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Merge pull request #26 from GeraldEV/private/geralde/rwlock
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CA-407313: Replace semaphore & spinlock with rwlock
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@GeraldEV
GeraldEV authored Mar 5, 2025
2 parents a9fa4cd + 92cf64b commit 05f5ea2
Showing 1 changed file with 81 additions and 125 deletions.
206 changes: 81 additions & 125 deletions daemon/log.c
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Original file line number Diff line number Diff line change
Expand Up @@ -43,8 +43,8 @@
#include <stdarg.h>
#include <string.h>
#include <errno.h>
#include <time.h>
#include <pthread.h>
#include <semaphore.h>
#include <ctype.h>
#include <fcntl.h>
#include <sys/stat.h>
Expand All @@ -58,8 +58,6 @@
#include "log.h"


#define USE_SEMAPHORE 0


#define MTC_LOG_FILE_NAME "/var/log/xha.log"
#define MTC_XHA_MODULE_NAME "xha"
Expand All @@ -73,12 +71,13 @@ static FILE *fpLogfile = NULL;
static MTC_BOOLEAN initialized = FALSE;


#if USE_SEMAPHORE
#define MTC_LOG_SEMAPHORE_NAME "/xha_log_semaphore"
sem_t *semaphore = SEM_FAILED;
#else
static pthread_spinlock_t lock;
#endif
/*
* lock exists to protect fpLogfile
* Readers should hold the lock when access fpLogfile and the FILE it points to
* Writers should hold the lock when assigning fpLogfile or when freeing the
* object it points to
*/
static pthread_rwlock_t lock;


PMTC_S8 monthnames[] = {
Expand Down Expand Up @@ -115,17 +114,10 @@ MTC_S32 log_initialize()
syslog(LOG_WARNING, "can't open local log file. (sys %d)", errno);
}

#if USE_SEMAPHORE
semaphore = sem_open(MTC_LOG_SEMAPHORE_NAME, O_CREAT, S_IRUSR | S_IWUSR, 1);
if (semaphore == SEM_FAILED)
{
syslog(LOG_ERR, "can't open semaphore %s. (sys %d)", MTC_LOG_SEMAPHORE_NAME, errno);
#else
ret = pthread_spin_init(&lock, PTHREAD_PROCESS_PRIVATE);
ret = pthread_rwlock_init(&lock, PTHREAD_PROCESS_PRIVATE);
if (ret)
{
syslog(LOG_ERR, "can't initialize spin lock. (sys %d)", ret);
#endif
syslog(LOG_ERR, "can't initialize rwlock. (sys %d)", ret);
return MTC_ERROR_LOG_PTHREAD;
}

Expand All @@ -141,7 +133,7 @@ MTC_S32 log_initialize()
// This function should be called from ha_log_reopen script
// when log files is rotated.
//
// Smaple logrotate config file </etc/logrotate.d/xha>
// Sample logrotate config file </etc/logrotate.d/xha>
// /var/log/xha.log {
// rotate 5
// size 100k
Expand All @@ -154,17 +146,11 @@ MTC_S32 log_initialize()
// paramaters
//
// return value
// 0: success
// not 0: fail
//

void log_reopen()
{
#if USE_SEMAPHORE
sem_wait(semaphore);
#else
pthread_spin_lock(&lock);
#endif
pthread_rwlock_wrlock(&lock);

if (fpLogfile)
{
Expand All @@ -177,11 +163,7 @@ void log_reopen()
syslog(LOG_WARNING, "can't open local log file. (sys %d)", errno);
}

#if USE_SEMAPHORE
sem_post(semaphore);
#else
pthread_spin_unlock(&lock);
#endif
pthread_rwlock_unlock(&lock);
}


Expand All @@ -199,11 +181,7 @@ void log_terminate()
{
initialized = FALSE;

#if USE_SEMAPHORE
sem_wait(semaphore);
#else
pthread_spin_lock(&lock);
#endif
pthread_rwlock_wrlock(&lock);

if (fpLogfile)
{
Expand All @@ -213,14 +191,8 @@ void log_terminate()

closelog();

#if USE_SEMAPHORE
sem_post(semaphore);
sem_close(semaphore);
sem_unlink(MTC_LOG_SEMAPHORE_NAME);
#else
pthread_spin_unlock(&lock);
pthread_spin_destroy(&lock);
#endif
pthread_rwlock_unlock(&lock);
pthread_rwlock_destroy(&lock);
}


Expand Down Expand Up @@ -253,57 +225,52 @@ void log_message(MTC_S32 priority, PMTC_S8 fmt, ...)
return;
}

