tmux-plugins/tmux-continuum
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tmux-continuum/scripts/continuum_save.sh

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First working version
2015-02-11 14:43:37 +00:00
#!/usr/bin/env bash
CURRENT_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
source "$CURRENT_DIR/helpers.sh"
source "$CURRENT_DIR/variables.sh"
Don't start continuous saving right after tmux is started
2015-02-12 00:31:56 +00:00
source "$CURRENT_DIR/shared.sh"
First working version
2015-02-11 14:43:37 +00:00
More bugfixing
2015-02-12 14:52:10 +00:00
supported_tmux_version_ok() {
Properly quote scripts
2015-02-20 14:48:36 +00:00
"$CURRENT_DIR/check_tmux_version.sh" "$SUPPORTED_VERSION"
More bugfixing
2015-02-12 14:52:10 +00:00
}
Disable autosave when interval is set to 0
2015-02-12 14:42:18 +00:00
get_interval() {
get_tmux_option "$auto_save_interval_option" "$auto_save_interval_default"
}
auto_save_not_disabled() {
[ "$(get_interval)" -gt 0 ]
}
First working version
2015-02-11 14:43:37 +00:00
enough_time_since_last_run_passed() {
local last_saved_timestamp="$(get_tmux_option "$last_auto_save_option" "0")"
Disable autosave when interval is set to 0
2015-02-12 14:42:18 +00:00
local interval_minutes="$(get_interval)"
First working version
2015-02-11 14:43:37 +00:00
local interval_seconds="$((interval_minutes * 60))"
local next_run="$((last_saved_timestamp + $interval_seconds))"
[ "$(current_timestamp)" -ge "$next_run" ]
}
fetch_and_run_tmux_resurrect_save_script() {
local resurrect_save_script_path="$(get_tmux_option "$resurrect_save_path_option" "")"
if [ -n "$resurrect_save_script_path" ]; then
Properly quote scripts
2015-02-20 14:48:36 +00:00
"$resurrect_save_script_path" "quiet" >/dev/null 2>&1 &
First working version
2015-02-11 14:43:37 +00:00
set_last_save_timestamp
fi
}
continuum_save.sh: Improvements to locking code * moved the locking to a separate function "acquire_lock" * changed $[ ] to $(( )), for consistency with the rest of the file * taking the lock only after checking all other preconditions (they are non-mutating and thread-safe)
2019-07-13 12:16:42 +00:00
acquire_lock() {
Replace flock with mkdir flock is not supported on MacOS. `mkdir` locks have a drawback: they are not cleaned up automatically. If the lock owner crashed before cleaning up the lock, the directory will stay in the filesystem and the lock will be never acquired by someone else. To avoid that, we create temporary locks (the lockdir name changes every 100 seconds). We grab two lock (N and N+1) to avoid the case where process A grabs lock N and process B grabs lock N+1 and both enter the critical section.
2019-07-08 13:58:42 +00:00
# Sometimes tmux starts multiple saves in parallel. We want only one
# save to be running, otherwise we can get corrupted saved state.
local lockdir_prefix="/tmp/tmux-continuum-$(current_tmux_server_pid)-lock-"
Fix race condition in saving lock Two consecutive calls to "date +%s" can return different values. Call "date" only once and reuse the result.
2019-07-09 08:46:56 +00:00
# The following implements a lock that auto-expires after 100...200s.
continuum_save.sh: Improvements to locking code * moved the locking to a separate function "acquire_lock" * changed $[ ] to $(( )), for consistency with the rest of the file * taking the lock only after checking all other preconditions (they are non-mutating and thread-safe)
2019-07-13 12:16:42 +00:00
local lock_generation=$((`date +%s` / 100))
Fix race condition in saving lock Two consecutive calls to "date +%s" can return different values. Call "date" only once and reuse the result.
2019-07-09 08:46:56 +00:00
local lockdir1="${lockdir_prefix}${lock_generation}"
continuum_save.sh: Improvements to locking code * moved the locking to a separate function "acquire_lock" * changed $[ ] to $(( )), for consistency with the rest of the file * taking the lock only after checking all other preconditions (they are non-mutating and thread-safe)
2019-07-13 12:16:42 +00:00
local lockdir2="${lockdir_prefix}$(($lock_generation + 1))"
Replace flock with mkdir flock is not supported on MacOS. `mkdir` locks have a drawback: they are not cleaned up automatically. If the lock owner crashed before cleaning up the lock, the directory will stay in the filesystem and the lock will be never acquired by someone else. To avoid that, we create temporary locks (the lockdir name changes every 100 seconds). We grab two lock (N and N+1) to avoid the case where process A grabs lock N and process B grabs lock N+1 and both enter the critical section.
2019-07-08 13:58:42 +00:00
if mkdir "$lockdir1"; then
trap "rmdir "$lockdir1"" EXIT
if mkdir "$lockdir2"; then
trap "rmdir "$lockdir1" "$lockdir2"" EXIT
continuum_save.sh: Improvements to locking code * moved the locking to a separate function "acquire_lock" * changed $[ ] to $(( )), for consistency with the rest of the file * taking the lock only after checking all other preconditions (they are non-mutating and thread-safe)
2019-07-13 12:16:42 +00:00
return 0
Fix race condition in autosave Fixes the case where multiple tmux sessions call auto-save at the same time, which occasionally results in multiple instances of save_all() running in parallel and causing issues like #3 and tmux-plugins/tmux-resurrect#294. The sequence in main() is: 1. Check enough_time_since_last_run_passed 2. Save 3. Update last_save_timestamp. The race here is: * process A finishes step 1 and is busy with step 2. The timestamp is not updated yet. * process B comes to step 1, sees the old timestamp and proceeds to step 2, too.
2019-07-04 17:35:47 +00:00
fi
Replace flock with mkdir flock is not supported on MacOS. `mkdir` locks have a drawback: they are not cleaned up automatically. If the lock owner crashed before cleaning up the lock, the directory will stay in the filesystem and the lock will be never acquired by someone else. To avoid that, we create temporary locks (the lockdir name changes every 100 seconds). We grab two lock (N and N+1) to avoid the case where process A grabs lock N and process B grabs lock N+1 and both enter the critical section.
2019-07-08 13:58:42 +00:00
fi
continuum_save.sh: Improvements to locking code * moved the locking to a separate function "acquire_lock" * changed $[ ] to $(( )), for consistency with the rest of the file * taking the lock only after checking all other preconditions (they are non-mutating and thread-safe)
2019-07-13 12:16:42 +00:00
return 1 # Someone else has the lock.
}
main() {
if supported_tmux_version_ok && auto_save_not_disabled && enough_time_since_last_run_passed && acquire_lock; then
fetch_and_run_tmux_resurrect_save_script
fi
First working version
2015-02-11 14:43:37 +00:00
}
main
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