0.8.28
[lttv.git] / usertrace-fast / ltt-usertrace-fast.c
index b56e3b5294377008933d4c956675d24fe9faf56d..1a57db154686f910b1eff7b7b553bf3c825df985 100644 (file)
  *
  */
 
+#define inline inline __attribute__((always_inline))
+
 #define _GNU_SOURCE
+#define LTT_TRACE
 #include <sys/types.h>
 #include <sys/wait.h>
 #include <unistd.h>
 #include <stdlib.h>
 #include <sys/param.h>
 #include <sys/time.h>
+#include <errno.h>
 
 #include <asm/atomic.h>
 #include <asm/timex.h> //for get_cycles()
 
-#include "ltt-usertrace-fast.h"
+_syscall0(pid_t,gettid)
+
+#include <ltt/ltt-usertrace-fast.h>
 
+#ifdef LTT_SHOW_DEBUG
+#define dbg_printf(...) dbg_printf(__VA_ARGS__)
+#else
+#define dbg_printf(...)
+#endif //LTT_SHOW_DEBUG
+
+       
 enum force_switch_mode { FORCE_ACTIVE, FORCE_FLUSH };
 
 /* Writer (the traced application) */
@@ -99,22 +112,22 @@ static int parent_exited = 0;
 /* signal handling */
 static void handler_sigusr1(int signo)
 {
-       printf("LTT Signal %d received : parent buffer switch.\n", signo);
+       dbg_printf("LTT Signal %d received : parent buffer switch.\n", signo);
 }
 
 static void handler_sigusr2(int signo)
 {
-       printf("LTT Signal %d received : parent exited.\n", signo);
+       dbg_printf("LTT Signal %d received : parent exited.\n", signo);
        parent_exited = 1;
 }
 
 static void handler_sigalarm(int signo)
 {
-       printf("LTT Signal %d received\n", signo);
+       dbg_printf("LTT Signal %d received\n", signo);
 
        if(getppid() != traced_pid) {
                /* Parent died */
-               printf("LTT Parent %lu died, cleaning up\n", traced_pid);
+               dbg_printf("LTT Parent %lu died, cleaning up\n", traced_pid);
                traced_pid = 0;
        }
        alarm(3);
@@ -306,14 +319,9 @@ static inline int ltt_buffer_put(struct ltt_buf *ltt_buf,
                 * It can also happen if this is a buffer we never got. */
                return -EIO;
        } else {
-               if(atomic_read(&ltt_buf->full) == 1) {
-                       /* tell the client that buffer is now unfull */
-                       ret = futex((unsigned long)&ltt_buf->full,
-                                       FUTEX_WAKE, 1, 0, 0, 0);
-                       if(ret != 1) {
-                               printf("LTT warning : race condition : writer not waiting or too many writers\n");
-                       }
-                       atomic_set(&ltt_buf->full, 0);
+               ret = sem_post(&ltt_buf->writer_sem);
+               if(ret < 0) {
+                       printf("error in sem_post");
                }
        }
 }
@@ -322,12 +330,12 @@ static int read_subbuffer(struct ltt_buf *ltt_buf, int fd)
 {
        unsigned int consumed_old;
        int err;
-       printf("LTT read buffer\n");
+       dbg_printf("LTT read buffer\n");
 
 
        err = ltt_buffer_get(ltt_buf, &consumed_old);
        if(err != 0) {
-               if(err != -EAGAIN) printf("LTT Reserving sub buffer failed\n");
+               if(err != -EAGAIN) dbg_printf("LTT Reserving sub buffer failed\n");
                goto get_error;
        }
 
@@ -353,7 +361,7 @@ write_error:
 
        if(err != 0) {
                if(err == -EIO) {
-                       printf("Reader has been pushed by the writer, last subbuffer corrupted.\n");
+                       dbg_printf("Reader has been pushed by the writer, last subbuffer corrupted.\n");
                        /* FIXME : we may delete the last written buffer if we wish. */
                }
                goto get_error;
@@ -367,10 +375,10 @@ get_error:
 static void ltt_usertrace_fast_daemon(struct ltt_trace_info *shared_trace_info,
                sigset_t oldset, pid_t l_traced_pid, pthread_t l_traced_tid)
 {
+       sigset_t set;
        struct sigaction act;
        int ret;
-       int fd_fac;
-       int fd_cpu;
+       int fd_process;
        char outfile_name[PATH_MAX];
        char identifier_name[PATH_MAX];
 
