Use static initialization for lists and mutexes.

This eliminates some run-time initialization, moving it to compile time.
Additional follow up work will expand on this to simplify initialization
and reduce the need for certain locks.

16 files changed, 65 insertions, 181 deletions

diff --git a/src/core/dialer.c b/src/core/dialer.c
index 3a749085..e3f435db 100644
--- a/src/core/dialer.c
+++ b/src/core/dialer.c
@@ -21,20 +21,18 @@ static void dialer_connect_cb(void *);
 static void dialer_timer_cb(void *);
 
 static nni_id_map dialers;
-static nni_mtx    dialers_lk;
+static nni_mtx    dialers_lk = NNI_MTX_INITIALIZER;
 
 void
 nni_dialer_sys_init(void)
 {
 	nni_id_map_init(&dialers, 1, 0x7fffffff, false);
-	nni_mtx_init(&dialers_lk);
 }
 
 void
 nni_dialer_sys_fini(void)
 {
 	nni_reap_drain();
-	nni_mtx_fini(&dialers_lk);
 	nni_id_map_fini(&dialers);
 }
 
diff --git a/src/core/idhash.h b/src/core/idhash.h
index 0c9043ce..b2259853 100644
--- a/src/core/idhash.h
+++ b/src/core/idhash.h
@@ -1,5 +1,5 @@
 //
-// Copyright 2020 Staysail Systems, Inc. <info@staysail.tech>
+// Copyright 2021 Staysail Systems, Inc. <info@staysail.tech>
 // Copyright 2018 Capitar IT Group BV <info@capitar.com>
 //
 // This software is supplied under the terms of the MIT License, a
@@ -23,28 +23,28 @@
 // use table sizes that are powers of two.  Note that hash items
 // must be non-NULL.  The table is protected by an internal lock.
 
-typedef struct nni_id_map       nni_id_map;
-typedef struct nni_id_entry     nni_id_entry;
+typedef struct nni_id_map   nni_id_map;
+typedef struct nni_id_entry nni_id_entry;
 
 // NB: These details are entirely private to the hash implementation.
 // They are provided here to facilitate inlining in structures.
 struct nni_id_map {
-	size_t        id_cap;
-	size_t        id_count;
-	size_t        id_load;
-	size_t        id_min_load; // considers placeholders
-	size_t        id_max_load;
+	uint32_t      id_cap;
+	uint32_t      id_count;
+	uint32_t      id_load;
+	uint32_t      id_min_load; // considers placeholders
+	uint32_t      id_max_load;
 	uint32_t      id_min_val;
 	uint32_t      id_max_val;
 	uint32_t      id_dyn_val;
 	nni_id_entry *id_entries;
 };
 
-extern void nni_id_map_init(nni_id_map *, uint32_t, uint32_t, bool);
-extern void nni_id_map_fini(nni_id_map *);
+extern void  nni_id_map_init(nni_id_map *, uint32_t, uint32_t, bool);
+extern void  nni_id_map_fini(nni_id_map *);
 extern void *nni_id_get(nni_id_map *, uint32_t);
-extern int nni_id_set(nni_id_map *, uint32_t, void *);
-extern int nni_id_alloc(nni_id_map *, uint32_t *, void *);
-extern int nni_id_remove(nni_id_map *, uint32_t);
+extern int   nni_id_set(nni_id_map *, uint32_t, void *);
+extern int   nni_id_alloc(nni_id_map *, uint32_t *, void *);
+extern int   nni_id_remove(nni_id_map *, uint32_t);
 
 #endif // CORE_IDHASH_H
diff --git a/src/core/init.c b/src/core/init.c
index c923fdf0..f9dee9e2 100644
--- a/src/core/init.c
+++ b/src/core/init.c
@@ -14,21 +14,16 @@
 #include <stdio.h>
 #include <stdlib.h>
 
-static nni_mtx  nni_init_mtx;
-static nni_list nni_init_list;
-static bool     nni_inited = false;
-
-extern int nni_tls_sys_init(void);
+extern int  nni_tls_sys_init(void);
 extern void nni_tls_sys_fini(void);
 
