打印log
fprintf (stderr, "YAO This is line %d of file %s (function %s)\n", __LINE__, __FILE__, __FUNCTION__);
unsigned int count = 0;
if (count % 10 == 0) {
fprintf (stderr, "YAO This is line %d of file %s (function %s)\n", __LINE__, __FILE__, __FUNCTION__);
count++;
}
dump_stack()
dump_stack不準確的原因分析
kernel panic後打印的堆棧信息是調用dump_stack函數獲得的。而dump_stack的原理是遍歷堆棧，把所有可能是內核函數的內容找出來，並打印對應的函數。因為函數調用時會把下一條指令的地址放到堆棧中。所以只要找到這些return address，就可以找到這些return address所在函數，進而打印函數的調用關係。
但是dump_stack可能不準確，可能的原因有三：
1.所有這些可以找到的函數地址，存在/proc/kallsyms中。它並不包括內核中所有的函數，而只包括內核中stext~etext和sinittext~einittext範圍的函數，及模塊中的函數。詳細可參考scripts/kallsyms.c
2.一些函數在編譯時進行了優化，把call指令優化為jmp指令，這樣在調用時就不會把return address放到堆棧，導致dump_stack時在堆棧中找不到對應的信息。
3.堆棧中可能有一些數值，它們不是return address，但是在內核函數地址的範圍裡，這些數值會被誤認為return address從而打印出錯誤的調用關係。
import os
import sys
def InsertToFunc(lines, funcLines, FileName):
for i in funcLines:
for j in range(i-1, len(lines)):
if str(lines[j]).find(';') != -1:
break
if str(lines[j]).find('{') != -1:
if str(lines[j]).find('}') != -1:
break
if str(FileName).find('.java') != -1:
lines.insert(j+1, '\tSlog.d(Thread.currentThread().getStackTrace()[2].getClassName(), "YAO ["+ Thread.currentThread().getStackTrace()[2].getMethodName() +" | "+Thread.currentThread().getStackTrace()[2].getFileName()+":"+Thread.currentThread().getStackTrace()[2].getLineNumber()+"]");\n');
elif str(FileName).find('.cpp') != -1 or str(FileName).find('.c') != -1:
lines.insert(j+1, '\tALOGW("YAO This is line %d of file %s (function %s)\\n", __LINE__, __FILE__, __func__);\n')
break
return lines
def main():
FileName = sys.argv[1]
print FileName
if str(FileName).find('.java') != -1:
os.system("ctags-exuberant -x " + FileName + " | ack -o -w 'method\s+.*' | ack -o '\d+\s+.*' | ack -o '^\d+\s+' | sort -k 1 -nr > /tmp/test.txt")
elif str(FileName).find('.cpp') != -1 or str(FileName).find('.c') != -1:
os.system("ctags-exuberant -x " + FileName + " | ack -o -w 'function\s+.*' | ack -o '\d+\s+.*' | ack -o '^\d+\s+' | sort -k 1 -nr > /tmp/test.txt")
else:
print 'noknow type'
sys.exit(0)
f = open('/tmp/test.txt', 'r+')
funcLines = [int(i)for i in f.read().splitlines()]
f.close()
f = open(str(FileName), 'r+')
lines = [i for i in f.read().splitlines()]
f.close()
InsertListfinish = InsertToFunc(lines, funcLines, FileName)
newfile = open(str(FileName), "w+")
newfile.truncate()
for l in InsertListfinish:
newfile.write(l + '\n')
newfile.close()
if __name__=='__main__':
if len(sys.argv) > 1:
main()
else:
pass
print "please input python test.py filename"
#include <stdio.h>
#include <pthread.h>
#include <sys/types.h>
#include <unistd.h>
#include <sys/syscall.h>
#define gettid() syscall(__NR_gettid)
typedef void* (*start_routine_t)(void*);
void* someThread(void* tmp)
{
printf("PID of this process: %d\n", getpid());
printf("The ID of this of this thread is: %ld\n", gettid());
sleep(2);
return NULL;
}
int main(int argc, char** argv)
{
printf("PID of this process: %d\n", getpid());
pthread_t thread1, thread2;
pthread_create(&thread1, NULL, someThread, NULL);
sleep(1);
