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authorRickard Green <[email protected]>2012-04-27 13:06:27 +0200
committerRickard Green <[email protected]>2012-04-27 13:06:27 +0200
commit398bb9a9a5b2a56f0333ce81efe00380692ec93a (patch)
treeadb7239744ae6f3d45f672e29d9c2bd97e0e67d9 /erts/emulator/beam/erl_process_lock.h
parent52312a8b93e8b250099e2f1b1b802e63e37971cc (diff)
parent3730e28ad736f0538141d4474e0038a9cc48df71 (diff)
downloadotp-398bb9a9a5b2a56f0333ce81efe00380692ec93a.tar.gz
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Merge branch 'rickard/proc-sched/OTP-9892'
* rickard/proc-sched/OTP-9892: Teach etp-commands to understand new emulator internal data structures Optimize process state changes Optimize process table access Implement possibility to use ordinary mutexes as process locks Conflicts: erts/emulator/beam/erl_alloc.types
Diffstat (limited to 'erts/emulator/beam/erl_process_lock.h')
-rw-r--r--erts/emulator/beam/erl_process_lock.h417
1 files changed, 187 insertions, 230 deletions
diff --git a/erts/emulator/beam/erl_process_lock.h b/erts/emulator/beam/erl_process_lock.h
index 413c45480c..7367e03b44 100644
--- a/erts/emulator/beam/erl_process_lock.h
+++ b/erts/emulator/beam/erl_process_lock.h
@@ -37,10 +37,21 @@
#include "erl_smp.h"
+#if defined(VALGRIND) || defined(ETHR_DISABLE_NATIVE_IMPLS)
+# define ERTS_PROC_LOCK_OWN_IMPL 0
+#else
+# define ERTS_PROC_LOCK_OWN_IMPL 1
+#endif
+
#define ERTS_PROC_LOCK_ATOMIC_IMPL 0
#define ERTS_PROC_LOCK_SPINLOCK_IMPL 0
#define ERTS_PROC_LOCK_MUTEX_IMPL 0
+#if !ERTS_PROC_LOCK_OWN_IMPL
+#define ERTS_PROC_LOCK_RAW_MUTEX_IMPL 1
+#else
+#define ERTS_PROC_LOCK_RAW_MUTEX_IMPL 0
+
#if defined(ETHR_HAVE_32BIT_NATIVE_ATOMIC_OPS)
# undef ERTS_PROC_LOCK_ATOMIC_IMPL
# define ERTS_PROC_LOCK_ATOMIC_IMPL 1
@@ -52,6 +63,8 @@
# define ERTS_PROC_LOCK_MUTEX_IMPL 1
#endif
+#endif
+
#define ERTS_PROC_LOCK_MAX_BIT 3
typedef erts_aint32_t ErtsProcLocks;
@@ -59,22 +72,31 @@ typedef erts_aint32_t ErtsProcLocks;
typedef struct erts_proc_lock_queues_t_ erts_proc_lock_queues_t;
typedef struct erts_proc_lock_t_ {
+#if ERTS_PROC_LOCK_OWN_IMPL
#if ERTS_PROC_LOCK_ATOMIC_IMPL
erts_smp_atomic32_t flags;
#else
ErtsProcLocks flags;
#endif
erts_proc_lock_queues_t *queues;
- Sint32 refc;
-#ifdef ERTS_PROC_LOCK_DEBUG
- erts_smp_atomic32_t locked[ERTS_PROC_LOCK_MAX_BIT+1];
-#endif
#ifdef ERTS_ENABLE_LOCK_COUNT
erts_lcnt_lock_t lcnt_main;
erts_lcnt_lock_t lcnt_link;
erts_lcnt_lock_t lcnt_msgq;
erts_lcnt_lock_t lcnt_status;
#endif
+#elif ERTS_PROC_LOCK_RAW_MUTEX_IMPL
+ erts_mtx_t main;
+ erts_mtx_t link;
+ erts_mtx_t msgq;
+ erts_mtx_t status;
+#else
+# error "no implementation"
+#endif
+ erts_atomic32_t refc;
+#ifdef ERTS_PROC_LOCK_DEBUG
+ erts_smp_atomic32_t locked[ERTS_PROC_LOCK_MAX_BIT+1];
+#endif
} erts_proc_lock_t;
/* Process lock flags */
@@ -107,11 +129,9 @@ typedef struct erts_proc_lock_t_ {
/*
* Status lock:
* Protects the following fields in the process structure:
- * * status
- * * rstatus
- * * status_flags
* * pending_suspenders
* * suspendee
+ * * ...
