| #import <Foundation/Foundation.h> | |
| @interface POD : NSObject<NSCopying> | |
| -(nonnull NSString *)description; | |
| -(nonnull NSDictionary *)toDictionary; | |
| +(nonnull id)fromDictionary:(nonnull NSDictionary *)dict; | |
| -(nonnull id)copyWithZone:(nullable NSZone *)zone; | |
| @end |
| This is a demonstration of how INT 13, ah=42 fails after a while. | |
| Run 'bash debug.sh`, then hit `c` a couple of times, you should | |
| see that INT 13 returns with CF set, which means it had an error. | |
| Why is it happening? The code is pretty simple, all it does is reading | |
| a sector from the disk, and copying it to some place in the memory. |
| int print_records_read(void *_this, void *buf, int size) { | |
| int nread = 0; | |
| struct perf_record_mmap *mmap_r; | |
| struct perf_record_lost *lost_r; | |
| struct perf_record_comm *comm_r; | |
| struct perf_record_exit *exit_r; | |
| struct perf_record_throttle *throttle_r; | |
| struct perf_record_fork *fork_r; | |
| struct perf_record_read *read_r; | |
| struct print_records *pr = _this; |
| alias gdbdump='hexdump -e '\''"0x%04_ax: " 8/1 "0x%02x\t" "\n"'\''' | |
| # hexdump format is: '"0x%04_ax: " 8/1 "0x%02x\t" "\n"' |
By @cmpxchg16 1%-100% writes samples for LongAdderBench.java:
for 1% writes=16,000 (16 threads * 100,000 ops each=1,600,000):
LongAdder 1.209ms
AtomicLong 0.281ms
AtomicLong faster than LongAdder by 76.77%
for 2% writes=32,000 (16 threads * 100,000 ops each=1,600,000):
LongAdder 2.019ms
AtomicLong 0.485ms
| /* | |
| Welcome to the game show "lies and benchmarks". | |
| We will present the participants a required result, and they would build a | |
| benchmark that reaches the predetermined conclusions. | |
| When done professionally, this activity is called "benchmarketing". | |
| Our task for today is to prove LongAdder is slower than AtomicLong. Our | |
| observation is, LongAdder prevents write contention to a single a atomic |
| /** | |
| * Usage: | |
| * $ javac KillRegions | |
| * $ # list all regions in cluster, search for first listed region in MYTABLE | |
| * $ java -cp `hbase classpath`:. KillRegions -l|grep MYTABLE|head -n1 >/tmp/regions.txt | |
| * $ # delete first regions in MYTABLE, listed above | |
| * $ java -cp `hbase classpath`:. KillRegions </tmp/regions.txt | |
| */ | |
| import com.google.common.base.Charsets; | |
| import com.google.common.collect.Lists; |
| // A signer/verifier compatible with openssl ecdsa signature scheme | |
| // | |
| // $ openssl ecparam -name prime256v1 -genkey -noout >ec.pem | |
| // $ openssl ec -pubout <ec.pem >ecpub.pem | |
| // | |
| // and with sha256 verification | |
| // | |
| // $ echo a|openssl sha256 -sign ec.pem > sig.bin | |
| // $ echo a|openssl sha256 -verify ecpub.pem -signature sig.bin | |
| // |
| package main | |
| func Panic() { panic("oooh, no stacktrace") } | |
| func make_bt_longer() { | |
| Panic() | |
| } | |
| func main() { | |
| Completer = func (text string, start, end int) (replacement string, options []string) { |
| package bug | |
| type returnPanic struct { | |
| err error | |
| } | |
| func F() (err error) { | |
| defer func() { | |
| if _, ok := recover().(returnPanic); !ok { | |
| panic(err) |