Snapshot pool integration, first version

Makefile.am

@@ -221,6 +221,7 @@ libraft_la_LDFLAGS = $(UV_LIBS)
 raft_core_unit_test_SOURCES = \
   $(libraft_la_SOURCES) \
   src/lib/sm.c \
+  src/lib/threadpool.c \
   src/tracing.c \
   test/raft/unit/main_core.c \
   test/raft/unit/test_byte.c \
@@ -238,6 +239,7 @@ raft_core_unit_test_LDADD = libtest.la
 raft_core_integration_test_SOURCES = \
   src/tracing.c \
   src/lib/sm.c \
+  src/lib/threadpool.c \
   test/raft/integration/main_core.c \
   test/raft/integration/test_apply.c \
   test/raft/integration/test_assign.c \
@@ -263,6 +265,7 @@ raft_core_integration_test_LDADD = libtest.la libraft.la
 
 raft_core_fuzzy_test_SOURCES = \
   src/lib/sm.c \
+  src/lib/threadpool.c \
   src/tracing.c \
   test/raft/fuzzy/main_core.c \
   test/raft/fuzzy/test_election.c \
@@ -295,6 +298,7 @@ raft_uv_integration_test_SOURCES = \
   $(libraft_la_SOURCES) \
   src/tracing.c \
   src/lib/sm.c \
+  src/lib/threadpool.c \
   test/raft/integration/main_uv.c \
   test/raft/integration/test_uv_init.c \
   test/raft/integration/test_uv_append.c \

src/lib/threadpool.c

@@ -1,13 +1,15 @@
 #include "threadpool.h"
 #include <assert.h>
 #include <stddef.h>
+#include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <unistd.h>
 #include <uv.h>
+#include <uv/unix.h>
 #include "../../src/lib/queue.h"
 #include "../../src/lib/sm.h"
 #include "../../src/utils.h"
-#include "../tracing.h"
 
 /**
  *  Planner thread state machine.
@@ -74,6 +76,9 @@
 	},
 };
 
+static const uint64_t pool_thread_magic = 0xf344e2;
+static uv_key_t thread_identifier_key;
+
 enum {
 	THREADPOOL_SIZE_MAX = 1024,
 };
@@ -125,6 +130,14 @@
 };
 /* clang-format on */
 
+/* Callback does not allow passing data, we use a static variable to report
+ * errors back. */
+static int thread_key_create_err = 0;
+static void thread_key_create(void) {
+	PRE(thread_key_create_err == 0);
+	thread_key_create_err = uv_key_create(&thread_identifier_key);
+}
+
 static inline bool pool_is_inited(const pool_t *pool)
 {
 	return pool->pi != NULL;
@@ -325,6 +338,7 @@
 	pool_work_t *w;
 	queue *q;
 
+	uv_key_set(&thread_identifier_key, (void*)pool_thread_magic);
 	uv_sem_post(ta->sem);
 	uv_mutex_lock(mutex);
 	for (;;) {
@@ -552,7 +566,17 @@
 		return rc;
 	}
 
+	static uv_once_t once = UV_ONCE_INIT;
+	uv_once(&once, thread_key_create);
+	if (thread_key_create_err != 0) {
+		uv_close((uv_handle_t *)&pi->outq_async, NULL);
+		uv_mutex_destroy(&pi->outq_mutex);
+		free(pi);
+		return thread_key_create_err;
+	}
+
 	pool_threads_init(pool);
+
 	return 0;
 }
 
@@ -581,6 +605,10 @@
 	uv_mutex_unlock(&pi->mutex);
 }
 
+bool pool_is_pool_thread(void) {
+	return uv_key_get(&thread_identifier_key) == (void*)pool_thread_magic;
+}
+
 pool_t *pool_ut_fallback(void)
 {
 	static pool_t pool;

src/lib/threadpool.h

@@ -2,6 +2,7 @@
 #define __THREAD_POOL__
 
 #include <uv.h>
+#include <stdbool.h>
 #include "queue.h"
 
 /**
@@ -111,6 +112,7 @@ void pool_queue_work(pool_t *pool,
 		     enum pool_work_type type,
 		     void (*work_cb)(pool_work_t *w),
 		     void (*after_work_cb)(pool_work_t *w));
+bool pool_is_pool_thread(void);
 
 pool_t *pool_ut_fallback(void);
 

src/raft.h

@@ -379,6 +379,7 @@ struct raft_signature {
 	struct page_from_to page_from_to;
 	pageno_t cs_page_no;
 	enum raft_result result;
+	bool ask_calculated;
 };
 #define RAFT_SIGNATURE_VERSION 0
 
@@ -390,6 +391,7 @@ struct raft_signature_result {
 	unsigned int cs_nr;
 	pageno_t cs_page_no;
 	enum raft_result result;
+	bool calculated;
 };
 #define RAFT_SIGNATURE_RESULT_VERSION 0