*/
#define ERTS_PROC_LOCK_STATUS (((ErtsProcLocks) 1) << ERTS_PROC_LOCK_MAX_BIT)
@@ -143,14 +163,11 @@ typedef struct erts_proc_lock_t_ {
* Other rules regarding process locking:
*
* Exiting processes:
- * When changing status to P_EXITING on a process, you are required
- * to take all process locks (ERTS_PROC_LOCKS_ALL). Thus, by holding
- * at least one process lock (whichever one doesn't matter) you
- * are guaranteed that the process won't exit until the lock you are
- * holding has been released. Appart from all process locks also
- * the pix lock corresponding to the process has to be held.
- * At the same time as status is changed to P_EXITING, also the
- * field 'is_exiting' in the process structure is set to a value != 0.
+ * When changing state to exiting (ERTS_PSFLG_EXITING) on a process,
+ * you are required to take all process locks (ERTS_PROC_LOCKS_ALL).
+ * Thus, by holding at least one process lock (whichever one doesn't
+ * matter) you are guaranteed that the process won't exit until the
+ * lock you are holding has been released.
*
* Lock order:
* Process locks with low numeric values has to be locked before
@@ -262,12 +279,10 @@ typedef struct {
} u;
} erts_pix_lock_t;
-#define ERTS_PIX2PIXLOCKIX(PIX) \
- ((PIX) & ((1 << ERTS_PIX_LOCKS_BITS) - 1))
-#define ERTS_PIX2PIXLOCK(PIX) \
- (&erts_pix_locks[ERTS_PIX2PIXLOCKIX((PIX))])
#define ERTS_PID2PIXLOCK(PID) \
- ERTS_PIX2PIXLOCK(internal_pid_data((PID)))
+ (&erts_pix_locks[(internal_pid_data((PID)) & ((1 << ERTS_PIX_LOCKS_BITS) - 1))])
+
+#if ERTS_PROC_LOCK_OWN_IMPL
#if ERTS_PROC_LOCK_ATOMIC_IMPL
@@ -337,11 +352,13 @@ erts_proc_lock_flags_cmpxchg(erts_proc_lock_t *lck, ErtsProcLocks new,
#define ERTS_PROC_LOCK_FLGS_READ_(L) ((L)->flags)
#endif /* end no opt atomic ops */
+#endif /* ERTS_PROC_LOCK_OWN_IMPL */
extern erts_pix_lock_t erts_pix_locks[ERTS_NO_OF_PIX_LOCKS];
void erts_init_proc_lock(int cpus);
void erts_proc_lock_prepare_proc_lock_waiter(void);
+#if ERTS_PROC_LOCK_OWN_IMPL
void erts_proc_lock_failed(Process *,
erts_pix_lock_t *,
ErtsProcLocks,
@@ -349,6 +366,7 @@ void erts_proc_lock_failed(Process *,
void erts_proc_unlock_failed(Process *,
erts_pix_lock_t *,
ErtsProcLocks);
+#endif
ERTS_GLB_INLINE void erts_pix_lock(erts_pix_lock_t *);
ERTS_GLB_INLINE void erts_pix_unlock(erts_pix_lock_t *);
@@ -412,6 +430,7 @@ ERTS_GLB_INLINE int erts_lc_pix_lock_is_locked(erts_pix_lock_t *pixlck)
ERTS_GLB_INLINE ErtsProcLocks
