erts: Refactor code loading with renaming

Rename lock_code_ix as seize_code_write_permission. Don't want to call
it a "lock" as it can be held between schedulings and different threads
and is not managed by lock checker.

Rename "activate" staging as "commit" staging. Why not be consistent
and use git terminology all the way.

8 files changed, 41 insertions, 44 deletions

diff --git a/erts/emulator/beam/beam_bif_load.c b/erts/emulator/beam/beam_bif_load.c
index fbab59f794..e06fe52c36 100644
--- a/erts/emulator/beam/beam_bif_load.c
+++ b/erts/emulator/beam/beam_bif_load.c
@@ -72,7 +72,7 @@ BIF_RETTYPE code_make_stub_module_3(BIF_ALIST_3)
     Module* modp;
     Eterm res;
 
-    if (!erts_try_lock_code_ix(BIF_P)) {
+    if (!erts_try_seize_code_write_permission(BIF_P)) {
 	ERTS_BIF_YIELD3(bif_export[BIF_code_make_stub_module_3],
 			BIF_P, BIF_ARG_1, BIF_ARG_2, BIF_ARG_3);
     }
@@ -94,14 +94,14 @@ BIF_RETTYPE code_make_stub_module_3(BIF_ALIST_3)
 
     if (res == BIF_ARG_1) {
 	erts_end_staging_code_ix();
-	erts_activate_staging_code_ix();
+	erts_commit_staging_code_ix();
     }
     else {
 	erts_abort_staging_code_ix();
     }
     erts_smp_thr_progress_unblock();
     erts_smp_proc_lock(BIF_P, ERTS_PROC_LOCK_MAIN);
-    erts_unlock_code_ix();
+    erts_release_code_write_permission();
     return res;
 }
 
@@ -177,7 +177,7 @@ finish_loading_1(BIF_ALIST_1)
     int is_blocking = 0;
     int do_commit = 0;
 
-    if (!erts_try_lock_code_ix(BIF_P)) {
+    if (!erts_try_seize_code_write_permission(BIF_P)) {
 	ERTS_BIF_YIELD1(bif_export[BIF_finish_loading_1], BIF_P, BIF_ARG_1);
     }
 
@@ -324,7 +324,7 @@ staging_epilogue(Process* c_p, int commit, Eterm res, int is_blocking)
     {
 	if (commit) {
 	    erts_end_staging_code_ix();
-	    erts_activate_staging_code_ix();
+	    erts_commit_staging_code_ix();
 	}
 	else {
 	    erts_abort_staging_code_ix();
@@ -333,7 +333,7 @@ staging_epilogue(Process* c_p, int commit, Eterm res, int is_blocking)
 	    erts_smp_thr_progress_unblock();
 	    erts_smp_proc_lock(c_p, ERTS_PROC_LOCK_MAIN);
 	}
-	erts_unlock_code_ix();
+	erts_release_code_write_permission();
 	return res;
     }
 #ifdef ERTS_SMP
@@ -461,7 +461,7 @@ BIF_RETTYPE delete_module_1(BIF_ALIST_1)
 	BIF_ERROR(BIF_P, BADARG);
     }
 
-    if (!erts_try_lock_code_ix(BIF_P)) {
+    if (!erts_try_seize_code_write_permission(BIF_P)) {
 	ERTS_BIF_YIELD1(bif_export[BIF_delete_module_1], BIF_P, BIF_ARG_1);
     }
 
@@ -572,7 +572,7 @@ BIF_RETTYPE finish_after_on_load_2(BIF_ALIST_2)
     Module* modp;
     Eterm on_load;
 
