update infos

git-svn-id: http://ltt.polymtl.ca/svn@1499 04897980-b3bd-0310-b5e0-8ef037075253

diff --git a/usertrace/lttng_usertrace.c b/usertrace/lttng_usertrace.c
index 14e19380398a0fb6d4b52000b32c26e8ff4d67f9..3458e6d51ea37278249d7185bb2deb1bddb6b170 100644 (file)
--- a/usertrace/lttng_usertrace.c
+++ b/usertrace/lttng_usertrace.c
@@ -18,29 +18,10 @@
 #include <malloc.h>
 #include <string.h>
 
-#include <asm/atomic.h>
 #include "lttng_usertrace.h"
 
 #define MAX_TRACES 16
 
-struct ltt_buf {
-       void *start;
-       atomic_t        offset;
-       atomic_t        reserve_count;
-       atomic_t        commit_count;
-
-       atomic_t        events_lost;
-};
-
-struct lttng_trace_info {
-       int     active:1;
-       int filter;
-       struct {
-               struct ltt_buf facilities;
-               struct ltt_buf cpu;
-       } channel;
-};
-
 
 /* TLS for the trace info
  * http://www.dis.com/gnu/gcc/C--98-Thread-Local-Edits.html
@@ -57,8 +38,10 @@ struct lttng_trace_info {
 static __thread struct lttng_trace_info lttng_trace_info[MAX_TRACES] =
 {      [ 0 ... MAX_TRACES-1 ].active = 0,
        [ 0 ... MAX_TRACES-1 ].filter = 0,
+       [ 0 ... MAX_TRACES-1 ].nesting = ATOMIC_INIT(0),
        [ 0 ... MAX_TRACES-1 ].channel = 
                { NULL,
+                       0,
                        ATOMIC_INIT(0),
                        ATOMIC_INIT(0),
                        ATOMIC_INIT(0),
@@ -68,18 +51,60 @@ static __thread struct lttng_trace_info lttng_trace_info[MAX_TRACES] =
 };
 
 
+/* Must be called we sure nobody else is using the info.
+ * It implies that the trace should have been previously stopped
+ * and that every writer has finished.
+ *
+ * Writers should always check if the trace must be destroyed when they
+ * finish writing and the nesting level is 0.
+ */
+void lttng_free_trace_info(struct lttng_trace_info *info)
+{
+       int ret;
+       
+       if(info->active) {
+               printf(
+               "LTTng ERROR : lttng_free_trace_info should be called on inactive trace\n");
+               exit(1);
+       }
+       if(!info->destroy) {
+               printf(
+               "LTTng ERROR : lttng_free_trace_info should be called on destroyed trace\n");
+               exit(1);
+       }
+       if(atomic_read(&info->nesting) > 0) {
+               printf(
+               "LTTng ERROR : lttng_free_trace_info should not be nested on tracing\n");
+               exit(1);
+       }
+       
+       /* Remove the maps */
+       ret = munmap(info->channel.cpu.start, info->channel.cpu.length);
+       if(ret) {
+               perror("LTTNG : error in munmap");
+       }
+       ret = munmap(info->channel.facilities.start, info->channel.facilities.length);
+       if(ret) {
+               perror("LTTNG : error in munmap");
+       }
+       
+       /* Zero the structure */
+       memset(info, 0, sizeof(struct lttng_trace_info));
+}
+
+
 static void lttng_get_new_info(void)
 {
        unsigned long cpu_addr, fac_addr;
        unsigned int i, first_empty;
-       int active, filter;
+       int active, filter, destroy;
        int ret;
 
        /* Get all the new traces */
        while(1) {
                cpu_addr = fac_addr = 0;
-               active = filter = 0;
-               ret = ltt_update(&cpu_addr, &fac_addr, &active, &filter);
+               active = filter = destroy = 0;
+               ret = ltt_update(&cpu_addr, &fac_addr, &active, &filter, &destroy);
                if(ret) {
                        printf("LTTng : error in ltt_update\n");
                        exit(1);
@@ -96,9 +121,14 @@ static void lttng_get_new_info(void)
                                        (unsigned long)lttng_trace_info[i].channel.cpu.start &&
                                 fac_addr == 
                                        (unsigned long)lttng_trace_info[i].channel.facilities.start) {
-
+                               /* Found */
                                lttng_trace_info[i].filter = filter;
                                lttng_trace_info[i].active = active;
+                               lttng_trace_info[i].destroy = destroy;
+                               if(destroy && !atomic_read(&lttng_trace_info[i].nesting)) {
+                                       lttng_free_trace_info(&lttng_trace_info[i]);
+                               }
+                               break;
                        }
 
                }
@@ -112,8 +142,10 @@ static void lttng_get_new_info(void)
 
                        } else {
                                lttng_trace_info[first_empty].channel.cpu.start = (void*)cpu_addr;
+                               lttng_trace_info[first_empty].channel.cpu.length = PAGE_SIZE;
                                lttng_trace_info[first_empty].channel.facilities.start =
                                                                                                                                                                                                                                        (void*)fac_addr;
+                               lttng_trace_info[first_empty].channel.facilities.length = PAGE_SIZE;
                                lttng_trace_info[first_empty].filter = filter;
                                lttng_trace_info[first_empty].active = active;
                        }

diff --git a/usertrace/lttng_usertrace.h b/usertrace/lttng_usertrace.h
index 079a85a92686346a1f6cac62baf82870d52fa247..600be4ffbb5915464e7874eab64b037cc7a6f95e 100644 (file)
--- a/usertrace/lttng_usertrace.h
+++ b/usertrace/lttng_usertrace.h
@@ -11,6 +11,8 @@
 #include <errno.h>
 #include <syscall.h>
 
+#include <asm/atomic.h>
+
 //Put in asm-i486/unistd.h
 #define __NR_ltt_update        294
 #define __NR_ltt_switch        295
@@ -24,12 +26,36 @@
 #define SYS_ltt_switch __NR_ltt_switch
 #endif
 
+struct ltt_buf {
+       void *start;
+       size_t length;
+       atomic_t        offset;
+       atomic_t        reserve_count;
+       atomic_t        commit_count;
+
+       atomic_t        events_lost;
+};
+
+struct lttng_trace_info {
+       int     active:1;
+       int destroy:1;
+       int filter;
+       atomic_t nesting;
+       struct {
+               struct ltt_buf facilities;
+               struct ltt_buf cpu;
+       } channel;
+};
+
+
 void __lttng_sig_trace_handler(int signo);
 
 /* Call this at the beginning of a new thread, except for the main() */
 void lttng_thread_init(void);
 
+void lttng_free_trace_info(struct lttng_trace_info *info);
+
 static inline _syscall1(int, ltt_switch, unsigned long, addr)
-static inline _syscall4(int, ltt_update, unsigned long *, cpu_addr, unsigned long *, fac_addr, int *, active, int *, filter)
+static inline _syscall5(int, ltt_update, unsigned long *, cpu_addr, unsigned long *, fac_addr, int *, active, int *, filter, int *, destroy)
 
 #endif //_LTTNG_USERTRACE_H