erts_smp_proc_raw_trylock__(Process *p, ErtsProcLocks locks)
{
+#if ERTS_PROC_LOCK_OWN_IMPL
ErtsProcLocks expct_lflgs = 0;
while (1) {
@@ -431,8 +450,38 @@ erts_smp_proc_raw_trylock__(Process *p, ErtsProcLocks locks)
/* cmpxchg failed, try again (should be rare). */
expct_lflgs = lflgs;
}
-}
+#elif ERTS_PROC_LOCK_RAW_MUTEX_IMPL
+
+ if (locks & ERTS_PROC_LOCK_MAIN)
+ if (erts_mtx_trylock(&p->lock.main) == EBUSY)
+ goto busy_main;
+ if (locks & ERTS_PROC_LOCK_LINK)
+ if (erts_mtx_trylock(&p->lock.link) == EBUSY)
+ goto busy_link;
+ if (locks & ERTS_PROC_LOCK_MSGQ)
+ if (erts_mtx_trylock(&p->lock.msgq) == EBUSY)
+ goto busy_msgq;
+ if (locks & ERTS_PROC_LOCK_STATUS)
+ if (erts_mtx_trylock(&p->lock.status) == EBUSY)
+ goto busy_status;
+
+ return 0;
+
+busy_status:
+ if (locks & ERTS_PROC_LOCK_MSGQ)
+ erts_mtx_unlock(&p->lock.msgq);
+busy_msgq:
+ if (locks & ERTS_PROC_LOCK_LINK)
+ erts_mtx_unlock(&p->lock.link);
+busy_link:
+ if (locks & ERTS_PROC_LOCK_MAIN)
+ erts_mtx_unlock(&p->lock.main);
+busy_main:
+
+ return EBUSY;
+#endif
+}
ERTS_GLB_INLINE void
#ifdef ERTS_ENABLE_LOCK_COUNT
@@ -446,10 +495,13 @@ erts_smp_proc_lock__(Process *p,
ErtsProcLocks locks)
#endif
{
+#if ERTS_PROC_LOCK_OWN_IMPL
+
ErtsProcLocks old_lflgs;
#if !ERTS_PROC_LOCK_ATOMIC_IMPL
erts_pix_lock(pix_lck);
#endif
+
#ifdef ERTS_ENABLE_LOCK_COUNT
erts_lcnt_proc_lock(&(p->lock), locks);
#endif
@@ -473,12 +525,14 @@ erts_smp_proc_lock__(Process *p,
erts_pix_unlock(pix_lck);
}
#endif
+
#ifdef ERTS_ENABLE_LOCK_COUNT
erts_lcnt_proc_lock_post_x(&(p->lock), locks, file, line);
#endif
#ifdef ERTS_ENABLE_LOCK_CHECK
erts_proc_lc_lock(p, locks);
#endif
+
#ifdef ERTS_PROC_LOCK_DEBUG
erts_proc_lock_op_debug(p, locks, 1);
#endif
@@ -486,6 +540,22 @@ erts_smp_proc_lock__(Process *p,
#if ERTS_PROC_LOCK_ATOMIC_IMPL
ETHR_COMPILER_BARRIER;
#endif
+
+#elif ERTS_PROC_LOCK_RAW_MUTEX_IMPL
+ if (locks & ERTS_PROC_LOCK_MAIN)
+ erts_mtx_lock(&p->lock.main);
+ if (locks & ERTS_PROC_LOCK_LINK)
+ erts_mtx_lock(&p->lock.link);
+ if (locks & ERTS_PROC_LOCK_MSGQ)
+ erts_mtx_lock(&p->lock.msgq);
+ if (locks & ERTS_PROC_LOCK_STATUS)
+ erts_mtx_lock(&p->lock.status);
+
+#ifdef ERTS_PROC_LOCK_DEBUG
+ erts_proc_lock_op_debug(p, locks, 1);
+#endif
+
+#endif
}
ERTS_GLB_INLINE void
@@ -493,6 +563,7 @@ erts_smp_proc_unlock__(Process *p,
erts_pix_lock_t *pix_lck,
ErtsProcLocks locks)
{
+#if ERTS_PROC_LOCK_OWN_IMPL
ErtsProcLocks old_lflgs;
#if ERTS_PROC_LOCK_ATOMIC_IMPL
