1 files changed, 76 insertions, 18 deletions

diff --git a/erts/emulator/nifs/common/zlib_nif.c b/erts/emulator/nifs/common/zlib_nif.c
index a9c5b05e47..b709ed5a6f 100644
--- a/erts/emulator/nifs/common/zlib_nif.c
+++ b/erts/emulator/nifs/common/zlib_nif.c
@@ -106,6 +106,7 @@ typedef struct {
     int inflateChunk_buffer_size;
 
     ErlNifPid controlling_process;
+    ErlNifMutex *controller_lock;
 
     ErlNifIOQueue *input_queue;
 
@@ -117,6 +118,8 @@ typedef struct {
 
 static ERL_NIF_TERM zlib_open(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]);
 static ERL_NIF_TERM zlib_close(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]);
+static ERL_NIF_TERM zlib_set_controller(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]);
+
 static ERL_NIF_TERM zlib_deflateInit(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]);
 static ERL_NIF_TERM zlib_deflateSetDictionary(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]);
 static ERL_NIF_TERM zlib_deflateReset(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]);
@@ -143,6 +146,11 @@ static ERL_NIF_TERM zlib_setBufSize(ErlNifEnv *env, int argc, const ERL_NIF_TERM
 static ERL_NIF_TERM zlib_enqueue_input(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]);
 
 static ErlNifFunc nif_funcs[] = {
+    {"close_nif", 1, zlib_close},
+    {"open_nif", 0, zlib_open},
+
+    {"set_controller_nif", 2, zlib_set_controller},
+
     /* deflate */
     {"deflateInit_nif", 6, zlib_deflateInit},
     {"deflateSetDictionary_nif", 2, zlib_deflateSetDictionary},
@@ -162,10 +170,6 @@ static ErlNifFunc nif_funcs[] = {
     /* running checksum */
     {"crc32_nif", 1, zlib_crc32},
 
-    /* open & close */
-    {"close_nif", 1, zlib_close},
-    {"open_nif", 0, zlib_open},
-
     /* The stash keeps a single term alive across calls, and is used in
      * exception_on_need_dict/1 to retain the old error behavior, and for
      * saving data flushed through deflateParams/3. */
@@ -281,9 +285,7 @@ static ERL_NIF_TERM zlib_return(ErlNifEnv *env, int code) {
     return reason;
 }
 
-static void gc_zlib(ErlNifEnv *env, void* data) {
-    zlib_data_t *d = (zlib_data_t*)data;
-
+static void zlib_internal_close(zlib_data_t *d) {
     if(d->state == ST_DEFLATE) {
         deflateEnd(&d->s);
     } else if(d->state == ST_INFLATE) {
@@ -291,8 +293,6 @@ static void gc_zlib(ErlNifEnv *env, void* data) {
     }
 
     if(d->state != ST_CLOSED) {
-        enif_ioq_destroy(d->input_queue);
-
         if(d->stash_env != NULL) {
             enif_free_env(d->stash_env);
         }
@@ -301,17 +301,36 @@ static void gc_zlib(ErlNifEnv *env, void* data) {
     }
 }
 
+static void gc_zlib(ErlNifEnv *env, void* data) {
+    zlib_data_t *d = (zlib_data_t*)data;
+
+    enif_mutex_destroy(d->controller_lock);
+    enif_ioq_destroy(d->input_queue);
+
+    zlib_internal_close(d);
+
+    (void)env;
+}
+
 static int get_zlib_data(ErlNifEnv *env, ERL_NIF_TERM opaque, zlib_data_t **d) {
     return enif_get_resource(env, opaque, rtype_zlib, (void **)d);
 }
 
 static int zlib_process_check(ErlNifEnv *env, zlib_data_t *d) {
+    int is_controlling_process;
     ErlNifPid current_process;
 
     enif_self(env, &current_process);
 
-    return enif_is_identical(enif_make_pid(env, &current_process),
+    enif_mutex_lock(d->controller_lock);
+
+    is_controlling_process = enif_is_identical(
+        enif_make_pid(env, &current_process),
         enif_make_pid(env, &d->controlling_process));
+
+    enif_mutex_unlock(d->controller_lock);
+
+    return is_controlling_process;
 }
 
 static void zlib_reset_input(zlib_data_t *d) {
@@ -516,6 +535,8 @@ static ERL_NIF_TERM zlib_open(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[
 
     d->input_queue = enif_ioq_create(ERL_NIF_IOQ_NORMAL);
 