-    if (!erts_try_lock_code_ix(BIF_P)) {
+    if (!erts_try_seize_code_write_permission(BIF_P)) {
 	ERTS_BIF_YIELD2(bif_export[BIF_finish_after_on_load_2],
 			BIF_P, BIF_ARG_1, BIF_ARG_2);
     }
@@ -589,7 +589,7 @@ BIF_RETTYPE finish_after_on_load_2(BIF_ALIST_2)
     error:
 	erts_smp_thr_progress_unblock();
         erts_smp_proc_lock(BIF_P, ERTS_PROC_LOCK_MAIN);
-	erts_unlock_code_ix();
+	erts_release_code_write_permission();
 	BIF_ERROR(BIF_P, BADARG);
     }
     if ((on_load = modp->curr.code[MI_ON_LOAD_FUNCTION_PTR]) == 0) {
@@ -639,7 +639,7 @@ BIF_RETTYPE finish_after_on_load_2(BIF_ALIST_2)
     }
     erts_smp_thr_progress_unblock();
     erts_smp_proc_lock(BIF_P, ERTS_PROC_LOCK_MAIN);
-    erts_unlock_code_ix();
+    erts_release_code_write_permission();
     BIF_RET(am_true);
 }
 
@@ -898,7 +898,7 @@ BIF_RETTYPE purge_module_1(BIF_ALIST_1)
 	BIF_ERROR(BIF_P, BADARG);
     }
 
-    if (!erts_try_lock_code_ix(BIF_P)) {
+    if (!erts_try_seize_code_write_permission(BIF_P)) {
 	ERTS_BIF_YIELD1(bif_export[BIF_purge_module_1], BIF_P, BIF_ARG_1);
     }
 
@@ -959,7 +959,7 @@ BIF_RETTYPE purge_module_1(BIF_ALIST_1)
 	erts_smp_thr_progress_unblock();
 	erts_smp_proc_lock(BIF_P, ERTS_PROC_LOCK_MAIN);
     }
-    erts_unlock_code_ix();
+    erts_release_code_write_permission();
     return ret;
 }
 
diff --git a/erts/emulator/beam/beam_debug.c b/erts/emulator/beam/beam_debug.c
index d288a37911..e69cbc3048 100644
--- a/erts/emulator/beam/beam_debug.c
+++ b/erts/emulator/beam/beam_debug.c
@@ -114,7 +114,7 @@ erts_debug_breakpoint_2(BIF_ALIST_2)
 	mfa[2] = signed_val(mfa[2]);
     }
 
-    if (!erts_try_lock_code_ix(BIF_P)) {
+    if (!erts_try_seize_code_write_permission(BIF_P)) {
 	ERTS_BIF_YIELD2(bif_export[BIF_erts_debug_breakpoint_2],
 			BIF_P, BIF_ARG_1, BIF_ARG_2);
     }
@@ -129,7 +129,7 @@ erts_debug_breakpoint_2(BIF_ALIST_2)
 
     erts_smp_thr_progress_unblock();
     erts_smp_proc_lock(p, ERTS_PROC_LOCK_MAIN);
-    erts_unlock_code_ix();
+    erts_release_code_write_permission();
     return res;
 
  error:
diff --git a/erts/emulator/beam/code_ix.c b/erts/emulator/beam/code_ix.c
index def7e164e2..9158d2d05c 100644
--- a/erts/emulator/beam/code_ix.c
+++ b/erts/emulator/beam/code_ix.c
@@ -75,7 +75,7 @@ void erts_end_staging_code_ix(void)
     CIX_TRACE("end");
 }
 
-void erts_activate_staging_code_ix(void)
+void erts_commit_staging_code_ix(void)
 {
     ErtsCodeIndex ix;
     /* We need to this lock as we are now making the staging export table active */
@@ -98,14 +98,14 @@ void erts_abort_staging_code_ix(void)
 }
 
 
-/* Try lock code_ix
+/*
  * Calller _must_ yield if we return 0
  */
-int erts_try_lock_code_ix(Process* c_p)
+int erts_try_seize_code_write_permission(Process* c_p)
 {
     int success;
 
-    ASSERT(!erts_smp_thr_progress_is_blocking());
+    ASSERT(!erts_smp_thr_progress_is_blocking()); /* to avoid deadlock */
 
     erts_smp_mtx_lock(&the_code_ix_queue_lock);
     success = !the_code_ix_lock;
@@ -125,9 +125,7 @@ int erts_try_lock_code_ix(Process* c_p)
    return success;
 }
 
