Backport: relayd: rename fd-cap parameter to fd-pool-size

[deliverable/lttng-tools.git] / src / common / defaults.h

diff --git a/src/common/defaults.h b/src/common/defaults.h
index efe7f3058c79f96ce46ee9954ac5d30052ed9c5a..2dff3908768ab24157dfd94cad012696520bcaa5 100644 (file)
--- a/src/common/defaults.h
+++ b/src/common/defaults.h
@@ -21,7 +21,7 @@
 #define _DEFAULTS_H
 
 #include <pthread.h>
-#include <src/common/macros.h>
+#include <common/macros.h>
 
 /* Default unix group name for tracing. */
 #define DEFAULT_TRACING_GROUP                   "tracing"
@@ -90,6 +90,21 @@
 #define DEFAULT_RELAYD_RUNDIR                  "%s"
 #define DEFAULT_RELAYD_PATH                    DEFAULT_RELAYD_RUNDIR "/relayd"
 
+#define DEFAULT_RELAYD_MIN_FD_POOL_SIZE                100
+/*
+ * The file descriptor pool size needs a reserve buffer to accomodate the
+ * indirect use of short-lived file descriptors. For instance, glibc will
+ * create a socket (and thus, use an fd) during calls to gethostname() or
+ * when querying the user's group. Other calls also probably make use of
+ * short-lived FDs.
+ *
+ * The theoritical maximal reserve corresponds to the number of threads as,
+ * in the worst case, they could all be making such calls.
+ *
+ * This value must be less than DEFAULT_RELAYD_MIN_FD_POOL_SIZE.
+ */
+#define DEFAULT_RELAYD_FD_POOL_SIZE_RESERVE    10
+
 /* Default lttng run directory */
 #define DEFAULT_LTTNG_HOME_ENV_VAR              "LTTNG_HOME"
 #define DEFAULT_LTTNG_FALLBACK_HOME_ENV_VAR    "HOME"