X-Git-Url: http://git.lttng.org./?a=blobdiff_plain;f=usertrace-fast%2Fltt-usertrace-fast.c;h=c809aff096f0fb359bdaf141c2b45d3477b103af;hb=5efa73ea0fa6562c46a966f56665022ccb018963;hp=cb1316951f101692dd6a71e6353a0c7859662e0e;hpb=700d350d4e2ae59d111306b9afa721a4ab0eb55a;p=lttv.git diff --git a/usertrace-fast/ltt-usertrace-fast.c b/usertrace-fast/ltt-usertrace-fast.c index cb131695..c809aff0 100644 --- a/usertrace-fast/ltt-usertrace-fast.c +++ b/usertrace-fast/ltt-usertrace-fast.c @@ -30,6 +30,13 @@ * dies, the data is not lost. * * Fast thread spawn : a pthread_create() is done by the application for each * new thread. + * + * We use a timer to check periodically if the parent died. I think it is less + * intrusive than a ptrace() on the parent, which would get every signal. The + * side effect of this is that we won't be notified if the parent does an + * exec(). In this case, we will just sit there until the parent exits. + * + * * Copyright 2006 Mathieu Desnoyers * */ @@ -47,140 +54,232 @@ #include #include #include +#include +#include +#include +#include + +#include //for get_cycles() #include "ltt-usertrace-fast.h" -/* TLS for the trace buffer - * http://www.dis.com/gnu/gcc/C--98-Thread-Local-Edits.html - * - * Add after paragraph 4 - * - * The storage for an object of thread storage duration shall be statically - * initialized before the first statement of the thread startup function. An - * object of thread storage duration shall not require dynamic - * initialization. - */ -#if 0 -__thread struct ltt_trace_info ltt_trace_info = -{ - .init = 0, - .filter = 0, - .nesting = ATOMIC_INIT(0), - .channel.facilities = - { ATOMIC_INIT(0), - ATOMIC_INIT(0), - ATOMIC_INIT(0), - ATOMIC_INIT(0) - }, - .channel.cpu = - { ATOMIC_INIT(0), - ATOMIC_INIT(0), - ATOMIC_INIT(0), - ATOMIC_INIT(0) - }, -}; -#endif //0 -__thread struct ltt_trace_info *thread_trace_info = NULL; +/* Writer (the traced application) */ +__thread struct ltt_trace_info *thread_trace_info = NULL; -/* signal handling */ +void ltt_usertrace_fast_buffer_switch(void) +{ + struct ltt_trace_info *tmp = thread_trace_info; + if(tmp) + kill(tmp->daemon_id, SIGUSR1); +} -static void handler(int signo) +/* The cleanup should never be called from a signal handler */ +static void ltt_usertrace_fast_cleanup(void *arg) { - printf("Signal %d received\n", signo); + struct ltt_trace_info *tmp = thread_trace_info; + if(tmp) { + thread_trace_info = NULL; + kill(tmp->daemon_id, SIGUSR2); + munmap(tmp, sizeof(*tmp)); + } } +/* Reader (the disk dumper daemon) */ +static pid_t traced_pid = 0; +static pthread_t traced_thread = 0; +static int parent_exited = 0; -void ltt_usertrace_fast_buffer_switch(void) +/* signal handling */ +static void handler_sigusr1(int signo) +{ + printf("LTT Signal %d received : parent buffer switch.\n", signo); +} + +static void handler_sigusr2(int signo) { - kill(thread_trace_info->daemon_id, SIGUSR1); + 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); + + if(getppid() != traced_pid) { + /* Parent died */ + printf("LTT Parent %lu died, cleaning up\n", traced_pid); + traced_pid = 0; + } + alarm(3); +} + + +/* This function is called by ltt_rw_init which has signals blocked */ static void ltt_usertrace_fast_daemon(struct ltt_trace_info *shared_trace_info, - sigset_t oldset) + sigset_t oldset, pid_t l_traced_pid, pthread_t l_traced_thread) { struct sigaction act; int ret; + int fd_fac; + int fd_cpu; + char outfile_name[PATH_MAX]; + char identifier_name[PATH_MAX]; + - printf("ltt_usertrace_fast_daemon : init is %d, pid is %lu\n", - shared_trace_info->init, getpid()); + traced_pid = l_traced_pid; + traced_thread = l_traced_thread; - act.sa_handler = handler; + printf("LTT ltt_usertrace_fast_daemon : init is %d, pid is %lu, traced_pid is %lu\n", + shared_trace_info->init, getpid(), traced_pid); + + act.sa_handler = handler_sigusr1; act.sa_flags = 0; sigemptyset(&(act.sa_mask)); sigaddset(&(act.sa_mask), SIGUSR1); sigaction(SIGUSR1, &act, NULL); + + act.sa_handler = handler_sigusr2; + act.sa_flags = 0; + sigemptyset(&(act.sa_mask)); + sigaddset(&(act.sa_mask), SIGUSR2); + sigaction(SIGUSR2, &act, NULL); + + act.sa_handler = handler_sigalarm; + act.sa_flags = 0; + sigemptyset(&(act.sa_mask)); + sigaddset(&(act.sa_mask), SIGALRM); + sigaction(SIGALRM, &act, NULL); + /* Enable signals */ ret = pthread_sigmask(SIG_SETMASK, &oldset, NULL); if(ret) { - printf("Error in pthread_sigmask\n"); + printf("LTT Error in pthread_sigmask\n"); } + alarm(3); + + /* Open output files */ + umask(00000); + ret = mkdir(LTT_USERTRACE_ROOT, 0777); + if(ret < 0 && errno != EEXIST) { + perror("LTT Error in creating output (mkdir)"); + exit(-1); + } + ret = chdir(LTT_USERTRACE_ROOT); + if(ret < 0) { + perror("LTT Error in creating output (chdir)"); + exit(-1); + } + snprintf(identifier_name, PATH_MAX-1, "%lu.%lu.%llu", + traced_pid, traced_thread, 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); + + while(1) { pause(); - printf("Doing a buffer switch read. pid is : %lu\n", getpid()); + if(traced_pid == 0) break; /* parent died */ + if(parent_exited) break; + printf("LTT Doing a buffer switch read. pid is : %lu\n", getpid()); + //printf("Test parent. pid is : %lu, ppid is %lu\n", getpid(), getppid()); } + /* Buffer force switch (flush) */ + //TODO + + close(fd_fac); + close(fd_cpu); + + /* The parent thread is dead and we have finished with the buffer */ + munmap(shared_trace_info, sizeof(*shared_trace_info)); + + exit(0); } -void ltt_thread_init(void) + +/* Reader-writer initialization */ + +static enum ltt_process_role { LTT_ROLE_WRITER, LTT_ROLE_READER } + role = LTT_ROLE_WRITER; + + +void ltt_rw_init(void) { pid_t pid; struct ltt_trace_info *shared_trace_info; int ret; sigset_t set, oldset; + pid_t l_traced_pid = getpid(); + pthread_t l_traced_thread = pthread_self(); /* parent : create the shared memory map */ - shared_trace_info = thread_trace_info = mmap(0, sizeof(*thread_trace_info), + 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(*thread_trace_info)); - thread_trace_info->init = 1; + memset(shared_trace_info, 0, sizeof(*shared_trace_info)); + shared_trace_info->init = 1; /* Disable signals */ ret = sigfillset(&set); if(ret) { - printf("Error in sigfillset\n"); + printf("LTT Error in sigfillset\n"); } ret = pthread_sigmask(SIG_BLOCK, &set, &oldset); if(ret) { - printf("Error in pthread_sigmask\n"); + printf("LTT Error in pthread_sigmask\n"); } - + pid = fork(); if(pid > 0) { /* Parent */ - thread_trace_info->daemon_id = pid; + shared_trace_info->daemon_id = pid; + thread_trace_info = shared_trace_info; /* Enable signals */ ret = pthread_sigmask(SIG_SETMASK, &oldset, NULL); if(ret) { - printf("Error in pthread_sigmask\n"); + printf("LTT Error in pthread_sigmask\n"); } } else if(pid == 0) { /* Child */ - ltt_usertrace_fast_daemon(shared_trace_info, oldset); + role = LTT_ROLE_READER; + ltt_usertrace_fast_daemon(shared_trace_info, oldset, l_traced_pid, + l_traced_thread); /* Should never return */ exit(-1); } else if(pid < 0) { /* fork error */ - perror("Error in forking ltt-usertrace-fast"); + perror("LTT Error in forking ltt-usertrace-fast"); } } +static __thread struct _pthread_cleanup_buffer cleanup_buffer; + +void ltt_thread_init(void) +{ + _pthread_cleanup_push(&cleanup_buffer, ltt_usertrace_fast_cleanup, NULL); + ltt_rw_init(); +} + void __attribute__((constructor)) __ltt_usertrace_fast_init(void) { printf("LTT usertrace-fast init\n"); - ltt_thread_init(); + ltt_rw_init(); } void __attribute__((destructor)) __ltt_usertrace_fast_fini(void) { - printf("LTT usertrace-fast fini\n"); - + if(role == LTT_ROLE_WRITER) { + printf("LTT usertrace-fast fini\n"); + ltt_usertrace_fast_cleanup(NULL); + } }