为每个线程分配独立的计数器，以提升FS_operate多线程性能。其中使用thread local storage存储计数器下标。v2.10.0

1 files changed, 76 insertions, 0 deletions

diff --git a/src/threadsafe_counter.h b/src/threadsafe_counter.h
new file mode 100644
index 0000000..8748764
--- /dev/null
+++ b/src/threadsafe_counter.h
@@ -0,0 +1,76 @@
+#pragma once
+#include <stdlib.h>
+#include <pthread.h>
+#define SLOTS_COUNT	256
+#define	CPU_CACHE_ALIGMENT	64
+
+#if(__GNUC__ * 100 + __GNUC_MINOR__ * 10 + __GNUC_PATCHLEVEL__ >= 410)
+#define atomic_inc(x) __sync_add_and_fetch((x),1)
+#define atomic_dec(x) __sync_sub_and_fetch((x),1)
+#define atomic_add(x,y) __sync_add_and_fetch((x),(y))
+#define atomic_sub(x,y) __sync_sub_and_fetch((x),(y))
+typedef long atomic_t;
+#define ATOMIC_INIT(i)  { (i) }
+#define atomic_read(x) __sync_add_and_fetch((x),0)
+#define atomic_set(x,y) __sync_lock_test_and_set((x),y)
+#else 
+typedef long atomic_t;
+#define atomic_inc(x)	((*(x))++)
+#define atomic_dec(x)	((*(x))--)
+#define atomic_add(x,y) ((*(x))+=(y))
+#define atomic_sub(x,y) ((*(x))-=(y))
+#define ATOMIC_INIT(i)  { (i) }
+#define atomic_read(x) 	(*(x))
+#define atomic_set(x,y)	((*(x))=(y))
+#endif 
+
+struct threadsafe_counter
+{
+	long long lcounters[(CPU_CACHE_ALIGMENT/sizeof(long long))*SLOTS_COUNT];
+};
+static __thread long slot_id=-1;
+static __thread pid_t thread_id=0;
+inline int get_lcounter_offset()
+{
+	int offset=0;
+	if(slot_id<0)
+	{
+		thread_id=pthread_self();
+		slot_id=random()%SLOTS_COUNT;
+	}
+	offset=(CPU_CACHE_ALIGMENT/sizeof(long long))*slot_id;
+	return offset;
+}
+inline void threadsafe_counter_add(struct threadsafe_counter* c, long long value)
+{
+	int offset=get_lcounter_offset();
+	atomic_add(&(c->lcounters[offset]), value);
+}
+inline void threadsafe_counter_sub(struct threadsafe_counter* c, long long value)
+{
+	int offset=get_lcounter_offset();
+	atomic_sub(&(c->lcounters[offset]), value);
+}
+
+inline long long threadsafe_counter_read(struct threadsafe_counter* c)
+{
+	int i=0, offset=0;
+	long long value=0;
+	for(i=0; i<SLOTS_COUNT; i++)
+	{
+		offset=i*CPU_CACHE_ALIGMENT/sizeof(long long);
+		value+=atomic_read(&(c->lcounters[offset]));
+	}
+	return value;
+}
+inline void threadsafe_counter_set(struct threadsafe_counter* c, long long value)
+{
+	int i=0, offset=0;
+	for(i=0; i<SLOTS_COUNT; i++)
+	{
+		offset=i*CPU_CACHE_ALIGMENT/sizeof(long long);
+		atomic_set(&(c->lcounters[offset]), 0);
+	}
+	atomic_set(&(c->lcounters[0]), value);
+}
+