From fada178df2c79f2a3a5fa5accd51d026fdeaf77c Mon Sep 17 00:00:00 2001
From: guo_peixu <guopeixu@geedgenetworks.com>
Date: Thu, 23 Jun 2022 14:20:32 +0800
Subject: [PATCH] =?UTF-8?q?=E4=BF=AE=E6=94=B9=E7=BA=BF=E7=A8=8B=E8=8E=B7?=
 =?UTF-8?q?=E5=8F=96=E7=BC=93=E5=86=B2=E5=8C=BA=E5=A4=B1=E8=B4=A5=E9=97=AE?=
 =?UTF-8?q?=E9=A2=98=E3=80=82=20=E4=BF=AE=E6=94=B9=E5=85=B1=E4=BA=AB?=
 =?UTF-8?q?=E5=86=85=E5=AD=98=E5=9C=B0=E5=9D=80=E6=98=A0=E5=B0=84=E5=A4=B1?=
 =?UTF-8?q?=E8=B4=A5=E6=97=B6=E7=9A=84=E5=88=A4=E9=94=99=E6=9D=A1=E4=BB=B6?=
 =?UTF-8?q?=EF=BC=8Cshmat=E5=A4=B1=E8=B4=A5=E4=BC=9A=E8=BF=94=E5=9B=9E(voi?=
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---
 shm_consumer/MESA_shm_consumer.c |  3 +-
 src/MESA_shm_ring_queue.c        | 48 +++++++++++++++-----------------
 2 files changed, 25 insertions(+), 26 deletions(-)

diff --git a/shm_consumer/MESA_shm_consumer.c b/shm_consumer/MESA_shm_consumer.c
index 5bdbfe6..9e4aba3 100644
--- a/shm_consumer/MESA_shm_consumer.c
+++ b/shm_consumer/MESA_shm_consumer.c
@@ -529,7 +529,8 @@ int main(int argc, char **argv)
 			}
 			if(ring_queue_head[i] == NULL){
 				ring_queue_head[i] = shmat(tmp_ovw->shmid, NULL, 0);
-				if(ring_queue_head[i] == NULL){
+				if(ring_queue_head[i] == (struct MESA_shm_queue_head *)-1){
+					ring_queue_head[i] = NULL;
 					break ;
 				}
 			}
diff --git a/src/MESA_shm_ring_queue.c b/src/MESA_shm_ring_queue.c
index 78fd6f9..aaaafd2 100644
--- a/src/MESA_shm_ring_queue.c
+++ b/src/MESA_shm_ring_queue.c
@@ -37,7 +37,7 @@ struct MESA_shm_overview *MESA_shm_alloc_overview()
 			return NULL;
 		}else{
 			shm_overview = (struct MESA_shm_overview *)shmat(shmid, NULL, 0);
-			if(shm_overview == NULL){
+			if(shm_overview == (struct MESA_shm_overview *)-1){
 				return NULL;
 			}
 			memset((void *)shm_overview, 0, shmsize);
@@ -51,6 +51,9 @@ struct MESA_shm_overview *MESA_shm_alloc_overview()
 		}
 	}else{    
 		shm_overview = (struct MESA_shm_overview *)shmat(shmid, NULL, 0);
+		if(shm_overview == (struct MESA_shm_overview *)-1){
+			return NULL;
+		}
 	}
 	return shm_overview;
 }
@@ -100,9 +103,6 @@ struct MESA_shm_queue_head *MESA_shm_alloc_new_ring_queue(struct MESA_shm_overvi
 	struct MESA_shm_queue_head *head = NULL;
 	int shmid = -1;
 	int shmsize = sizeof(struct MESA_shm_queue_head) + (MESA_SHM_RING_QUEUE_BLOCK_NUM * MESA_SHM_RING_QUEUE_BLOCK_SIZE);
-	if(!MESA_shm_mutex_trylock_success(ovw)){
-		return NULL;
-	}
 	shmid = shmget(ovw->shmkey, 0, 0);
 	if(shmid == -1){
 		shmid = shmget(ovw->shmkey, shmsize, (SHM_R|SHM_W|IPC_CREAT));
@@ -113,31 +113,20 @@ struct MESA_shm_queue_head *MESA_shm_alloc_new_ring_queue(struct MESA_shm_overvi
 	}else{
 		head = (struct MESA_shm_queue_head *)shmat(shmid, NULL, 0);	
 	}
-	if(head != NULL){
-		MESA_shm_init_new_ring_queue(head, ovw);
-		ovw->shmid = shmid;
-	}else{
-		pthread_mutex_unlock(&ovw->mutex);
+	if(head == (struct MESA_shm_queue_head *)-1){
+		return NULL;
 	}
+	MESA_shm_init_new_ring_queue(head, ovw);
+	ovw->shmid = shmid;
 	return head;	
 }
 
-struct MESA_shm_queue_head *MESA_shm_try_ring_queue(struct MESA_shm_overview *ovw)
+struct MESA_shm_queue_head *MESA_shm_try_reuse_ring_queue(struct MESA_shm_overview *ovw)
 {
 	struct MESA_shm_queue_head *head = NULL;
-	if(ovw->shmid == -1){
-		return NULL;
-	}
-	if(!MESA_shm_mutex_trylock_success(ovw)){
-		return NULL;
-	}
 	head = (struct MESA_shm_queue_head *)shmat(ovw->shmid, NULL, 0);
-	if(head == NULL){
-		pthread_mutex_unlock(&ovw->mutex);
-	}
-	if(!MESA_shm_ring_queue_is_empty(head)){
-		pthread_mutex_unlock(&ovw->mutex);
-		head == NULL;
+	if(head == (struct MESA_shm_queue_head *)-1){
+		return NULL;
 	}
 	return head;	
 }
@@ -151,14 +140,23 @@ struct MESA_shm_queue_head *MESA_shm_get_ring_queue(int pid)
 	}
 	for(i = 0; i < MESA_SHM_RING_QUEUE_NUM; i++){
 		tmp_ovw = MESA_shm_ovw + i;
+		if(!MESA_shm_mutex_trylock_success(tmp_ovw)){
+			continue ;
+		}		
 		if(tmp_ovw->shmid == -1){
 			head = MESA_shm_alloc_new_ring_queue(tmp_ovw);
+			if(head == NULL){
+				pthread_mutex_unlock(&tmp_ovw->mutex);
+			}
 			break;
 		}
-		head = MESA_shm_try_ring_queue(tmp_ovw);
+		head = MESA_shm_try_reuse_ring_queue(tmp_ovw);
 		if(head != NULL){
-			break;
-		}	
+			break ;
+		}else{
+			pthread_mutex_unlock(&tmp_ovw->mutex);
+			continue ;
+		}
 	}
 	if(head != NULL){
 		tmp_ovw->producer_pid = pid;