put thread offline while waiting for the init flag

[userspace-rcu.git] / urcu-bp.c

diff --git a/urcu-bp.c b/urcu-bp.c
index 2973574436b7977e491df3a6634e5c99d2ea2a85..7412b5b6add6b0edfb4e7ca53966487fe9fb3664 100644 (file)
--- a/urcu-bp.c
+++ b/urcu-bp.c
@@ -45,10 +45,44 @@
 #define MAP_ANONYMOUS MAP_ANON
 #endif
 
+#ifndef __linux__
+
+#define MREMAP_MAYMOVE 1
+#define MREMAP_FIXED   2
+
+/*
+ * mremap wrapper for non-Linux systems. Maps a RW, anonymous private mapping.
+ * This is not generic.
+*/
+void *mremap(void *old_address, size_t old_size, size_t new_size, int flags)
+{
+       void *new_address;
+
+       assert(flags & MREMAP_MAYMOVE);
+       assert(!(flags & MREMAP_FIXED));
+       new_address = mmap(old_address, new_size,
+                          PROT_READ | PROT_WRITE,
+                          MAP_ANONYMOUS | MAP_PRIVATE,
+                          -1, 0);
+       if (new_address == MAP_FAILED)
+               return MAP_FAILED;
+       if (old_address) {
+               memcpy(new_address, old_address, old_size);
+               munmap(old_address, old_size);
+       }
+       return new_address;
+}
+#endif
+
 /* Sleep delay in us */
 #define RCU_SLEEP_DELAY                1000
 #define ARENA_INIT_ALLOC       16
 
+/*
+ * Active attempts to check for reader Q.S. before calling sleep().
+ */
+#define RCU_QS_ACTIVE_ATTEMPTS 100
+
 void __attribute__((destructor)) rcu_bp_exit(void);
 
 static pthread_mutex_t rcu_gp_lock = PTHREAD_MUTEX_INITIALIZER;
@@ -266,7 +300,7 @@ static void add_thread(void)
        if (registry_arena.len
            < registry_arena.used + sizeof(struct rcu_reader))
                resize_arena(&registry_arena,
-               max(registry_arena.len << 1, ARENA_INIT_ALLOC));
+               caa_max(registry_arena.len << 1, ARENA_INIT_ALLOC));
        /*
         * Find a free spot.
         */