+static bool nni_inited = false;
+
 static int
 nni_init_helper(void)
 {
 	int rv;
 
-	nni_mtx_init(&nni_init_mtx);
-	NNI_LIST_INIT(&nni_init_list, nni_initializer, i_node);
-	nni_inited = true;
 #ifdef NNG_TEST_LIB
 	static bool cleanup = false;
 	if (!cleanup) {
@@ -54,6 +49,8 @@ nni_init_helper(void)
 	nni_pipe_sys_init();
 	nni_sp_tran_sys_init();
 
+	nni_inited = true;
+
 	return (0);
 }
 
@@ -69,19 +66,6 @@ nni_fini(void)
 	if (!nni_inited) {
 		return;
 	}
-	if (!nni_list_empty(&nni_init_list)) {
-		nni_initializer *init;
-
-		nni_mtx_lock(&nni_init_mtx);
-		while ((init = nni_list_first(&nni_init_list)) != NULL) {
-			if (init->i_fini != NULL) {
-				init->i_fini();
-			}
-			init->i_once = 0;
-			nni_list_remove(&nni_init_list, init);
-		}
-		nni_mtx_unlock(&nni_init_mtx);
-	}
 	nni_sp_tran_sys_fini();
 	nni_tls_sys_fini();
 	nni_pipe_sys_fini();
@@ -95,27 +79,6 @@ nni_fini(void)
 	nni_reap_sys_fini(); // must be before timer and aio (expire)
 	nni_stat_sys_fini();
 
-	nni_mtx_fini(&nni_init_mtx);
 	nni_plat_fini();
 	nni_inited = false;
 }
-
-int
-nni_initialize(nni_initializer *init)
-{
-	int rv;
-	if (init->i_once) {
-		return (0);
-	}
-	nni_mtx_lock(&nni_init_mtx);
-	if (init->i_once) {
-		nni_mtx_unlock(&nni_init_mtx);
-		return (0);
-	}
-	if ((rv = init->i_init()) == 0) {
-		init->i_once = 1;
-		nni_list_append(&nni_init_list, init);
-	}
-	nni_mtx_unlock(&nni_init_mtx);
-	return (rv);
-}
diff --git a/src/core/init.h b/src/core/init.h
index d21bb4c5..7875ba4c 100644
--- a/src/core/init.h
+++ b/src/core/init.h
@@ -23,23 +23,4 @@ int nni_init(void);
 // that all resources used by the library are released back to the system.
 void nni_fini(void);
 
-typedef struct nni_initializer {
-	int (*i_init)(void);  // i_init is called exactly once
-	void (*i_fini)(void); // i_fini is called on shutdown
-	int           i_once; // private -- initialize to zero
-	nni_list_node i_node; // private -- initialize to zero
-} nni_initializer;
-
-// nni_initialize will call the initialization routine exactly once.  This is
-// done efficiently, so that if the caller has initialized already, then
-// subsequent calls are "cheap" (no synchronization cost).  The initialization
-// function must not itself cause any further calls to nni_initialize; the
-// function should limit itself to initialization of locks and static data
-// structures.  When shutting down, the finalizer will be called.  The
-// order in which finalizers are called is unspecified.
-//
-// An initializer may fail (due to resource exhaustion), in which case the
-// return value of nni_initialize will be non-zero.
-int nni_initialize(nni_initializer *);
-
 #endif // CORE_INIT_H
diff --git a/src/core/list.h b/src/core/list.h
index 204057a2..d3c703bb 100644
--- a/src/core/list.h
+++ b/src/core/list.h
@@ -29,6 +29,16 @@ extern void nni_list_init_offset(nni_list *list, size_t offset);
 #define NNI_LIST_INIT(list, type, field) \
 	nni_list_init_offset(list, offsetof(type, field))
 