@@ -557,6 +628,23 @@ erts_smp_proc_unlock__(Process *p,
break;
}
+
+#elif ERTS_PROC_LOCK_RAW_MUTEX_IMPL
+
+#ifdef ERTS_PROC_LOCK_DEBUG
+ erts_proc_lock_op_debug(p, locks, 0);
+#endif
+
+ if (locks & ERTS_PROC_LOCK_STATUS)
+ erts_mtx_unlock(&p->lock.status);
+ if (locks & ERTS_PROC_LOCK_MSGQ)
+ erts_mtx_unlock(&p->lock.msgq);
+ if (locks & ERTS_PROC_LOCK_LINK)
+ erts_mtx_unlock(&p->lock.link);
+ if (locks & ERTS_PROC_LOCK_MAIN)
+ erts_mtx_unlock(&p->lock.main);
+#endif
+
}
ERTS_GLB_INLINE int
@@ -564,6 +652,7 @@ erts_smp_proc_trylock__(Process *p,
erts_pix_lock_t *pix_lck,
ErtsProcLocks locks)
{
+#if ERTS_PROC_LOCK_OWN_IMPL
int res;
#ifdef ERTS_ENABLE_LOCK_CHECK
@@ -575,6 +664,7 @@ erts_smp_proc_trylock__(Process *p,
else
#endif
{
+
#if !ERTS_PROC_LOCK_ATOMIC_IMPL
erts_pix_lock(pix_lck);
#endif
@@ -613,8 +703,18 @@ erts_smp_proc_trylock__(Process *p,
#if ERTS_PROC_LOCK_ATOMIC_IMPL
ETHR_COMPILER_BARRIER;
#endif
-
return res;
+
+#elif ERTS_PROC_LOCK_RAW_MUTEX_IMPL
+ if (erts_smp_proc_raw_trylock__(p, locks) != 0)
+ return EBUSY;
+ else {
+#ifdef ERTS_PROC_LOCK_DEBUG
+ erts_proc_lock_op_debug(p, locks, 1);
+#endif
+ return 0;
+ }
+#endif
}
#ifdef ERTS_PROC_LOCK_DEBUG
@@ -713,44 +813,36 @@ erts_smp_proc_trylock(Process *p, ErtsProcLocks locks)
#endif
}
-
ERTS_GLB_INLINE void erts_smp_proc_inc_refc(Process *p)
{
#ifdef ERTS_SMP
- erts_pix_lock_t *pixlck = ERTS_PID2PIXLOCK(p->id);
- erts_pix_lock(pixlck);
- ERTS_LC_ASSERT(p->lock.refc > 0);
- p->lock.refc++;
- erts_pix_unlock(pixlck);
+#ifdef ERTS_ENABLE_LOCK_CHECK
+ erts_aint32_t refc = erts_atomic32_inc_read_nob(&p->lock.refc);
+ ERTS_SMP_LC_ASSERT(refc > 1);
+#else
+ erts_atomic32_inc_nob(&p->lock.refc);
+#endif
#endif
}
ERTS_GLB_INLINE void erts_smp_proc_dec_refc(Process *p)
{
#ifdef ERTS_SMP
- Process *fp;
- erts_pix_lock_t *pixlck = ERTS_PID2PIXLOCK(p->id);
- erts_pix_lock(pixlck);
- ERTS_LC_ASSERT(p->lock.refc > 0);
- fp = --p->lock.refc == 0 ? p : NULL;
- erts_pix_unlock(pixlck);
- if (fp)
- erts_free_proc(fp);
+ erts_aint32_t refc = erts_atomic32_dec_read_nob(&p->lock.refc);
+ ERTS_SMP_LC_ASSERT(refc >= 0);
+ if (refc == 0)
+ erts_free_proc(p);
#endif
}
-ERTS_GLB_INLINE void erts_smp_proc_add_refc(Process *p, Sint32 refc)
+ERTS_GLB_INLINE void erts_smp_proc_add_refc(Process *p, Sint32 add_refc)
{
#ifdef ERTS_SMP
- Process *fp;
- erts_pix_lock_t *pixlck = ERTS_PID2PIXLOCK(p->id);
- erts_pix_lock(pixlck);
- ERTS_LC_ASSERT(p->lock.refc > 0);
- p->lock.refc += refc;