@@ -378,7 +386,7 @@ static void ltt_usertrace_fast_daemon(struct ltt_trace_info *shared_trace_info,
        traced_pid = l_traced_pid;
        traced_tid = l_traced_tid;
 
-       printf("LTT ltt_usertrace_fast_daemon : init is %d, pid is %lu, traced_pid is %lu, traced_tid is %lu\n",
+       dbg_printf("LTT ltt_usertrace_fast_daemon : init is %d, pid is %lu, traced_pid is %lu, traced_tid is %lu\n",
                        shared_trace_info->init, getpid(), traced_pid, traced_tid);
 
        act.sa_handler = handler_sigusr1;
@@ -399,12 +407,6 @@ static void ltt_usertrace_fast_daemon(struct ltt_trace_info *shared_trace_info,
        sigaddset(&(act.sa_mask), SIGALRM);
        sigaction(SIGALRM, &act, NULL);
 
-       /* Enable signals */
-       ret = pthread_sigmask(SIG_SETMASK, &oldset, NULL);
-       if(ret) {
-               printf("LTT Error in pthread_sigmask\n");
-       }
-
        alarm(3);
 
        /* Open output files */
@@ -421,25 +423,33 @@ static void ltt_usertrace_fast_daemon(struct ltt_trace_info *shared_trace_info,
        }
        snprintf(identifier_name, PATH_MAX-1,   "%lu.%lu.%llu",
                        traced_tid, traced_pid, get_cycles());
-       snprintf(outfile_name, PATH_MAX-1,      "facilities-%s", identifier_name);
-       fd_fac = creat(outfile_name, 0644);
-
-       snprintf(outfile_name, PATH_MAX-1,      "cpu-%s", identifier_name);
-       fd_cpu = creat(outfile_name, 0644);
-       
+       snprintf(outfile_name, PATH_MAX-1,      "process-%s", identifier_name);
+#ifndef LTT_NULL_OUTPUT_TEST
+       fd_process = creat(outfile_name, 0644);
+#else
+       /* NULL test */
+       ret = symlink("/dev/null", outfile_name);
+       if(ret < 0) {
+               perror("error in symlink");
+       }
+       fd_process = open(outfile_name, O_WRONLY);
+       if(fd_process < 0) {
+               perror("Error in open");
+       }
+#endif //LTT_NULL_OUTPUT_TEST
        
        while(1) {
-               pause();
+               ret = sigsuspend(&oldset);
+               if(ret != -1) {
+                       perror("LTT Error in sigsuspend\n");
+               }
+               
                if(traced_pid == 0) break; /* parent died */
                if(parent_exited) break;
-               printf("LTT Doing a buffer switch read. pid is : %lu\n", getpid());
-       
-               do {
-                       ret = read_subbuffer(&shared_trace_info->channel.cpu, fd_cpu);
-               } while(ret == 0);
+               dbg_printf("LTT Doing a buffer switch read. pid is : %lu\n", getpid());
 
                do {
-                       ret = read_subbuffer(&shared_trace_info->channel.facilities, fd_fac);
+                       ret = read_subbuffer(&shared_trace_info->channel.process, fd_process);
                } while(ret == 0);
        }
 
@@ -447,20 +457,18 @@ static void ltt_usertrace_fast_daemon(struct ltt_trace_info *shared_trace_info,
 
        /* Buffer force switch (flush). Using FLUSH instead of ACTIVE because we know
         * there is no writer. */
-       flush_buffer(&shared_trace_info->channel.cpu, FORCE_FLUSH);
+       flush_buffer(&shared_trace_info->channel.process, FORCE_FLUSH);
        do {
-               ret = read_subbuffer(&shared_trace_info->channel.cpu, fd_cpu);
+               ret = read_subbuffer(&shared_trace_info->channel.process, fd_process);
        } while(ret == 0);
 
 
-       flush_buffer(&shared_trace_info->channel.facilities, FORCE_FLUSH);
-       do {
-               ret = read_subbuffer(&shared_trace_info->channel.facilities, fd_fac);
-       } while(ret == 0);
-
-       close(fd_fac);
-       close(fd_cpu);
+       close(fd_process);
        
