From 8a3eb523d2747b8637eda989799821db0e78d360 Mon Sep 17 00:00:00 2001
From: Ilya Averyanov <av@rubybox.dev>
Date: Sat, 6 Apr 2024 17:48:25 +0300
Subject: [PATCH 1/2] fix: do not try to save future creator's env

---
 c_src/main.c      | 14 +-------------
 c_src/resources.h |  1 -
 2 files changed, 1 insertion(+), 14 deletions(-)

diff --git a/c_src/main.c b/c_src/main.c
index 9a96400..8778cca 100644
--- a/c_src/main.c
+++ b/c_src/main.c
@@ -75,24 +75,13 @@ static void
 erlfdb_future_cb(FDBFuture* fdb_future, void* data)
 {
     ErlFDBFuture* future = (ErlFDBFuture*) data;
-    ErlNifEnv* caller;
     ERL_NIF_TERM msg;
 
-    // FoundationDB callbacks can fire from the thread
-    // that created them. Check if we were actually
-    // submitted to the network thread or not so that
-    // we pass the correct environment to enif_send
-    if(enif_thread_type() == ERL_NIF_THR_UNDEFINED) {
-        caller = NULL;
-    } else {
-        caller = future->pid_env;
-    }
-
     enif_mutex_lock(future->lock);
 
     if(!future->cancelled) {
         msg = T2(future->msg_env, future->msg_ref, ATOM_ready);
-        enif_send(caller, &(future->pid), future->msg_env, msg);
+        enif_send(NULL, &(future->pid), future->msg_env, msg);
     }
 
     enif_mutex_unlock(future->lock);
@@ -119,7 +108,6 @@ erlfdb_create_future(ErlNifEnv* env, FDBFuture* future, ErlFDBFutureGetter gette
     f->future = future;
     f->fgetter = getter;
     enif_self(env, &(f->pid));
-    f->pid_env = env;
     f->msg_env = enif_alloc_env();
     f->msg_ref = enif_make_copy(f->msg_env, ref);
     f->lock = enif_mutex_create("fdb:future_lock");
diff --git a/c_src/resources.h b/c_src/resources.h
index 42e0630..265f725 100644
--- a/c_src/resources.h
+++ b/c_src/resources.h
@@ -33,7 +33,6 @@ struct _ErlFDBFuture
     FDBFuture* future;
     ErlFDBFutureGetter fgetter;
     ErlNifPid pid;
-    ErlNifEnv* pid_env;
     ErlNifEnv* msg_env;
     ERL_NIF_TERM msg_ref;
     ErlNifMutex* lock;

From 5636dc895a1431ca725831f4b4b5dcd8b1d2c38d Mon Sep 17 00:00:00 2001
From: Ilya Averyanov <av@rubybox.dev>
Date: Sun, 7 Apr 2024 23:57:02 +0300
Subject: [PATCH 2/2] fix: span future lock only on  field operations

---
 c_src/main.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/c_src/main.c b/c_src/main.c
index 8778cca..090ff70 100644
--- a/c_src/main.c
+++ b/c_src/main.c
@@ -76,15 +76,18 @@ erlfdb_future_cb(FDBFuture* fdb_future, void* data)
 {
     ErlFDBFuture* future = (ErlFDBFuture*) data;
     ERL_NIF_TERM msg;
+    bool cancelled;
+
 
     enif_mutex_lock(future->lock);
+    cancelled = future->cancelled;
+    enif_mutex_unlock(future->lock);
 
-    if(!future->cancelled) {
+    if(!cancelled) {
         msg = T2(future->msg_env, future->msg_ref, ATOM_ready);
         enif_send(NULL, &(future->pid), future->msg_env, msg);
     }
 
-    enif_mutex_unlock(future->lock);
 
     // We're now done with this future which means we need
     // to release our handle to it. See erlfdb_create_future
@@ -557,9 +560,10 @@ erlfdb_future_cancel(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
     enif_mutex_lock(future->lock);
 
     future->cancelled = true;
+    enif_mutex_unlock(future->lock);
+
     fdb_future_cancel(future->future);
 
-    enif_mutex_unlock(future->lock);
 
     return ATOM_ok;
 }