diff options
Diffstat (limited to '')
| -rw-r--r-- | lib/tdb/test/lock-tracking.c | 157 |
1 files changed, 157 insertions, 0 deletions
diff --git a/lib/tdb/test/lock-tracking.c b/lib/tdb/test/lock-tracking.c new file mode 100644 index 0000000..b2f092c --- /dev/null +++ b/lib/tdb/test/lock-tracking.c @@ -0,0 +1,157 @@ +/* We save the locks so we can reaquire them. */ +#include "../common/tdb_private.h" +#include <unistd.h> +#include <fcntl.h> +#include <stdarg.h> +#include <stdlib.h> +#include "tap-interface.h" +#include "lock-tracking.h" + +struct testlock { + struct testlock *next; + unsigned int off; + unsigned int len; + int type; +}; +static struct testlock *testlocks; +int locking_errors = 0; +bool suppress_lockcheck = false; +bool nonblocking_locks; +int locking_would_block = 0; +void (*unlock_callback)(int fd); + +int fcntl_with_lockcheck(int fd, int cmd, ... /* arg */ ) +{ + va_list ap; + int ret, arg3; + struct flock *fl; + bool may_block = false; + + if (cmd != F_SETLK && cmd != F_SETLKW) { + /* This may be totally bogus, but we don't know in general. */ + va_start(ap, cmd); + arg3 = va_arg(ap, int); + va_end(ap); + + return fcntl(fd, cmd, arg3); + } + + va_start(ap, cmd); + fl = va_arg(ap, struct flock *); + va_end(ap); + + if (cmd == F_SETLKW && nonblocking_locks) { + cmd = F_SETLK; + may_block = true; + } + ret = fcntl(fd, cmd, fl); + + /* Detect when we failed, but might have been OK if we waited. */ + if (may_block && ret == -1 && (errno == EAGAIN || errno == EACCES)) { + locking_would_block++; + } + + if (fl->l_type == F_UNLCK) { + struct testlock **l; + struct testlock *old = NULL; + + for (l = &testlocks; *l; l = &(*l)->next) { + if ((*l)->off == fl->l_start + && (*l)->len == fl->l_len) { + if (ret == 0) { + old = *l; + *l = (*l)->next; + free(old); + } + break; + } + if (((*l)->off == fl->l_start) + && ((*l)->len == 0) + && (ret == 0)) { + /* + * Remove a piece from the start of the + * allrecord_lock + */ + old = *l; + (*l)->off += fl->l_len; + break; + } + } + if (!old && !suppress_lockcheck) { + diag("Unknown unlock %u@%u - %i", + (int)fl->l_len, (int)fl->l_start, ret); + locking_errors++; + } + } else { + struct testlock *new, *i; + unsigned int fl_end = fl->l_start + fl->l_len; + if (fl->l_len == 0) + fl_end = (unsigned int)-1; + + /* Check for overlaps: we shouldn't do this. */ + for (i = testlocks; i; i = i->next) { + unsigned int i_end = i->off + i->len; + if (i->len == 0) + i_end = (unsigned int)-1; + + if (fl->l_start >= i->off && fl->l_start < i_end) + break; + if (fl_end >= i->off && fl_end < i_end) + break; + + /* tdb_allrecord_lock does this, handle adjacent: */ + if (fl->l_start == i_end && fl->l_type == i->type) { + if (ret == 0) { + i->len = fl->l_len + ? i->len + fl->l_len + : 0; + } + goto done; + } + } + if (i) { + /* Special case: upgrade of allrecord lock. */ + if (i->type == F_RDLCK && fl->l_type == F_WRLCK + && i->off == FREELIST_TOP + && fl->l_start == FREELIST_TOP + && i->len == 0 + && fl->l_len == 0) { + if (ret == 0) + i->type = F_WRLCK; + goto done; + } + if (!suppress_lockcheck) { + diag("%s testlock %u@%u overlaps %u@%u", + fl->l_type == F_WRLCK ? "write" : "read", + (int)fl->l_len, (int)fl->l_start, + i->len, (int)i->off); + locking_errors++; + } + } + + if (ret == 0) { + new = malloc(sizeof *new); + new->off = fl->l_start; + new->len = fl->l_len; + new->type = fl->l_type; + new->next = testlocks; + testlocks = new; + } + } +done: + if (ret == 0 && fl->l_type == F_UNLCK && unlock_callback) + unlock_callback(fd); + return ret; +} + +unsigned int forget_locking(void) +{ + unsigned int num = 0; + while (testlocks) { + struct testlock *next = testlocks->next; + free(testlocks); + testlocks = next; + num++; + } + return num; +} |