pthread_create(&thread2, NULL, someThread, NULL);
pthread_join(thread1, NULL);
pthread_join(thread2, NULL);
return (0);
}
gcc -Wall -g -pthread test.c -o test
./test
- linux c++ constructor deconstructor log
#include <stdio.h>
#include <time.h>
#include <sys/types.h>
#include <unistd.h>
#include <string.h>
#include <sys/syscall.h>
class __CallLog__
{
private:
const char* logtag;
const char* file;
int line;
const char* func;
long mEnterTime;
public:
inline __CallLog__(const char* __logtag, const char* __file, int __line,
const char* __func):
logtag(__logtag), file(__file), line(__line), func(__func),
mEnterTime(clock()) {
printf("%s\n", file);
::printf("TAG=%s TID:%d ...%s:%d:\tEnter %s\n",
logtag, static_cast<int>(syscall(__NR_gettid)), strrchr(file, '/'), line, func);
}
inline void timeDiff(int diffLine) {
#if 0
LOG(LOG_DEBUG, logtag,
"TID:%d ...%s:%d:\tTime diff from line %d is %lld millis\n",
static_cast<int32_t>(syscall(__NR_gettid)), strrchr(file, '/'), line, diffLine,
android::uptimeMillis() - mEnterTime);
#endif
}
inline ~__CallLog__() {
::printf("TAG=%s TID:%d ...%s:%d:\tLeave %s (takes %ld millis)\n",
logtag, static_cast<int>(syscall(__NR_gettid)), strrchr(file, '/'), line, func, clock() - mEnterTime);
}
};
#define GLOGENTRY(args...) __CallLog__ __call_log__(LOG_TAG, __FILE__, __LINE__, __FUNCTION__);
#define GLOGTENTRY(logtag, args...) __CallLog__ __call_log__(logtag, __FILE__, __LINE__, __FUNCTION__);
#define LOG_TAG "YAO"
int main(int argc, char* argv[])
{
GLOGENTRY();
return 0;
}
C log in linux
#include <stdlib.h>
#include <stdio.h>
#include <pthread.h>
#include <sys/types.h>
#include <unistd.h>
#include <sys/syscall.h>
#define gettid() syscall(__NR_gettid)
#define TAG "JASON"
#define dlog() do \
{ \
fprintf(stderr, "%s:PID=[%d] TID=[%ld] func=%s %s:%d\n", \
TAG, \
getpid(), \
gettid(), \
__FUNCTION__, \
__FILE__, \
__LINE__); \
} while(0)
void thread2_f(void* args)
{
int i;
for (i = 0; i < 13; i++) {
dlog();
sleep(1);
}
}
void thread1_f(void* args)
{
int i;
for (i = 0; i < 13; i++) {
sleep(1);
}
}
int main(void)
{
int ret;
pthread_t thread1, thread2;
ret = pthread_create(&thread1, NULL, (void* (*)(void*))thread1_f, NULL);
if (ret != 0) {
printf("Create pthread error!\n");
exit(1);
}
ret = pthread_create(&thread2, NULL, (void* (*)(void*))thread2_f, NULL);
if (ret != 0) {
printf("Create pthread error!\n");
exit(1);
}
pthread_join(thread1, NULL);
pthread_join(thread2, NULL);
return (0);
}
- windows 印出 pid tid , 需要裝 pthread lib
#include <process.h>
printf("PID =%d, TID=%d\n", _getpid(), pthread_self());
Windows下如何用C語言打印當前進程的進程號？
#include <windows.h> // for GetCurrentProcessId
std::cout << "!!!! imuPath=" << m_imuPath
<< " pid=" << GetCurrentProcessId()
<< " tid=" << GetCurrentThreadId() << std::endl;
android NDK write logs to a file
https:
FILE f = fopen("/data/data/<application name>/<file name>", 'w');
fprintf(f, "my message\n");
fclose(f);
#define WRITE_LOG(s, ...) do { \
FILE *f = fopen("/data/local/tmp/log.txt", "a+"); \
fprintf(f, s, __VA_ARGS__); \
fflush(f); \
fclose(f); \
} while (0)