ust: continue implementation of ustd

[ust.git] / libtracing / relay.c

diff --git a/libtracing/relay.c b/libtracing/relay.c
index d78fa72a7ae2ac248cc07e309ba1c48236fcfbc2..a8775ec77d2554e30bee693a1c6a102c49ec91fd 100644 (file)
--- a/libtracing/relay.c
+++ b/libtracing/relay.c
@@ -22,8 +22,10 @@
 //ust// #include <linux/cpu.h>
 //ust// #include <linux/splice.h>
 //ust// #include <linux/bitops.h>
-#include <sys/mman.h>
 #include "kernelcompat.h"
+#include <sys/mman.h>
+#include <sys/ipc.h>
+#include <sys/shm.h>
 #include "list.h"
 #include "relay.h"
 #include "channels.h"
@@ -93,21 +95,44 @@ static int relay_alloc_buf(struct rchan_buf *buf, size_t *size)
        unsigned int n_pages;
        struct buf_page *buf_page, *n;
 
-       void *result;
+       void *ptr;
+       int result;
 
        *size = PAGE_ALIGN(*size);
 
-       /* Maybe do read-ahead */
-       result = mmap(NULL, *size, PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
-       if(result == MAP_FAILED) {
-               PERROR("mmap");
+       result = buf->shmid = shmget(getpid(), *size, IPC_CREAT | IPC_EXCL | 0700);
+       if(buf->shmid == -1) {
+               PERROR("shmget");
                return -1;
        }
 
-       buf->buf_data = result;
+       ptr = shmat(buf->shmid, NULL, 0);
+       if(ptr == (void *) -1) {
+               perror("shmat");
+               goto destroy_shmem;
+       }
+
+       /* Already mark the shared memory for destruction. This will occur only
+         * when all users have detached.
+        */
+       result = shmctl(buf->shmid, IPC_RMID, NULL);
+       if(result == -1) {
+               perror("shmctl");
+               return -1;
+       }
+
+       buf->buf_data = ptr;
        buf->buf_size = *size;
 
        return 0;
+
+       destroy_shmem:
+       result = shmctl(buf->shmid, IPC_RMID, NULL);
+       if(result == -1) {
+               perror("shmctl");
+       }
+
+       return -1;
 }
 
 /**
@@ -181,7 +206,7 @@ static void relay_destroy_buf(struct rchan_buf *buf)
 static void relay_remove_buf(struct kref *kref)
 {
        struct rchan_buf *buf = container_of(kref, struct rchan_buf, kref);
-       buf->chan->cb->remove_buf_file(buf);
+//ust//        buf->chan->cb->remove_buf_file(buf);
        relay_destroy_buf(buf);
 }
 
@@ -748,37 +773,6 @@ void *ltt_relay_offset_address(struct rchan_buf *buf, size_t offset)
 #define printk_dbg(fmt, args...)
 #endif
 
-/* LTTng lockless logging buffer info */
-struct ltt_channel_buf_struct {
-       /* First 32 bytes cache-hot cacheline */
-       local_t offset;                 /* Current offset in the buffer */
-       local_t *commit_count;          /* Commit count per sub-buffer */
-       atomic_long_t consumed;         /*
-                                        * Current offset in the buffer
-                                        * standard atomic access (shared)
-                                        */
-       unsigned long last_tsc;         /*
-                                        * Last timestamp written in the buffer.
-                                        */
-       /* End of first 32 bytes cacheline */
-       atomic_long_t active_readers;   /*
-                                        * Active readers count
-                                        * standard atomic access (shared)
-                                        */
-       local_t events_lost;
-       local_t corrupted_subbuffers;
-       spinlock_t full_lock;           /*
-                                        * buffer full condition spinlock, only
-                                        * for userspace tracing blocking mode
-                                        * synchronization with reader.
-                                        */
-//ust//        wait_queue_head_t write_wait;   /*
-//ust//                                         * Wait queue for blocking user space
-//ust//                                         * writers
-//ust//                                         */
-       atomic_t wakeup_readers;        /* Boolean : wakeup readers waiting ? */
-} ____cacheline_aligned;
-
 /*
  * Last TSC comparison functions. Check if the current TSC overflows
  * LTT_TSC_BITS bits from the last TSC read. Reads and writes last_tsc
@@ -1041,7 +1035,7 @@ static notrace void ltt_buf_unfull(struct rchan_buf *buf,
 //ust//        return mask;
 //ust// }
 
-static int ltt_do_get_subbuf(struct rchan_buf *buf, struct ltt_channel_buf_struct *ltt_buf, long *pconsumed_old)
+int ltt_do_get_subbuf(struct rchan_buf *buf, struct ltt_channel_buf_struct *ltt_buf, long *pconsumed_old)
 {
        struct ltt_channel_struct *ltt_channel = (struct ltt_channel_struct *)buf->chan->private_data;
        long consumed_old, consumed_idx, commit_count, write_offset;
@@ -1081,7 +1075,7 @@ static int ltt_do_get_subbuf(struct rchan_buf *buf, struct ltt_channel_buf_struc
        return 0;
 }
 
-static int ltt_do_put_subbuf(struct rchan_buf *buf, struct ltt_channel_buf_struct *ltt_buf, u32 uconsumed_old)
+int ltt_do_put_subbuf(struct rchan_buf *buf, struct ltt_channel_buf_struct *ltt_buf, u32 uconsumed_old)
 {
        long consumed_new, consumed_old;
 
@@ -2375,9 +2369,14 @@ static struct ltt_transport ust_relay_transport = {
 //ust//        return 0;
 //ust// }
 
-void init_ustrelay_transport(void)
+static char initialized = 0;
+
+void __attribute__((constructor)) init_ustrelay_transport(void)
 {
-       ltt_transport_register(&ust_relay_transport);
+       if(!initialized) {
+               ltt_transport_register(&ust_relay_transport);
+               initialized = 1;
+       }
 }
 
 static void __exit ltt_relay_exit(void)