+// NNI_LIST_INITIALIZER is used to initialize structures at declaration time.
+// The list argument is the structure being initialized and the type and
+// offset determine where the node lives within each item.
+#define NNI_LIST_INITIALIZER(list, type, field)          \
+	{                                                \
+		.ll_head.ln_next = &(list).ll_head,      \
+		.ll_head.ln_prev = &(list).ll_head,      \
+		.ll_offset       = offsetof(type, field) \
+	}
+
 #define NNI_LIST_NODE_INIT(node)                       \
 	do {                                           \
 		(node)->ln_prev = (node)->ln_next = 0; \
diff --git a/src/core/listener.c b/src/core/listener.c
index 74e5e22b..4d4a4e24 100644
--- a/src/core/listener.c
+++ b/src/core/listener.c
@@ -22,20 +22,18 @@ static void listener_accept_cb(void *);
 static void listener_timer_cb(void *);
 
 static nni_id_map listeners;
-static nni_mtx    listeners_lk;
+static nni_mtx    listeners_lk = NNI_MTX_INITIALIZER;
 
 void
 nni_listener_sys_init(void)
 {
 	nni_id_map_init(&listeners, 1, 0x7fffffff, false);
-	nni_mtx_init(&listeners_lk);
 }
 
 void
 nni_listener_sys_fini(void)
 {
 	nni_reap_drain();
-	nni_mtx_fini(&listeners_lk);
 	nni_id_map_fini(&listeners);
 }
 
diff --git a/src/core/socket.c b/src/core/socket.c
index 6c43e43d..d9ac12b6 100644
--- a/src/core/socket.c
+++ b/src/core/socket.c
@@ -16,12 +16,6 @@
 
 // Socket implementation.
 
-static nni_list   sock_list;
-static nni_id_map sock_ids;
-static nni_mtx    sock_lk;
-static nni_id_map ctx_ids;
-static bool       inited;
-
 struct nni_ctx {
 	nni_list_node     c_node;
 	nni_sock         *c_sock;
@@ -107,6 +101,11 @@ struct nni_socket {
 #endif
 };
 
+static nni_list sock_list = NNI_LIST_INITIALIZER(sock_list, nni_sock, s_node);
+static nni_mtx    sock_lk = NNI_MTX_INITIALIZER;
+static nni_id_map sock_ids;
+static nni_id_map ctx_ids;
+
 static void nni_ctx_destroy(nni_ctx *);
 
 #define SOCK(s) ((nni_sock *) (s))
@@ -611,12 +610,8 @@ nni_sock_create(nni_sock **sp, const nni_proto *proto)
 void
 nni_sock_sys_init(void)
 {
-	NNI_LIST_INIT(&sock_list, nni_sock, s_node);
-	nni_mtx_init(&sock_lk);
-
 	nni_id_map_init(&sock_ids, 1, 0x7fffffff, false);
 	nni_id_map_init(&ctx_ids, 1, 0x7fffffff, false);
-	inited = true;
 }
 
 void
@@ -624,8 +619,6 @@ nni_sock_sys_fini(void)
 {
 	nni_id_map_fini(&sock_ids);
 	nni_id_map_fini(&ctx_ids);
-	nni_mtx_fini(&sock_lk);
-	inited = false;
 }
 
 int
@@ -822,9 +815,6 @@ nni_sock_closeall(void)
 {
 	nni_sock *s;
 
-	if (!inited) {
-		return;
-	}
 	for (;;) {
 		nni_mtx_lock(&sock_lk);
 		if ((s = nni_list_first(&sock_list)) == NULL) {
diff --git a/src/core/stats.c b/src/core/stats.c
index e4765078..f7e52fb0 100644
--- a/src/core/stats.c
+++ b/src/core/stats.c
@@ -19,21 +19,21 @@ struct nng_stat {
 	const nni_stat_info *s_info;
 	const nni_stat_item *s_item; // Used during snapshot collection
 	nni_list             s_children;
-	nni_stat *           s_parent;
+	nni_stat            *s_parent;
 	nni_list_node        s_node;
 	nni_time             s_timestamp;
 	union {
 		int      sv_id;
 		bool     sv_bool;
 		uint64_t sv_value;
-		char *   sv_string;
+		char    *sv_string;
 	} s_val;
 };
 
