Temple Pilots Dead Bloated
155 Aero *** ith Livin’ On The Edge
154 Offspring Self Esteem
153 Guns N’ Roses Live and Let Die
152 U2 New Year’s Day
151 Rob Zombie Dragula
150 Black Crowes Hard To Handle
149 Soundgarden The Day I Tried To Live
148 Judas Priest Breaking The Law
147 Van Halen Everybody Wants Some
146 AC/DC Have A Drink On Me
145 Pearl Jam Corduroy
144 Ratt Round And Round
143 Led Zeppelin Ocean
142 Ozzy O *** ourne Mama, I’m Coming Home
141 White Zombie More Human That Human
140 Metallica One
139 AC/DC Thunderstruck
138 Aero *** ith Rag Doll
137 Staind Outside
136 Rush Tom Sawyer
135 Stone Temple Pilots Big Empty
134 Guns N’ Roses You Could Be Mine
133 Red Hot Chilly Peppers Scar Tissue
132 Van Halen Unchained
131 Who Won’t Get Fooled
130 Ozzy O *** ourne Over The Mountain
129 Pink Floyd Hey You
128 Red Hot Chili Peppers Under The Bridge
127 Van Halen Jamie’s Cryin’
126 Led Zepplin Living Loving Maid (she’s?)
125 Led Zeppelin Heartbreaker
124 Jimi Hendrix Wind Cries Mary
123 Def Leppard Love Bites
122 Temple Of The Dog Hunger Strike
121 Alice In Chains No Excuses
120 Van Halen And The Cradle Will Rock
119 Van Halen Ain’t Talking ’Bout Love
118 Ozzy O *** ourne No More Tears
117 Led Zeppelin Dazed Confused
116 Pink Floyd Young Lust
115 Soundgarden Outshined
114 Def Leppard Animal
113 Pearl Jam Daughter
112 Stone Temple Pilots Sex Type Thing
111 Candlebox Far Behind
110 AC/DC Girls Got Rhythm
109 Alice In Chains Them Bones
108 God *** ack I Stand Alone
107 Stone Temple Pilots Vasoline
106 Jimi Hendrix All Along The Watchtower
105 Stone Temple Pilots Creep
104 Scorpions Rock You Like A Hurricane
103 Guns N’ Roses Patience
102 Billy Idol White Wedding
101 Led Zeppelin Moby Dick
100 Guns N’ Roses Civil War
200-299
299 Scorpions Rhythm of Love
298 Judas Priest Living After Midnight
297 Rush Working Man
296 Pearl Jam Glorified G
295 Ozzy O *** ourne Mr. Tinkertrain
294 Van Halen Beautiful Girls
293 Black Sabbath Electric Funeral
292 Alice In Chains Angry Chair
291 Aero *** ith What It Takes
290 La Guns Ballad Of Jane
289 Filter Hey Man, Nice Shot
288 AC/DC Big Gun
287 Aero *** ith Toys In The Attic
286 Offspring Gone Away
285 Motley Crue Wild Side
284 Stone Temple Pilots Unglued
283 Green Day When I Come Around
282 Aero *** ith Love In An Elevator
281 Rush Closer To The Heart
280 Rush Freewill
279 Puddle Of Mudd Blurry
278 Aero *** ith Eat The Rich
277 Motley Crue Looks That Kill
276 Kiss Detroit Rock City
275 Aero *** ith Big 10 Inch Record
274 Jimi Hendrix Stone Free
273 Lenny Kravitz American Woman
272 Kiss Shout It Out Loud
271 Metallica Fuel
270 Metallica I Disappear
269 Skid Row I Remember You
268 Aero *** ith Come Together
267 Pink Floyd Mother
266 Offspring The Kids Aren’t Alright
265 Aero *** ith Cryin’
264 Linkin Park One Step Closer
263 AC/DC Rock Roll Ain’t No
262 Ted Nugent Cat Scratch Fever
261 Alice In Chains Sea Of Sorrow
