From c60f599bcb9bf9256eb87c1c60add55d23f76de3 Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Sun, 17 Apr 2022 11:29:47 -0700 Subject: [PATCH] util/log: Rename qemu_log_lock to qemu_log_trylock MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This function can fail, which makes it more like ftrylockfile or pthread_mutex_trylock than flockfile or pthread_mutex_lock, so rename it. To closer match the other trylock functions, release rcu_read_lock along the failure path, so that qemu_log_unlock need not be called on failure. Reviewed-by: Alex Bennée Signed-off-by: Richard Henderson Message-Id: <20220417183019.755276-8-richard.henderson@linaro.org> --- accel/tcg/cpu-exec.c | 2 +- accel/tcg/translate-all.c | 2 +- accel/tcg/translator.c | 2 +- cpu.c | 2 +- hw/net/can/can_sja1000.c | 2 +- include/exec/log.h | 2 +- include/qemu/log.h | 2 +- net/can/can_socketcan.c | 2 +- target/i386/tcg/translate.c | 2 +- tcg/tcg.c | 8 ++++---- tests/unit/test-logging.c | 2 +- util/log.c | 6 ++++-- 12 files changed, 18 insertions(+), 16 deletions(-) diff --git a/accel/tcg/cpu-exec.c b/accel/tcg/cpu-exec.c index 083ada76b1..f61b056571 100644 --- a/accel/tcg/cpu-exec.c +++ b/accel/tcg/cpu-exec.c @@ -214,7 +214,7 @@ static inline void log_cpu_exec(target_ulong pc, CPUState *cpu, #if defined(DEBUG_DISAS) if (qemu_loglevel_mask(CPU_LOG_TB_CPU)) { - FILE *logfile = qemu_log_lock(); + FILE *logfile = qemu_log_trylock(); int flags = 0; if (qemu_loglevel_mask(CPU_LOG_TB_FPU)) { diff --git a/accel/tcg/translate-all.c b/accel/tcg/translate-all.c index a6e03c1e50..5937d6b7b2 100644 --- a/accel/tcg/translate-all.c +++ b/accel/tcg/translate-all.c @@ -1527,7 +1527,7 @@ TranslationBlock *tb_gen_code(CPUState *cpu, #ifdef DEBUG_DISAS if (qemu_loglevel_mask(CPU_LOG_TB_OUT_ASM) && qemu_log_in_addr_range(tb->pc)) { - FILE *logfile = qemu_log_lock(); + FILE *logfile = qemu_log_trylock(); int code_size, data_size; const tcg_target_ulong *rx_data_gen_ptr; size_t chunk_start; diff --git a/accel/tcg/translator.c b/accel/tcg/translator.c index f06c314266..1506755f3c 100644 --- a/accel/tcg/translator.c +++ b/accel/tcg/translator.c @@ -139,7 +139,7 @@ void translator_loop(const TranslatorOps *ops, DisasContextBase *db, #ifdef DEBUG_DISAS if (qemu_loglevel_mask(CPU_LOG_TB_IN_ASM) && qemu_log_in_addr_range(db->pc_first)) { - FILE *logfile = qemu_log_lock(); + FILE *logfile = qemu_log_trylock(); qemu_log("----------------\n"); ops->disas_log(db, cpu); qemu_log("\n"); diff --git a/cpu.c b/cpu.c index 0fef70e18e..9db144761d 100644 --- a/cpu.c +++ b/cpu.c @@ -399,7 +399,7 @@ void cpu_abort(CPUState *cpu, const char *fmt, ...) fprintf(stderr, "\n"); cpu_dump_state(cpu, stderr, CPU_DUMP_FPU | CPU_DUMP_CCOP); if (qemu_log_separate()) { - FILE *logfile = qemu_log_lock(); + FILE *logfile = qemu_log_trylock(); qemu_log("qemu: fatal: "); qemu_log_vprintf(fmt, ap2); qemu_log("\n"); diff --git a/hw/net/can/can_sja1000.c b/hw/net/can/can_sja1000.c index 3ba803e947..300313dfb8 100644 --- a/hw/net/can/can_sja1000.c +++ b/hw/net/can/can_sja1000.c @@ -247,7 +247,7 @@ int can_sja_accept_filter(CanSJA1000State *s, static void can_display_msg(const char *prefix, const qemu_can_frame *msg) { int i; - FILE *logfile = qemu_log_lock(); + FILE *logfile = qemu_log_trylock(); qemu_log("%s%03X [%01d] %s %s", prefix, diff --git a/include/exec/log.h b/include/exec/log.h index 3c7fa65ead..fb595d1eb7 100644 --- a/include/exec/log.h +++ b/include/exec/log.h @@ -71,7 +71,7 @@ static inline void log_disas(const void *code, unsigned long size) /* page_dump() output to the log file: */ static inline void log_page_dump(const char *operation) { - FILE *logfile = qemu_log_lock(); + FILE *logfile = qemu_log_trylock(); if (logfile) { qemu_log("page layout changed following %s\n", operation); page_dump(logfile); diff --git