From: Jeff Hostetler <jeffhost@xxxxxxxxxxxxx>
Create another thread to watch over the daemon process and
automatically shut it down if necessary.
This commit creates the basic framework for a "health" thread
to monitor the daemon and/or the file system. Later commits
will add platform-specific code to do the actual work.
The "health" thread is intended to monitor conditions that
would be difficult to track inside the IPC thread pool and/or
the file system listener threads. For example, when there are
file system events outside of the watched worktree root or if
we want to have an idle-timeout auto-shutdown feature.
Signed-off-by: Jeff Hostetler <jeffhost@xxxxxxxxxxxxx>
---
Makefile | 6 ++-
builtin/fsmonitor--daemon.c | 39 +++++++++++++++
compat/fsmonitor/fsm-health-darwin.c | 24 ++++++++++
compat/fsmonitor/fsm-health-win32.c | 72 ++++++++++++++++++++++++++++
compat/fsmonitor/fsm-health.h | 47 ++++++++++++++++++
contrib/buildsystems/CMakeLists.txt | 2 +
fsmonitor--daemon.h | 4 ++
7 files changed, 192 insertions(+), 2 deletions(-)
create mode 100644 compat/fsmonitor/fsm-health-darwin.c
create mode 100644 compat/fsmonitor/fsm-health-win32.c
create mode 100644 compat/fsmonitor/fsm-health.h
diff --git a/Makefile b/Makefile
index ed3d5231ea1..85a61934f21 100644
--- a/Makefile
+++ b/Makefile
@@ -467,8 +467,9 @@ all::
#
# If your platform supports a built-in fsmonitor backend, set
# FSMONITOR_DAEMON_BACKEND to the "<name>" of the corresponding
-# `compat/fsmonitor/fsm-listen-<name>.c` that implements the
-# `fsm_listen__*()` routines.
+# `compat/fsmonitor/fsm-listen-<name>.c` and
+# `compat/fsmonitor/fsm-health-<name>.c` files
+# that implement the `fsm_listen__*()` and `fsm_health__*()` routines.
#
# If your platform has os-specific ways to tell if a repo is incompatible with
# fsmonitor (whether the hook or ipc daemon version), set FSMONITOR_OS_SETTINGS
@@ -1944,6 +1945,7 @@ endif
ifdef FSMONITOR_DAEMON_BACKEND
COMPAT_CFLAGS += -DHAVE_FSMONITOR_DAEMON_BACKEND
COMPAT_OBJS += compat/fsmonitor/fsm-listen-$(FSMONITOR_DAEMON_BACKEND).o
+ COMPAT_OBJS += compat/fsmonitor/fsm-health-$(FSMONITOR_DAEMON_BACKEND).o
endif
ifdef FSMONITOR_OS_SETTINGS
diff --git a/builtin/fsmonitor--daemon.c b/builtin/fsmonitor--daemon.c
index f3fb865a9d8..591433e897d 100644
--- a/builtin/fsmonitor--daemon.c
+++ b/builtin/fsmonitor--daemon.c
@@ -3,6 +3,7 @@
#include "parse-options.h"
#include "fsmonitor.h"
#include "fsmonitor-ipc.h"
+#include "compat/fsmonitor/fsm-health.h"
#include "compat/fsmonitor/fsm-listen.h"
#include "fsmonitor--daemon.h"
#include "simple-ipc.h"
@@ -1124,6 +1125,18 @@ void fsmonitor_publish(struct fsmonitor_daemon_state *state,
pthread_mutex_unlock(&state->main_lock);
}
+static void *fsm_health__thread_proc(void *_state)
+{
+ struct fsmonitor_daemon_state *state = _state;
+
+ trace2_thread_start("fsm-health");
+
+ fsm_health__loop(state);
+
+ trace2_thread_exit();
+ return NULL;
+}
+
static void *fsm_listen__thread_proc(void *_state)
{
struct fsmonitor_daemon_state *state = _state;
@@ -1162,6 +1175,7 @@ static int fsmonitor_run_daemon_1(struct fsmonitor_daemon_state *state)
*/
.uds_disallow_chdir = 0
};
+ int health_started = 0;
int listener_started = 0;
int err = 0;
@@ -1189,6 +1203,17 @@ static int fsmonitor_run_daemon_1(struct fsmonitor_daemon_state *state)
}
listener_started = 1;
+ /*
+ * Start the health thread to watch over our process.
+ */
+ if (pthread_create(&state->health_thread, NULL,
+ fsm_health__thread_proc, state) < 0) {
+ ipc_server_stop_async(state->ipc_server_data);
+ err = error(_("could not start fsmonitor health thread"));
+ goto cleanup;
+ }
+ health_started = 1;
+
/*
* The daemon is now fully functional in background threads.
