* Copyright 2002-2012, Axel Dörfler, axeld@pinc-software.de. All rights reserved.
* Distributed under the terms of the MIT License.
*
* Copyright 2001-2002, Travis Geiselbrecht. All rights reserved.
* Distributed under the terms of the NewOS License.
*/
#include "fssh_lock.h"
#include "fssh_kernel_export.h"
#define FSSH_RW_MAX_READERS 100000
extern "C" int32_t
fssh_recursive_lock_get_recursion(fssh_recursive_lock *lock)
{
if (lock->holder == fssh_find_thread(NULL))
return lock->recursion;
return -1;
}
extern "C" void
fssh_recursive_lock_init_etc(fssh_recursive_lock *lock, const char *name,
uint32_t flags)
{
if (lock == NULL)
return;
if (name == NULL)
name = "recursive lock";
lock->holder = -1;
lock->recursion = 0;
lock->sem = fssh_create_sem(1, name);
if (lock->sem < FSSH_B_OK)
fssh_panic("could not create recursive lock");
}
extern "C" void
fssh_recursive_lock_init(fssh_recursive_lock *lock, const char *name)
{
fssh_recursive_lock_init_etc(lock, name, 0);
}
extern "C" void
fssh_recursive_lock_destroy(fssh_recursive_lock *lock)
{
if (lock == NULL)
return;
fssh_delete_sem(lock->sem);
lock->sem = -1;
}
extern "C" fssh_status_t
fssh_recursive_lock_lock(fssh_recursive_lock *lock)
{
fssh_thread_id thread = fssh_find_thread(NULL);
if (thread != lock->holder) {
fssh_status_t status = fssh_acquire_sem(lock->sem);
if (status < FSSH_B_OK)
return status;
lock->holder = thread;
}
lock->recursion++;
return FSSH_B_OK;
}
extern "C" fssh_status_t
fssh_recursive_lock_trylock(fssh_recursive_lock *lock)
{
fssh_thread_id thread = fssh_find_thread(NULL);
if (thread != lock->holder) {
fssh_status_t status = fssh_acquire_sem_etc(lock->sem, 1,
FSSH_B_RELATIVE_TIMEOUT, 0);
if (status < FSSH_B_OK)
return status;
lock->holder = thread;
}
lock->recursion++;
return FSSH_B_OK;
}
extern "C" void
fssh_recursive_lock_unlock(fssh_recursive_lock *lock)
{
if (fssh_find_thread(NULL) != lock->holder)
fssh_panic("recursive_lock %p unlocked by non-holder thread!\n", lock);
if (--lock->recursion == 0) {
lock->holder = -1;
fssh_release_sem(lock->sem);
}
}
extern "C" void
fssh_recursive_lock_transfer_lock(fssh_recursive_lock *lock,
fssh_thread_id thread)
{
if (lock->recursion != 1)
fssh_panic("invalid recursion level for lock transfer!");
lock->holder = thread;
}
extern "C" void
fssh_mutex_init(fssh_mutex *m, const char *name)
{
if (m == NULL)
return;
if (name == NULL)
name = "mutex_sem";
m->holder = -1;
m->sem = fssh_create_sem(1, name);
if (m->sem < FSSH_B_OK)
fssh_panic("could not create mutex");
}
extern "C" void
fssh_mutex_init_etc(fssh_mutex *m, const char *name, uint32_t flags)
{
fssh_mutex_init(m, name);
}
extern "C" void
fssh_mutex_destroy(fssh_mutex *mutex)
{
if (mutex == NULL)
return;
if (mutex->sem >= 0) {
fssh_delete_sem(mutex->sem);
mutex->sem = -1;
}
mutex->holder = -1;
}
extern "C" fssh_status_t
fssh_mutex_lock(fssh_mutex *mutex)
{
fssh_thread_id me = fssh_find_thread(NULL);
fssh_status_t status;
status = fssh_acquire_sem(mutex->sem);
if (status < FSSH_B_OK)
return status;
if (me == mutex->holder)
fssh_panic("mutex_lock failure: mutex %p (sem = 0x%x) acquired twice by thread 0x%x\n", mutex, (int)mutex->sem, (int)me);
mutex->holder = me;
return FSSH_B_OK;
}
extern "C" void
fssh_mutex_unlock(fssh_mutex *mutex)
{
fssh_thread_id me = fssh_find_thread(NULL);
if (me != mutex->holder) {
fssh_panic("mutex_unlock failure: thread 0x%x is trying to release mutex %p (current holder 0x%x)\n",
(int)me, mutex, (int)mutex->holder);
}
mutex->holder = -1;
fssh_release_sem(mutex->sem);
}
extern "C" void
fssh_mutex_transfer_lock(fssh_mutex *mutex, fssh_thread_id thread)
{
mutex->holder = thread;
}
extern "C" void
fssh_rw_lock_init(fssh_rw_lock *lock, const char *name)
{
if (lock == NULL)
return;
if (name == NULL)
name = "r/w lock";
lock->count = 0;
lock->holder = -1;
lock->sem = fssh_create_sem(FSSH_RW_MAX_READERS, name);
if (lock->sem < FSSH_B_OK)
fssh_panic("could not create r/w lock");
}
extern "C" void
fssh_rw_lock_init_etc(fssh_rw_lock *lock, const char *name, uint32_t flags)
{
fssh_rw_lock_init(lock, name);
}
extern "C" void
fssh_rw_lock_destroy(fssh_rw_lock *lock)
{
if (lock == NULL)
return;
fssh_delete_sem(lock->sem);
}
extern "C" fssh_status_t
fssh_rw_lock_read_lock(fssh_rw_lock *lock)
{
if (lock->holder == fssh_find_thread(NULL)) {
lock->count++;
return FSSH_B_OK;
}
return fssh_acquire_sem(lock->sem);
}
extern "C" fssh_status_t
fssh_rw_lock_read_unlock(fssh_rw_lock *lock)
{
if (lock->holder == fssh_find_thread(NULL) && --lock->count > 0)
return FSSH_B_OK;
return fssh_release_sem(lock->sem);
}
extern "C" fssh_status_t
fssh_rw_lock_write_lock(fssh_rw_lock *lock)
{
if (lock->holder == fssh_find_thread(NULL)) {
lock->count++;
return FSSH_B_OK;
}
fssh_status_t status = fssh_acquire_sem_etc(lock->sem, FSSH_RW_MAX_READERS,
0, 0);
if (status == FSSH_B_OK) {
lock->holder = fssh_find_thread(NULL);
lock->count = 1;
}
return status;
}
extern "C" fssh_status_t
fssh_rw_lock_write_unlock(fssh_rw_lock *lock)
{
if (--lock->count > 0)
return FSSH_B_OK;
lock->holder = -1;
return fssh_release_sem_etc(lock->sem, FSSH_RW_MAX_READERS, 0);
}
