diff options
Diffstat (limited to 'linuxthreads/pthread.c')
| -rw-r--r-- | linuxthreads/pthread.c | 49 |
1 files changed, 34 insertions, 15 deletions
diff --git a/linuxthreads/pthread.c b/linuxthreads/pthread.c index 8d892b7bb5..29e7682105 100644 --- a/linuxthreads/pthread.c +++ b/linuxthreads/pthread.c @@ -150,9 +150,11 @@ const int __pthread_offsetof_pid = offsetof(struct _pthread_descr_struct, #ifdef SIGRTMIN int __pthread_sig_restart; int __pthread_sig_cancel; +int __pthread_sig_debug; #else int __pthread_sig_restart = DEFAULT_SIG_RESTART; int __pthread_sig_cancel = DEFAULT_SIG_CANCEL; +int __pthread_sig_debug = 0; /* disabled */ #endif /* These variables are used by the setup code. */ @@ -169,6 +171,7 @@ static void pthread_handle_sigrestart(int sig); static void pthread_handle_sigcancel(int sig, struct sigcontext ctx); static void pthread_handle_sigrestart(int sig, struct sigcontext ctx); #endif +static void pthread_handle_sigdebug(int sig); /* Initialize the pthread library. Initialization is split in two functions: @@ -220,12 +223,17 @@ static void pthread_initialize(void) /* Allocate the signals used. */ __pthread_sig_restart = __libc_allocate_rtsig (1); __pthread_sig_cancel = __libc_allocate_rtsig (1); - if (__pthread_sig_restart < 0 || __pthread_sig_cancel < 0) + __pthread_sig_debug = __libc_allocate_rtsig (2); + if (__pthread_sig_restart < 0 || + __pthread_sig_cancel < 0 || + __pthread_sig_debug < 0) { /* The kernel does not support real-time signals. Use as before - the available signals in the fixed set. */ + the available signals in the fixed set. + Debugging is not supported in this case. */ __pthread_sig_restart = DEFAULT_SIG_RESTART; __pthread_sig_cancel = DEFAULT_SIG_CANCEL; + __pthread_sig_debug = 0; } #endif /* Setup signal handlers for the initial thread. @@ -237,8 +245,7 @@ static void pthread_initialize(void) sa.sa_handler = (__sighandler_t) pthread_handle_sigrestart; #endif sigemptyset(&sa.sa_mask); - sa.sa_flags = SA_RESTART; /* does not matter for regular threads, but - better for the thread manager */ + sa.sa_flags = 0; __sigaction(__pthread_sig_restart, &sa, NULL); #ifndef __i386__ sa.sa_handler = pthread_handle_sigcancel; @@ -247,7 +254,12 @@ static void pthread_initialize(void) #endif sa.sa_flags = 0; __sigaction(__pthread_sig_cancel, &sa, NULL); - + if (__pthread_sig_debug > 0) { + sa.sa_handler = pthread_handle_sigdebug; + sigemptyset(&sa.sa_mask); + sa.sa_flags = 0; + __sigaction(__pthread_sig_debug, &sa, NULL); + } /* Initially, block __pthread_sig_restart. Will be unblocked on demand. */ sigemptyset(&mask); sigaddset(&mask, __pthread_sig_restart); @@ -479,16 +491,8 @@ static void pthread_handle_sigrestart(int sig, struct sigcontext ctx) /* The handler for the CANCEL signal checks for cancellation (in asynchronous mode), for process-wide exit and exec requests. - For the thread manager thread, redirect the signal to - __pthread_manager_sighandler. - The debugging strategy is as follows: - On reception of a REQ_DEBUG request (sent by new threads created to - the thread manager under debugging mode), the thread manager throws - __pthread_sig_cancel to itself. The debugger (if active) intercepts - this signal, takes into account new threads and continue execution - of the thread manager by propagating the signal because it doesn't - know what it is specifically done for. In the current implementation, - the thread manager simply discards it. */ + For the thread manager thread, redirect the signal to + __pthread_manager_sighandler. */ #ifndef __i386__ static void pthread_handle_sigcancel(int sig) @@ -528,6 +532,21 @@ static void pthread_handle_sigcancel(int sig, struct sigcontext ctx) } } +/* Handler for the DEBUG signal. + The debugging strategy is as follows: + On reception of a REQ_DEBUG request (sent by new threads created to + the thread manager under debugging mode), the thread manager throws + __pthread_sig_cancel to itself. The debugger (if active) intercepts + this signal, takes into account new threads and continue execution + of the thread manager by propagating the signal because it doesn't + know what it is specifically done for. In the current implementation, + the thread manager simply discards it. */ + +static void pthread_handle_sigdebug(int sig) +{ + /* Nothing */ +} + /* Reset the state of the thread machinery after a fork(). Close the pipe used for requests and set the main thread to the forked thread. |