260 Van Halen Why Can’t This Be L
259 Ozzy O *** ourne Perry Mason
258 Rush Spirit Of Radio
257 Pink Floyd Wish You Were Here
256 AC/DC Jailbreak
255 U2 Desire
254 Aero *** ith Crazy
253 Aero *** ith Amazing
252 Pink Floyd Comfortably Numb
251 Megadeth Trust
250 Rush 2112/Temples Of Syrinx
249 Motley Crue Kickstart My Heart
248 Metallica The Memory Remains
247 Led Zeppelin Fool In The Rain
246 Guns N’ Roses Don’t Cry
245 God *** ack Awake
244 Ozzy O *** ourne Time After Time
243 Pink Floyd Welcome To The Machine
242 AC/DC Whole Lotta Rosie
241 Billy Idol Rebel Yell
240 Cult Love Removal Machine
239 Bush Comedown
238 AC/DC Touch Too Much
237 Smashing Pumpkins Today
236 Pink Floyd Learning To Fly
235 AC/DC Shot Down In The Flame
234 God *** ack Whatever
233 Led Zeppelin Ramble On
232 Aero *** ith The Other Side
231 Dio Rainbow In The Dark
230 Offspring Gotta Get Away
229 AC/DC Shoot To Thrill
228 Pearl Jam I Got Id
227 Queen We Will Rock You/We Are The Campions
226 Def Leppard Woman
225 Europe The Final Countdown
224 Pearl Jam Yellow Ledbetter
223 Alice In Chains Down In A Hole
222 AC/DC Problem Child
221 Creed One
220 Pearl Jam Dissident
219 Living Color Cult Of Personality
218 Metallica Holier Than Thou
217 Motley Crue Home Sweet Home
216 Faith No More Epic
215 Collective Soul Shine
214 Metallica King Nothing
213 Sammy Hagar I Can’t Drive 55
212 AC/DC Live Wire
211 Jimi Hendrix Voodoo Chile (Slite Retu
210 Bush Machinehead
209 Led Zeppelin Communication Brea
208 Jane’s Addiction Been Caught Stealing
207 AC/DC High Voltage
206 Iron Maiden Run To The Hills
205 Foo Fighters Everlong
204 Pearl Jam Go
203 Led Zeppelin Going To California
202 Pearl Jam Animal
201 Ozzy O *** ourne Road To Nowhere
200 Van Halen When It’s Love
300-399
399 Guns N’ Roses Rocket Queen
398 Stone Temple Pilots Crackerman
397 Green Day Welcome To Paradise
396 U2 Gloria
395 Great Wh Once Bitten Twice
394 God *** ack Voodoo
393 Fuel Hemorrhage (In My Hands)
392 Lita Ford Close My Eyes Forever
391 Rage Against/Machine Bulls On Parade
390 Poison Talk Dirty To Me
389 Scorpions Big City Nights
388 Alice In Chains Don’t Follow
387 Faster Pussycat House of Pain
386 Everlast What It’s Like
385 Black Sabbath Psycho Man
384 Eric Johnson Cliffs Of Dover
383 U2 With Or With Out You
382 Alice In Chains Queen Of The Rodeo
381 Dokken Breaking The Chains
380 Live I Alone
379 AC/DC Stiff Upper Lip
378 Smashing Pumpkins Bullet With Butterfly Wings
377 Creed What’s This Life For
376 Dio Holy Diver
375 Tool Aenema
374 Def Leppard Rock! Rock! (Till You Drop)
373 Metallica Ain’t My Bitch
372 Twisted Sister We’re Not Gonna Take It
371 Beastie Boys Sabotage
370 David Lee Roth Just Like Paradise
369 Cinderella Gypsy Road
368 Danzig Mother
367 7 Mary 3 Cumbersome
366 Cult She Sells Sanctuary
365 Rob Zombie Living Dead Girl
364 Van Halen Drop Dead Legs
363 Cult Wild Flower
362 Pink Floyd Us Them
361 Pearl Jam Immortality
