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authorSteve Vinoski <[email protected]>2015-05-06 23:15:04 -0400
committerSteve Vinoski <[email protected]>2015-05-26 11:59:24 -0400
commit17735c9f3879145f43a3e4be0369b7117b1b7b84 (patch)
tree023c9e747367897606aca135e39e6f1f1fae5788 /erts/emulator/beam/erl_nif.c
parent884afd8efb8672df2889df98b5b94f3dbb53952c (diff)
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Add enif_raise_exception
Add enif_raise_exception function to allow NIFs to raise error exceptions holding any Erlang terms. This does not replace or deprecate the enif_make_badarg function, though, because raising badarg errors is so idiomatic in NIFs. Reimplement enif_make_badarg on top of enif_raise_exception. Add new tests for enif_raise_exception for both normal and dirty NIFs. Add documentation for enif_raise_exception.
Diffstat (limited to 'erts/emulator/beam/erl_nif.c')
-rw-r--r--erts/emulator/beam/erl_nif.c63
1 files changed, 41 insertions, 22 deletions
diff --git a/erts/emulator/beam/erl_nif.c b/erts/emulator/beam/erl_nif.c
index 36da6519f7..8c222a6db7 100644
--- a/erts/emulator/beam/erl_nif.c
+++ b/erts/emulator/beam/erl_nif.c
@@ -737,14 +737,20 @@ Eterm enif_make_sub_binary(ErlNifEnv* env, ERL_NIF_TERM bin_term,
Eterm enif_make_badarg(ErlNifEnv* env)
{
+ return enif_raise_exception(env, am_badarg);
+}
+
+Eterm enif_raise_exception(ErlNifEnv* env, ERL_NIF_TERM reason)
+{
env->exception_thrown = 1;
- BIF_ERROR(env->proc, BADARG);
+ env->proc->fvalue = reason;
+ BIF_ERROR(env->proc, EXC_ERROR);
}
int enif_has_pending_exception(ErlNifEnv* env, ERL_NIF_TERM* reason)
{
if (env->exception_thrown && reason != NULL) {
- *reason = am_badarg;
+ *reason = env->proc->fvalue;
}
return env->exception_thrown;
}
@@ -1541,12 +1547,13 @@ int enif_consume_timeslice(ErlNifEnv* env, int percent)
* NIF exports need a few more items than the Export struct provides,
* including the erl_module_nif* and a NIF function pointer, so the
* NifExport below adds those. The Export member must be first in the
- * struct. The saved_mfa, saved_argc, nif_level, alloced_argv_sz and argv
- * members are used to track the MFA and arguments of the top NIF in case a
- * chain of one or more enif_schedule_nif() calls results in an exception,
- * since in that case the original MFA and registers have to be restored
- * before returning to Erlang to ensure stacktrace information associated
- * with the exception is correct.
+ * struct. The saved_mfa, exception_thrown, saved_argc, rootset_extra, and
+ * rootset members are used to track the MFA, any pending exception, and
+ * arguments of the top NIF in case a chain of one or more
+ * enif_schedule_nif() calls results in an exception, since in that case
+ * the original MFA and registers have to be restored before returning to
+ * Erlang to ensure stacktrace information associated with the exception is
+ * correct.
*/
typedef ERL_NIF_TERM (*NativeFunPtr)(ErlNifEnv*, int, const ERL_NIF_TERM[]);
@@ -1555,25 +1562,28 @@ typedef struct {
struct erl_module_nif* m;
NativeFunPtr fp;
Eterm saved_mfa[3];
+ int exception_thrown;
int saved_argc;
- int alloced_argv_sz;
- Eterm argv[1];
+ int rootset_extra;
+ Eterm rootset[1];
} NifExport;
/*
* If a process has saved arguments, they need to be part of the GC
* rootset. The function below is called from setup_rootset() in
- * erl_gc.c. This function is declared in erl_process.h.
+ * erl_gc.c. This function is declared in erl_process.h. Any exception term
+ * saved in the NifExport is also made part of the GC rootset here; it
+ * always resides in rootset[0].
