[RFC PATCH v1 1/2] chnet: Prepare global struct ch_thpool array

[Ammar Faizi <ammarfaizi2@gnuweeb.org>]

This is a preparation patch to add "fixed number of chromium workers".
Initialize array of pointers `struct ch_thpool` with size
`std::thread::hardware_concurrency() - 1`.

Signed-off-by: Ammar Faizi <ammarfaizi2@gnuweeb.org>
---
 chnet/chnet.cc | 47 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 47 insertions(+)

diff --git a/chnet/chnet.cc b/chnet/chnet.cc
index 155dba8..8662374 100644
--- a/chnet/chnet.cc
+++ b/chnet/chnet.cc
@@ -607,6 +607,51 @@ const char *CHNet::read_buf(void)
 	return ch_->read_buf();
 }
 
+struct ch_thpool {
+public:
+	base::Thread		thread_;
+	uint32_t		ref_count_;
+	uint32_t		idx_;
+
+	ch_thpool(void);
+};
+
+ch_thpool::ch_thpool(void):
+	thread_("chromium_thread"),
+	ref_count_(0)
+{
+	CHECK((void *)this == (void *)&thread_);
+	base::Thread::Options options(base::MessagePumpType::IO, 0);
+	CHECK(thread_.StartWithOptions(std::move(options)));
+}
+
+static uint32_t g_max_ch_thpool;
+static std::mutex g_thpool_lock_;
+static struct ch_thpool **g_thpool;
+
+static void init_g_ch_thpool(void)
+{
+	struct ch_thpool **tmp;
+
+	g_max_ch_thpool = std::thread::hardware_concurrency() - 1;
+	if (g_max_ch_thpool < 1)
+		g_max_ch_thpool = 1;
+
+	tmp = (struct ch_thpool **)calloc(g_max_ch_thpool, sizeof(*tmp));
+	g_thpool_lock_.lock();
+	free(g_thpool);
+	g_thpool = tmp;
+	g_thpool_lock_.unlock();
+}
+
+static void destroy_g_ch_thpool(void)
+{
+	g_thpool_lock_.lock();
+	free(g_thpool);
+	g_thpool = nullptr;
+	g_thpool_lock_.unlock();
+}
+
 extern "C" {
 
 static base::AtExitManager *at_exit_manager;
@@ -641,6 +686,7 @@ __cold void chnet_global_init(void)
 	chnet_fix_chromium_boringssl();
 	SSL_library_init();
 	__chnet_global_init();
+	init_g_ch_thpool();
 	has_initialized = true;
 	init_lock.unlock();
 }
@@ -653,6 +699,7 @@ __cold void chnet_global_stop(void)
 	delete cleanup;
 	at_exit_manager = NULL;
 	cleanup = NULL;
+	destroy_g_ch_thpool();
 	has_initialized = false;
 	init_lock.unlock();
 }
-- 
Ammar Faizi