- fp = p->lock.refc == 0 ? p : NULL;
- erts_pix_unlock(pixlck);
- if (fp)
- erts_free_proc(fp);
+ erts_aint32_t refc = erts_atomic32_add_read_nob(&p->lock.refc,
+ (erts_aint32_t) add_refc);
+ ERTS_SMP_LC_ASSERT(refc >= 0);
+ if (refc == 0)
+ erts_free_proc(p);
#endif
}
@@ -758,6 +850,7 @@ ERTS_GLB_INLINE void erts_smp_proc_add_refc(Process *p, Sint32 refc)
#ifdef ERTS_SMP
void erts_proc_lock_init(Process *);
+void erts_proc_lock_fin(Process *);
void erts_proc_safelock(Process *a_proc,
ErtsProcLocks a_have_locks,
ErtsProcLocks a_need_locks,
@@ -790,211 +883,75 @@ extern const Process erts_proc_lock_busy;
#define erts_pid2proc(PROC, HL, PID, NL) \
erts_pid2proc_opt((PROC), (HL), (PID), (NL), 0)
-ERTS_GLB_INLINE Process *
-erts_pid2proc_opt(Process *, ErtsProcLocks, Eterm, ErtsProcLocks, int);
-#ifdef ERTS_SMP
-void
-erts_pid2proc_safelock(Process *c_p,
- ErtsProcLocks c_p_have_locks,
- Process **proc,
- ErtsProcLocks need_locks,
- erts_pix_lock_t *pix_lock,
- int flags);
-ERTS_GLB_INLINE Process *erts_pid2proc_unlocked_opt(Eterm pid, int flags);
-#define erts_pid2proc_unlocked(PID) erts_pid2proc_unlocked_opt((PID), 0)
-#else
-#define erts_pid2proc_unlocked_opt(PID, FLGS) \
- erts_pid2proc_opt(NULL, 0, (PID), 0, FLGS)
-#define erts_pid2proc_unlocked(PID) erts_pid2proc_opt(NULL, 0, (PID), 0, 0)
+ERTS_GLB_INLINE Process *erts_pix2proc(int ix);
+ERTS_GLB_INLINE Process *erts_proc_lookup_raw(Eterm pid);
+ERTS_GLB_INLINE Process *erts_proc_lookup(Eterm pid);
+
+#ifndef ERTS_SMP
+ERTS_GLB_INLINE
#endif
+Process *erts_pid2proc_opt(Process *, ErtsProcLocks, Eterm, ErtsProcLocks, int);
#if ERTS_GLB_INLINE_INCL_FUNC_DEF
-ERTS_GLB_INLINE Process *
-#ifdef ERTS_SMP
-erts_pid2proc_unlocked_opt(Eterm pid, int flags)
-#else
-erts_pid2proc_opt(Process *c_p_unused,
- ErtsProcLocks c_p_have_locks_unused,
- Eterm pid,
- ErtsProcLocks pid_need_locks_unused,
- int flags)
-#endif
+ERTS_GLB_INLINE Process *erts_pix2proc(int ix)
{
- Uint pix;
Process *proc;
+ ASSERT(0 <= ix && ix < erts_proc.max);
+ proc = (Process *) erts_smp_atomic_read_nob(&erts_proc.tab[ix]);
+ return proc == ERTS_PROC_LOCK_BUSY ? NULL : proc;
+}
+
+ERTS_GLB_INLINE Process *erts_proc_lookup_raw(Eterm pid)
+{
+ Process *proc;
+ int pix;
+
+ /*
+ * In SMP case: Only scheduler threads are allowed
+ * to use this function. Other threads need to
+ * atomicaly increment refc at lookup, i.e., use
+ * erts_pid2proc_opt() with ERTS_P2P_FLG_SMP_INC_REFC.
