#define _LGPL_SOURCE
#include <stddef.h>
#include <unistd.h>
+#include <stdbool.h>
+#include <sys/resource.h>
+#include <pthread.h>
#include "defaults.h"
#include "macros.h"
#include "align.h"
+#include "error.h"
-static size_t default_channel_subbuf_size;
-static size_t default_metadata_subbuf_size;
-static size_t default_kernel_channel_subbuf_size;
-static size_t default_ust_pid_channel_subbuf_size;
-static size_t default_ust_uid_channel_subbuf_size;
+static int pthread_attr_init_done;
+static pthread_attr_t tattr;
LTTNG_HIDDEN
size_t default_get_channel_subbuf_size(void)
{
return max(DEFAULT_UST_UID_CHANNEL_SUBBUF_SIZE, PAGE_SIZE);
}
+
+LTTNG_HIDDEN
+pthread_attr_t *default_pthread_attr(void)
+{
+ if (pthread_attr_init_done) {
+ return &tattr;
+ }
+
+ WARN("Uninitialized pthread attributes, using libc defaults.");
+ return NULL;
+}
+
+static void __attribute__((constructor)) init_default_pthread_attr(void)
+{
+ int ret;
+ struct rlimit rlim;
+ size_t pthread_ss, system_ss, selected_ss;
+
+ ret = pthread_attr_init(&tattr);
+ if (ret) {
+ errno = ret;
+ PERROR("pthread_attr_init");
+ goto error;
+ }
+
+ /* Get system stack size limits. */
+ ret = getrlimit(RLIMIT_STACK, &rlim);
+ if (ret < 0) {
+ PERROR("getrlimit");
+ goto error_destroy;
+ }
+ DBG("Stack size limits: soft %lld, hard %lld bytes",
+ (long long) rlim.rlim_cur,
+ (long long) rlim.rlim_max);
+
+ /*
+ * getrlimit() may return a stack size of "-1", meaning "unlimited".
+ * In this case, we impose a known-good default minimum value which will
+ * override the libc's default stack size if it is smaller.
+ */
+ system_ss = rlim.rlim_cur != -1 ? rlim.rlim_cur :
+ DEFAULT_LTTNG_THREAD_STACK_SIZE;
+
+ /* Get pthread default thread stack size. */
+ ret = pthread_attr_getstacksize(&tattr, &pthread_ss);
+ if (ret < 0) {
+ PERROR("pthread_attr_getstacksize");
+ goto error_destroy;
+ }
+ DBG("Default pthread stack size is %zu bytes", pthread_ss);
+
+ selected_ss = max_t(size_t, pthread_ss, system_ss);
+ if (selected_ss < DEFAULT_LTTNG_THREAD_STACK_SIZE) {
+ DBG("Default stack size is too small, setting it to %zu bytes",
+ (size_t) DEFAULT_LTTNG_THREAD_STACK_SIZE);
+ selected_ss = DEFAULT_LTTNG_THREAD_STACK_SIZE;
+ }
+
+ if (rlim.rlim_max > 0 && selected_ss > rlim.rlim_max) {
+ WARN("Your system's stack size restrictions (%zu bytes) may be too low for the LTTng daemons to function properly, please set the stack size limit to at leat %zu bytes to ensure reliable operation",
+ (size_t) rlim.rlim_max, (size_t) DEFAULT_LTTNG_THREAD_STACK_SIZE);
+ selected_ss = (size_t) rlim.rlim_max;
+ }
+
+ ret = pthread_attr_setstacksize(&tattr, selected_ss);
+ if (ret < 0) {
+ PERROR("pthread_attr_setstacksize");
+ goto error_destroy;
+ }
+ pthread_attr_init_done = 1;
+error:
+ return;
+error_destroy:
+ ret = pthread_attr_destroy(&tattr);
+ if (ret) {
+ errno = ret;
+ PERROR("pthread_attr_destroy");
+ }
+}
+
+static void __attribute__((destructor)) fini_default_pthread_attr(void)
+{
+ int ret;
+
+ if (!pthread_attr_init_done) {
+ return;
+ }
+
+ ret = pthread_attr_destroy(&tattr);
+ if (ret) {
+ errno = ret;
+ PERROR("pthread_attr_destroy");
+ }
+}