* Our primary thread should now just wait while the threads
@@ -1211,10 +1236,17 @@ cleanup:
pthread_join(state->listener_thread, NULL);
}
+ if (health_started) {
+ fsm_health__stop_async(state);
+ pthread_join(state->health_thread, NULL);
+ }
+
if (err)
return err;
if (state->listen_error_code)
return state->listen_error_code;
+ if (state->health_error_code)
+ return state->health_error_code;
return 0;
}
@@ -1230,6 +1262,7 @@ static int fsmonitor_run_daemon(void)
pthread_mutex_init(&state.main_lock, NULL);
pthread_cond_init(&state.cookies_cond, NULL);
state.listen_error_code = 0;
+ state.health_error_code = 0;
state.current_token_data = fsmonitor_new_token_data();
/* Prepare to (recursively) watch the <worktree-root> directory. */
@@ -1309,6 +1342,11 @@ static int fsmonitor_run_daemon(void)
goto done;
}
+ if (fsm_health__ctor(&state)) {
+ err = error(_("could not initialize health thread"));
+ goto done;
+ }
+
/*
* CD out of the worktree root directory.
*
@@ -1332,6 +1370,7 @@ done:
pthread_cond_destroy(&state.cookies_cond);
pthread_mutex_destroy(&state.main_lock);
fsm_listen__dtor(&state);
+ fsm_health__dtor(&state);
ipc_server_free(state.ipc_server_data);
diff --git a/compat/fsmonitor/fsm-health-darwin.c b/compat/fsmonitor/fsm-health-darwin.c
new file mode 100644
index 00000000000..b9f709e8548
--- /dev/null
+++ b/compat/fsmonitor/fsm-health-darwin.c
@@ -0,0 +1,24 @@
+#include "cache.h"
+#include "config.h"
+#include "fsmonitor.h"
+#include "fsm-health.h"
+#include "fsmonitor--daemon.h"
+
+int fsm_health__ctor(struct fsmonitor_daemon_state *state)
+{
+ return 0;
+}
+
+void fsm_health__dtor(struct fsmonitor_daemon_state *state)
+{
+ return;
+}
+
+void fsm_health__loop(struct fsmonitor_daemon_state *state)
+{
+ return;
+}
+
+void fsm_health__stop_async(struct fsmonitor_daemon_state *state)
+{
+}
diff --git a/compat/fsmonitor/fsm-health-win32.c b/compat/fsmonitor/fsm-health-win32.c
new file mode 100644
index 00000000000..94b1d020f25
--- /dev/null
+++ b/compat/fsmonitor/fsm-health-win32.c
@@ -0,0 +1,72 @@
+#include "cache.h"
+#include "config.h"
+#include "fsmonitor.h"
+#include "fsm-health.h"
+#include "fsmonitor--daemon.h"
+
+struct fsm_health_data
+{
+ HANDLE hEventShutdown;
+
+ HANDLE hHandles[1]; /* the array does not own these handles */
+#define HEALTH_SHUTDOWN 0
+ int nr_handles; /* number of active event handles */
+};
+
+int fsm_health__ctor(struct fsmonitor_daemon_state *state)
+{
+ struct fsm_health_data *data;
+
+ CALLOC_ARRAY(data, 1);
+
+ data->hEventShutdown = CreateEvent(NULL, TRUE, FALSE, NULL);
+
+ data->hHandles[HEALTH_SHUTDOWN] = data->hEventShutdown;
+ data->nr_handles++;
+
+ state->health_data = data;
+ return 0;
+}
+
+void fsm_health__dtor(struct fsmonitor_daemon_state *state)
+{
+ struct fsm_health_data *data;
+
+ if (!state || !state->health_data)
+ return;
+
+ data = state->health_data;
+
+ CloseHandle(data->hEventShutdown);
+
+ FREE_AND_NULL(state->health_data);
+}
+
+void fsm_health__loop(struct fsmonitor_daemon_state *state)
+{
+ struct fsm_health_data *data = state->health_data;
+
+ for (;;) {
+ DWORD dwWait = WaitForMultipleObjects(data->nr_handles,
+ data->hHandles,
+ FALSE, INFINITE);
+
+ if (dwWait == WAIT_OBJECT_0 + HEALTH_SHUTDOWN)
+ goto clean_shutdown;
+
+ error(_("health thread wait failed [GLE %ld]"),
+ GetLastError());
+ goto force_error_stop;
+ }
+
+force_error_stop:
+ state->health_error_code = -1;
+ ipc_server_stop_async(state->ipc_server_data);
+clean_shutdown:
+ return;
+}
+
+void fsm_health__stop_async(struct fsmonitor_daemon_state *state)
+{
+ SetEvent(state->health_data->hHandles[HEALTH_SHUTDOWN]);
+}
diff --git a/compat/fsmonitor/fsm-health.h b/compat/fsmonitor/fsm-health.h
new file mode 100644
index 00000000000..45547ba9380
--- /dev/null
+++ b/compat/fsmonitor/fsm-health.h
@@ -0,0 +1,47 @@
+#ifndef FSM_HEALTH_H
+#define FSM_HEALTH_H
+
+/* This needs to be implemented by each backend */
+
+#ifdef HAVE_FSMONITOR_DAEMON_BACKEND
+
+struct fsmonitor_daemon_state;
+
+/*
+ * Initialize platform-specific data for the fsmonitor health thread.
