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authorAdrian Kummerlaender2016-02-11 18:43:27 +0100
committerAdrian Kummerlaender2016-02-11 18:43:27 +0100
commit7582ab165b4c57d2325561b59d99a6665af28cc3 (patch)
tree7d1ed1845b149d1727c949e6fc6a15b36b90334d
parentb9f79c106295f2f2589b92b17f60711a43bfbbce (diff)
Delay tracking activation
Introduce global static `enabled` variable used to signal the interposed functions to either start tracking or perform plain forwarding without any additional logic. This is required as e.g. `nvim` crashed when wrapped in `libChangeLog` because it called interposed functions during library initialization.
-rw-r--r--src/change_log.cc65
1 files changed, 44 insertions, 21 deletions
diff --git a/src/change_log.cc b/src/change_log.cc
index a6f1437..8ff99e4 100644
--- a/src/change_log.cc
+++ b/src/change_log.cc
@@ -8,20 +8,14 @@
#include "utility/logger.h"
#include "tracking/change_tracker.h"
+// `true` signals the interposed functions to execute tracking logic
+// `false` signals the interposed functions to do plain forwarding
+static bool enabled = false;
+
static std::unique_ptr<utility::FileDescriptorGuard> fd_guard;
static std::unique_ptr<utility::Logger> logger;
static std::unique_ptr<tracking::ChangeTracker> tracker;
-void track_write(const int fd) {
- if ( fd != *fd_guard && utility::is_regular_file(fd) ) {
- const std::string file_name{ utility::get_file_name(fd) };
-
- if ( !tracker->is_tracked(file_name) ) {
- tracker->track(file_name);
- }
- }
-}
-
void init() __attribute__ ((constructor));
void init() {
if ( getenv("CHANGE_LOG_TARGET") != NULL ) {
@@ -40,6 +34,41 @@ void init() {
} else {
tracker = std::make_unique<tracking::ChangeTracker>(logger.get());
}
+
+ // tracking is only enabled when everything is initialized as both
+ // the actual tracking and the decision if a event should be tracked
+ // depend on `logger` and `tracker` being fully instantiated.
+ // In most cases this library will work correctly without delayed
+ // activation but e.g. `nvim` crashes as it performs tracked syscalls
+ // before `init` has been called.
+ enabled = true;
+}
+
+inline void track_write(const int fd) {
+ if ( enabled && fd != *fd_guard && utility::is_regular_file(fd) ) {
+ const std::string file_name{ utility::get_file_name(fd) };
+
+ if ( !tracker->is_tracked(file_name) ) {
+ tracker->track(file_name);
+ }
+ }
+}
+
+inline void track_rename(
+ const std::string& old_path, const std::string& new_path) {
+ if ( enabled ) {
+ if ( !tracker->is_tracked(old_path) ) {
+ tracker->track(old_path);
+ }
+
+ logger->append("renamed '", old_path, "' to '", new_path, "'");
+ }
+}
+
+inline void track_remove(const std::string& path) {
+ if ( enabled && utility::is_regular_file(path.c_str()) ) {
+ logger->append("removed '", path, "'");
+ }
}
ssize_t write(int fd, const void* buffer, size_t count) {
@@ -55,34 +84,28 @@ ssize_t writev(int fd, const iovec* iov, int iovcnt) {
}
int rename(const char* old_path, const char* new_path) {
- if ( !tracker->is_tracked(old_path) ) {
- tracker->track(old_path);
- }
-
- logger->append("renamed '", old_path, "' to '", new_path, "'");
+ track_rename(old_path, new_path);
return actual::rename(old_path, new_path);
}
int rmdir(const char* path) {
- logger->append("removed directory '", path, "'");
+ track_remove(path);
return actual::rmdir(path);
}
int unlink(const char* path) {
- if ( utility::is_regular_file(path) ) {
- logger->append("remove '", path, "'");
- }
+ track_remove(path);
return actual::unlink(path);
}
int unlinkat(int dirfd, const char* path, int flags) {
if ( dirfd == AT_FDCWD ) {
- logger->append("removed '", path, "'");
+ track_remove(path);
} else {
- logger->append("removed '", utility::get_file_name(dirfd), path, "'");
+ track_remove(utility::get_file_name(dirfd) + path);
}
return actual::unlinkat(dirfd, path, flags);