compat_mutex.h File Reference

Header for compat_mutex.c. More...

#include "orconfig.h"
#include "lib/cc/torint.h"
#include "lib/malloc/malloc.h"

Go to the source code of this file.

Data Structures
struct	tor_mutex_t

Macros
#define	tor_mutex_free(m)   FREE_AND_NULL(tor_mutex_t, tor_mutex_free_, (m))

Functions
tor_mutex_t *	tor_mutex_new (void)
tor_mutex_t *	tor_mutex_new_nonrecursive (void)
void	tor_mutex_init (tor_mutex_t *m)
void	tor_mutex_init_nonrecursive (tor_mutex_t *m)
void	tor_mutex_acquire (tor_mutex_t *m)
void	tor_mutex_release (tor_mutex_t *m)
void	tor_mutex_free_ (tor_mutex_t *m)
void	tor_mutex_uninit (tor_mutex_t *m)
void	tor_locking_init (void)

Detailed Description

Header for compat_mutex.c.

Definition in file compat_mutex.h.

Macro Definition Documentation

tor_mutex_free

#define tor_mutex_free

(

m

)

FREE_AND_NULL(tor_mutex_t, tor_mutex_free_, (m))

Release all storage and system resources held by m.

Destroying a locked mutex is undefined behaviour. Global mutexes may be locked when they are passed to this function, because multiple threads can still access them. So we can either:

• destroy on shutdown, and re-initialise when tor re-initialises, or
• skip destroying and re-initialisation, using a sentinel variable. See #31735 for details.

Additionally, set the pointer m to NULL.

Definition at line 73 of file compat_mutex.h.

Function Documentation

tor_locking_init()

void tor_locking_init

(

void

)

Initialize the locking module, if it is not already initialized.

Definition at line 29 of file compat_mutex_pthreads.c.

Referenced by tor_mutex_init_nonrecursive(), and tor_threads_init().

tor_mutex_acquire()

void tor_mutex_acquire

(

tor_mutex_t *

m

)

Wait until m is free, then acquire it.

Definition at line 71 of file compat_mutex_pthreads.c.

Referenced by atomic_counter_add(), atomic_counter_exchange(), atomic_counter_get(), dup_onion_keys(), expire_old_onion_keys(), openssl_locking_cb_(), queue_reply(), threadpool_queue_update(), worker_thread_main(), and workqueue_entry_cancel().

tor_mutex_free_()

void tor_mutex_free_

(

tor_mutex_t *

m

)

Release all storage and system resources held by m.

Destroying a locked mutex is undefined behaviour. Global mutexes may be locked when they are passed to this function, because multiple threads can still access them. So we can either:

• destroy on shutdown, and re-initialise when tor re-initialises, or
• skip destroying and re-initialisation, using a sentinel variable. See #31735 for details.

Definition at line 42 of file compat_mutex.c.

tor_mutex_init()

void tor_mutex_init

(

tor_mutex_t *

mutex

)

Initialize mutex so it can be locked. Every mutex must be set up with tor_mutex_init() or tor_mutex_new(); not both.

Definition at line 41 of file compat_mutex_pthreads.c.

Referenced by init_logging().

tor_mutex_init_nonrecursive()

void tor_mutex_init_nonrecursive

(

tor_mutex_t *

mutex

)

As tor_mutex_init, but initialize a mutex suitable that may be non-recursive, if the OS supports that.

Definition at line 56 of file compat_mutex_pthreads.c.

Referenced by atomic_counter_init().

tor_mutex_new()

tor_mutex_t* tor_mutex_new

(

void

)

Return a newly allocated, ready-for-use mutex.

Definition at line 17 of file compat_mutex.c.

Referenced by tor_gmtime_r_msg(), and tor_localtime_r_msg().

tor_mutex_new_nonrecursive()

tor_mutex_t* tor_mutex_new_nonrecursive

(

void

)

Return a newly allocated, ready-for-use mutex. This one might be non-recursive, if that's faster.

Definition at line 26 of file compat_mutex.c.

tor_mutex_release()

void tor_mutex_release

(

tor_mutex_t *

m

)

Release the lock m so another thread can have it.

Definition at line 84 of file compat_mutex_pthreads.c.

Referenced by atomic_counter_add(), atomic_counter_exchange(), atomic_counter_get(), dup_onion_keys(), openssl_locking_cb_(), queue_reply(), socket_accounting_unlock(), worker_thread_main(), and workqueue_entry_cancel().

tor_mutex_uninit()

void tor_mutex_uninit

(

tor_mutex_t *

m

)

Clean up the mutex m so that it no longer uses any system resources. Does not free m. This function must only be called on mutexes from tor_mutex_init().

Destroying a locked mutex is undefined behaviour. Global mutexes may be locked when they are passed to this function, because multiple threads can still access them. So we can either:

• destroy on shutdown, and re-initialise when tor re-initialises, or
• skip destroying and re-initialisation, using a sentinel variable. See #31735 for details.

Definition at line 107 of file compat_mutex_pthreads.c.

Referenced by atomic_counter_destroy(), and tor_mutex_free_().