+ * This will be called from the main thread PRIOR to staring the
+ * thread.
+ *
+ * Returns 0 if successful.
+ * Returns -1 otherwise.
+ */
+int fsm_health__ctor(struct fsmonitor_daemon_state *state);
+
+/*
+ * Cleanup platform-specific data for the health thread.
+ * This will be called from the main thread AFTER joining the thread.
+ */
+void fsm_health__dtor(struct fsmonitor_daemon_state *state);
+
+/*
+ * The main body of the platform-specific event loop to monitor the
+ * health of the daemon process. This will run in the health thread.
+ *
+ * The health thread should call `ipc_server_stop_async()` if it needs
+ * to cause a shutdown. (It should NOT do so if it receives a shutdown
+ * shutdown signal.)
+ *
+ * It should set `state->health_error_code` to -1 if the daemon should exit
+ * with an error.
+ */
+void fsm_health__loop(struct fsmonitor_daemon_state *state);
+
+/*
+ * Gently request that the health thread shutdown.
+ * It does not wait for it to stop. The caller should do a JOIN
+ * to wait for it.
+ */
+void fsm_health__stop_async(struct fsmonitor_daemon_state *state);
+
+#endif /* HAVE_FSMONITOR_DAEMON_BACKEND */
+#endif /* FSM_HEALTH_H */
diff --git a/contrib/buildsystems/CMakeLists.txt b/contrib/buildsystems/CMakeLists.txt
index fc70dd2fc1d..80704406895 100644
--- a/contrib/buildsystems/CMakeLists.txt
+++ b/contrib/buildsystems/CMakeLists.txt
@@ -289,12 +289,14 @@ if(SUPPORTS_SIMPLE_IPC)
if(CMAKE_SYSTEM_NAME STREQUAL "Windows")
add_compile_definitions(HAVE_FSMONITOR_DAEMON_BACKEND)
list(APPEND compat_SOURCES compat/fsmonitor/fsm-listen-win32.c)
+ list(APPEND compat_SOURCES compat/fsmonitor/fsm-health-win32.c)
add_compile_definitions(HAVE_FSMONITOR_OS_SETTINGS)
list(APPEND compat_SOURCES compat/fsmonitor/fsm-settings-win32.c)
elseif(CMAKE_SYSTEM_NAME STREQUAL "Darwin")
add_compile_definitions(HAVE_FSMONITOR_DAEMON_BACKEND)
list(APPEND compat_SOURCES compat/fsmonitor/fsm-listen-darwin.c)
+ list(APPEND compat_SOURCES compat/fsmonitor/fsm-health-darwin.c)
add_compile_definitions(HAVE_FSMONITOR_OS_SETTINGS)
list(APPEND compat_SOURCES compat/fsmonitor/fsm-settings-darwin.c)
diff --git a/fsmonitor--daemon.h b/fsmonitor--daemon.h
index f7de7882517..716e0e4d28d 100644
--- a/fsmonitor--daemon.h
+++ b/fsmonitor--daemon.h
@@ -34,9 +34,11 @@ void fsmonitor_batch__free_list(struct fsmonitor_batch *batch);
void fsmonitor_batch__add_path(struct fsmonitor_batch *batch, const char *path);
struct fsm_listen_data; /* opaque platform-specific data for listener thread */
+struct fsm_health_data; /* opaque platform-specific data for health thread */
struct fsmonitor_daemon_state {
pthread_t listener_thread;
+ pthread_t health_thread;
pthread_mutex_t main_lock;
struct strbuf path_worktree_watch;
@@ -51,7 +53,9 @@ struct fsmonitor_daemon_state {
struct hashmap cookies;
int listen_error_code;
+ int health_error_code;
struct fsm_listen_data *listen_data;
+ struct fsm_health_data *health_data;
struct ipc_server_data *ipc_server_data;
struct strbuf path_ipc;
--
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