 #ifdef NNG_ENABLE_STATS
 static nni_stat_item stats_root;
-static nni_mtx       stats_lock;
-static nni_mtx       stats_val_lock;
+static nni_mtx       stats_lock     = NNI_MTX_INITIALIZER;
+static nni_mtx       stats_val_lock = NNI_MTX_INITIALIZER;
 #endif
 
 void
@@ -171,7 +171,7 @@ nni_stat_set_string(nni_stat_item *item, const char *s)
 {
 #ifdef NNG_ENABLE_STATS
 	const nni_stat_info *info = item->si_info;
-	char *               old  = item->si_u.sv_string;
+	char                *old  = item->si_u.sv_string;
 
 	nni_mtx_lock(&stats_val_lock);
 	if ((s != NULL) && (old != NULL) && (strcmp(s, old) == 0)) {
@@ -235,7 +235,7 @@ nng_stats_free(nni_stat *st)
 static int
 stat_make_tree(nni_stat_item *item, nni_stat **sp)
 {
-	nni_stat *     stat;
+	nni_stat      *stat;
 	nni_stat_item *child;
 
 	if ((stat = NNI_ALLOC_STRUCT(stat)) == NULL) {
@@ -266,8 +266,8 @@ stat_update(nni_stat *stat)
 {
 	const nni_stat_item *item = stat->s_item;
 	const nni_stat_info *info = item->si_info;
-	char *               old;
-	char *               str;
+	char                *old;
+	char                *str;
 
 	switch (info->si_type) {
 	case NNG_STAT_SCOPE:
@@ -397,7 +397,6 @@ nng_stat_bool(nni_stat *stat)
 	return (stat->s_val.sv_bool);
 }
 
-
 const char *
 nng_stat_string(nng_stat *stat)
 {
@@ -498,8 +497,6 @@ nni_stat_sys_init(void)
 		.si_desc = "all statistics",
 		.si_type = NNG_STAT_SCOPE,
 	};
-	nni_mtx_init(&stats_lock);
-	nni_mtx_init(&stats_val_lock);
 	nni_stat_init(&stats_root, &root);
 #endif
 	return (0);
@@ -508,10 +505,6 @@ nni_stat_sys_init(void)
 void
 nni_stat_sys_fini(void)
 {
-#ifdef NNG_ENABLE_STATS
-	nni_mtx_fini(&stats_lock);
-	nni_mtx_fini(&stats_val_lock);
-#endif
 }
 
 #ifdef NNG_ENABLE_STATS
@@ -538,10 +531,10 @@ nng_stats_dump(nng_stat *stat)
 #ifdef NNG_ENABLE_STATS
 	static char        buf[128]; // to minimize recursion, not thread safe
 	int                len;
-	char *             scope;
-	char *             indent = "        ";
+	char              *scope;
+	char              *indent = "        ";
 	unsigned long long val;
-	nni_stat *         child;
+	nni_stat          *child;
 
 	switch (nng_stat_type(stat)) {
 	case NNG_STAT_SCOPE:
diff --git a/src/platform/posix/posix_impl.h b/src/platform/posix/posix_impl.h
index 234d1501..97924a45 100644
--- a/src/platform/posix/posix_impl.h
+++ b/src/platform/posix/posix_impl.h
@@ -58,10 +58,16 @@ struct nni_plat_mtx {
 	pthread_mutex_t mtx;
 };
 
+#define NNI_MTX_INITIALIZER { PTHREAD_MUTEX_INITIALIZER }
+
 struct nni_rwlock {
 	pthread_rwlock_t rwl;
 };
 
