From 77632b7554000f2e832a0e9fded1a3894b2502c3 Mon Sep 17 00:00:00 2001 From: Jakob Unterwurzacher Date: Sun, 21 Jun 2020 11:59:08 +0200 Subject: getdents_c: read from two threads This was an attempt to make the C code more similar to Go (which also reads from multiple threads). However, I still could not repro the ENOENT problems. https://github.com/rfjakob/gocryptfs/issues/483 --- contrib/getdents-debug/getdents_c/Makefile | 2 +- contrib/getdents-debug/getdents_c/getdents.c | 65 +++++++++++++++++++++------- 2 files changed, 50 insertions(+), 17 deletions(-) (limited to 'contrib') diff --git a/contrib/getdents-debug/getdents_c/Makefile b/contrib/getdents-debug/getdents_c/Makefile index 95e47dc..1a9d4d2 100644 --- a/contrib/getdents-debug/getdents_c/Makefile +++ b/contrib/getdents-debug/getdents_c/Makefile @@ -1,2 +1,2 @@ getdents_c: *.c Makefile - gcc getdents.c -o getdents_c + gcc getdents.c -lpthread -o getdents_c diff --git a/contrib/getdents-debug/getdents_c/getdents.c b/contrib/getdents-debug/getdents_c/getdents.c index 936bd0b..d504976 100644 --- a/contrib/getdents-debug/getdents_c/getdents.c +++ b/contrib/getdents-debug/getdents_c/getdents.c @@ -1,6 +1,7 @@ // See ../getdents/getdents.go for some info on why // this exists. +#define _GNU_SOURCE #include #include #include @@ -9,6 +10,38 @@ #include #include #include +#include + +static pthread_mutex_t mutex; +static int sum; + +struct up { + pthread_mutex_t *my_mutex; + pthread_mutex_t *other_mutex; + int fd; +}; + +void *reader(void *arg) { + struct up* up = (struct up*)arg; + int fd = up->fd; + char tmp[10000]; + while(1) { + pthread_mutex_lock(up->my_mutex); + int n = syscall(SYS_getdents64, fd, tmp, sizeof(tmp)); + if (n > 0) { + printf("t%ld: n=%d\n", gettid(), n); + } else { + printf("t%ld: n=0 errno=%d total %d bytes\n", gettid(), errno, sum); + if (n < 0) { + exit(1); + } + pthread_mutex_unlock(up->other_mutex); + break; + } + sum += n; + pthread_mutex_unlock(up->other_mutex); + } +} int main(int argc, char *argv[]) { @@ -21,28 +54,28 @@ int main(int argc, char *argv[]) const char *path = argv[1]; for (int i = 1 ; ; i ++ ) { + sum = 0; int fd = open(path, O_RDONLY); if (fd == -1) { perror("open"); exit(1); } - - char tmp[10000]; - int sum = 0; - printf("%3d: getdents64: ", i); - for ( ; ; ) { - int n = syscall(SYS_getdents64, fd, tmp, sizeof(tmp)); - printf("n=%d; ", n); - if (n <= 0) { - printf("errno=%d total %d bytes\n", errno, sum); - if (n < 0) { - exit(1); - } - break; - } - sum += n; - } + pthread_t reader1_thread, reader2_thread; + pthread_mutex_t m1 = PTHREAD_MUTEX_INITIALIZER, m2 = PTHREAD_MUTEX_INITIALIZER; + pthread_mutex_lock(&m2); + struct up up1, up2; + up1.fd = fd; + up1.my_mutex = &m1; + up1.other_mutex = &m2; + up2.fd = fd; + up2.my_mutex = &m2; + up2.other_mutex = &m1; + pthread_create(&reader1_thread, NULL, reader, &up1); + pthread_create(&reader2_thread, NULL, reader, &up2); + pthread_join(reader1_thread, NULL); + pthread_join(reader2_thread, NULL); close(fd); + printf("---\n"); usleep(100000); } } -- cgit v1.2.3