360 Derek The Dominoes Layla
359 Van Halen Mean Street
358 Queensryche Jet City Woman
357 Creed Torn
356 Nirvana Polly
355 Metallica Don’t Tread On Me
354 Led Zeppelin Hey Hey What Can I Say
353 Guns N’ Roses Knockin’ On Heaven’s Door
352 Collective Soul December
351 AC/DC What Do You Do For Money, Honey
350 Foo Fighters I’ll Stick Around
349 Bush Little Things
348 Scorpions Tease Me Please Me
347 Clash Should I Stay Or Should I go
346 Queensryche Silent Lucidity
345 Van Halen Dance The Night Away
344 Black Crowes She Talks To Angels
343 Cinderella Nobody’s Fool
342 Candlebox You
341 Motley Crue Shout At The Devil
340 U2 Bullet The Blue Sky
339 Scorpions Blackout
338 Warrant Uncle Tom’s Cabin
337 Aero *** ith Train Keep A-Rollin’
336 Cracker Low
335 Buck Cherry Lit Up
334 Linkin Park Crawling
333 Van Halen Dancing In The Street
332 Kid Rock Bawitdaba
331 Aero *** ith Mama Kin
330 Tool Sober
329 Soundgarden Rusty Cage
328 Rage Against/Machine Killing In The Name
327 Dokken It’s Not Love
326 Alice In Chains Again
325 Metallica Stone Cold Crazy
324 Guns N’ Roses Used To Love Her
323 Lenny Kravitz Fly Away
322 Bon Jovi Livin’ On A Prayer
321 Foo Fighters My Hero
320 Aero *** ith Last Child
319 Black Sabbath Fairies Wear Boots
318 White Zombie Thunder Kiss ’65
317 Rush Fly By Night
316 U2 I Still Haven’t Found
315 Led Zeppelin Dancing Days
314 Black Crowes Jealous Again
313 Ozzy O *** ourne Mr. Crowley
312 Def Leppard Let It Go
311 Autograph Turn Up The Radio
310 Rush Limelight
309 Bon Jovi You Give Love A Ba
308 Alice In Chains Over Now
307 Nirvana Rape Me
306 Led Zeppelin Your Time Is Gonna Come
305 Skid Row 18 to Life
304 Alice In Chains Heaven Beside You
303 Aero *** ith Back In The Saddle Again
302 Papa Roach Last Resort
301 Alice In Chains Got Me Wrong
300 AC/DC Flick Of Thetch
400-499
499 Guns N’ Roses Pretty Tied up
498 Kiss Heaven’s On Fire
497 Korn Make Me Bad
496 Nirvana On A Plain
495 Fastway Say What You Will
494 Metallica Breadfan
493 Guns N’ Roses My Michelle
492 Led Zeppelin Tangerine
491 Nine Inch Nails Head Like A Hole
490 Rush Subdivisions
489 Led Zeppelin In The Evening
488 Helmet Unsung
487 Nazareth Hair Of The Dog
486 Motorhead Ace Of Spades
485 Rush The Trees
484 Motley Crue Too Young Too Fall In Love
483 Metallica Last Caress/Green Hell
482 Pearl Jam Once
481 Metallica Creeping Death
480 Motley Crue Starry Eyes
479 Motley Crue Smokin’ In The Boys Room
478 Mother Love Bone Hold Your Head Up
477 Sammy Hagar There’s Only One Way
476 Scorpions Zoo
475 Korn Got The Life
474 Mother Love Bone Chloe Dancer/Crown Of Thorns
473 Metallica ...And Justice For All
472 Cult Sweet Soul Sister
471 Montrose Bad Motorscooter
470 Black Crowes Twice As Hard
469 Van Halen Poundcake
468 Metallica Whiplash
467 Def Leppard Let’s Get Rocked
466 Foo Fighters Learn To Fly
465 Metallica Welcome Home (Sanitarium)
464 Metallica No Leaf Clover (Live *** )