+       ret = sem_destroy(&shared_trace_info->channel.process.writer_sem);
+       if(ret < 0) {
+               perror("error in sem_destroy");
+       }
        munmap(shared_trace_info, sizeof(*shared_trace_info));
        
        exit(0);
@@ -485,22 +493,23 @@ void ltt_rw_init(void)
        /* parent : create the shared memory map */
        shared_trace_info = mmap(0, sizeof(*thread_trace_info),
                        PROT_READ|PROT_WRITE, MAP_SHARED|MAP_ANONYMOUS, 0, 0);
-       memset(shared_trace_info, 0, sizeof(*shared_trace_info));
-       /* Tricky semaphore : is in a shared memory space, so it's ok for a fast
-        * mutex (futex). */
-       atomic_set(&shared_trace_info->channel.facilities.full, 0);
-       shared_trace_info->channel.facilities.alloc_size = LTT_BUF_SIZE_FACILITIES;
-       shared_trace_info->channel.facilities.subbuf_size = LTT_SUBBUF_SIZE_FACILITIES;
-       shared_trace_info->channel.facilities.start =
-               shared_trace_info->channel.facilities_buf;
-       ltt_buffer_begin_callback(&shared_trace_info->channel.facilities,
-                       ltt_get_timestamp(), 0);
-
-       atomic_set(&shared_trace_info->channel.cpu.full, 0);
-       shared_trace_info->channel.cpu.alloc_size = LTT_BUF_SIZE_CPU;
-       shared_trace_info->channel.cpu.subbuf_size = LTT_SUBBUF_SIZE_CPU;
-       shared_trace_info->channel.cpu.start = shared_trace_info->channel.cpu_buf;
-       ltt_buffer_begin_callback(&shared_trace_info->channel.cpu,
+       shared_trace_info->init=0;
+       shared_trace_info->filter=0;
+       shared_trace_info->daemon_id=0;
+       shared_trace_info->nesting=0;
+       memset(&shared_trace_info->channel.process, 0,
+                       sizeof(shared_trace_info->channel.process));
+       //Need NPTL!
+       ret = sem_init(&shared_trace_info->channel.process.writer_sem, 1,
+                                                                       LTT_N_SUBBUFS);
+       if(ret < 0) {
+               perror("error in sem_init");
+       }
+       shared_trace_info->channel.process.alloc_size = LTT_BUF_SIZE_PROCESS;
+       shared_trace_info->channel.process.subbuf_size = LTT_SUBBUF_SIZE_PROCESS;
+       shared_trace_info->channel.process.start =
+                                               shared_trace_info->channel.process_buf;
+       ltt_buffer_begin_callback(&shared_trace_info->channel.process,
                        ltt_get_timestamp(), 0);
        
        shared_trace_info->init = 1;
@@ -508,13 +517,13 @@ void ltt_rw_init(void)
        /* Disable signals */
   ret = sigfillset(&set);
   if(ret) {
-    printf("LTT Error in sigfillset\n");
+    dbg_printf("LTT Error in sigfillset\n");
   } 
        
        
   ret = pthread_sigmask(SIG_BLOCK, &set, &oldset);
   if(ret) {
-    printf("LTT Error in pthread_sigmask\n");
+    dbg_printf("LTT Error in pthread_sigmask\n");
   }
 
        pid = fork();
@@ -526,11 +535,22 @@ void ltt_rw_init(void)
                /* Enable signals */
                ret = pthread_sigmask(SIG_SETMASK, &oldset, NULL);
                if(ret) {
-                       printf("LTT Error in pthread_sigmask\n");
+                       dbg_printf("LTT Error in pthread_sigmask\n");
                }
        } else if(pid == 0) {
+               pid_t sid;
                /* Child */
                role = LTT_ROLE_READER;
+               sid = setsid();
+               //Not a good idea to renice, unless futex wait eventually implement
+               //priority inheritence.
+               //ret = nice(1);
+               //if(ret < 0) {
+               //      perror("Error in nice");
+               //}
+               if(sid < 0) {
+                       perror("Error setting sid");
+               }
                ltt_usertrace_fast_daemon(shared_trace_info, oldset, l_traced_pid,
                                        l_traced_tid);
                /* Should never return */
@@ -551,7 +571,7 @@ void ltt_thread_init(void)
        
 void __attribute__((constructor)) __ltt_usertrace_fast_init(void)
 {
-  printf("LTT usertrace-fast init\n");
+  dbg_printf("LTT usertrace-fast init\n");
 
        ltt_rw_init();
 }
@@ -559,7 +579,7 @@ void __attribute__((constructor)) __ltt_usertrace_fast_init(void)
 void __attribute__((destructor)) __ltt_usertrace_fast_fini(void)
 {
        if(role == LTT_ROLE_WRITER) {
-         printf("LTT usertrace-fast fini\n");
+         dbg_printf("LTT usertrace-fast fini\n");
                ltt_usertrace_fast_cleanup(NULL);
        }
 }
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