a/include/qemu/log.h b/include/qemu/log.h index 6a6b1efce5..d090faf22a 100644 --- a/include/qemu/log.h +++ b/include/qemu/log.h @@ -67,7 +67,7 @@ static inline bool qemu_log_separate(void) /* Lock/unlock output. */ -FILE *qemu_log_lock(void); +FILE *qemu_log_trylock(void); void qemu_log_unlock(FILE *fd); /* Logging functions: */ diff --git a/net/can/can_socketcan.c b/net/can/can_socketcan.c index 4b68f60c6b..4a505643e9 100644 --- a/net/can/can_socketcan.c +++ b/net/can/can_socketcan.c @@ -76,7 +76,7 @@ QEMU_BUILD_BUG_ON(offsetof(qemu_can_frame, data) static void can_host_socketcan_display_msg(struct qemu_can_frame *msg) { int i; - FILE *logfile = qemu_log_lock(); + FILE *logfile = qemu_log_trylock(); qemu_log("[cansocketcan]: %03X [%01d] %s %s", msg->can_id & QEMU_CAN_EFF_MASK, msg->can_dlc, diff --git a/target/i386/tcg/translate.c b/target/i386/tcg/translate.c index 3ba1c99fff..f3cffee520 100644 --- a/target/i386/tcg/translate.c +++ b/target/i386/tcg/translate.c @@ -2580,7 +2580,7 @@ static void gen_unknown_opcode(CPUX86State *env, DisasContext *s) gen_illegal_opcode(s); if (qemu_loglevel_mask(LOG_UNIMP)) { - FILE *logfile = qemu_log_lock(); + FILE *logfile = qemu_log_trylock(); target_ulong pc = s->pc_start, end = s->pc; qemu_log("ILLOPC: " TARGET_FMT_lx ":", pc); diff --git a/tcg/tcg.c b/tcg/tcg.c index f8542529d0..abe4ef7799 100644 --- a/tcg/tcg.c +++ b/tcg/tcg.c @@ -756,7 +756,7 @@ void tcg_prologue_init(TCGContext *s) #ifdef DEBUG_DISAS if (qemu_loglevel_mask(CPU_LOG_TB_OUT_ASM)) { - FILE *logfile = qemu_log_lock(); + FILE *logfile = qemu_log_trylock(); qemu_log("PROLOGUE: [size=%zu]\n", prologue_size); if (s->data_gen_ptr) { size_t code_size = s->data_gen_ptr - s->code_gen_ptr; @@ -4200,7 +4200,7 @@ int tcg_gen_code(TCGContext *s, TranslationBlock *tb) #ifdef DEBUG_DISAS if (unlikely(qemu_loglevel_mask(CPU_LOG_TB_OP) && qemu_log_in_addr_range(tb->pc))) { - FILE *logfile = qemu_log_lock(); + FILE *logfile = qemu_log_trylock(); qemu_log("OP:\n"); tcg_dump_ops(s, false); qemu_log("\n"); @@ -4245,7 +4245,7 @@ int tcg_gen_code(TCGContext *s, TranslationBlock *tb) #ifdef DEBUG_DISAS if (unlikely(qemu_loglevel_mask(CPU_LOG_TB_OP_IND) && qemu_log_in_addr_range(tb->pc))) { - FILE *logfile = qemu_log_lock(); + FILE *logfile = qemu_log_trylock(); qemu_log("OP before indirect lowering:\n"); tcg_dump_ops(s, false); qemu_log("\n"); @@ -4266,7 +4266,7 @@ int tcg_gen_code(TCGContext *s, TranslationBlock *tb) #ifdef DEBUG_DISAS if (unlikely(qemu_loglevel_mask(CPU_LOG_TB_OP_OPT) && qemu_log_in_addr_range(tb->pc))) { - FILE *logfile = qemu_log_lock(); + FILE *logfile = qemu_log_trylock(); qemu_log("OP after optimization and liveness analysis:\n"); tcg_dump_ops(s, true); qemu_log("\n"); diff --git a/tests/unit/test-logging.c b/tests/unit/test-logging.c index d071400ebc..4c595356ae 100644 --- a/tests/unit/test-logging.c +++ b/tests/unit/test-logging.c @@ -162,7 +162,7 @@ static void test_logfile_lock(gconstpointer data) * our handle remains valid for use due to RCU. */ qemu_set_log_filename(file_path, &error_abort); - logfile = qemu_log_lock(); + logfile = qemu_log_trylock(); g_assert(logfile); fprintf(logfile, "%s 1st write to file\n", __func__); fflush(logfile); diff --git a/util/log.c b/util/log.c index 1a3121610a..6b7b358573 100644 --- a/util/log.c +++ b/util/log.c @@ -36,15 +36,17 @@ static GArray *debug_regions; /* Lock/unlock output. */ -FILE *qemu_log_lock(void) +FILE *qemu_log_trylock(void) { QemuLogFile *logfile; + rcu_read_lock(); logfile = qatomic_rcu_read(&qemu_logfile); if (logfile) { qemu_flockfile(logfile->fd); return logfile->fd; } else { + rcu_read_unlock(); return NULL; } } @@ -53,8 +55,8 @@ void qemu_log_unlock(FILE *fd) { if (fd) { qemu_funlockfile(fd); + rcu_read_unlock(); } - rcu_read_unlock(); } /* Return the number of characters emitted. */