463 Rage Against/Machine Guerrilla Radio
462 Bush Everything Zen
461 Dio Last In Line
460 Led Zeppelin Gallows Poll
459 Foo Fighters This Is A Call
458 Rush New World Man
457 Soundgarden Blow Up The Outside World
456 Creed What If
455 Cult Sun King
454 Metallica "Die, Die My Darling"
453 Creed Higher
452 Megadeth Symphony Of Destruction
451 Pearl Jam Rearview Mirror
450 Pearl Jam Nothingman
449 Toadies Possum Kingdom
448 Megadeth Almost Honest
447 Alice In Chains Grind
446 Poison Every Rose Has..
445 Ted Nugent Stranglehold
444 Meat Puppets Backwater
443 Scorpions Still Loving You
442 Aero *** ith Chip Away The Stone
441 Live Lightning Crashes
440 Tesla Signs
439 Limp Bizkit Nookie
438 Metallica So What
437 Screaming Trees Nearly Lost You
436 Pink Floyd Breathe
435 God *** ack Bad Religion
434 Bon Jovi Wanted Dead Or Alive
433 Red Hot Chili Peppers Around The World
432 Led Zeppelin When The Levee Breaks
431 Pearl Jam Not For You
430 Judas Priest Some Heads Are Gonna Roll
429 Soundgarden Burden In My Hand
428 7 Mary 3 Water’s Edge
427 Warrant Cherry Pie
426 Tool Prison Sex
425 AC/DC Hard As A Rock
424 Led Zeppelin All of My Love
423 Lenny Kravitz Are You Gonna Go My Way
422 Jimi Hendrix Castles Made of Sand
421 Van Halen Ice Cream Man
420 Kiss Lick It Up
419 Foo Fighters Monkey Wrench
418 Monster Magnet Space Lord
417 Days Of The New Shelf In The Room
416 Metallica Bleeding Me
415 Alice In Chains Dirt
414 Aero *** ith Same Old Song D
413 Kingdom Come Get it On
412 Judas Priest Heading Out To The High
411 Disturbed Down With The Sickness
410 Van Halen Finish What Ya Started
409 Lynyrd S Sweet Home Alabama
408 Jackyl Lumberjack Song
407 Iron Maiden Number Of The Beats
406 Red Hot Chili Peppers Otherside
405 Led Zeppelin You Shook Me
404 Joe Satriani Satch Boogie
403 Jimi Hendrix Red House
402 Tool 462
401 AC/DC The Jack
400 Sammy Hagar I’ll Fall In Love Again
500-599
599 Thin Lizzy Jailbreak
598 Mad Season River Of Deceit
597 Ratt Lay it Down
596 Great Wh Save Your Love
595 Rainbow Man On The Silver Mountain
594 Judas Priest Diamonds and Rust
593 Slaughter Up All Night
592 Blue Oyster Cult Burning For You
591 Korn Freak On A Leash
590 Van Halen Dreams
589 Led Zeppelin Houses Of The Holy
588 Jimi Hendrix If Six Was Nine
587 Kiss God Gave Rock and Roll To You
586 Great Wh Rock Me
585 Kiss Cold Gin
584 Metallica Turn The Page
583 Quiet Riot Bang Your Head
582 Queensryche Empire
581 Black Sabbath The Wizard
580 Queensryche Another Rany Night
579 White Zombie Supercharger Heaven
578 AC/DC Night Prowler
577 White Zombie Electric Heat Pt 2 (the ecstasy)
576 Alice In Chains Get Born Again
575 Van Halen So This Is Love
574 Puddle Of Mudd Control
573 Metallica Trapped Under Ice
572 God *** ack Keep Away
571 Metallica Through The Never
570 Poison Nothing But A Good Time
569 Black Crowes Remedy
568 Pink Floyd On The Turning Away
567 Van Halen Right Now
566 Metallica Hero Of The Day