+    d->controller_lock = enif_mutex_create("zlib_controller_lock");
+
     d->s.zalloc = zlib_alloc;
     d->s.zfree  = zlib_free;
     d->s.opaque = d;
@@ -556,7 +577,28 @@ static ERL_NIF_TERM zlib_close(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv
         return enif_raise_exception(env, am_not_initialized);
     }
 
-    gc_zlib(env, d);
+    zlib_internal_close(d);
+
+    return am_ok;
+}
+
+static ERL_NIF_TERM zlib_set_controller(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) {
+    zlib_data_t *d;
+
+    ErlNifPid new_owner;
+
+    if(argc != 2 || !get_zlib_data(env, argv[0], &d)
+                 || !enif_get_local_pid(env, argv[1], &new_owner)) {
+        return enif_make_badarg(env);
+    } else if(!zlib_process_check(env, d)) {
+        return enif_raise_exception(env, am_not_on_controlling_process);
+    }
+
+    enif_mutex_lock(d->controller_lock);
+
+    d->controlling_process = new_owner;
+
+    enif_mutex_unlock(d->controller_lock);
 
     return am_ok;
 }
@@ -675,7 +717,9 @@ static ERL_NIF_TERM zlib_deflateEnd(ErlNifEnv *env, int argc, const ERL_NIF_TERM
 
 static ERL_NIF_TERM zlib_deflateParams(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) {
     zlib_data_t *d;
+
     int res, level, strategy;
+    Bytef dummy_buffer;
 
     if(argc != 3 || !get_zlib_data(env, argv[0], &d)
                  || !enif_get_int(env, argv[1], &level)
@@ -687,12 +731,27 @@ static ERL_NIF_TERM zlib_deflateParams(ErlNifEnv *env, int argc, const ERL_NIF_T
         return enif_raise_exception(env, am_not_initialized);
     }
 
-    /* deflateParams will flush everything currently in the stream, corrupting
-     * the heap unless it's empty. We therefore pretend to have a full output
-     * buffer, forcing a Z_BUF_ERROR if there's anything left to be flushed. */
-    d->s.avail_out = 0;
+    /* This is a bit of a hack; deflateParams flushes with Z_BLOCK which won't
+     * stop at a byte boundary, so we can't split this operation up, and we
+     * can't allocate a buffer large enough to fit it in one go since we have
+     * to support zlib versions that lack deflatePending.
+     *
+     * We therefore flush everything prior to this call to ensure that we are
+     * stopped on a byte boundary and have no pending data. We then hand it a
+     * dummy buffer to detect when this assumption doesn't hold (Hopefully
+     * never), and to smooth over an issue with zlib 1.2.11 which always
+     * returns Z_BUF_ERROR when d->s.avail_out is 0, regardless of whether
+     * there's any pending data or not. */
+
+    d->s.next_out = &dummy_buffer;
+    d->s.avail_out = 1;
+
     res = deflateParams(&d->s, level, strategy);
 
+    if(d->s.avail_out == 0) {
+        return zlib_return(env, Z_STREAM_ERROR);
+    }
+
     return zlib_return(env, res);
 }
 
@@ -887,7 +946,7 @@ static ERL_NIF_TERM zlib_inflate(ErlNifEnv *env, int argc, const ERL_NIF_TERM ar
         return enif_raise_exception(env, am_not_initialized);
     }
 
-    if(d->eos_seen) {
+    if(d->eos_seen && enif_ioq_size(d->input_queue) > 0) {
         int res;
 
         switch(d->eos_behavior) {
@@ -901,11 +960,10 @@ static ERL_NIF_TERM zlib_inflate(ErlNifEnv *env, int argc, const ERL_NIF_TERM ar
             }
 
             d->eos_seen = 0;
+
             break;
         case EOS_BEHAVIOR_CUT:
             zlib_reset_input(d);
-
-            return enif_make_tuple2(env, am_finished, enif_make_list(env, 0));
         }
     }