Re: [PATCH v2 4/4] fsmonitor: Delay updating state until after split index is merged

[Ben Peart]

On 10/25/2017 9:31 PM, Alex Vandiver wrote:

If the fsmonitor extension is used in conjunction with the split index
extension, the set of entries in the index when it is first loaded is
only a subset of the real index.  This leads to only the non-"base"
index being marked as CE_FSMONITOR_VALID.

Delay the expansion of the ewah bitmap until after tweak_split_index
has been called to merge in the base index as well.

The new fsmonitor_dirty is kept from being leaked by dint of being
cleaned up in post_read_index_from, which is guaranteed to be called
after do_read_index in read_index_from.

Signed-off-by: Alex Vandiver 
---
  cache.h |  1 +
  fsmonitor.c | 39 ---
  2 files changed, 25 insertions(+), 15 deletions(-)

diff --git a/cache.h b/cache.h
index 25adcf681..0a4f43ec2 100644
--- a/cache.h
+++ b/cache.h
@@ -348,6 +348,7 @@ struct index_state {
unsigned char sha1[20];
struct untracked_cache *untracked;
uint64_t fsmonitor_last_update;
+   struct ewah_bitmap *fsmonitor_dirty;
  };
  
  extern struct index_state the_index;

diff --git a/fsmonitor.c b/fsmonitor.c
index 0d26ff34f..fad9c6b13 100644
--- a/fsmonitor.c
+++ b/fsmonitor.c
@@ -49,20 +49,7 @@ int read_fsmonitor_extension(struct index_state *istate, 
const void *data,
ewah_free(fsmonitor_dirty);
return error("failed to parse ewah bitmap reading fsmonitor index 
extension");
}
-
-   if (git_config_get_fsmonitor()) {
-   /* Mark all entries valid */
-   for (i = 0; i < istate->cache_nr; i++)
-   istate->cache[i]->ce_flags |= CE_FSMONITOR_VALID;
-
-   /* Mark all previously saved entries as dirty */
-   ewah_each_bit(fsmonitor_dirty, fsmonitor_ewah_callback, istate);
-
-   /* Now mark the untracked cache for fsmonitor usage */
-   if (istate->untracked)
-   istate->untracked->use_fsmonitor = 1;
-   }
-   ewah_free(fsmonitor_dirty);
+   istate->fsmonitor_dirty = fsmonitor_dirty;
  
  	trace_printf_key(_fsmonitor, "read fsmonitor extension successful");

return 0;
@@ -239,7 +226,29 @@ void remove_fsmonitor(struct index_state *istate)
  
  void tweak_fsmonitor(struct index_state *istate)

  {
-   switch (git_config_get_fsmonitor()) {
+   int i;
+   int fsmonitor_enabled = git_config_get_fsmonitor();
+


The logic looks good this time.  It is nice to know this will now be 
optimal when split index is also turned on.  Thank you.



+   if (istate->fsmonitor_dirty) {
+   if (fsmonitor_enabled) {
+   /* Mark all entries valid */
+   for (i = 0; i < istate->cache_nr; i++) {
+   istate->cache[i]->ce_flags |= 
CE_FSMONITOR_VALID;
+   }
+
+   /* Mark all previously saved entries as dirty */
+   ewah_each_bit(istate->fsmonitor_dirty, 
fsmonitor_ewah_callback, istate);
+
+   /* Now mark the untracked cache for fsmonitor usage */
+   if (istate->untracked)
+   istate->untracked->use_fsmonitor = 1;
+   }
+
+   ewah_free(istate->fsmonitor_dirty);
+   istate->fsmonitor_dirty = NULL;
+   }
+
+   switch (fsmonitor_enabled) {
case -1: /* keep: do nothing */
break;
case 0: /* false */

[PATCH v2 4/4] fsmonitor: Delay updating state until after split index is merged

[Alex Vandiver]

If the fsmonitor extension is used in conjunction with the split index
extension, the set of entries in the index when it is first loaded is
only a subset of the real index.  This leads to only the non-"base"
index being marked as CE_FSMONITOR_VALID.

Delay the expansion of the ewah bitmap until after tweak_split_index
has been called to merge in the base index as well.

The new fsmonitor_dirty is kept from being leaked by dint of being
cleaned up in post_read_index_from, which is guaranteed to be called
after do_read_index in read_index_from.

Signed-off-by: Alex Vandiver 
---
 cache.h |  1 +
 fsmonitor.c | 39 ---
 2 files changed, 25 insertions(+), 15 deletions(-)

diff --git a/cache.h b/cache.h
index 25adcf681..0a4f43ec2 100644
--- a/cache.h
+++ b/cache.h
@@ -348,6 +348,7 @@ struct index_state {
unsigned char sha1[20];
struct untracked_cache *untracked;
uint64_t fsmonitor_last_update;
+   struct ewah_bitmap *fsmonitor_dirty;
 };
 
 extern struct index_state the_index;
diff --git a/fsmonitor.c b/fsmonitor.c
index 0d26ff34f..fad9c6b13 100644
--- a/fsmonitor.c
+++ b/fsmonitor.c
@@ -49,20 +49,7 @@ int read_fsmonitor_extension(struct index_state *istate, 
const void *data,
ewah_free(fsmonitor_dirty);
return error("failed to parse ewah bitmap reading fsmonitor 
index extension");
}
-
-   if (git_config_get_fsmonitor()) {
-   /* Mark all entries valid */
-   for (i = 0; i < istate->cache_nr; i++)
-   istate->cache[i]->ce_flags |= CE_FSMONITOR_VALID;
-
-   /* Mark all previously saved entries as dirty */
-   ewah_each_bit(fsmonitor_dirty, fsmonitor_ewah_callback, istate);
-
-   /* Now mark the untracked cache for fsmonitor usage */
-   if (istate->untracked)
-   istate->untracked->use_fsmonitor = 1;
-   }
-   ewah_free(fsmonitor_dirty);
+   istate->fsmonitor_dirty = fsmonitor_dirty;
 
trace_printf_key(_fsmonitor, "read fsmonitor extension 
successful");
return 0;
@@ -239,7 +226,29 @@ void remove_fsmonitor(struct index_state *istate)
 
 void tweak_fsmonitor(struct index_state *istate)
 {
-   switch (git_config_get_fsmonitor()) {
+   int i;
+   int fsmonitor_enabled = git_config_get_fsmonitor();
+
+   if (istate->fsmonitor_dirty) {
+   if (fsmonitor_enabled) {
+   /* Mark all entries valid */
+   for (i = 0; i < istate->cache_nr; i++) {
+   istate->cache[i]->ce_flags |= 
CE_FSMONITOR_VALID;
+   }
+
+   /* Mark all previously saved entries as dirty */
+   ewah_each_bit(istate->fsmonitor_dirty, 
fsmonitor_ewah_callback, istate);
+
+   /* Now mark the untracked cache for fsmonitor usage */
+   if (istate->untracked)
+   istate->untracked->use_fsmonitor = 1;
+   }
+
+   ewah_free(istate->fsmonitor_dirty);
+   istate->fsmonitor_dirty = NULL;
+   }
+
+   switch (fsmonitor_enabled) {
case -1: /* keep: do nothing */
break;
case 0: /* false */
-- 
2.15.0.rc1.413.g76aedb451