fixes #769 How to limit worker threads

* Expose cmake variable to set number of DNS resolver threads: NNG_RESOLV_CONCURRENCY
* Expose cmake variable to set number of taskq threads: NNG_NUM_TASKQ_THREADS

4 files changed, 26 insertions, 12 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index cfbc618a..c13a1678 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -142,6 +142,16 @@ if (NNG_ENABLE_STATS)
 endif()
 mark_as_advanced(NNG_ENABLE_STATS)
 
+if (NNG_RESOLV_CONCURRENCY)
+    add_definitions(-DNNG_RESOLV_CONCURRENCY=${NNG_RESOLV_CONCURRENCY})
+endif()
+mark_as_advanced(NNG_RESOLV_CONCURRENCY)
+
+if (NNG_NUM_TASKQ_THREADS)
+    add_definitions(-DNNG_NUM_TASKQ_THREADS=${NNG_NUM_TASKQ_THREADS})
+endif()
+mark_as_advanced(NNG_NUM_TASKQ_THREADS)
+
 #  Platform checks.
 
 if (CMAKE_C_COMPILER_ID STREQUAL "GNU")
diff --git a/src/core/taskq.c b/src/core/taskq.c
index 9dde6981..12a986b1 100644
--- a/src/core/taskq.c
+++ b/src/core/taskq.c
@@ -266,10 +266,14 @@ nni_taskq_sys_init(void)
 {
 	int nthrs;
 
+#ifndef NNG_NUM_TASKQ_THREADS
 	nthrs = nni_plat_ncpu() * 2;
 	if (nthrs < 2) {
 		nthrs = 2;
 	}
+#else
+	nthrs = NNG_NUM_TASKQ_THREADS;
+#endif
 
 	return (nni_taskq_init(&nni_taskq_systq, nthrs));
 }
diff --git a/src/platform/posix/posix_resolv_gai.c b/src/platform/posix/posix_resolv_gai.c
index 1c56778e..b4d63b59 100644
--- a/src/platform/posix/posix_resolv_gai.c
+++ b/src/platform/posix/posix_resolv_gai.c
@@ -34,15 +34,15 @@
 // changed with this define.  Note that some platforms may not have a
 // thread-safe getaddrinfo().  In that case they should set this to 1.
 
-#ifndef NNG_POSIX_RESOLV_CONCURRENCY
-#define NNG_POSIX_RESOLV_CONCURRENCY 4
+#ifndef NNG_RESOLV_CONCURRENCY
+#define NNG_RESOLV_CONCURRENCY 4
 #endif
 
 static nni_mtx  resolv_mtx;
 static nni_cv   resolv_cv;
 static bool     resolv_fini;
 static nni_list resolv_aios;
-static nni_thr  resolv_thrs[NNG_POSIX_RESOLV_CONCURRENCY];
+static nni_thr  resolv_thrs[NNG_RESOLV_CONCURRENCY];
 
 typedef struct resolv_item resolv_item;
 struct resolv_item {
@@ -383,14 +383,14 @@ nni_posix_resolv_sysinit(void)
 
 	resolv_fini = false;
 
-	for (int i = 0; i < NNG_POSIX_RESOLV_CONCURRENCY; i++) {
+	for (int i = 0; i < NNG_RESOLV_CONCURRENCY; i++) {
 		int rv = nni_thr_init(&resolv_thrs[i], resolv_worker, NULL);
 		if (rv != 0) {
 			nni_posix_resolv_sysfini();
 			return (rv);
 		}
 	}
-	for (int i = 0; i < NNG_POSIX_RESOLV_CONCURRENCY; i++) {
+	for (int i = 0; i < NNG_RESOLV_CONCURRENCY; i++) {
 		nni_thr_run(&resolv_thrs[i]);
 	}
 
@@ -405,7 +405,7 @@ nni_posix_resolv_sysfini(void)
 	nni_cv_wake(&resolv_cv);
 	nni_mtx_unlock(&resolv_mtx);
 
-	for (int i = 0; i < NNG_POSIX_RESOLV_CONCURRENCY; i++) {
+	for (int i = 0; i < NNG_RESOLV_CONCURRENCY; i++) {
 		nni_thr_fini(&resolv_thrs[i]);
 	}
 	nni_cv_fini(&resolv_cv);
diff --git a/src/platform/windows/win_resolv.c b/src/platform/windows/win_resolv.c
index aca07ecb..d361a1e8 100644
--- a/src/platform/windows/win_resolv.c
+++ b/src/platform/windows/win_resolv.c
@@ -22,15 +22,15 @@
 // host file, WINS, or other naming services.  As a result, we just build
 // our own limited asynchronous resolver with threads.
 
-#ifndef NNG_WIN_RESOLV_CONCURRENCY
-#define NNG_WIN_RESOLV_CONCURRENCY 4
+#ifndef NNG_RESOLV_CONCURRENCY
+#define NNG_RESOLV_CONCURRENCY 4
 #endif
 
 static nni_mtx  resolv_mtx;
 static nni_cv   resolv_cv;
 static bool     resolv_fini;
 static nni_list resolv_aios;
-static nni_thr  resolv_thrs[NNG_WIN_RESOLV_CONCURRENCY];
+static nni_thr  resolv_thrs[NNG_RESOLV_CONCURRENCY];
 
 typedef struct resolv_item resolv_item;
 struct resolv_item {
@@ -355,14 +355,14 @@ nni_win_resolv_sysinit(void)
 	nni_aio_list_init(&resolv_aios);
 
 	resolv_fini = false;
-	for (int i = 0; i < NNG_WIN_RESOLV_CONCURRENCY; i++) {
+	for (int i = 0; i < NNG_RESOLV_CONCURRENCY; i++) {
 		int rv = nni_thr_init(&resolv_thrs[i], resolv_worker, NULL);
 		if (rv != 0) {
 			nni_win_resolv_sysfini();
 			return (rv);
 		}
 	}
-	for (int i = 0; i < NNG_WIN_RESOLV_CONCURRENCY; i++) {
+	for (int i = 0; i < NNG_RESOLV_CONCURRENCY; i++) {
 		nni_thr_run(&resolv_thrs[i]);
 	}
 	return (0);
@@ -375,7 +375,7 @@ nni_win_resolv_sysfini(void)
 	resolv_fini = true;
 	nni_cv_wake(&resolv_cv);
 	nni_mtx_unlock(&resolv_mtx);
-	for (int i = 0; i < NNG_WIN_RESOLV_CONCURRENCY; i++) {
+	for (int i = 0; i < NNG_RESOLV_CONCURRENCY; i++) {
 		nni_thr_fini(&resolv_thrs[i]);
 	}
 	nni_cv_fini(&resolv_cv);