-/* Unlock code_ix (resume all waiters)
-*/
-void erts_unlock_code_ix(void)
+void erts_release_code_write_permission(void)
 {
     erts_smp_mtx_lock(&the_code_ix_queue_lock);
     while (the_code_ix_queue != NULL) { /* unleash the entire herd */
diff --git a/erts/emulator/beam/code_ix.h b/erts/emulator/beam/code_ix.h
index c37a5fe8f4..068ff0e6ba 100644
--- a/erts/emulator/beam/code_ix.h
+++ b/erts/emulator/beam/code_ix.h
@@ -81,38 +81,37 @@ ErtsCodeIndex erts_active_code_ix(void);
 ERTS_GLB_INLINE
 ErtsCodeIndex erts_staging_code_ix(void);
 
-/* Try lock code_ix that is needed for (exlusive) access of the staging area.
+/* Try seize exclusive code write permission. Needed for code staging.
  * Main process lock (only) must be held.
  * System thread progress must not be blocked.
  * Caller is suspended and *must* yield if 0 is returned. 
  */
-int erts_try_lock_code_ix(struct process*);
+int erts_try_seize_code_write_permission(struct process*);
 
-/* Unlock code_ix
+/* Release code write permission.
+ * Will resume any suspended waiters.
  */
-void erts_unlock_code_ix(void);
+void erts_release_code_write_permission(void);
 
 /* Prepare the "staging area" to be a complete copy of the active code.
- * code_ix must be locked.
- * Must be followed by calls to either "end" and "activate" or "abort" before
- * code_ix lock is released.
+ * Code write permission must have been seized.
+ * Must be followed by calls to either "end" and "commit" or "abort" before
+ * code write permission can be released.
  */
 void erts_start_staging_code_ix(void);
 
 /* End the staging.
- * code_ix must be locked.
- * Must be followed by a call to either "activate" or "abort"
- * before code_ix lock is released.
+ * Preceded by "start" and followed by "commit" or "abort".
  */
 void erts_end_staging_code_ix(void);
 
 /* Set staging code index as new active code index.
- * code_ix must be locked and "start" and "end" called.
+ * Preceded by "end".
  */
-void erts_activate_staging_code_ix(void);
+void erts_commit_staging_code_ix(void);
 
 /* Abort the staging.
- * code_ix must be locked and "start" called.
+ * Preceded by "start" or "end".
  */
 void erts_abort_staging_code_ix(void);
 
diff --git a/erts/emulator/beam/erl_bif_trace.c b/erts/emulator/beam/erl_bif_trace.c
index 6f04787478..1c99fcdaa6 100644
--- a/erts/emulator/beam/erl_bif_trace.c
+++ b/erts/emulator/beam/erl_bif_trace.c
@@ -108,7 +108,7 @@ trace_pattern(Process* p, Eterm MFA, Eterm Pattern, Eterm flaglist)
     Process *meta_tracer_proc = p;
     Eterm meta_tracer_pid = p->id;
 
-    if (!erts_try_lock_code_ix(p)) {
+    if (!erts_try_seize_code_write_permission(p)) {
 	ERTS_BIF_YIELD3(bif_export[BIF_trace_pattern_3], p, MFA, Pattern, flaglist);
     }
     erts_smp_proc_unlock(p, ERTS_PROC_LOCK_MAIN);
@@ -338,7 +338,7 @@ trace_pattern(Process* p, Eterm MFA, Eterm Pattern, Eterm flaglist)
     UnUseTmpHeap(3,p);
     erts_smp_thr_progress_unblock();
     erts_smp_proc_lock(p, ERTS_PROC_LOCK_MAIN);
-    erts_unlock_code_ix();
+    erts_release_code_write_permission();
 
     if (matches >= 0) {
 	return make_small(matches);
@@ -464,7 +464,7 @@ Eterm trace_3(BIF_ALIST_3)
 	BIF_ERROR(p, BADARG);
     }
 