565 Smashing Pumpkins Disarm
564 Guns N’ Roses It’s So Easy
563 Led Zeppelin Thank-you
562 Guns N’ Roses Don’t Damn Me
561 Billy Idol Mony Mony
560 Guns N’ Roses Anything Goes
559 Pearl Jam Who You Are
558 Metallica Wasting My Hate
557 Pearl Jam Tremor Christ
556 La Guns Never Enough
555 Mad Season I Don’t Know Anything
554 Led Zeppelin I Can’t Quit Baby
553 Nine Inch Nails Closer
552 Krokus Screaming Iin The Night
551 Aero *** ith Shut Up And Dance
550 Pearl Jam State Of Love and Trust
549 Led Zeppelin Four Sticks
548 Cult Edie (Ciao Baby)
547 Black Sabbath Heaven and Hell
546 Rush Roll The Bones
545 God *** ack Greed
544 Metallica Blackened
543 Led Zeppelin Ten Years Gone
542 Nirvana Sliver
541 Bullet Boys Smooth Up In Ya
540 Pearl Jam Insignifigance
539 AC/DC Mistress For Christmas
538 Pearl Jam In Hiding
537 Candlebox Change
536 Megadeth Train Of Consequences
535 Judas Priest Turbo Lover
534 Pearl Jam Breath
533 Doors Roadhouse Blues
532 Led Zeppelin Traveling Riverside Blues
531 Metallica The Call of Kutulu
530 Def Leppard Billy’s Got A Gun
529 Pantera Walk
528 U2 Mysterious Ways
527 Nirvana You Know You’re Right
526 Jimi Hendrix Bold As Love
525 Pantera Cemetary Gates
524 Jane’s Addiction Jane Says
523 Creed My Sacrifice
522 Rush Red Barchetta
521 Alice In Chains Whale and Wasp
520 Metallica The Four Horsemen
519 Joe Satriani Summer Song
518 Alice In Chainsng On This
517 Ozzy O *** ourne You Can’t Kill Rock Roll
516 Warrant Down Boys
515 Creed Are You Ready?
514 Led Zeppelin Custard Pie
513 Ozzy O *** ourne Miracle Man
512 Jane’s Addiction Stop
511 Ozzy O *** ourne Gets Me Through
510 Dokken In My Dreams
509 Ted Nugent Wango Tango
508 Creed With Arms Wide Open
507 Alice In Chains Rotten Apple
506 Ozzy O *** ourne See You On The Other Side
505 Pantera Planet Caravan
504 Ted Nugent Hey Baby
503 Ted Nugent Great White Buffalo
502 Metallica Whiskey In A Jar
501 Cinderella Shake Me
500 Ted Nugent Free For All
为什么CMS GC时出现Concurrent Mode Failure
出现此现象的原因主要有两个：一个是在年老代被用完之前不能完成对无引用对象的回收；一个是当新空间分配请求在年老代的剩余空间中得到满足。原文如（if theconcurrent collector is unable to finish reclaiming the unreachable object *** efore the tenured generation fills up, or if an allocation cannot be satisfiedwith the available free space blocks in the tenured generation, then theapplication is paused and the collection is completed with all the applicationthreads stopped）。
出现此现象的具体gc日志如下：
90003.167: [GC 90003.167: [ParNew: 261760K-0K(261952K), 0.0204310secs] 778897K-520196K(1310528K), 0.0207190 secs]
90006.049: [GC 90006.050: [ParNew: 261760K-0K(261952K), 0.0136380 secs]781956K-521446K(1310528K), 0.0138720 secs]
90010.628: [GC 90010.628: [ParNew: 261760K-261760K(261952K), 0.0000350secs]90010.628: [CMS (concurrent mode failure)[Unloadingclass sun.reflect.GeneratedSerializationConstructorAccessor1818]
[Unloading class sun.reflect.GeneratedSerializationConstructorAccessor1816]