#if USE_SEMAPHORE
sem_wait(semaphore);
#else
pthread_spin_lock(&lock);
#endif

if (priority & MTC_LOG_PRIVATELOG && fpLogfile != NULL && privatelogflag)
if (priority & MTC_LOG_PRIVATELOG && privatelogflag)
{
MTC_S32 i = 0;
pthread_rwlock_rdlock(&lock);

while (prioritynames[i].c_val != -1 &&
prioritynames[i].c_val != LOG_PRI(priority))
if (fpLogfile != NULL)
{
i++;
}
MTC_S32 i = 0;

while (prioritynames[i].c_val != -1 &&
prioritynames[i].c_val != LOG_PRI(priority))
{
i++;
}

now = time(NULL);
ptm = localtime(&now);
fprintf(fpLogfile, "%s %02d %02d:%02d:%02d %s %04d [%s] ",
monthnames[ptm->tm_mon], ptm->tm_mday,
ptm->tm_hour, ptm->tm_min, ptm->tm_sec,
ptm->tm_zone, 1900 + ptm->tm_year, prioritynames[i].c_name);
now = time(NULL);
ptm = localtime(&now);
flockfile(fpLogfile);
fprintf(fpLogfile, "%s %02d %02d:%02d:%02d %s %04d [%s] ",
monthnames[ptm->tm_mon], ptm->tm_mday,
ptm->tm_hour, ptm->tm_min, ptm->tm_sec,
ptm->tm_zone, 1900 + ptm->tm_year, prioritynames[i].c_name);

va_start(ap, fmt);
vfprintf(fpLogfile, fmt, ap);
va_end(ap);

fflush(fpLogfile);

//
// Sometime, fsync() takes seconds or more.
// It may cause unexpected watchdog timeout.
// So we deceided that we do not use fsync().
//
// fsync(fileno(fpLogfile));
//

va_start(ap, fmt);
vfprintf(fpLogfile, fmt, ap);
funlockfile(fpLogfile);
va_end(ap);

fflush(fpLogfile);

//
// Sometime, fsync() takes seconds or more.
// It may cause unexpected watchdog timeout.
// So we deceided that we do not use fsync().
//
// fsync(fileno(fpLogfile));
//
}

pthread_rwlock_unlock(&lock);
}
if ((logmask & MTC_LOG_MASK_SYSLOG) || (priority & MTC_LOG_SYSLOG))
{
va_start(ap, fmt);
vsyslog(LOG_PRI(priority), fmt, ap);
va_end(ap);
}

#if USE_SEMAPHORE
sem_post(semaphore);
#else
pthread_spin_unlock(&lock);
#endif
}


Expand Down Expand Up @@ -332,46 +299,43 @@ void log_bin(MTC_S32 priority, PMTC_S8 data, MTC_S32 size)
return;
}

#if USE_SEMAPHORE
sem_wait(semaphore);
#else
pthread_spin_lock(&lock);
#endif

if (priority & MTC_LOG_PRIVATELOG && fpLogfile != NULL && privatelogflag)
if (priority & MTC_LOG_PRIVATELOG && privatelogflag)
{
for (line = 0, pos = 0; pos < size; line++)
{
fprintf(fpLogfile, "\t%04x: ", line);

for (col = 0; col < MAX_COL && pos < size; col++, pos++)
{
fprintf(fpLogfile, "%02x ", (MTC_U8) data[pos]);
asc_dmp[col] = (isprint(data[pos]))? data[pos]: '.';
}
asc_dmp[col] = '\0';
pthread_rwlock_rdlock(&lock);

for (; col < MAX_COL; col++)
if (fpLogfile != NULL)
{
flockfile(fpLogfile);
for (line = 0, pos = 0; pos < size; line++)
{
fprintf(fpLogfile, " ");
fprintf(fpLogfile, "\t%04x: ", line);

for (col = 0; col < MAX_COL && pos < size; col++, pos++)
{
fprintf(fpLogfile, "%02x ", (MTC_U8) data[pos]);
asc_dmp[col] = (isprint(data[pos]))? data[pos]: '.';
}
asc_dmp[col] = '\0';

for (; col < MAX_COL; col++)
{
fprintf(fpLogfile, " ");
}

fprintf(fpLogfile, ": %s\n", asc_dmp);
}

fprintf(fpLogfile, ": %s\n", asc_dmp);
funlockfile(fpLogfile);
fflush(fpLogfile);

//
// We don't use fsync(). See comments in log_message().
//
// fsync(fileno(fpLogfile));
//
}
fflush(fpLogfile);

//
// We don't use fsync(). See comments in log_message().
//
// fsync(fileno(fpLogfile));
//
pthread_rwlock_unlock(&lock);
}

#if USE_SEMAPHORE
sem_post(semaphore);
#else
pthread_spin_unlock(&lock);
#endif
}

//
Expand Down Expand Up @@ -572,18 +536,10 @@ log_fsync()
return;
}

#if USE_SEMAPHORE
sem_wait(semaphore);
#else
pthread_spin_lock(&lock);
#endif
pthread_rwlock_rdlock(&lock);
if (fpLogfile)
{
fsync(fileno(fpLogfile));
}
#if USE_SEMAPHORE
sem_post(semaphore);
#else
pthread_spin_unlock(&lock);
#endif
pthread_rwlock_unlock(&lock);
}

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