-    if (!erts_try_lock_code_ix(BIF_P)) {
+    if (!erts_try_seize_code_write_permission(BIF_P)) {
 	ERTS_BIF_YIELD3(bif_export[BIF_trace_3], BIF_P, BIF_ARG_1, BIF_ARG_2, BIF_ARG_3);
     }
 
@@ -732,7 +732,7 @@ Eterm trace_3(BIF_ALIST_3)
 	erts_smp_proc_lock(p, ERTS_PROC_LOCK_MAIN);
     }
 #endif
-    erts_unlock_code_ix();
+    erts_release_code_write_permission();
 
     BIF_RET(make_small(matches));
 
@@ -748,7 +748,7 @@ Eterm trace_3(BIF_ALIST_3)
 	erts_smp_proc_lock(p, ERTS_PROC_LOCK_MAIN);
     }
 #endif
-    erts_unlock_code_ix();
+    erts_release_code_write_permission();
 
     BIF_ERROR(p, BADARG);
 }
diff --git a/erts/emulator/beam/erl_init.c b/erts/emulator/beam/erl_init.c
index a4690891d5..4db23a0a18 100644
--- a/erts/emulator/beam/erl_init.c
+++ b/erts/emulator/beam/erl_init.c
@@ -1474,7 +1474,7 @@ erl_start(int argc, char **argv)
     init_shared_memory(boot_argc, boot_argv);
     load_preloaded();
     erts_end_staging_code_ix();
-    erts_activate_staging_code_ix();
+    erts_commit_staging_code_ix();
 
     erts_initialized = 1;
 
diff --git a/erts/emulator/beam/erl_nif.c b/erts/emulator/beam/erl_nif.c
index a0182630b9..bdbeb3bcf6 100644
--- a/erts/emulator/beam/erl_nif.c
+++ b/erts/emulator/beam/erl_nif.c
@@ -1522,7 +1522,7 @@ BIF_RETTYPE load_nif_2(BIF_ALIST_2)
     }
     lib_name[len] = '\0';
 
-    if (!erts_try_lock_code_ix(BIF_P)) {
+    if (!erts_try_seize_code_write_permission(BIF_P)) {
 	erts_free(ERTS_ALC_T_TMP, lib_name);
 	ERTS_BIF_YIELD2(bif_export[BIF_load_nif_2],
 			BIF_P, BIF_ARG_1, BIF_ARG_2);
@@ -1722,7 +1722,7 @@ BIF_RETTYPE load_nif_2(BIF_ALIST_2)
 
     erts_smp_thr_progress_unblock();
     erts_smp_proc_lock(BIF_P, ERTS_PROC_LOCK_MAIN);
-    erts_unlock_code_ix();
+    erts_release_code_write_permission();
     erts_free(ERTS_ALC_T_TMP, lib_name);
 
     if (reload_warning) {
diff --git a/erts/emulator/beam/erl_process.c b/erts/emulator/beam/erl_process.c
index aaee951107..a7707e9498 100644
--- a/erts/emulator/beam/erl_process.c
+++ b/erts/emulator/beam/erl_process.c
@@ -1178,7 +1178,7 @@ handle_code_ix_activation(ErtsAuxWorkData *awdp, erts_aint32_t aux_work)
 #endif
     erts_smp_proc_lock(p, ERTS_PROC_LOCK_STATUS);
     if (!ERTS_PROC_IS_EXITING(p)) {
-	erts_activate_staging_code_ix();
+	erts_commit_staging_code_ix();
 	erts_resume(p, ERTS_PROC_LOCK_STATUS);
 	erts_smp_proc_unlock(p, ERTS_PROC_LOCK_STATUS);
     }
@@ -1186,7 +1186,7 @@ handle_code_ix_activation(ErtsAuxWorkData *awdp, erts_aint32_t aux_work)
 	erts_smp_proc_unlock(p, ERTS_PROC_LOCK_STATUS);
 	erts_abort_staging_code_ix();
     }
-    erts_unlock_code_ix();
+    erts_release_code_write_permission();
     erts_smp_proc_dec_refc(p);
     return aux_work & ~ERTS_SSI_AUX_WORK_CODE_IX_ACTIVATION;
 }