+ */
+ ERTS_SMP_LC_ASSERT(erts_get_scheduler_id());
if (is_not_internal_pid(pid))
return NULL;
pix = internal_pid_index(pid);
- if(pix >= erts_max_processes)
+
+ proc = (Process *) erts_smp_atomic_read_ddrb(&erts_proc.tab[pix]);
+
+ if (proc && proc->id != pid)
return NULL;
- proc = process_tab[pix];
- if (proc) {
- if (proc->id != pid
- || (!(flags & ERTS_P2P_FLG_ALLOW_OTHER_X)
- && proc->status == P_EXITING))
- proc = NULL;
- }
+
return proc;
}
-#ifdef ERTS_SMP
+ERTS_GLB_INLINE Process *erts_proc_lookup(Eterm pid)
+{
+ Process *proc = erts_proc_lookup_raw(pid);
+ if (proc && ERTS_PROC_IS_EXITING(proc))
+ return NULL;
+ return proc;
+}
+#ifndef ERTS_SMP
ERTS_GLB_INLINE Process *
-erts_pid2proc_opt(Process *c_p,
- ErtsProcLocks c_p_have_locks,
+erts_pid2proc_opt(Process *c_p_unused,
+ ErtsProcLocks c_p_have_locks_unused,
Eterm pid,
- ErtsProcLocks pid_need_locks,
+ ErtsProcLocks pid_need_locks_unused,
int flags)
{
- erts_pix_lock_t *pix_lock;
- ErtsProcLocks need_locks;
- Uint pix;
- Process *proc;
-#ifdef ERTS_ENABLE_LOCK_COUNT
- ErtsProcLocks lcnt_locks;
-#endif
-
-#ifdef ERTS_ENABLE_LOCK_CHECK
- if (c_p) {
- ErtsProcLocks might_unlock = c_p_have_locks & pid_need_locks;
- if (might_unlock)
- erts_proc_lc_might_unlock(c_p, might_unlock);
- }
-#endif
- if (is_not_internal_pid(pid)) {
- proc = NULL;
- goto done;
- }
- pix = internal_pid_index(pid);
- if(pix >= erts_max_processes) {
- proc = NULL;
- goto done;
- }
-
- ERTS_LC_ASSERT((pid_need_locks & ERTS_PROC_LOCKS_ALL) == pid_need_locks);
- need_locks = pid_need_locks;
-
- pix_lock = ERTS_PIX2PIXLOCK(pix);
-
- if (c_p && c_p->id == pid) {
- ASSERT(c_p->id != ERTS_INVALID_PID);
- ASSERT(c_p == process_tab[pix]);
- if (!(flags & ERTS_P2P_FLG_ALLOW_OTHER_X) && c_p->is_exiting) {
- proc = NULL;
- goto done;
- }
- need_locks &= ~c_p_have_locks;
- if (!need_locks) {
- proc = c_p;
- erts_pix_lock(pix_lock);
- if (flags & ERTS_P2P_FLG_SMP_INC_REFC)
- proc->lock.refc++;
- erts_pix_unlock(pix_lock);
- goto done;
- }
- }
-
- erts_pix_lock(pix_lock);
-
- proc = process_tab[pix];
- if (proc) {
- if (proc->id != pid || (!(flags & ERTS_P2P_FLG_ALLOW_OTHER_X)
- && ERTS_PROC_IS_EXITING(proc))) {
- proc = NULL;
- }
- else if (!need_locks) {
