grep: clean up num_threads handling
[git/git.git] / preload-index.c
CommitLineData
671c9b7e
LT
1/*
2 * Copyright (C) 2008 Linus Torvalds
3 */
4#include "cache.h"
64acde94 5#include "pathspec.h"
429bb40a 6#include "dir.h"
883e248b 7#include "fsmonitor.h"
5aacc63f 8#include "config.h"
ae9af122 9#include "progress.h"
46059cc6
JH
10
11#ifdef NO_PTHREADS
5ab2a2da 12static void preload_index(struct index_state *index,
ae9af122
NTND
13 const struct pathspec *pathspec,
14 unsigned int refresh_flags)
46059cc6
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15{
16 ; /* nothing */
17}
18#else
19
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20#include <pthread.h>
21
22/*
23 * Mostly randomly chosen maximum thread counts: we
24 * cap the parallelism to 20 threads, and we want
25 * to have at least 500 lstat's per thread for it to
26 * be worth starting a thread.
27 */
28#define MAX_PARALLEL (20)
29#define THREAD_COST (500)
30
ae9af122
NTND
31struct progress_data {
32 unsigned long n;
33 struct progress *progress;
34 pthread_mutex_t mutex;
35};
36
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37struct thread_data {
38 pthread_t pthread;
39 struct index_state *index;
5ab2a2da 40 struct pathspec pathspec;
ae9af122 41 struct progress_data *progress;
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42 int offset, nr;
43};
44
45static void *preload_thread(void *_data)
46{
ae9af122 47 int nr, last_nr;
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48 struct thread_data *p = _data;
49 struct index_state *index = p->index;
50 struct cache_entry **cep = index->cache + p->offset;
e7c73053 51 struct cache_def cache = CACHE_DEF_INIT;
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52
53 nr = p->nr;
54 if (nr + p->offset > index->cache_nr)
55 nr = index->cache_nr - p->offset;
ae9af122 56 last_nr = nr;
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57
58 do {
59 struct cache_entry *ce = *cep++;
60 struct stat st;
61
62 if (ce_stage(ce))
63 continue;
125fd984
JH
64 if (S_ISGITLINK(ce->ce_mode))
65 continue;
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LT
66 if (ce_uptodate(ce))
67 continue;
e596acc2
JH
68 if (ce_skip_worktree(ce))
69 continue;
883e248b
BP
70 if (ce->ce_flags & CE_FSMONITOR_VALID)
71 continue;
ae9af122
NTND
72 if (p->progress && !(nr & 31)) {
73 struct progress_data *pd = p->progress;
74
75 pthread_mutex_lock(&pd->mutex);
76 pd->n += last_nr - nr;
77 display_progress(pd->progress, pd->n);
78 pthread_mutex_unlock(&pd->mutex);
79 last_nr = nr;
80 }
f9beff03 81 if (!ce_path_match(index, ce, &p->pathspec, NULL))
671c9b7e 82 continue;
f62ce3de
LT
83 if (threaded_has_symlink_leading_path(&cache, ce->name, ce_namelen(ce)))
84 continue;
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LT
85 if (lstat(ce->name, &st))
86 continue;
883e248b 87 if (ie_match_stat(index, ce, &st, CE_MATCH_RACY_IS_DIRTY|CE_MATCH_IGNORE_FSMONITOR))
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88 continue;
89 ce_mark_uptodate(ce);
883e248b 90 mark_fsmonitor_valid(ce);
671c9b7e 91 } while (--nr > 0);
ae9af122
NTND
92 if (p->progress) {
93 struct progress_data *pd = p->progress;
94
95 pthread_mutex_lock(&pd->mutex);
96 display_progress(pd->progress, pd->n + last_nr);
97 pthread_mutex_unlock(&pd->mutex);
98 }
2a608391 99 cache_def_clear(&cache);
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100 return NULL;
101}
102
5ab2a2da 103static void preload_index(struct index_state *index,
ae9af122
NTND
104 const struct pathspec *pathspec,
105 unsigned int refresh_flags)
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106{
107 int threads, i, work, offset;
108 struct thread_data data[MAX_PARALLEL];
ae9af122 109 struct progress_data pd;
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110
111 if (!core_preload_index)
112 return;
113
114 threads = index->cache_nr / THREAD_COST;
5765d97b 115 if ((index->cache_nr > 1) && (threads < 2) && git_env_bool("GIT_TEST_PRELOAD_INDEX", 0))
3e2c6696 116 threads = 2;
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117 if (threads < 2)
118 return;
c46c406a 119 trace_performance_enter();
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120 if (threads > MAX_PARALLEL)
121 threads = MAX_PARALLEL;
122 offset = 0;
98cb6f30 123 work = DIV_ROUND_UP(index->cache_nr, threads);
5ab2a2da 124 memset(&data, 0, sizeof(data));
ae9af122
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125
126 memset(&pd, 0, sizeof(pd));
127 if (refresh_flags & REFRESH_PROGRESS && isatty(2)) {
128 pd.progress = start_delayed_progress(_("Refreshing index"), index->cache_nr);
129 pthread_mutex_init(&pd.mutex, NULL);
130 }
131
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132 for (i = 0; i < threads; i++) {
133 struct thread_data *p = data+i;
134 p->index = index;
5ab2a2da
NTND
135 if (pathspec)
136 copy_pathspec(&p->pathspec, pathspec);
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137 p->offset = offset;
138 p->nr = work;
ae9af122
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139 if (pd.progress)
140 p->progress = &pd;
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141 offset += work;
142 if (pthread_create(&p->pthread, NULL, preload_thread, p))
143 die("unable to create threaded lstat");
144 }
145 for (i = 0; i < threads; i++) {
146 struct thread_data *p = data+i;
147 if (pthread_join(p->pthread, NULL))
148 die("unable to join threaded lstat");
149 }
ae9af122
NTND
150 stop_progress(&pd.progress);
151
c46c406a 152 trace_performance_leave("preload index");
671c9b7e 153}
46059cc6 154#endif
671c9b7e 155
5ab2a2da 156int read_index_preload(struct index_state *index,
ae9af122
NTND
157 const struct pathspec *pathspec,
158 unsigned int refresh_flags)
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159{
160 int retval = read_index(index);
161
ae9af122 162 preload_index(index, pathspec, refresh_flags);
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163 return retval;
164}