[Unloading class sun.reflect.GeneratedSerializationConstructorAccessor1819]
[Unloading class sun.reflect.GeneratedSerializationConstructorAccessor1821]
[Unloading class sun.reflect.GeneratedSerializationConstructorAccessor1817]
[Unloading class sun.reflect.GeneratedSerializationConstructorAccessor1822]
[Unloading class sun.reflect.GeneratedSerializationConstructorAccessor1820]
: 521446K-415777K(1048576K), 2.2550270 secs] 783206K-415777K(1310528K),2.2553820 secs]
90015.099: [GC 90015.099: [ParNew: 261760K-0K(261952K), 0.0198180 secs]677537K-418003K(1310528K), 0.0200650 secs]
90018.670: [GC 90018.670: [ParNew: 261760K-0K(261952K), 0.0131610 secs]679763K-419115K(1310528K), 0.0133750 secs]
90022.254: [GC 90022.254: [ParNew: 261760K-0K(261952K), 0.0151240 secs]680875K-420505K(1310528K), 0.0154180 secs]
当时的JVM参数如下：
-server -Xms1280m -Xmx1280m -Xmn256m -Xss256k -XX:PermSize=128m-XX:MaxPermSize=128m -XX:+UseConcMarkSweepGC -XX:+UseParNewGC-XX:CMSFullGCsBeforeCompaction=5 -XX:+UseCMSCompactAtFullCollection -XX:+UseCMSInitiatingOccupancyOnly -XX:+CMSClassUnloadingEnabled-XX:+DisableExplicitGC -verbose:gc -XX:+PrintGCDetails -XX:+PrintGCTimeStamps
因为配置了+CMSClassUnloadingEnabled参数，所以出现Unloading classsun.reflect.GeneratedSerializationConstructorAccessor的日志，这是个好习惯，如果空间不够时可以卸载类来释放空间，以进行FULL GC，相反，如果gc日志中出现了此日志，应该检查各代的大小设置是否合理。这里应用从启动到上述现象出现时还没有进行过CMS GC，出现concurrent modefailure现象的原因是年轻代GC（ParNew），年老代所剩下的空间不足以满足年轻代，也就是开头提到的原因二。要避免此现象， *** 一是降低触发CMS的阀值，即参数-XX:CMSInitiatingOccupancyFraction的值，默认值是68，所以这里调低到50，让CMS GC尽早执行，以保证有足够的空间，如下：
-server -Xms1280m -Xmx1280m -Xmn256m -Xss256k -XX:PermSize=128m-XX:MaxPermSize=128m -XX:+UseConcMarkSweepGC -XX:+UseParNewGC-XX:CMSFullGCsBeforeCompaction=1 -XX:+UseCMSCompactAtFullCollection -XX:+UseCMSInitiatingOccupancyOnly -XX:CMSInitiatingOccupancyFraction=50-XX:+CMSClassUnloadingEnabled -XX:+DisableExplicitGC -verbose:gc-XX:+PrintGCDetails -XX:+PrintGCTimeStamps
调完之后发现还是一样的现象（这里有点不是很明白，年老代空间为1024m（1280m-256m），50%时触发CMS GC，也就是在年老代512m的时候，剩下的堆空间有512m，就算年轻代全部装进去应该也是够的）,所以怀疑是年轻代太大，有大的对象，在年老代有碎片的情况下将很难分配，所以有了第二个解决办法，即减少年轻代大小，避免放入年老代时需要分配大的空间，同时调整full gc时压缩碎片的频次，减少持久代大小，以及将触发CMS GC的阀值适当增大（因为年轻代小了，这个调大点没关系，后面可以再调试这个参数），参数如下：
-server -Xms1280m -Xmx1280m -Xmn128m -Xss256k -XX:PermSize=96m -XX:MaxPermSize=96m -XX:+UseConcMarkSweepGC -XX:+UseParNewGC -XX:CMSFullGCsBeforeCompaction=1 -XX:+UseCMSCompactAtFullCollection -XX:+CMSParallelRemarkEnabled -XX:+UseCMSInitiatingOccupancyOnly -XX:CMSInitiatingOccupancyFraction=70 -XX:+CMSClassUnloadingEnabled -XX:+DisableExplicitGC -verbose:gc -XX:+PrintGCDetails -XX:+PrintGCTimeStamps
调整完后没有那个现象了，这里主要起作用的就是调小年轻代大小。在年老代到达826m(触发CMS阀值(1280-128)*0.7=806m)时出现了CMS GC，用时27ms，日志如下：
705.444: [GC 705.445: [ParNew: 130944K-0K(131008K), 0.0197680 secs]954628K-826284K(1310656K), 0.0199720 secs]
705.467:[GC [1 CMS-initial-mark: 826284K(1179648K)] 826744K(1310656K), 0.0271540 secs]
705.494:[CMS-concurrent-mark-start]
