r15266@tombo: nickm | 2008-04-22 12:05:07 -0400

Backport: On platforms using pthreads, allow a thread to acquire a lock it already holds.  This is crucial for logging: otherwise any log message thrown from inside the logging process (especially from control.c) will deadlock.  Win32 CriticalSections are already recursive.  Bug spotted by nwf.  Bugfix on 0.2.0.16-alpha.


svn:r14407
This commit is contained in:
Nick Mathewson 2008-04-22 16:05:11 +00:00
parent 68b2a57ffd
commit 8a05bd90ce
2 changed files with 7 additions and 1 deletions

View File

@ -23,6 +23,9 @@ Changes in version 0.2.0.24-rc - 2008-04-0?
Fixes bug 660. Bugfix on 0.1.2.x.
- Avoid allocating extra space when computing consensuses on
64-bit platforms. Bug spotted by aakova.
- Use recursive pthread mutexes in order to avoid deadlock when
logging debug-level messages to a controller. Bug spotted by
nwf, bugfix on 0.2.0.16-alpha.
Changes in version 0.2.0.23-rc - 2008-03-24

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@ -1746,13 +1746,14 @@ tor_get_thread_id(void)
struct tor_mutex_t {
pthread_mutex_t mutex;
};
static pthread_mutexattr_t attr_reentrant;
/** Allocate and return new lock. */
tor_mutex_t *
tor_mutex_new(void)
{
int err;
tor_mutex_t *mutex = tor_malloc_zero(sizeof(tor_mutex_t));
err = pthread_mutex_init(&mutex->mutex, NULL);
err = pthread_mutex_init(&mutex->mutex, &attr_reentrant);
if (PREDICT_UNLIKELY(err)) {
log_err(LD_GENERAL, "Error %d creating a mutex.", err);
tor_fragile_assert();
@ -1868,6 +1869,8 @@ tor_cond_signal_all(tor_cond_t *cond)
void
tor_threads_init(void)
{
pthread_mutexattr_init(&attr_reentrant);
pthread_mutexattr_settype(&attr_reentrant, PTHREAD_MUTEX_RECURSIVE);
}
#elif defined(USE_WIN32_THREADS)
#if 0