+#define NNI_RWLOCK_INITIALIZER { PTHREAD_RWLOCK_INITIALIZER }
+
+// No static form of CV initialization because of the need to use
+// attributes to set the clock type.
 struct nni_plat_cv {
 	pthread_cond_t cv;
 	nni_plat_mtx  *mtx;
diff --git a/src/platform/posix/posix_thread.c b/src/platform/posix/posix_thread.c
index c47bcec6..b7cd5e1e 100644
--- a/src/platform/posix/posix_thread.c
+++ b/src/platform/posix/posix_thread.c
@@ -34,7 +34,7 @@
 #endif
 
 static pthread_mutex_t nni_plat_init_lock = PTHREAD_MUTEX_INITIALIZER;
-static int             nni_plat_inited    = 0;
+static volatile int    nni_plat_inited    = 0;
 static int             nni_plat_forked    = 0;
 
 pthread_condattr_t  nni_cvattr;
diff --git a/src/platform/windows/win_impl.h b/src/platform/windows/win_impl.h
index 608a065e..b3c08edf 100644
--- a/src/platform/windows/win_impl.h
+++ b/src/platform/windows/win_impl.h
@@ -37,15 +37,17 @@ struct nni_plat_thr {
 
 struct nni_plat_mtx {
 	SRWLOCK srl;
-	DWORD   owner;
-	int     init;
 };
 
+#define NNI_MTX_INITIALIZER { SRWLOCK_INIT }
+
 struct nni_rwlock {
 	SRWLOCK rwl;
 	BOOLEAN exclusive;
 };
 
+#define NNI_RWLOCK_INITIALIZER { SRWLOCK_INIT }
+
 struct nni_plat_cv {
 	CONDITION_VARIABLE cv;
 	PSRWLOCK           srl;
diff --git a/src/platform/windows/win_thread.c b/src/platform/windows/win_thread.c
index 31e783a3..b131c067 100644
--- a/src/platform/windows/win_thread.c
+++ b/src/platform/windows/win_thread.c
@@ -55,13 +55,11 @@ void
 nni_plat_mtx_init(nni_plat_mtx *mtx)
 {
 	InitializeSRWLock(&mtx->srl);
-	mtx->init = 1;
 }
 
 void
 nni_plat_mtx_fini(nni_plat_mtx *mtx)
 {
-	mtx->init = 0;
 }
 
 void
diff --git a/src/sp/transport.c b/src/sp/transport.c
index ed27ebeb..9f4c6522 100644
--- a/src/sp/transport.c
+++ b/src/sp/transport.c
@@ -14,8 +14,9 @@
 #include <stdio.h>
 #include <string.h>
 
-static nni_list   sp_tran_list;
-static nni_rwlock sp_tran_lk;
+static nni_list sp_tran_list =
+    NNI_LIST_INITIALIZER(sp_tran_list, nni_sp_tran, tran_link);
+static nni_rwlock sp_tran_lk = NNI_RWLOCK_INITIALIZER;
 
 void
 nni_sp_tran_register(nni_sp_tran *tran)
@@ -73,9 +74,6 @@ extern void nni_sp_zt_register(void);
 void
 nni_sp_tran_sys_init(void)
 {
-	NNI_LIST_INIT(&sp_tran_list, nni_sp_tran, tran_link);
-	nni_rwlock_init(&sp_tran_lk);
-
 #ifdef NNG_TRANSPORT_INPROC
 	nni_sp_inproc_register();
 #endif
@@ -110,5 +108,4 @@ nni_sp_tran_sys_fini(void)
 		nni_list_remove(&sp_tran_list, t);
 		t->tran_fini();
 	}
-	nni_rwlock_fini(&sp_tran_lk);
 }
diff --git a/src/supplemental/http/http_client.c b/src/supplemental/http/http_client.c
index 3737cb7b..b156794c 100644
--- a/src/supplemental/http/http_client.c
+++ b/src/supplemental/http/http_client.c
@@ -1,5 +1,5 @@
 //
-// Copyright 2020 Staysail Systems, Inc. <info@staysail.tech>
+// Copyright 2021 Staysail Systems, Inc. <info@staysail.tech>
 // Copyright 2018 Capitar IT Group BV <info@capitar.com>
 // Copyright 2019 Devolutions <info@devolutions.net>
 //
@@ -19,7 +19,7 @@
 
 #include "http_api.h"
 
-static nni_mtx http_txn_lk;
+static nni_mtx http_txn_lk = NNI_MTX_INITIALIZER;
 
 struct nng_http_client {
 	nni_list           aios;
@@ -198,15 +198,6 @@ nni_http_client_connect(nni_http_client *c, nni_aio *aio)
 	nni_mtx_unlock(&c->mtx);
 }
 