706.717:[CMS-concurrent-mark: 1.223/1.223 secs]
706.717:[CMS-concurrent-preclean-start]
706.717:[CMS-concurrent-preclean: 0.000/0.000 secs]
706.742:[CMS-concurrent-abortable-preclean-start]
706.742:[CMS-concurrent-abortable-preclean: 0.000/0.000 secs]
707.067: [GC 707.067: [ParNew: 130944K-0K(131008K), 0.0160200 secs]957228K-827348K(1310656K), 0.0162110 secs]
707.796: [GC[YG occupancy: 66671 K (131008 K)]707.796: [Rescan (parallel) ,0.0278280 secs]707.824: [weak refs processing, 0.0420770 secs] [1 CMS-remark:827348K(1179648K)] 894019K(1310656K), 0.0711970 secs]
707.877: [CMS-concurrent-sweep-start]
708.453: [GC 708.454: [ParNew: 130944K-0K(131008K), 0.0203760 secs]848439K-718796K(1310656K), 0.0205780 secs]
709.833: [GC 709.833: [ParNew: 130944K-0K(131008K), 0.0160170 secs]430484K-301411K(1310656K), 0.0161840 secs]
709.916: [CMS-concurrent-sweep: 1.974/2.040 secs]
709.916: [CMS-concurrent-reset-start]
709.951: [CMS-concurrent-reset: 0.034/0.034 secs]
711.187: [GC 711.187: [ParNew: 130944K-0K(131008K), 0.0130890 secs]413136K-283326K(1310656K), 0.0132600 secs]
观察一段时间的gc情况，gc效率也很高，单次YGCT20ms，FGCT 40ms：
$ jstat -gcutil 31935 1000
S0 S1 E O P YGC YGCT FGC FGCT GCT
0.00 0.00 64.29 36.47 73.15 1293 19.514 6 0.211 19.725
0.00 0.00 64.33 36.47 73.15 1293 19.514 6 0.211 19.725
0.00 0.00 64.41 36.47 73.15 1293 19.514 6 0.211 19.725
0.00 0.00 64.45 36.47 73.15 1293 19.514 6 0.211 19.725
0.00 0.00 64.49 36.47 73.15 1293 19.514 6 0.211 19.725
0.00 0.00 64.58 36.47 73.15 1293 19.514 6 0.211 19.725
0.00 0.00 64.63 36.47 73.15 1293 19.514 6 0.211 19.725
0.00 0.00 64.69 36.47 73.15 1293 19.514 6 0.211 19.725
0.00 0.00 64.72 36.47 73.15 1293 19.514 6 0.211 19.725
0.00 0.00 64.75 36.47 73.15 1293 19.514 6 0.211 19.725
0.00 0.00 64.79 36.47 73.15 1293 19.514 6 0.211 19.725
0.00 0.00 64.84 36.47 73.15 1293 19.514 6 0.211 19.725
0.00 0.00 64.90 36.47 73.15 1293 19.514 6 0.211 19.725
0.00 0.00 64.95 36.47 73.15 1293 19.514 6 0.211 19.725
0.00 0.00 64.99 36.47 73.15 1293 19.514 6 0.211 19.725
这时，想再测试下-XX:CMSInitiatingOccupancyFraction的值，调到80时又出现了上述现象Concurrent ModeFailure，启动后还没进行过CMS GC，在年老代914m时就出现了：
759.994: [GC 759.994: [ParNew: 130944K-0K(131008K), 0.0172910 secs]1040896K-911480K(1310656K), 0.0174730 secs]
760.879: [GC 760.879: [ParNew: 130944K-0K(131008K), 0.0300920 secs]1042424K-914190K(1310656K), 0.0302950 secs]
761.768: [GC 761.769: [ParNew: 130944K-130944K(131008K), 0.0000340secs]761.769: [CMS (concurrent mode failure)[Unloading classsun.reflect.GeneratedMethodAccessor342]edMethodAccessor348]
[Unloading class sun.reflect.GeneratedMethodAccessor411]
[Unloading class sun.reflect.GeneratedMethodAccessor407]
[Unloading class sun.reflect.GeneratedMethodAccessor541]
最后总结下，出现Concurrent ModeFailure现象时，解决办法就是要让年老代留有足够的空间，以保证新对象空间的分配。另外在JVM BUG中有提到，JDK1.5_09版本之前，JVM参数-XX:CMSInitiatingOccupancyFraction是无效的，我这里应用环境的版本是JDK1.5_08，从gc日志来看是可以生效的。
GC时还有一个常见的错误PromotionFailed，解决办法类似，也是调整年轻代和年老代的比例，还有CMSGC的时机。
