diff options
Diffstat (limited to 'src/mwindow.c')
| -rw-r--r-- | src/mwindow.c | 109 |
1 files changed, 78 insertions, 31 deletions
diff --git a/src/mwindow.c b/src/mwindow.c index b59c4d2f7..b35503d46 100644 --- a/src/mwindow.c +++ b/src/mwindow.c @@ -1,5 +1,5 @@ /* - * Copyright (C) 2009-2012 the libgit2 contributors + * Copyright (C) the libgit2 contributors. All rights reserved. * * This file is part of libgit2, distributed under the GNU GPL v2 with * a Linking Exception. For full terms see the included COPYING file. @@ -20,17 +20,11 @@ #define DEFAULT_MAPPED_LIMIT \ ((1024 * 1024) * (sizeof(void*) >= 8 ? 8192ULL : 256UL)) -/* - * These are the global options for mmmap limits. - * TODO: allow the user to change these - */ -static struct { - size_t window_size; - size_t mapped_limit; -} _mw_options = { - DEFAULT_WINDOW_SIZE, - DEFAULT_MAPPED_LIMIT, -}; +size_t git_mwindow__window_size = DEFAULT_WINDOW_SIZE; +size_t git_mwindow__mapped_limit = DEFAULT_MAPPED_LIMIT; + +/* Whenever you want to read or modify this, grab git__mwindow_mutex */ +static git_mwindow_ctl mem_ctl; /* * Free all the windows in a sequence, typically because we're done @@ -38,8 +32,14 @@ static struct { */ void git_mwindow_free_all(git_mwindow_file *mwf) { - git_mwindow_ctl *ctl = &GIT_GLOBAL->mem_ctl; - unsigned int i; + git_mwindow_ctl *ctl = &mem_ctl; + size_t i; + + if (git_mutex_lock(&git__mwindow_mutex)) { + giterr_set(GITERR_THREAD, "unable to lock mwindow mutex"); + return; + } + /* * Remove these windows from the global list */ @@ -67,6 +67,8 @@ void git_mwindow_free_all(git_mwindow_file *mwf) mwf->windows = w->next; git__free(w); } + + git_mutex_unlock(&git__mwindow_mutex); } /* @@ -82,14 +84,13 @@ int git_mwindow_contains(git_mwindow *win, git_off_t offset) /* * Find the least-recently-used window in a file */ -void git_mwindow_scan_lru( +static void git_mwindow_scan_lru( git_mwindow_file *mwf, git_mwindow **lru_w, git_mwindow **lru_l) { git_mwindow *w, *w_l; - puts("LRU"); for (w_l = NULL, w = mwf->windows; w; w = w->next) { if (!w->inuse_cnt) { /* @@ -108,12 +109,13 @@ void git_mwindow_scan_lru( /* * Close the least recently used window. You should check to see if - * the file descriptors need closing from time to time. + * the file descriptors need closing from time to time. Called under + * lock from new_window. */ static int git_mwindow_close_lru(git_mwindow_file *mwf) { - git_mwindow_ctl *ctl = &GIT_GLOBAL->mem_ctl; - unsigned int i; + git_mwindow_ctl *ctl = &mem_ctl; + size_t i; git_mwindow *lru_w = NULL, *lru_l = NULL, **list = &mwf->windows; /* FIXME: Does this give us any advantage? */ @@ -147,18 +149,20 @@ static int git_mwindow_close_lru(git_mwindow_file *mwf) return 0; } +/* This gets called under lock from git_mwindow_open */ static git_mwindow *new_window( git_mwindow_file *mwf, git_file fd, git_off_t size, git_off_t offset) { - git_mwindow_ctl *ctl = &GIT_GLOBAL->mem_ctl; - size_t walign = _mw_options.window_size / 2; + git_mwindow_ctl *ctl = &mem_ctl; + size_t walign = git_mwindow__window_size / 2; git_off_t len; git_mwindow *w; w = git__malloc(sizeof(*w)); + if (w == NULL) return NULL; @@ -166,16 +170,16 @@ static git_mwindow *new_window( w->offset = (offset / walign) * walign; len = size - w->offset; - if (len > (git_off_t)_mw_options.window_size) - len = (git_off_t)_mw_options.window_size; + if (len > (git_off_t)git_mwindow__window_size) + len = (git_off_t)git_mwindow__window_size; ctl->mapped += (size_t)len; - while (_mw_options.mapped_limit < ctl->mapped && + while (git_mwindow__mapped_limit < ctl->mapped && git_mwindow_close_lru(mwf) == 0) /* nop */; /* - * We treat _mw_options.mapped_limit as a soft limit. If we can't find a + * We treat `mapped_limit` as a soft limit. If we can't find a * window to close and are above the limit, we still mmap the new * window. */ @@ -208,9 +212,14 @@ unsigned char *git_mwindow_open( size_t extra, unsigned int *left) { - git_mwindow_ctl *ctl = &GIT_GLOBAL->mem_ctl; + git_mwindow_ctl *ctl = &mem_ctl; git_mwindow *w = *cursor; + if (git_mutex_lock(&git__mwindow_mutex)) { + giterr_set(GITERR_THREAD, "unable to lock mwindow mutex"); + return NULL; + } + if (!w || !(git_mwindow_contains(w, offset) && git_mwindow_contains(w, offset + extra))) { if (w) { w->inuse_cnt--; @@ -228,8 +237,10 @@ unsigned char *git_mwindow_open( */ if (!w) { w = new_window(mwf, mwf->fd, mwf->size, offset); - if (w == NULL) + if (w == NULL) { + git_mutex_unlock(&git__mwindow_mutex); return NULL; + } w->next = mwf->windows; mwf->windows = w; } @@ -247,26 +258,62 @@ unsigned char *git_mwindow_open( if (left) *left = (unsigned int)(w->window_map.len - offset); - fflush(stdout); + git_mutex_unlock(&git__mwindow_mutex); return (unsigned char *) w->window_map.data + offset; } int git_mwindow_file_register(git_mwindow_file *mwf) { - git_mwindow_ctl *ctl = &GIT_GLOBAL->mem_ctl; + git_mwindow_ctl *ctl = &mem_ctl; + int ret; + + if (git_mutex_lock(&git__mwindow_mutex)) { + giterr_set(GITERR_THREAD, "unable to lock mwindow mutex"); + return -1; + } if (ctl->windowfiles.length == 0 && - git_vector_init(&ctl->windowfiles, 8, NULL) < 0) + git_vector_init(&ctl->windowfiles, 8, NULL) < 0) { + git_mutex_unlock(&git__mwindow_mutex); return -1; + } - return git_vector_insert(&ctl->windowfiles, mwf); + ret = git_vector_insert(&ctl->windowfiles, mwf); + git_mutex_unlock(&git__mwindow_mutex); + + return ret; +} + +void git_mwindow_file_deregister(git_mwindow_file *mwf) +{ + git_mwindow_ctl *ctl = &mem_ctl; + git_mwindow_file *cur; + size_t i; + + if (git_mutex_lock(&git__mwindow_mutex)) + return; + + git_vector_foreach(&ctl->windowfiles, i, cur) { + if (cur == mwf) { + git_vector_remove(&ctl->windowfiles, i); + git_mutex_unlock(&git__mwindow_mutex); + return; + } + } + git_mutex_unlock(&git__mwindow_mutex); } void git_mwindow_close(git_mwindow **window) { git_mwindow *w = *window; if (w) { + if (git_mutex_lock(&git__mwindow_mutex)) { + giterr_set(GITERR_THREAD, "unable to lock mwindow mutex"); + return; + } + w->inuse_cnt--; + git_mutex_unlock(&git__mwindow_mutex); *window = NULL; } } |