- if (flags & ERTS_P2P_FLG_SMP_INC_REFC)
- proc->lock.refc++;
- }
- else {
- int busy;
-
-#ifdef ERTS_ENABLE_LOCK_COUNT
- lcnt_locks = need_locks;
- if (!(flags & ERTS_P2P_FLG_TRY_LOCK)) {
- erts_lcnt_proc_lock(&proc->lock, need_locks);
- }
-#endif
-
-#ifdef ERTS_ENABLE_LOCK_CHECK
- /* Make sure erts_pid2proc_safelock() is enough to handle
- a potential lock order violation situation... */
- busy = erts_proc_lc_trylock_force_busy(proc, need_locks);
- if (!busy)
-#endif
- {
- /* Try a quick trylock to grab all the locks we need. */
- busy = (int) erts_smp_proc_raw_trylock__(proc, need_locks);
-#ifdef ERTS_ENABLE_LOCK_CHECK
- erts_proc_lc_trylock(proc, need_locks, !busy);
-#endif
-#ifdef ERTS_PROC_LOCK_DEBUG
- if (!busy)
- erts_proc_lock_op_debug(proc, need_locks, 1);
-#endif
- }
-
-#ifdef ERTS_ENABLE_LOCK_COUNT
- if (flags & ERTS_P2P_FLG_TRY_LOCK) {
- if (busy) {
- erts_lcnt_proc_trylock(&proc->lock, need_locks, EBUSY);
- } else {
- erts_lcnt_proc_trylock(&proc->lock, need_locks, 0);
- }
- }
-#endif
- if (!busy) {
- if (flags & ERTS_P2P_FLG_SMP_INC_REFC)
- proc->lock.refc++;
-#ifdef ERTS_ENABLE_LOCK_COUNT
- /* all is great */
- if (!(flags & ERTS_P2P_FLG_TRY_LOCK)) {
- erts_lcnt_proc_lock_post_x(&proc->lock, lcnt_locks, __FILE__, __LINE__);
- }
-#endif
- }
- else {
- if (flags & ERTS_P2P_FLG_TRY_LOCK)
- proc = ERTS_PROC_LOCK_BUSY;
- else {
-#ifdef ERTS_ENABLE_LOCK_COUNT
- erts_lcnt_proc_lock_unaquire(&proc->lock, lcnt_locks);
-#endif
- erts_pid2proc_safelock(c_p,
- c_p_have_locks,
- &proc,
- pid_need_locks,
- pix_lock,
- flags);
- if (proc && (flags & ERTS_P2P_FLG_SMP_INC_REFC))
- proc->lock.refc++;
- }
- }
- }
- }
-
- erts_pix_unlock(pix_lock);
-#ifdef ERTS_PROC_LOCK_DEBUG
- ERTS_LC_ASSERT(!proc
- || proc == ERTS_PROC_LOCK_BUSY
- || (pid_need_locks ==
- (ERTS_PROC_LOCK_FLGS_READ_(&proc->lock)
- & pid_need_locks)));
-#endif
-
-
- done:
-
-#if ERTS_PROC_LOCK_ATOMIC_IMPL
- ETHR_COMPILER_BARRIER;
-#endif
-
- return proc;
+ Process *proc = erts_proc_lookup_raw(pid);
+ return ((!(flags & ERTS_P2P_FLG_ALLOW_OTHER_X)
+ && proc
+ && ERTS_PROC_IS_EXITING(proc))
+ ? NULL
+ : proc);
}
-#endif /* ERTS_SMP */
+#endif /* !ERTS_SMP */
#endif /* #if ERTS_GLB_INLINE_INCL_FUNC_DEF */