-static int  http_client_sys_init(void);
-static void http_client_sys_fini(void);
-
-static nni_initializer http_client_initializer = {
-	.i_init = http_client_sys_init,
-	.i_fini = http_client_sys_fini,
-	.i_once = 0,
-};
-
 typedef enum http_txn_state {
 	HTTP_CONNECTING,
 	HTTP_SENDING,
@@ -385,8 +376,6 @@ nni_http_transact_conn(
 	http_txn *txn;
 	int       rv;
 
-	nni_initialize(&http_client_initializer);
-
 	if (nni_aio_begin(aio) != 0) {
 		return;
 	}
@@ -430,8 +419,6 @@ nni_http_transact(nni_http_client *client, nni_http_req *req,
 	http_txn *txn;
 	int       rv;
 
-	nni_initialize(&http_client_initializer);
-
 	if (nni_aio_begin(aio) != 0) {
 		return;
 	}
@@ -470,16 +457,3 @@ nni_http_transact(nni_http_client *client, nni_http_req *req,
 	nni_http_client_connect(client, txn->aio);
 	nni_mtx_unlock(&http_txn_lk);
 }
-
-static int
-http_client_sys_init(void)
-{
-	nni_mtx_init(&http_txn_lk);
-	return (0);
-}
-
-static void
-http_client_sys_fini(void)
-{
-	nni_mtx_fini(&http_txn_lk);
-}
diff --git a/src/supplemental/http/http_server.c b/src/supplemental/http/http_server.c
index 7f6f9abe..b7e7ac80 100644
--- a/src/supplemental/http/http_server.c
+++ b/src/supplemental/http/http_server.c
@@ -22,15 +22,6 @@
 
 #include "http_api.h"
 
-static int  http_server_sys_init(void);
-static void http_server_sys_fini(void);
-
-static nni_initializer http_server_initializer = {
-	.i_init = http_server_sys_init,
-	.i_fini = http_server_sys_fini,
-	.i_once = 0,
-};
-
 struct nng_http_handler {
 	nni_list_node   node;
 	char *          uri;
@@ -279,8 +270,9 @@ nni_http_handler_set_method(nni_http_handler *h, const char *method)
 	return (0);
 }
 
-static nni_list http_servers;
-static nni_mtx  http_servers_lk;
+static nni_list http_servers =
+    NNI_LIST_INITIALIZER(http_servers, nni_http_server, node);
+static nni_mtx  http_servers_lk = NNI_MTX_INITIALIZER;
 
 static void
 http_sc_reap(void *arg)
@@ -1001,8 +993,6 @@ nni_http_server_init(nni_http_server **serverp, const nni_url *url)
 	int              rv;
 	nni_http_server *s;
 
-	nni_initialize(&http_server_initializer);
-
 	nni_mtx_lock(&http_servers_lk);
 	NNI_LIST_FOREACH (&http_servers, s) {
 		if ((!s->closed) && (atoi(url->u_port) == s->port) &&
@@ -1924,18 +1914,3 @@ nni_http_server_fini(nni_http_server *s)
 	}
 	nni_mtx_unlock(&http_servers_lk);
 }
-
-static int
-http_server_sys_init(void)
-{
-	NNI_LIST_INIT(&http_servers, nni_http_server, node);
-	nni_mtx_init(&http_servers_lk);
-	return (0);
-}
-
-static void
-http_server_sys_fini(void)
-{
-	nni_reap_drain();
-	nni_mtx_fini(&http_servers_lk);
-}
diff --git a/src/supplemental/tls/tls_common.c b/src/supplemental/tls/tls_common.c
index 3e497b0c..357c8411 100644
--- a/src/supplemental/tls/tls_common.c
+++ b/src/supplemental/tls/tls_common.c
@@ -1495,7 +1495,6 @@ nni_tls_sys_init(void)
 void
 nni_tls_sys_fini(void)
 {
-	nni_reap_drain();
 	NNG_TLS_ENGINE_FINI();
 }