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authorBoris Kolpackov <boris@codesynthesis.com>2022-11-30 11:49:56 +0200
committerBoris Kolpackov <boris@codesynthesis.com>2022-11-30 11:49:56 +0200
commit59f70280dee90957a672810a3845af2dec8552e8 (patch)
tree609b729c394b44a38418a6f19d03893dbfbd0e9f /libbuild2
parent3bbbe09e8629ab5311a1bcbb9f56aa6a33e36f55 (diff)
Reserve targets, variables to avoid rehashing
Diffstat (limited to 'libbuild2')
-rw-r--r--libbuild2/context.cxx15
-rw-r--r--libbuild2/context.hxx17
-rw-r--r--libbuild2/module.cxx7
-rw-r--r--libbuild2/target.cxx12
-rw-r--r--libbuild2/target.hxx4
-rw-r--r--libbuild2/variable.hxx19
6 files changed, 74 insertions, 0 deletions
diff --git a/libbuild2/context.cxx b/libbuild2/context.cxx
index 1da6fd3..967577f 100644
--- a/libbuild2/context.cxx
+++ b/libbuild2/context.cxx
@@ -60,6 +60,18 @@ namespace build2
var_patterns (&c /* shared */, &var_pool) {}
};
+ void context::
+ reserve (reserves res)
+ {
+ assert (phase == run_phase::load);
+
+ if (res.targets != 0)
+ data_->targets.map_.reserve (res.targets);
+
+ if (res.variables != 0)
+ data_->var_pool.map_.reserve (res.variables);
+ }
+
context::
context (scheduler& s,
global_mutexes& ms,
@@ -70,6 +82,7 @@ namespace build2
bool ndb,
bool kg,
const strings& cmd_vars,
+ reserves res,
optional<context*> mc,
const loaded_modules_lock* ml)
: data_ (new data (*this)),
@@ -102,6 +115,8 @@ namespace build2
l6 ([&]{trace << "initializing build state";});
+ reserve (res);
+
scope_map& sm (data_->scopes);
variable_pool& vp (data_->var_pool);
variable_patterns& vpats (data_->var_patterns);
diff --git a/libbuild2/context.hxx b/libbuild2/context.hxx
index b71a068..27c3cc0 100644
--- a/libbuild2/context.hxx
+++ b/libbuild2/context.hxx
@@ -652,6 +652,15 @@ namespace build2
// Note: see also the trace_* data members that, if needed, must be set
// separately, after construction.
//
+ struct reserves
+ {
+ size_t targets;
+ size_t variables;
+
+ reserves (): targets (0), variables (0) {}
+ reserves (size_t t, size_t v): targets (t), variables (v) {}
+ };
+
explicit
context (scheduler&,
global_mutexes&,
@@ -662,9 +671,17 @@ namespace build2
bool no_diag_buffer = false,
bool keep_going = true,
const strings& cmd_vars = {},
+ reserves = {0, 160},
optional<context*> module_context = nullptr,
const loaded_modules_lock* inherited_mudules_lock = nullptr);
+ // Reserve elements in containers to avoid re-allocation/re-hashing. Zero
+ // values are ignored (that is, the corresponding container reserve()
+ // function is not called). Can only be called in the load phase.
+ //
+ void
+ reserve (reserves);
+
// Enter project-wide (as opposed to global) variable overrides.
//
void
diff --git a/libbuild2/module.cxx b/libbuild2/module.cxx
index 96901ff..62145ca 100644
--- a/libbuild2/module.cxx
+++ b/libbuild2/module.cxx
@@ -77,6 +77,9 @@ namespace build2
// same global mutexes. Also disable nested module context for good
// measure.
//
+ // The reserve values were picked experimentally by building libbuild2 and
+ // adding a reasonable margin for future growth.
+ //
ctx.module_context_storage->reset (
new context (ctx.sched,
ctx.mutexes,
@@ -87,6 +90,10 @@ namespace build2
ctx.no_diag_buffer,
ctx.keep_going,
ctx.global_var_overrides, /* cmd_vars */
+ context::reserves {
+ 2500, /* targets */
+ 900 /* variables */
+ },
nullopt)); /* module_context */
// We use the same context for building any nested modules that might be
diff --git a/libbuild2/target.cxx b/libbuild2/target.cxx
index 9f26eee..76d45c7 100644
--- a/libbuild2/target.cxx
+++ b/libbuild2/target.cxx
@@ -760,6 +760,18 @@ namespace build2
if (p.second)
{
+#if 0
+ {
+ size_t n (map_.bucket_count ());
+ if (n > buckets_)
+ {
+ text << "target_set buckets: " << buckets_ << " -> " << n
+ << " (" << map_.size () << ")";
+ buckets_ = n;
+ }
+ }
+#endif
+
t->ext_ = &i->first.ext;
t->decl = decl;
t->state.inner.target_ = t;
diff --git a/libbuild2/target.hxx b/libbuild2/target.hxx
index 684fce9..26c7208 100644
--- a/libbuild2/target.hxx
+++ b/libbuild2/target.hxx
@@ -1879,6 +1879,10 @@ namespace build2
mutable shared_mutex mutex_;
map_type map_;
+
+#if 0
+ size_t buckets_ = 0;
+#endif
};
// Modification time-based target.
diff --git a/libbuild2/variable.hxx b/libbuild2/variable.hxx
index 3b444e6..400aaf1 100644
--- a/libbuild2/variable.hxx
+++ b/libbuild2/variable.hxx
@@ -16,6 +16,7 @@
#include <libbuild2/context.hxx>
#include <libbuild2/target-type.hxx>
+#include <libbuild2/diagnostics.hxx>
#include <libbuild2/export.hxx>
@@ -1470,7 +1471,21 @@ namespace build2
auto r (map_.insert (map::value_type (&n, move (var))));
if (r.second)
+ {
+#if 0
+ if (shared_ && outer_ == nullptr) // Global pool in context.
+ {
+ size_t n (map_.bucket_count ());
+ if (n > buckets_)
+ {
+ text << "variable_pool buckets: " << buckets_ << " -> " << n
+ << " (" << map_.size () << ")";
+ buckets_ = n;
+ }
+ }
+#endif
r.first->first.p = &r.first->second.name;
+ }
return r;
}
@@ -1482,6 +1497,10 @@ namespace build2
variable_pool* outer_;
const variable_patterns* patterns_;
map map_;
+
+#if 0
+ size_t buckets_ = 0;
+#endif
};
// Variable patterns.