*/
int
erts_setup_nif_gc(Process* proc, Eterm** objv, int* nobj)
{
NifExport* ep = (NifExport*) ERTS_PROC_GET_NIF_TRAP_EXPORT(proc);
- int gc = (ep && ep->saved_argc > 0);
+ int gc = ep && (ep->saved_argc > 0 || ep->rootset[0] != NIL);
if (gc) {
- *objv = ep->argv;
- *nobj = ep->saved_argc;
+ *objv = ep->rootset;
+ *nobj = 1 + ep->saved_argc;
}
return gc;
}
@@ -1585,14 +1595,14 @@ static NifExport*
allocate_nif_sched_data(Process* proc, int argc)
{
NifExport* ep;
- size_t argv_extra, total;
+ size_t total;
int i;
- argv_extra = argc > 1 ? sizeof(Eterm)*(argc-1) : 0;
- total = sizeof(NifExport) + argv_extra;
+ total = sizeof(NifExport) + argc*sizeof(Eterm);
ep = erts_alloc(ERTS_ALC_T_NIF_TRAP_EXPORT, total);
sys_memset((void*) ep, 0, total);
- ep->alloced_argv_sz = argc;
+ ep->rootset_extra = argc;
+ ep->rootset[0] = NIL;
for (i=0; i<ERTS_NUM_CODE_IX; i++) {
ep->exp.addressv[i] = &ep->exp.code[3];
}
@@ -1633,15 +1643,22 @@ init_nif_sched_data(ErlNifEnv* env, NativeFunPtr direct_fp, NativeFunPtr indirec
ep = (NifExport*) ERTS_PROC_GET_NIF_TRAP_EXPORT(proc);
if (!ep)
ep = allocate_nif_sched_data(proc, argc);
- else if (need_save && ep->alloced_argv_sz < argc) {
+ else if (need_save && ep->rootset_extra < argc) {
NifExport* new_ep = allocate_nif_sched_data(proc, argc);
destroy_nif_export(ep);
ep = new_ep;
}
+ if (env->exception_thrown) {
+ ep->exception_thrown = 1;
+ ep->rootset[0] = env->proc->fvalue;
+ } else {
+ ep->exception_thrown = 0;
+ ep->rootset[0] = NIL;
+ }
ERTS_VBUMP_ALL_REDS(proc);
for (i = 0; i < argc; i++) {
if (need_save)
- ep->argv[i] = reg[i];
+ ep->rootset[i+1] = reg[i];
reg[i] = (Eterm) argv[i];
}
if (need_save) {
@@ -1677,7 +1694,7 @@ restore_nif_mfa(Process* proc, NifExport* ep, int exception)
proc->current[2] = ep->saved_mfa[2];
if (exception)
for (i = 0; i < ep->saved_argc; i++)
- reg[i] = ep->argv[i];
+ reg[i] = ep->rootset[i+1];
ep->saved_argc = 0;
ep->saved_mfa[0] = THE_NON_VALUE;
}
@@ -1702,6 +1719,7 @@ dirty_nif_finalizer(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
ASSERT(!ERTS_SCHEDULER_IS_DIRTY(env->proc->scheduler_data));
ep = (NifExport*) ERTS_PROC_GET_NIF_TRAP_EXPORT(proc);
ASSERT(ep);
+ ASSERT(!ep->exception_thrown);
if (ep->fp)
restore_nif_mfa(proc, ep, 0);
return argv[0];
@@ -1719,9 +1737,10 @@ dirty_nif_exception(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
ASSERT(!ERTS_SCHEDULER_IS_DIRTY(env->proc->scheduler_data));
ep = (NifExport*) ERTS_PROC_GET_NIF_TRAP_EXPORT(proc);
ASSERT(ep);
+ ASSERT(ep->exception_thrown);
if (ep->fp)
restore_nif_mfa(proc, ep, 1);
- return enif_make_badarg(env);
+ return enif_raise_exception(env, ep->rootset[0]);
}
/*